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Cystic Lesions of Bone FIBROUS LESIONS OF BONE Fibrous

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Cystic Lesions of Bone FIBROUS LESIONS OF BONE Fibrous Powered By Docstoc
					      Cystic Lesions of Bone              #1 cause of Rib lesions, mostly     Ossifying Fibroma - most in
FIBROUS LESIONS OF BONE                   lytic, well circuscribed            face
Fibrous dysplasia - NO peri-              slowly expanding & assoc w ex-      Cortical based fibrous dysplasia
osteal rxn or pain unless fx              trapleural mass                     w same ground glass appear-
Fx frequent but no pseudoarthro-          Regress w puberty                   ance
sis, no ST component                      Malignant degeneration reported     homogeneous 1-5cm lesions,
Elongated Diaphyseal lesion w             in <1%                              maxilla & frontal #1
"Ground Glass" matrix                     MRI - Hyper T2 unlike most fi-      assoc w loosening of the teeth in
centered in medullary cav, "al-           brous processes                     mandible
phabet soup" of woven bone                Malig degen to Osteosarc poss,      Pt <10yrs, vascularized fibrous
lucent, sclerotic, expasnsile,            esp w polyostotic form              stroma like FD
patchy, etc... MRI high T2                                                    No alphabet soup of woven bone
Monostotic - #1 presentation,             McCune-Albright syn - polyos-
prox femur 78%, ribs, skull               totic fibrous dysplasia             Osteofibrous Dysplasia - fi-
if in pelvis it will also be in ipsilat   Florid disseminated form, usually   brous lesion of tibia & fibula in
prox femur                                unilat, female>male                 child <5yrs
Diaphyseal if mild case, rarely           assoc w cafe au lait spots and      present w unilat bowing & pain-
affects spine                             precocious puberty                  less enlargement of the leg
Polyostotic - lesions usually                                                 trabecula surrounded by osteo-
larger, freq Cafe-Au-Lait                 Adamantinoma - appears simi-        blasts, mixed lytic Diaphyseal le-
"Sheperds Crook" femur & cystic           lar, mid tibia and jaw only         sion
pelvic lesions assoc                      can appear aggressive, 30+ yrs,     no osteoclasts as in fibrous dys-
Skull base thickening, CN en-             trauma often assoc                  plasia
croachment, asym orbits                   may be assoc w osteofibrous         Juvenile Adamantinoma - possi-
involvement of spine & soft tis-          dysplasia, 15% met to lungs         ble assoc
sue myxoma more common
Congenital Multiple Fibroma-          Desmoplastic Fibroma - aggre-        its clinical pres - pain
tosis - Infantile Fibromatosis        sive expansile con tis lesion        50% can degenerate to chondro-
ST fibromas diagnosed at birth,       Tibia #1, 10-20y/o, most benign      sarcoma, histo identical
stabalize by 4mo, regress by          or low grade malignancy              Diaphyseal long bone lesions
2yrs                                  resembles soft tissue desmoid,       more likely to deg
forms lytic lesion along metaphy-     50% recur P resection                Surgically excise, Bx is not a re-
sis of long bones, variable size      NO ST mass, never metastisize        liable way to DDx
                                      DDx Giant Cell, ABC or Fibrosarc
Juvenile Fibroma - benign fi-         Very vascular, not easily distin-    Ollier's Dz - mult enchondromas,
brous tumors, cause pressure          guished from FD                      NO inc in malig deg
erosions                                                                   Predominate Unilat, punctate
can be aggressive, high T2 in-                                             calc remain distinctive
tensity, freq recur after resection   ENCHONDROMA                          Bizzarre bulbous expansions of
Juvenile Aponeurotic Fibroma -        Lucent defect w Ring & arc           tubular bones early
subset w fibrochondral matrix         chondroid, 40-50                     Columnar growth of cartilage-
occurs in deep palmar facia of        Metaphyseal, unilat & solitary,      nous tissue from epi
young males                           never epiphyseal                     Become more rounded w older
ST mass over wrist w stippled         NO periostitis, central, eccentric   Pts, Pathog
calc, bone errosion poss              & expansile                          Longitudinal striation - poss in
                                      Cartilage formed bones only, NO      long bone metaphysis
Cortical Desmoid - Reactive re-       skull lesions
pair at site of musc insertion        #1 cystic lesion of phalanges, but   Maffucci's syn - mult enchon-
freq at adductor tubercle, "Don't     no calc here                         dromas, Inc malig deg
Touch" lesion.                        Sim bone infarct but not well de-    Hemangiomas assoc, phleboliths
                                      fined or serpiginous                 seen.
                                      Chondrosarcoma differs only in
LANGERHANS CELL HISTIO-            of benign polyostotic                ticular nodular in lungs
CYTOSIS - HISTIOCYTOSIS X          Periostitis freq, usually thick,
                                   wavy, & uniform                      Letterer-Siwe - Acute Dissemi-
Birbeck Bodies - inclusions        Fever poss similating osteo-         nated Histiocytosis, <1y/o
seen in cells on EM                myelits                              Fulminate - 95% die, often bone
Penilaminar Organnels also as-     Skull #1, Beveled NONSCLE-           lesions don't form
soc                                ROTIC edges                          Permeative pattern sim to Ew-
50% have skin, eye, respiratory    Calverial in 40%, often isolated     ings sarc possible.
& fever w enlarged nodes           parietal, mandible 20%
pts >2yrs w no organ dysfxn        present as painful enlarging skull   OTHER CAUSES OF BENIGN
have 90% 5yr survival              mass, rarely into dura               CYSTIC LESIONS
with organ dysfxn about 40% 5yr    hearing loss & otitis type sx if     Osteoblastoma - rare, Giant os-
survival                           temporal bone involved               teiod osteoma, >2cm
Tx - chemo reserved only for       Vertebra Plana - often effect post   Expansile bubbly lesion, Scle-
most severe cases                  elements as well, neuro sx rare      rotic margins poss, sim ABC
                                                                        can have speckled calc or even
Eosinophilic Granuloma - Non-      Hand-schuller - Chronic Dis-         blastic in long bones
disseminated form, Bone only       seminated Histiocytosis, <5y/o       freq in post spine, predominatly
90% occur from 5-15yrs, 95%        Triad of destructive lesions,        lytic here
white, 2:1 male, 70% in flat       exophthalmos & diabetes insip-       30% are vertebral, may cause
bones,                             idus                                 cord compression
femur & humerus #1 long bones,     D. Insipidus II' to hypothalmus      Appendicular are lytic w NO soft
60% diaphyseal, rare in hands      involvement, hyper T2 in pit stalk   tissue mass
central bony sequestrum like os-   90% have cranial involvement,
teomylitis & fibrosarc poss        15% have classic triad               Osteoid Osteoma - not tumor or
Monostotic usually but #1 cause    NO osteopenia or erosions, Re-       infection, unkown etiology
Cortically based sclerotic lesion   CT, very vascular
w nidus <2cm, pt under 30           DDx - Osteomyelitis is always #1    Solitary Bone Cyst - Must be
Metaphyseal 75%, 2/3 around         in sclerotic lesion w nidus         central in a pt under 30
knee                                may resemble sequestrum, can        simple or unicamiral cyst, ex-
Medulary - nidus in medula or       also mimic stress Fx                cluded if not central
joint less sclerosis seen, 20%                                          2/3 occur prox humerus, prox
Intrarticular - mimics synovitis,   Aneurysmal Bone Cyst - must         femur #2, any bone poss
Sclerotic, joint eff seen           be expansile in pt under 30         NOT most commonly seen
Periosteal - minimal sclerosis,     Tibia #1, 30% occur in assoc w a    around knee unlike others
cortical scalloping & ST swelling   primary neoplasm                    Metaphyseal, grows in from phy-
Spine - prefers appendages, freq    Diaphyseal but usually near end,    sis, rarely epiphyseal
cause of Scoliosis                  extend to metaphysis                Fallen fragment sign is pathag-
unilat pars Fx still a more freq    Markedly destructive esp in pel-    nomonic
cause though                        vic bones                           Asymptomatic unless fx, triangu-
Spontaneous regression,             can have densly sclerotic border,   lar in calcaneus Recur if packed
NEVER seen over age 30              Fx freq                             too early
Resection curative, recurrance      Can sim Osteoblastoma
due to incomplete resection         Spine appendages often in-          Hyperparathyroidism -
Pain at night releived by aspirin   volved, lg soft tissue mass         HYPERcalemia, HYPOphos-
NUCS - Double Density sign          Present w pain, may follow          phatemia
caused by hot nidus                 truama                              Subperiosteal Resorbtion - radial
Angio - Nidus is hypervascular,     CT - can show multiple com-         aspect of dist phalanx
rapid washout                       partments, fluid-fluid levels in    dist clavicles, med prox tibia, &
MRI - shows nidus lying in region   30%                                 sacroilliac joints
of marrow edema                     Can show rim enhancement w          osteopenia & cortical resorb of
nidus enhances on both MRI &        cent low atten                      long bones late
Brown Tumors - flat bones & ribs    MDP, only seen w 50% in I' HPT       Chondromyxoid fibroma - men-
#1, sim ABC, giant cell             Phosphate retained, Ca+ low          tion w nonossifying fibroma
most assoc w I' form, must have     (Normal Ca+ 8.4-10.2, phos           can present w pain in any age,
other HPT Sx as well                2.2-4.5)                             most in dist toe phalange
Parathyroid Adenoma may cause                                            Diaphyseal w subendosteal
tracheal deviation                  Chondroblastoma - must be            thickening & scalloping
Tx of HPT - all sx resolve, brown   Epiphyseal in a pt under 30          Usually NO chondroid matrix, NO
tumors scleros, resorb              Most occur at Knee, Calc fre-        malig degen
Calcitonin - has opposite effect    quently seen                         Difficult to distinguish from chon-
as Parathyroid Hormone              50% will have sm extention           droblastoma histologically
decreases bone resorbtion, inc      across the epi to metaphy
renal Ca+ clearance                 70% assoc w periostitis in dia-      Cystic Angiomatosis - rare, as-
causes Hypophosphatemia &           phymetaphyseal region adjacent       soc w Osler-Weber-Rendu, asym
Hypocalcemia                        Lytic & epiphyseal: 1) infection,    when isolated
                                    2) this, 3) giant cell               mult complex cystic lesions any-
II' Hyperparathyroidism - Renal     EG and ABC also but very rare,       where, may spontaneously re-
Osteodystrophy, more common         mets & myeloma over 40               gress
Soft tissue calc, Chondrocalcino-   consider subchondral cyst if joint   70% w viceral involvement have
sis & Osteosclerosis MORE           DJD assoc                            bad prognosis.
common                              carpal, tarsal bones, and patella
kidney can't hydroxylate 25-        behave like epihysis
hydroxy to 1,25-                    Apophysis (ligamentous attach-
dihydroxycholecalciferol            ment) is similar
causes compensatory elev in         MRI - often low T2 in child due to
parathyroid hormone                 cellular nature
Freq cause of "Super Scan" w
RARE CAUSES OF BENIGN                seen in 15% w multiple mye-        Synovitis -benign synovial swel-
LYTIC LESIONS                        loma, preserves joint space        ling
1.Inclusion Cyst - follows           osteopenia & rib lesions com-      Subarticular erosions poss w
trauma to dist digits mostly         mon, NO subperiosteal resorb       joint pain & swelling
Epidermoid lines cyst walls          Course trabeculation in hands      Lg subchondral cysts w NO joint
                                     poss, sim SLE                      space narrowing typical
2.Glomus Tumor - ST mass w           Protenacious deposits in heart &   CALC NEVER SEEN, no os-
destructive lesion, sharp margins    GI #1, bone rare                   teoperosis
Dist phalanges #1 esp in female,     may calc in lung & kidney          see section on benign joint proc-
elsewhere in male                    plaque like deposits may be seen   esses
Arise from glomeruli or pericytes    in synovium
in vessel wall                       II' Amyloidosis assoc w RA, ank    7. Sarcoid - 10%, lace-like de-
                                     spondylitis & others               struction in metaphsis of phal
3. Hydatid Cyst - Dog tapeworm                                          Periosteal rxn & endosteal scle-
larvae, Pelvis & Spine #1 bone       5. Hemangioma - lytic w scle-      rosis, NO errosions, penia
Sharply demarcated & sclerotic       rotic marg, esp in long bone
margin, "bunch of grapes"            head                               8. Intraosseus Ganglion - sub-
can simulate an aggresive lytic      Spine or Calvaria #1, asym &       chondral cytic lesion
process                              solitary, pt >40y/o                Sharply defined sclerotic border,
75% in liver, 15% lungs, freq calc   Vertebral body - vertical lines    NO calc, NO ST portion
in ST, 2% in bone                    Calvaria - honeycomb or sun-       Dist Tibia #1, Talus #2, presents
Sheep & human intermediate to        burst pattern                      w pain in ankle
dog (definitive host)                Soft tissue hemangiomas can        Simulates a Geode, but no de-
                                     cause errosions                    generative changes
4. Primary Amyloidosis - can                                            mucoid center, fibrous capsule in
cause mult lytic bone lesions        6. Pigmented Villonodular          both
                                   Knee #1, expansile w NO perios-         roid or renal
9. Acroosteolysis - dist pha-      titis                                   Renal cell ca said to always be
langes erroded away                lytic w thin sclerotic border, slight   lytic
Scleroderma, frost-bite, burn,     scalloping                              Skull mets often lytic due to slow
Hadju-Cheney.                      Fx poss esp if >2cm or occupy           healing
                                   more than 50% of dia                    Sclerosis results from slow
MALIGNANT CAUSES OF                MRI - low T2 due to fibrous ma-         growth allowing bone Rxn
WELL DEFINED LYTIC BONE            trix                                    Carcinoid & Hodgkins frequently
LESIONS                            20% of children, spont regres-          sclerotic
Giant Cell Tumor - 15% malig-      sion w calc of matrix late              Breast Mets - often imitate mult
nant, may recur even if not        synonymous w fibrous cortical           myeloma
1. Epiphyses must be closed, but   defect & Fibroxanthoma
rare in elderly >50y/o             Involute by age 30, may be hot          Myeloma - Aggressive, bubbly
2. Must abut the articular sur-    during this time                        lytic pattern esp in ribs
face, knee #1, spine rare          Multiple NOF - freq assoc w Neu-        #1 cause of extraplueral masses
3. A sharp zone of trans w a       rofibromatosis                          @40
nonsclerotic margin                                                        Plasmacytoma can occur in
4. Must be eccentric, NO matrix    Metastatic disease - consider w         younger pt (over 35)
calc, pathologic fx freq           any lesion IF pt over 40                Pelvis, thoracic & lumbar spine
Nonossifying Fibroma - must        Hemopoetic marrow first, no X-          freq, skull rare
be under 30, Metaphyseal           ray evidence initially                  collapses vert body, appendages
Fibroxanthoma - AFIP name,         NO soft tissue mass, less peri-         not involved
Whorls of fibrous tiss &           osteal Rxn than I' mass                 preceed mult mye by 3-5 y
Xanthoma Cells                     #1 site is lesser trochanter of fe-
Occur in long bones, emanate       mur
from cortex                        any ca can be lytic, usually thy-
Childhood Mets - Horizontal ra-      Cystic Tuberculosis                  over 40 = mets
diolucent bands freq                 Syphilis                             osteiod osteoma, fibrous dyspla-
Neuroblastoma - freq lytic lesions   Tabes dorsalis                       sia, infection, brown tumors.
esp in skull                         Actinomycosis
Sutures spread from Inc intrac-      Sporotrichosis                       POSTTRAUMATIC LYTIC LE-
ranial pres                          Brucellosis                          SIONS
Pulm mets only late, Retinoblas-     Leporsy                              Myositis ossificans - aggres-
toma sim                             Salmonella Osteomyelitis             sive histology can mimic sar-
Leukemia - 50% w Metaphyseal         Maternal Rubella Syndrome            coma
bands, less freq lytic               Septic Hip                           circufrencial calc w lucent center
Bands probably II' to nutritional                                         pathognomonic
deficiet, not infiltation            CLASSIFICATION OF LYTIC              CT shows best, can have peri-
Diffuse periosteal Rxn & demin-      BONE LESIONS                         osteal rxn
eralization                          Under 30 lesions - EG, NOF,          no ill-defined periph, or central
DDx w blood: inc lymphoblasts        ABC, SBC, & Chondroblastoma          calc
vs inc catacholeamines               No Periostitis - Fibrous Dyspla-     between muscle fibers, not within
Wilms does NOT met to bone,          sia, Enchondroma, NOF, SBC
mostly pulmonary.                    Epiphyseal - Infection, Chondro,     Avulsion injury - seen at inser-
                                     GCT, EG, mets & myeloma              tion sites, delayed films help
INFECTIONS                           consider subchondral cyst            Cortical desmoid - prob an avul-
                                     ABC diaphyseal but may ap-           sion of the medial
Pyogenic Osteomyelitis               proach end                           supracondylar ridge, periostitis
Chronic Sclerosing Osteomyelitis     Multiple - FEEMHI                    poss, hot on nuc
Brodie's abscess                     Sclerotic lesions - often regress-   often occur in young people,
Septic Arthritis                     ing lytic lesions, under 30          histo can sim sarcoma
TB                                   NOF, EG, SBC, ABC, chondro,
Subchondral cysts - geodes            NORMAL VARIANTS                        Musculoskeletal Infections
assoc w degenerative dz               Dorsal Defect of the Patella -      INFECTION
assoc w joint narrowing, sclero-      lytic defect in upper out quad      NO discriminating factors, scle-
sis, etc                              mimics chondroblastoma, inf, or     rotic border #1
assoc w CPPD crystal dz, rheu-        osteochondritis dissecan            periostitis, soft tissue assoc, ex-
matoid, & avasc nec                                                       pansile, all possible
                                      Pseudocysts - paucity of trabe-     if adj to articular surface cartilage
Discogenic Vertebral Dz - a           cula at G tuberosity of Humerus     loss & eff poss
schmorl's node variant                hyperimia II' to shoulder pain      Bony Sequestra - seen w this,
sclerosis of vert end plates, lytic   causing dissuse                     EG, and fibrosarcoma
or mixed poss                         no sclerotic margin or wide zone    Crosses Disk like Gorham's Van-
always assoc w osteophytosis          of transition                       ishing Bone & Renal Osteodys-
                                      also seen in mid calcaneus,         trophy
Fracture - if not set can have        tuberosity of radius also
exuberant callus                                                          Pyogenic Osteomyelitis - 75%
Pseudodislocation of the hu-          Os Odontoideum - unfused            in kids, blood born staph aureus
merus - fx w hemarthrosis             dens which may be post trauma       No anas between metaph & epi-
blood distends joint & displaces      smooth well corticated inf margin   phy plates at 2yrs to maturity
head inf, no disloc                                                       More vigorous periosteal rxn in
axial veiw key to detection, can      Osteopoikilosis - mult sclerotic    kids due to lose periost
aspirate for blood                    foci assoc w epiphysis              Main cause of nec bone due to
                                      familial bone islands, can mimic    vasc disruption Soft tissue com-
Tietze's Syn - costochodritis of      mets but no lytic proc.             ponent seen at 2-3days, fat
the rib                                                                   planes blur
causes bulbous painful swelling                                           Bone changes start after 10
due to periostitis.                                                       days, Lg ST component assoc
Metaphysis #1, susceptability inc     bacteria are phagocytized but not     in spine
w size of bone                        properly killed                       Septic Arthritis - cart errosion due
NO joint involvement                                                        to collagenase from leukocyte
Sequestrum - necrotic bone re-        Chronic Sclerosing Osteomye-          Autoimmune response to dam-
sidual, forms late                    litis - often nearly sterile          aged cart, further resorption
Involucrum - Sheath enclosing         Reactive process left over, lytic     Fibrin deposits inhibit cart nutri-
sequestrum                            component variable                    tion & metabolism
Skull - Hx of frontal sinus Dz,       Lg ST component w breaks in           TB - hematogenous spread to
Trauma or mastoiditis                 cortex                                Metaphysis, extends to Joint
Moth eaten pattern, no sequestra      Cartilage thinning & Juxtarticular    Progressive bone destruction &
Vertebral - usually involves end-     osteoperosis assoc                    subarticular osteoperosis
plates, can cross Disk                Sinus tracts freq - fibrosarcoma      Well localized Abcess, Cold due
collapses symetrically due to         can develop in tract                  to slow inflam process
post element involvment               Epidermoid ca also seen in tract      Casseating lesions - calcify, pa-
No kyphosis as seen w TB, less                                              thog when paraspinous
extensive                             Brodie's abscess - sclerotic          Spine & Hip #1 - Always see
Paraspinous abcess freq compli-       sharp margins, freq periosteal R      muscle atrophy
cation, LOOK FOR IT                   Metaphyseal - dist tibia #1, cavity   upper thoracic in kids, lower &
Penetrating injury & drug abuse       in spongiosa, elongated along         lumbar in adults
#1 causes                             shaft                                 Kyphosis - errodes ant 1/3 of vert
Pseudomonas - seen in penetra-        freq serpentine tracts to cortex,     body, 90% angle
tion inj of foot                      good for DDx from osteoid os-         preserve post elements
Salmonella - assoc w sickle cell,     teoma                                 Non-casseating types - M.
S. Aureus still #1                    In-111 & Ga-67 less sensitive,        Kansasei & Scrofulaceum
Chronic Granulomatous Dz in           detect acute osteomyelitis better     Cervical nodes mostly, rare bone
Child - mult sites of osteomyelitis   Afebrile & pain free possible, rare   involvement
Cystic Tuberculosis - Symetric        posits in cortex of ant tib          Abdominal form starts in cecum
long bone involvement in child        thickening & increased density of    or appendix - liver abcess
Mult well defined ovoid lytic le-     any long bone poss                   "Mycetoma" - tumorlike ST swel-
sions                                 Onset at 20-30 y/o, pathogno-        ling & draining sinus
NO periosteal rxn except in late      monic if bilat                       most commonly seen in the foot
phase                                 Assoc w neuropathic process          following puncture wound
                                      Aquired III' form - periosteal rxn
Syphilis - bone changes w con-        less evident                         Sporotrichosis - fungus aquired
genital & III' aquired forms          Clavicles - cortical & endosteal     from plants thru skin wounds
Gumma - oseous necrosis which         new bone                             causes septic arthritis & joint de-
heals w fibrosis & inflam             Calvaria - Mixed lytic/sclerotic     struction, lytic bone lesions poss
Lytic lesions - Tibia, vomer & cal-   lesions ant & lat                    Brucellosis - causes exuberant
varia #1, adj thickening freq         Neuropathic lesions - in Lower       "parrot beak" osteophytes of
can cause lucency in diaphysis        ext & Spine                          spine
of any long bone                      II' to trauma, Tabes Dorsalis as-
Trophic lesions, symetric depos-      soc w this                           Leprosy - 2 forms caused by
its in periosteum                     Check Serology - VDRL, Trepo-        mycobacterium leprae
Congenital form - exuberant pe-       nemal Antibody                       Lepromatous - 5% have bone
riostitis @ birth                                                          changes, neuropathic type
heal spontaneously or responds        Actinomycosis - Anerobic G+          Neural leprosy - 64% have bone
rapidly to PCN                        bacilli, permeative aggresive pat-   destruction
minimal soft tissue component         tern                                 Cystic lesions in fingers w II'
Fragmentation & infarction of         #1 in thorax, spine & metaphysis     sclerosis severe contracture or
long bone metaphysis                  of long bones                        bone loss, not both
DDx scurvy                            Does not cross disk space,           Calc in Radial or Ulnar nerve pa-
Tabes dorsalis -Gummatous de-         craniofacial form from tooth         thognomonic
Salmonella Osteomyelitis - esp         Bone Forming Benign Lesions          4. Melorheostosis - Thickened
in sickle cell child <2y/o                                                  & enlarged cortical bone
                                       1. Enostosis -Bone islands can       Haversian canals present but
Maternal Rubella Syndrome -            mimic sclerotic met if >1cm          abn, inc marrow cellularity
"Celery stick" around knee at          1) oblong w axis along stress        "Candle Wax" excrescences
8mo                                    plane                                along outer cortex
longitudinal metaphyseal bands,        2) Well difined spicules extend to   Pain, Contractures & limb short-
NO periostitis                         N bone along margins                 ening occur
50% have PDA & hepatosple-             May grow very slowly, can have       often in a single lower limb
nomegaly                               inc uptake on nucs Rare in chil-     Scleroderma like skin lesions
                                       dren                                 poss over osseus lesions
Septic Hip - B strep in neonate,                                            Bone scan intensly hot
H. flu in infant, S. aureus in child   2. Osteopoikiolosis - Small is-
present w fever and immobile           lands of compact bone, ASYMP-        5. Bone infarct - Always diaphy-
joint, X-ray N initially               TOMATIC                              sometaphyseal in long bone
Effusion displaces med aspect of       involves spongy bone of epiphy-      Dense amorphic calc initially, lu-
head >1mm relative to opposite         sis & metaphysis in long bone        cent 10 days later
Aspirtation for Dx, Emergent ar-       NO inc activity on bone scan         Sclerotic "serpentine" border
throtomy & open drainage for Tx        Important to surgeon due to inc      good for DDx from EG
high risk of cartilage destruction,    Keloid formation                     Benign type pereosteal rxn poss,
15% assoc w head osteomyelitis.                                             permeative app poss
                                       3. Osteopathia Striata - linear      NO endosteal scalloping, NO
                                       bands of sclerosis at metaphysis     cysts, NO malig transformation
                                       assoc w osteopoikiolosis, no inc     freq underlying disorders - sickle
                                       uptake on nuc scan                   cell, SLE, Gaucher's
                                                                            Pancreatitis, atherosclerosis,
Emboli                                MRI - shows intact low intensity     bones, Madelung wrist deformity
MRI demonstrates a serpiginous        cap on both T1 & T2
sharp black border                    Thicker the cap the more likely to   8. Osteoid Osteoma - not tumor
Presents w Pain                       transform                            or infection, unkown etiology
                                      Arises from bone surface w hya-      Cortically based sclerotic lesion
Epiphyseal-metaphyseal Os-            line cartilage cap                   <2cm, pt under 30
teonecrosis - infarct assoc w         Cortical & Marrow CONTINUITY         Nidus within a small central lu-
steroid use                           key to Dx, away from epi             cency, 2/3 around knee
possible due to microscopic em-       30% on femur, Sx due to size,        if nidus in medula or joint less
boli from fatty liver or marrow ex-   often lobulated                      sclerosis seen, 20%
pansion                               Spine - can cause scoliosis, grow    joint eff if lesion intracapsular
                                      into canal                           if nidus in periosteum see perios-
6. Juxtacortical Chondroma -          Sessile form can sim Juxtacorti-     titis like malig
arise between cortex & perios-        cal chondroma on humerus             may resemble sequestrum or
teum                                  Aquired II' to truama also           disappear if calcifies
Medial aspect of prox humerus,        Subungual Exostosis - assoc w        Spine - prefers appendages,
femur or tibia metaphysis NO          trauma to fingers                    FREQ painful Scoliosis
contiguous marrow cav, Sauceri-                                            DDx - Brodies Abcess #1 in scle-
zation of cortex                      Trevor's Dz - Osteochondroma         rotic lesion w nidus
variable ST mass, sclerosis &         in joint, swell & deform, unilat     use Bone scan, Double Density
periosteal Rxn - Dx w Bx                                                   sign due to nidusNORMAL
                                      Hereditary Multiple Exostoses        VARIANTS
7. Osteochondroma - Osteocar-         - Auto dom, seen younger
tilagenous Exostosis, to joint        Variable severity, may be asym,      Dorsal Defect of the Patella -
Most common benign neoplasm,          20% malig transformation             lytic defect in upper out quad
rare malig transformation             Bowing deformities, shortened        mimics chondroblastoma, inf, or
osteochondritis dissecan            protruding mass of dense bone,     EG, Bone infarct & infection oc-
                                    usually incidental                 casionally
Pseudocysts - paucity of trabe-     can cause sinusitus, HA or
cula at G tuberosity of Humerus     exophthalmos if lg                 2) Cortical Destruction - can be
hyperimia II' t                     Arises from cortex, freq no ha-    missleading alone
MRI - shows NO ST component         versian sys                        cortex replaced by benign fibrous
Spontaneous regression,             Multiple Osteomas assoc w Gar-     or chondroid matrix
NEVER seen over age 30              dener's Syn                        infection, & EG also cause this
Resection curative, NO malig-       polyposis, dental lestions, des-   giant cell tumor & ABC can thin
nant potential                      moids & seb cysts also.            cortex so not seen
Pain at night releived by aspirin
                                                                       3) Periostitis - II' to irritation,
9. Osteoblastoma - rare, Giant           Malignant Bone Tumors         very nonspecific patterns
osteiod osteoma, >2cm               DIFFERENTIATING MALIG-             benign - thick wavy formation,
Expansile bubbly lesion, Scle-      NANT FROM BENIGN                   EG or inf may be agg
rotic margins poss, sim ABC         1) Zone of transition - most re-   aggresive - lamellated, amor-
can have speckled calc              liable, seen w every lesion        phous, or sunburst
Usually in post elements of         Narrow - benign w few excep-       Codman's triangle often seen at
spine, NO soft tissue mass          tions                              leading edge
Can recur but more likely to be     this includes sclerotic margins    can not thicken if malignant
osteosarcoma 2nd time               Wide - aggresive, usually be-      may thicken in late stages of
more lace like osteoid matrix       cause they are fast acting         healing if benign
seen                                Permeative - multiple sm holes w
                                    no clear border                    4) Axis of orientation - unreli-
10. Osteoma - slow growing be-      Round cell tumors - m myeloma,     able
nign tumor of sinuses & cranium     reticulum cell sarc                benign - in long axis of long bone
Ewing's sarcoma is a clear ex-       Major Long Bones - #1 in child,        rosis, breakout from med
ception                              Permeative & Diaphyseal                ST component freq, cumulus
malignant - round lesions            50% in flat bones - more com-          cloud of calcified osteoid
fibrous cortical defects are often   mon in adolescents                     75% cross epiphysis & joint, 20%
round however                        NO bone or cart formation, freq        w intramedullary skips
                                     hem & nec                              Diaphyseal form often present w
5) Arteriography - helps define      Freq periostitis, Onion skin #1,       Fx, bad prognosis
ST vs bone involvement               causes bone thickening                 MRI - evaluate ST component,
Demonstrate Neovascularity -         ST component in 90% - more             encroachment on joint, vasc
pathognomonic of malig               freq & larger than osteosarc           Pulmonary mets assoc w Pneu-
Arterial cutoffs & Venous lakes      Painful, severe systemic Sx early      mothorax, skeletal mets rare
Guide Bx away from necrotic re-      in Dz                                  Pain & elevated alk phos, Assoc
gions                                30% present w Mets - Lung #1,          w Pagets Dz
AGE GROUPS                           skeletal #2
1-30) Ewing' sarcoma, Osteosar-      DDx - Reticulum cell & neuro-          Well-Differentiated Osteosar-
coma                                 blastoma mets sim                      coma - #1 at dist femur
30-40) parosteal sarcoma, Fibro-     EG or infection more likely if thick   histo similar to low-grade pa-
sarcoma, Malignant giant cell        periostitis                            rosteal osteosarcoma
Reticulum cell sarcoma (primary                                             simulates desmoplastic fibroma
lymphoma of bone)                    Intramedullary Osteosarcoma -
40+) Mets, Myeloma, Chondro-         #1 primary bone tumor, 2:1 male        Telangiectatic osteosarcoma -
sarcoma                              Metaphyseal 80%, diaphyseal            lytic only, better prognosis, sim
                                     10%, 75% occur around knee             ABC
PATIENTS 1-30 YEARS OLD              epiphyseal very rare, flat bones       small areas of osteoid key to Dx,
Ewing's Sarcoma - Mysenchy-          10%                                    smaller tumor load
mal prolif from marrow, 5-30y/o      Destructive w freq reactive scle-
Osteosarcomatosis - multifocal        imitates a cortical desmoid (avul)   Sequestrum poss, NO periosteal
w very bad prognosis                  benign avul inj can appear very      rxn, NO ST mass
                                      malig                                #1 around knee, Diaphyseal
Burkitts Lymphoma - Sim ew-           Dense Centrally w cleavage           every where else
ings or reticulum cell in child       plane between it & cortex
assoc w CMV virus, good sur-          Cauliflower like, may not see        Malignant Fibrous Histiocy-
vival                                 conection to cortex                  toma - same appearance, see
                                      ** DDx - Myositis ossificans can     ST
Rhabdomyosarcoma - present            imitate but dense peripherally
at 5yrs, 50% head & neck, pelvis                                           Desmoid - low grade, usually
#2                                    Periosteal Osteosarc - cotical,      well defined, slow growing
freq mets to lung, nodes & liver,     no medul invasion, rare              benign periostitis w thick spic-
one in 20% but rare direct exten-     Saucerized cortex, intense peri-     ules, thick septa
tion                                  osteal Rxn                           no met, but extensive local inva-
                                      Poorly diferentiated, predomi-       sion
PATIENTS 30-40 YEARS OLD              nately Chondroblastic
Parosteal Osteosarcoma - less         prognosis better than intramedul-    Periosteal Fibrosarcoma - in-
deadly, extracortical bone dep        lary osteosarcoma                    vades cortex, medullary II'
Originates form the periosteum &                                           Fibrosarcoma of Soft Tissue - in-
grows outside the bone                Gnathic Osteosarcoma - older         vade bone II'
once cortex is penetrated it is a     pts, less aggressive
central osteosarc                                                          Malignant Giant Cell Tumor -
ST calc with a central distribution   Fibrosarcoma of Bone - usually       15% are malig, primarily 30-40
in the mass                           pure lytic, variable aggresive       Dx w recurrance, or met to lungs
Postmed dist femur #1 at site of      Expansile in medullary cavity,       histology is identical to benign
adductor insertion                    freq associated calc                 variaty
subarticular, closed epiphysis,    PATIENT OVER 40                     lytic & metaphyseal
eccentric, sharp zone              Metastatic Disease - include in     can be aggressive, Perosteal
                                   any DDx if pt over 40               rxn, ST mass & path Fx in 25%
Reticulum Cell Sarcoma - I'        Pain presents in 60%, Fx if >2cm    Hodgkin's - always met, assoc w
lymphoma of bone, male 2:1         or >50% of dia                      sclerosis & Ivory Vert
Permeative pattern identical to    Hypercalcemia - mets #1 cause       Neuroblastoma - Permeative
ewings sarc                        in hosp pts                         metaphyseal lesion, periosteal
#1 around knee & prox tibia,       Hypertrophic Osteoarthropathy -     Rxn
Rarely expansile                   Lung #1, mesothelioma               often symetric & sim Ewing's,
can involve a lg amt of bone w     Sclerotic multiple foci #1 for      leukemia or osteomyelitis
no sytemic symptoms                breast and prostate
I' Hodgkins & Lymphosarcoma        Hodgkins - the only lymphoma w      Myeloma - Aggressive, bubbly
are variants, very rare            sclerotic mets                      lytic pattern esp in ribs
Hemagiopericytoma - rare vasc      Ivory Vertebra - Paget's #1, mets   Plasma cell prolif in red marrow,
tumor, benign or malig             & Hodkin's #2                       edosteal errosion
Lytic & expansile but permeating   Prostate also presents w freq pe-   Polyneuropathy, Organomeg,
pattern poss                       riosteal rxn                        Enocrine, M-protien, Skin
Histo sim to Glomus Tumor          Renal Cell Ca - 90% Blown out       #1 cause of extraplueral masses
                                   lytic expansion                     @40
Chordoma - 55% sacroiliac,         25% present w mets, NO calc,        Pelvis, thoracic & lumbar spine
25% clivus, 20% cerv spine esp     Periosteal Rxn                      freq, skull rare
C2                                 Thyroid - Lytic, 8% present w       collapses vert body, effects mar-
Grossly expanding, highly ag-      bone mets                           row not post elements
gressive w lg ST mass              Lung - 80% lytic, more often        Diffuse Form - Osteoporosis #1
Slow growing, met late w NO        blastic if sm cell, 15% w bone      presentation, rarely sclerotic
skeletal met, fatal.               Lymphoma - NHL can be I', 75%       Bone Survey nît nuc scan
                                     nucs, enchondroma not              lands of malig cartilage
Plasmacytoma - presents 10yrs        Selenium75 - good for ID of tu-    Myxoid type - also pure ST, poor
younger (over 35)                    mors w cart matrix                 prognosis, avg 50yrs
preceed mult mye by 3-5 y            Freq cartilaginous lesion of ant
Chondrosarcoma - Intramedul-         ribs in adults
lary type #1, geographic permea-                                          Benign Causes of Periosteal
tive                                 Periosteal Chondrosarcoma -                    Elevation
Lg lytic component, ring & arc       larger ST mass, no medulary        1. Hypertrophic Pulmonary Os-
chondroid matrix                     comp                               teoarthropathy - clubbing
#1 in prox long bones, aggresive     sim periosteal chondroma or        Subperiosteal new bone, Meta-
w flat bone                          sessile osteochondroma             physis only, NO epiphyseal
ST mass is large, slower growing                                        Caused by pulm mass, I' bone or
than osteosarcoma                    Clear Cell Chondrosarcoma -        met, Benign cause poss
lung mets #1, skeletal rare          less aggresive w sclerotic rim
Assoc w Enchondroma, Osteo-          Present 30-40, improved prog-      2. Familial Pachydermoperios-
chondroma & Pagets                   nosis, can be totally lytic        tosis - assoc w clubbing
Low grade lesions indistinguish-     Epiphyseal & often confused w a
able even w path                     chondroblastoma                    3. Caffey's Dz - Infantil Cortical
Also sim Bone Infarcts               MRI - very high T2                 Hyperostosis, before 6mo
ST component is key to DDx                                              ST swelling, Immature laminar
from enchondroma                     Mesenchymal Chondrosar-            bone adjacent to cortex
Always presents w PAIN, en-          coma - Very aggresive, lg ST       Etiology may be viral
chondroma may not                    component
Lidocaine in joint stops DJD pain,   Present 20-30, often assoc w       4. Scurvy - Subperiosteal Hem-
not lesion pain                      prev intrmedullary chondrosarc     orrage in healing phase, P 6mo
hotter than ant iliac crest on       Can be pure ST, multifocal is-
5. Sarcoid - Elevated phalangeal     Synovial Sarcoma can also           In general the deeper the growth,
lytic lesions, Endosteal sclerosis   cause scalloping                    the worse the prognosis
                                                                         Shoulder #1, errodes outer cor-
                                     2. Liposarcoma - #2 ST mass,        tex of bone if deep
        Soft Tissue Disease          presents at 40-60yrs, rare in       Aggressive Infantile Type - dis-
MALIGNANT SOFT TISSUE                child                               covered before 2yrs
TUMORS                               Extremities & retroperitoneum, 5-   no met but locally aggresive &
1. Malignant Fibrous Histiocy-       10yrs earlier in extremities        recurs
toma - #1 malig ST tumor, 40-70      Low Grade - well differentiated,    All are very vasc w intense en-
Presents as painless soft tis        cannot met, local recur             hancement, NO necrosis
mass >5cm                            synonymous w Atypical Lipoma,
3 cell types, spindles predomi-      ALWAYS has fat                      Dupuytrens Contracture - Pal-
nate, histiocytes                    retroperitoneal form assoc w freq   mar Fibromatosis, ulnar side
Giant cells also poss, malig or      recur, bowel obs & death            If removed while cellular will re-
benign                               Myxoid Type - most common,          cur, wait until fibrosed
Poorly defined calc, poss in-        50% have visible fat by CT
volvement of adj bone                MRI - benign cyst like app poss,    Infantile Myofibromatosis -
Can cause scalloping of outer        freq assoc hem                      Myoblastic & fibroblastic lesion
cortex of adj bone                   Round Cell Type - poorly diff hy-   Bone lesions common, poor
Osseous MFH rare - geographic        percellular form                    prognosis if mult & deep
lytic lesions                        Dedifferentiated Liposarcoma -
No periosteal rxn or sclerosis       refers to mixed types               4. Synovioma - Synovial sar-
Closely related to fibrosarcoma,                                         coma, predominatly a spheroid
identical app                        3. Fibromatosis - Extraabd          ST mass
DDx - Liposarcoma, but no fat        Desmoid of deep & superficial       #1 at knee, hands & feet also
present in MFH                       tissues                             Originate from tendon sheath,
rarely assoc w joint                 Superficial ST & extremities        cortical holes poss
joint masses are not malig           CT - sim liposarcoma but not        cortex remains intact unlike per-
Calc 30%, Bone errosion freq,        seen in young pts                   meative round cell proc
occur up to 2cm from joint                                               Phlebliths often assoc
                                     Angiolipoma - encapsulated w        MRI - flow voids, Lace like pat-
BENIGN SOFT TISSUE TU-               vasc stroma & fibrin, young         tern of FAT in interstitium
MORS                                 adults                              Cavernous hemangiomas often
1. Lipoma - Mature fat in 40-60y/    rare infiltrating form seen w no    larger w less nonvasc tissue
o, female predominance               capsule, hemangioma like
95% solitary, Tumor fat not avail-                                       3. Elastofibroma - Benign RE-
able for metabolism                  Lipomatosis - diffuse over-         ACTIVE tumor like lesion of
CT - -65 to -120HU mass, well        growth of mature adipose tissue     chest
circ w NO enhancement                presents before 2yrs, often in      Comma shaped mass under
thin fibrous strands poss, if ex-    foot or hand                        scapula & chest wall in elderly pt
tensive think fibrosarc              bony hypertrophy freq, nerve not    II' to mechanical friction, usually
                                     affected                            asym, freq bilat
Neural Fibrolipoma - aka lipo-
matous hamartoma of median           Hibernoma - brown fat lipoma,       4. Synovial osteochondroma-
nerve                                extremely vascular on angio         tosis - benign synovial metepla-
Most in young adults, present w      occur in young adults, scapula &    sia
pain & paresthesia                   axillary region #1                  mult loose calc bodies in joint pa-
Macrodactly - freq in 2nd or 3rd     extremely rare in pure form         thognomonic
digit                                                                    loose bodies not always calc,
                                     2. Hemangiomas - Benign Vasc        mimics villonodular syn
Lipoblastoma - cellular imma-        neoplasm, fibrous tiss & Fat freq   erosions of the acetabulum may
ture lipoma, infants before 3yrs     Plain Film - ST mass w assoc        be seen
                                    8. Radiation Myositis - T1 im-      changes sim but less marked
5. Pigmented Villonodular           ages show N fibrofatty septations   Joint contracture, but NO termi-
Synovitis - benign synovial         T2 shows inc signal due to in-      nal tuft resorbtion
swelling                            flama etc                           Assoc w malig, genital Ca in fe-
Subarticular errosions w Joint                                          males
swelling & pain                     9. Thickening of Heal Pad -         NO assoc elevation in serum
Lg subchondral cysts w NO joint     seen w corticosteroid excess,       calcium levels
space narrowing typical             Cushings                            Juvenile form - most resolve
CALC NEVER SEEN assoc w             also seen w acromegaly, abn if      spontaneously, 40% mortality w/
this process, NO osteoperosis       >21mm                               o Tx
see section on benign joint proc-
esses                               SOFT TISSUE CALCIFICTA-             3. Scleroderma - Fluffy calcific
                                    TION                                deposits
6. Baker's Cyst - synovial cyst     1. Myosistis Ossificans -           Calcinosis Cutis - from tight over-
between semitend & med gas-         Trauma, rim of cortical bone        lying skin
troc m                                                                  Dist phalangeal resorbtion, Pen-
MRI will show fluid, II' to med     2. Dermatomyositis - Collagen       ciling & Autoamputation
meniscus tear                       vasc Dz, linear & confluent ST
                                    Ca+                                 4. Werners Syndrome - Osteo-
7. Tumoral Calcinosis - mult        Hands, Axilla, Inguinal & chest     porosis, ST Atrophy & Calc
calc deposits near major joints     wall most freq                      Neuropathic changes & DJD
Etiology unknown, occurs in         Lymphadenopathy, Spe-               Premature ageing, short stature
young blacks                        nomegaly, Rash & eventual           & arteriosclerotic probs
Multilobular & Cystic, Milky Ca+    death
phosphate fluid present             atony & dilation of esophagus       5. Leporsy - Calcifiction in
                                    DDx scleroderma & RA - bony         Nerves only
                                    Radiotherapy - usually lg holes     II' hyperparathyroidism induced
    Metabolic Bone Disease          but can be small                    by dec Ca+ level
OSTEOPENIA                                                              Ca+ Def & hyper or hypophos-
Osteoporosis - diminished bone      Osteomalacia - due to defect in     phatemia assoc
quantity in otherwise N bone        Vitamin D metabolism                Changes of HPT more common
Aging - 95%, postmenopausal         Dietary, Absorbtion problem,        in older pt rather than rickets
females                             Liver Dz or Renal Dz                Dietary - Inadequate Vit D intake,
Steroids - Exogenous more           excess nonmineralized osteoid,      rare before 1y/o
common than Cushing's               always assoc w bone pain            Defective fat uptake - prevents
also assoc w exuberant callus       Prominent trabeculae replace        transport of Vit D
formation                           normal small structural type        Sprue or defective bile salts
Plain Film - Cortical thinning #1   Looser's Zones - unmineralized      Liver - fails to convert vit D to 25
sign, middiaphysis 2nd metacarp     osteoid seam on concave side        OH cholecalciferol
Permeative Pattern - can result                                         Hepatic Osteodystrophy - seen in
from dissuse, sim Ewing             Renal Osteodystrophy - #1,          alcoholics
cortex riddled w holes, Ewing       fails to convert 25-OH-D3 to
originates in medullary             1,25-OH-D3                          Ricket's - Osteomalacia in an
thin transverse trabeculae & ac-    2 mechanisms contribute to as-      immature skeleton
centuated vertical trabeculae       soc osteopenia - Vit D prob & II'   Cartilage fails to mature in en-
No assoc lab abnormality, elev of   HPT                                 chondral bone growth
urine hydroxyproline poss           Renal tubular dysfxn causes Vit     Loss of zone of provisional calci-
                                    D resistant type                    fication, Dist femur #1
Pseudopermeative pattern in cor-    Fanconi Syn - tubules spill phos-   Inc space between metaphysis &
tex has 2 other causes              phate                               epiphysis, wide physis
Hemangioma - hyperemia II' to       Glomerular Dz - Retain phos-        Cartilage overgrows in long & lat
inc flow & tunneling                phate causing dec Ca+               dimensions
Flared irreg epiphysis, Metaphy      guishable from idiopathic type
cupping, diaphy bow                  Infantile Form - always lethal, NO   Hyperparathyroidism
Squared & flattened post calvar-     ossification of skull, AUNT MIN-     Primary Hyperparathyroidism
ium, basilar invag                   NIE                                  90% Adenomas, 10% hyperpla-
Periosteal elev, pain, coarse tra-                                        sia or mult glands
bec                                  X-Linked Hypophosphatemia -          Osteoblasts stimulated to mobi-
Rachitic Rosary - overgrowth of      previously called vit D resistant    lize Ca+ from bone
cart in ant ribs & wrist             rickets                              HYPERcalcemia results &
Looser's Fx - poorly mineralized     Proximal tubules fail to resorb      causes HYPOphosphatemia
bone laid w remodeling               filtered phosphate                   Subperiosteal Bone Resorbtion -
                                     Osteomalacia & insufficiency Fx      pathognomonic
Hypophosphatemia - Inherited         common, presents after 1st year      Radial aspect of mid phalanges
defect in alkaline phosphatase       Periosteal Hyperostosis freq, ac-    of 2nd & 3rd finger #1
activity                             tually see inc bone mass in          can prog to spiculation & com-
extracelluar accumulation of in-     adults                               plete cortical resorb
organic phosphate causes os-         Enthesopathy - bone formation at     Juxta-articular errosions - pubic
teomalacia                           liagament & tendon attachment        syph & sternoclavic
Sx - same as rickets, symptoms       freq                                 Subchondral Bone Resorbtion -
can improve with maturation          Defective dentin formation           involves axial skeleton
Adult form - 50% have slow on-       causes freq tooth problems           osteoclastic resorbtion of trabe-
set with no childhood Dz                                                  culae beneath cart
ST calcification seen in all forms   Non-Hereditary Hypophos-             Microfractures result & can
but most pronounced in adult         phatemia - oncogenic osteomal-       cause collapse
Enthesopathy - prominent bone        cia                                  Brown Tumors - characteristic of
spurs at tendinous insertions        most commonly due to mesen-          I' but seen w II' also
CPPD arthropathy freq, indistin-     chymal tumor                         Fibrous Tis & Giant cells replace
bone, expansile                       congenital renal malform            Vinyl Chloride Exposure - Tuft
May become sclerotic after Tx of      Adults - urinary tract obs or       resorbtion & SI ankylosis
HPT                                   chronic pyelonephritis              Returns to N after exposure
Osteosclerosis - mostly in II', in-   leads to glomerular failure &       stopped
volves axial skeleton                 phosphate retention
"Salt & Pepper" skull - Trabecular    Osteosclerosis more freq, Chon-     OSTEOSCLEROSIS
Resorb & scleros                      drocalcinosis less than I'          R) Renal Osteodystrophy - or
"Rugger Jersey" Spine - Sub-          "Tumoral Calc" - extensive ST       any cause of HPT, but this #1
chondral bone sclerosis               calc, more freq than I'             Subperiosteal bone resorb #1
Chondrocalcinosis - CPPD oc-          Hyperuricemia can also result       sign
curs in 40% of pts w I' HPT           causing II' Gout                    10-20% have sclerosis, etiology
Ligamentous laxity - atrophy of                                           unkown
ligament & attachment                 Scurvy - Impaired Osteoid For-
Seen best at syph pubis & SI,         mation, ST Ca+ phos deposites       S) Sickle Cell Dz - sm percent-
joints supported by ST                Metaphyseal - Dense calc of         age for unknown reason
                                      metaphysis w prox zone of attri-    assoc w bone infarcts & vert end
Renal Osteodystrophy - Sec-           tion                                plate step-offs
ondary Hyperparathyroidism            Trummerfield zone w the white
Phosphate retained, Ca+ drops         line of Frankel                     M) Myelofibrosis - myeloprolif-
HYPOcalcemia due to HYPER-            Pelkin's Fractures - Corner Fx of   erative syn, prog marrow fibrosis
phosphatemia                          brittle metaphysis freq             in pt over 50
Low Ca+ causes hyperplasia of         Periostitis due to subperiosteal    Anemia causes extramedullary
Cheif Cells in Parathyroid            bleeding                            hematopoesis & lg spleen
N Vit D metabolism disrupted          Never seen before 6mo, mater-       Assoc w Mets, Poisoning,
causing osteomalacia also             nal Vit C protective                chronic inf, AML, McCune-
Children - usually caused by                                              Albright
                                                                        dullary side, Axial skeleton I'
O) Osteopetrosis - generalized      P) Pyknodystosis - Toulouse-        Scattered sharp sclerotic foci,
dense amorphous bone                Lautrec Syn, an artist w the Dz     areas of rarefacation
N trabecular structure obliter-     Auto Dom, short w HYPOPLAS-         assoc w thickened sm bowel
ated, NORMAL MANDIBLE               TIC MANDIBLE                        folds, bone pain seen in <30%
Defective Osteoclasts - fine I'     Dense pointed dist phal pathag-
spicules persist                    nomonic, 2:1 male                   P) Paget's Dz - rarely diffuse,
medulla filled, die from anemia &   Sutures spread & persistent         20% monostotic, any bone can
infection                           wormian bones seen                  be affected
denser prox due to greater                                              Bone ENLARGEMENT & cortical
growth prox                         M) Metastatic Ca - prostate &       thickening, 3 phases
growth spurts cause lucent          breast #1, Hodgkins also            Osteolytic, Sclerotic bone forma-
bands                               assoc w cortical destruction or     tion & Mixed
clasts keep only during slow        lytic lesions                       II' bone has no haversian sys, Fx
growth                                                                  & avulse easily
Infantile Form - CN compression,    M) Mastocytosis - Mast cell ac-     Thickened haphazard trabecula,
throbocytopenia, death              cum in mult organs, 50% occur       freq bowing
Adult Form - 50% asym, recur-       at <6mo                             Prog end to center w Flame
rent trans Fx II' to brittle        Uticaria Pigmentosa- skin rash is   shape, Tibia only exeption
CN foramen narrow, mastoid air      #1 Sx, 90%                          Fibula never involved
cells obliterated                   assoc w LUEKEMIA, pancy-            "Banana fractures" & partial frac-
Erlenmeyer Flask long bones         topenia, hepatomeg, lymphade-       tures on convex side
-clublike & flarring end            nopathy                             SLOW progression, rapid
Longitudinal metaphyseal stria-     Hematopoetic marrow process,        changes considered malig de-
tions                               X-ray detectable in 70%             generation
end plate fibrosis, sandwich vert   Trabecula Thickened from me-        Pelvis - Ileopectineal line must
be thickened                        bones                                 OTHER CAUSES OF DENSE
Medial migration of femoral head    Tumors more likely to metasta-        BONES
poss, sim RA                        size                                  Hypervitamanosis A - Cortical
Skull - Osteoperosis Circum-        Nucs - marked uptake w active         thickening of Tubular bones
scripta, early lytic process        blastic                               Diaphyseal & symetric, diffuse
"Cotton-wool" Thickening & En-      Neoplasm - cold on bone scan,         periosteal Rxn
largement, blastic phase            hot on gallium                        NO subperiosteal hem seen, NO
Impingement of Cranial Nerves       MRI - not indicated, inc fat inten-   mandibular involvement
assoc                               sity on T1                            Metaphyseal spurring & In-
Basilar Invagination, no inc ICP    LAB - Increased Alkaline Phos-        creased ICP
assoc                               phatase levels                        Assoc w itching, dec appetite,
Spine - Dense picture frame vert,   Inc Ca+ causes renal calculi &        hard tender lumps on ext
appendages involved                 Nephrocalcinosis                      Hepatosplenomegaly, anorexia,
Symetric collapse poss, "vertebra   Urinary hydroxyproline levels         alopecia
plana", sim EG                      also inc                              never seen under 1y/o
Striations may mimic heman-         High output cardiac failure due to    DDx - Ricketts, Caffey's, Syphil-
gioma but usually sclerotic         mult tiny AVM's                       lis, healing Scurvy
Sarcomatous Degeneration -
<1%, to Osteo, chondro or fibro     A) Atheletes - II' to inc stress      Hypervitaminosis D - affects
undiff w elements of all 3 freq,                                          adults & children opposite
osteo #1                            F) Flourosis - II' to dietary in-     Child - Thickening of provisional
Only time Sarcomas of Skull oc-     take, rare                            zone of calc & Cortex
cur                                 assoc w ligamentous calcifica-        Adult - Osteoporosis & tumoral
Giant Cell Ca - Only time they      tion, esp sacrotuberous               ST calc esp at joints
occur in older pt's
ALL occur in the skull & facial                                           Hyperphosphatemia - "Juvenile
Paget's Dz", auto rec in Puerto     phatemia but elevated PTH level      occurs years after Tx for hyper-
Rican's                                                                  thyroidism
Fusiform expansion of               Pseudopseudohypoparathy-
Spongiosa, no normal maturation     roidism - clinical syndrome,         Cretinism - Hypothryoid from
Dwarfism, bowed bones, wide         NORMAL labs                          birth, Delayed Skeletal matura-
irreg epiphysis sim to rickets                                           tion
Skull enlarged w Sclerotic          Cushings - Axial Osteoporosis        Endosteal cortical thickening
patches, Cranial Nerve deficits     #1, 3:1 female                       obliterating marrow cavity
Biconcave vert bodies, Cystic le-   Assoc w adrenal hyperplasia in       Irreg ossifacation esp in femoral
sions poss                          adults                               epiphysis
                                    Vertebra - Prom vertical stria-      Vert bodies flat & hypoplastic,
Hypoparathyroidism - HY-            tions, Dense cupped endplates        esp T12-L1 causing KYPHOSIS
POcalcemia & resulting neuro-       Fx's heal w excessive callus (esp
musc Sx                             RIBS), mult bone infarcts            Acromegaly - Eosinophilic Ade-
Parathyroid defeciency - usually    Calveria stippled, demineralized     noma #1 cause, equal in sexes
II' type, Iatrogenic                sella                                50% show Skull thickening esp
Osteosclerosis & calveral thick-    Adrenal tumors in children - de-     at base, 20% w N sella
ening is I' manifestation           layed skeletal maturation            Periosteal Apositional bone for-
Basal Ganglia & SubQ tissue                                              mation in long bones
calc also                           Thyroid Acropachy - periosteal       Exagerated tuberosities, general-
                                    rxn & thickening of tubular bones    ized ST thickening, esp heal pad
Pseudohypoparathyroidism -          fuzy periostitis on radial side of   to >21mm
end organ resistance                metacarpals & mid phalanges          Premature Oteoarthritis - carti-
Characteristic short stature,       very distinctive                     lage thickens then dies
round face, obesity & MR result     Present HYPO or euthyroid w          due to inadequate blood supply,
Hypocalcemia & Hyperphos-           exopthalmos & pretibial edema        post vert scalloping
Vert - post scalloping in 30%        Diaphyseal Dysplasia, not famil-     Clavicle - thickend trabecula due
Enthesopathy - "Spade Digits" &      ial                                  to stress
lg spurs of distal metacarpals       Rapid prolif of new cortical bone,   normal joint space maintained,
                                     symetrical thickening                clavicle head may be expanded
Post Radiation Tx - Pattern          Sim paget's but Diaphyseal only,     increased density confined to
matches ports, ST calc assoc         stops at metaphyseal line            lower medial clavicle, UNILAT
                                                                          pain & swelling but no skin in-
Worth Syndrome - Auto Dom,           Pachydermoperiostosis - Hy-          flammation
Endosteal Hyperostosis               pertrophic Oteoarthopathy, Auto
Endosteal thickening of tubular      Dom
bones obliterating marro             M>>F, middle age, lg thick skin         Congenital Bone Disease
Osteosclerosis of skull begins at    folds, enlarged paranasal si-        CONGENITAL BONE DIS-
base, extends to face                nuses                                EASES
Mandible freq involved, pelvis &     Irreg periosteal proif of phalnges   Subperiosteal new bone can be
ribs not involved                    & dist long bones - CLUBBING         seen in N infants
Spine - primarily post elements      Epiphysis & metphyseal regions
thickened                            of tubular long bones #1             Scoliosis - Adolescent type most
                                     cortex thickens but NO narrowing     common, multifactorial inheri-
Lead Poisoning - can create          of medullary cavity                  tance
dense metaphyseal line               can have acro-osteolysis, pro-       Congenital Scoliosis - look for
abnormal remodeling of tubular       gression ceases after several        assoc vert body anomalies, hemi
bones possible                       years                                or butterfly
widened cranial sutures due to       DDx - pulm osteoarthropathy          Idiopathic Scoliosis - usually
inc intracranial pressure possible   (painful) & thyroid acropachy        convex to the right, L assoc w
                                                                          other anomali
Englemann' Dz - Progressive          Osteitis Condensans of the           15% assoc w congenital heart Dz
Wedged vert body at apex of           BLUE Sclera, least severe form       Osteosclerosis, Calverial thicken-
curve,                                NO congenital fractures but Rib-     ing
I' curve forms w II' curves above     bon Ribs & Deafness                  Dwarfism - Shortened & bowed
& below                               Long bones - Diaphyseal Bow-         long bones
8:1 female, starts P 10y/o &          ing, Cyst-like lesions               Shortened 4th & 5th metacarpals
stops w cessation of growth           Skull - Wormian bones ALWAYS         & distal thumb phalanx
NF-1, TB, Osteoid Osteoma,            seen, Basilar Invagination           2) Soft Tissue Calc - Basal Gan-
Marfan's                              Fx freq w Exuberant callus for-      glia, Dentate nuc, skin & subQ
Wilm's - due to radiation necrosis    mation, NO IUGR by US                Broad Facies, Mental Retarda-
of ipsilateral apophysis              No further fx usually occur P pu-    tion & Cataracts also assoc
                                      berty                                3) Abn Blood Chemistry - LOW
Infantile Cortical Hyperostosis       "Popcorn" metaphysis - cystic le-    Ca+, HIGH phos
- marked cortical thickening          sions pathog for OI                  Turner's Syndrome - XO, De-
<6mo old, acutlely ill, irritable -   Type IV - similar but mild deaf &    layed epiphyseal fusion
probably infectious                   bowing, No blue sclera               Shortened 4th & 5th metacar-
Metaphysis spared, Freq exac-         Congenita - (Types II & III), Auto   pals, Shortened ulna
erbation & remission                  Rec, accordian bones, II lethal      "Drumstick" metacarpals & pha-
resolves completely within a few      Thin skull                           langes
months                                Wedge or bow-tie vert bodies         Cubitus Valgus - large medial
Vert bodies also spared                                                    femoral condyle
                                      Pseudohypoparathyroidism -           Odontoid hypoplasia & small
Osteogenesis Imperfecta - bad         End organ resistance to hormone      sella tursica
osteoblasts, poor osteogenesis        Heritable syndrome w 3 compo-        "Squared" vertebra - shortened
Collagen also abn, Fibroblast         nents                                A-P diameter
cultures for Dx                       1) Skeletal abn - Manifestations     Horseshoe Kidney, Coarctation
Tarda - (Types I), Auto Dom,          of HYPOparathyroidism                of the aorta & Infantilism
                                   Tuberous Sclerosis - Cortical         Bizarre facial dysplasia - Sphe-
Syphilis - Trophic depostits of    thickening, can sim pagets            noid #1, orbit asymetry
endochondral bone                  Flat osteomatous protuberances        Post orbit does not develop,
Zone of provisional Calc widens,   on cortex                             Poss II' to optic gliomas
lucent fibrous zone prox           Paraventricular tubers, Renal         Sharply angled Scoliosis - wors-
"Saber shin" - severe form of      masses, Pulm infiltrates              ens even P growth stops
subperiosteal bone growth          Zits, Fits & Nitwits, lytic lesions   Scalloped post vert bodies - mult
occurs everywhere but ant tibia    poss but rare                         spinal meningoceles
most common                                                              small vert body, long sclerotic
Charcot joints & minimal ST        Neurofibromatosis - Von Reck-         post elements
component, rapid response to       linghausens (NF-1) assoc w            "Dumb-bell" tumors - widen for-
PCN                                bone                                  mena & erode pedicles
DDx - scurvy & ricketts, but pt    Family Hx #1 presentation, Fx w       Focal Gigantism of a digit
too young                          pseudoarthrosis also                  Cafe Au lait spots, gliomas, lesch
                                   ST dysplasia induced by abn           nodules of iris
Hereditary Osteocartilaginous      nerves - Elephant Man                 Renal artery Stenosis & Neurofi-
Exostoses - effects long bones     ABN TRABECULATION PAT-                brosarcoma poss
exostoses are not as large or      TERN, "Ribbon Ribs", mult NOF         Blount's Dz - Osteochondrosis
spike-like as isolated form        Ossification centers & digits can     Deformans Tibiae
Madelung deformity of wrist -      have marked overgrowth                lat dilocation of tibia, wedge-
Paired bones show dif growth       UNILAT ANTERIOR bowing of             shaped deformity of medial tibia
Supernumary Digits & radial        distal leg                            Infantile Form - physiologic bow-
head dislocation                   (osteogenesis is bilat, fetal mal-    ing fails to straighten w growth
Chondrosarcomatous Degenera-       position causes post bow)             Histo shows disturbed medial
tion - occurs in 20%, esp hips     Extensive subperiosteal hem w         epiphyseal endochondral oss
                                   exuberant callus poss                 Juvenile Form - less common,
segmental arrest of medial            Morquio's - the only one NOT          marrow hyperplasia
growth plate                          assoc w mental retardation            Widened Spongiosa w coarse
usually unilat, affects children 8-   type IV, skeletal changes pre-        trabecular pattern, thin cortex
15yrs                                 dominate, auto rec
                                      "Bullet" shaped vert w gibbus         Hadju-Cheney - Primary Acroos-
Gaucher's Dz - Auto Rec, Dec          due to dysplasia of L1 or T12         teolysis, tufts never develop, os-
lysosomal Hydrolase                   "Wineglass" pelvis & iliac wing       teoporosis
Glucosyl Ceramide accumulates         flaring, dwarfism                     Wormian bones & Kyphoscolio-
in RES organs, 3 forms                shortened & thickened metacar-        sis
Adult - #1, mult spleen nodes,        pals & carpals                        Acroosteolysis also occurs w
pulm & hepatic fail, death            Premature degenerative arthritis,     scleroderma, frost-bite & burn
Juvenile - 2-6yrs, mild w pre-        corneal opacities                     Pyknodysostosis, psorisis &
dominate neurologic Sx                Hurler's - type I, gargoylism, auto   Pachydermoperiostitis
Infantile - hepatosplenomeg, se-      rec, dwarfism, MR after 1-3yrs
vere neuro, early death               main Sx are neuro, "bullet" ver-      Holt-Oram Syn - Cardiomelic
90% have bone Sx - Avasc Nec,         tebra are seen though less            syndrome, Auto dom, effects up-
Osteomyelits, Myelofibrosis           calverial thickening, J shaped        per ext only
"Erlenmeyer Flask" - marked cor-      sella, frontal bossing                assoc w variety of clavicle, ster-
tical thickenig at dist fem           Scaphocephaly due to closure of       num, radius anomalies
"Fish Mouth" vertebra, bone in-       sag suture                            Hands #1 - carpal coalition, ab-
farcts, Periosteal Rxn                Claw hands, thick flaring ribs        sent thumb etc
mult sharply demarcated lytic le-                                           Heart defects predominatly con-
sions poss                            Hemolytic Anemias - Thalas-           ductive, septal #1 structural de-
                                      semia, sickle cell, Non-              fects
Mucopolysaccharidoses - lyso-         spherocytic                           Marfan's Syndrome - auto dom
somal storage disorder                Congenital, causes profound           defect in collagen cross linking
Generalized Osteopenia, Doli-       macrodactyly due to neural fi-        space widened
chocepahly, prominent jaw           brolipoma                             forms a V shaped radial & ulnar
Thumb & 1st toe dispropor-          increase in size of all elements &    articulartion w carpals
tionatly long, pes planus           structures of one or more digits      carpal angle decreased, volar
Scoliosis in 60%, Scheuremann       fibrofatty tissue infiltrates epi-    subluxation
Dz, Dural ectasia w post scallop-   neurium, growth stops at puberty      II' to premature fusion of radial
ing                                                                       physis, assoc w trauma
ligamentous laxity, premature os-   Polydactyly - Preaxial means          also seen w Turner's & multiple
teoarthritis, slipped cap fem       lateral, index or thumb duplica-      enchondromatosis
epiphysis                           tion
Cardiovascular - cause of death     Postaxial - medial, more com-         Radial Ray Defects - rare, 40%
in 90%, recurrent biliary obs       mon 5th digit duplication             assoc w VACTERL anomalies
Occular lens dilocation, cystic     Syndactyly - most commonly in-        can be absent thumb or entire
lung Dz, recurrent pneumothorax     volves the 3rd & 4th digits           radius

Homocystinuria - familial defect    Infantile Coxa Vara - proximal        Klippel-Feil Syndrome - Fused
in collagen synthesis, simulates    focal femoral neck defeciency,        cerv & upper thoracic vertebra
Marfan's                            unilat
arachnodactaly, scoliosis & post    causes varus deformity of femo-       Sprengel's Deformity - scapula
scalloping of vert bodies in both   ral neck, widened growth plate        elevated & fused to cervical ver-
Osteoporosis occurs w this but      child presents w lurching pain-       tebra
not Marfan's                        less gait
ligamentous laxity present but no                                         Congenital Posterior Bowing
joint contracture as in Marfan's    Madelung Deformity - volar an-        of Tibia - foot dorsiflexed
                                    gulation of distal Radius             etiology unkown, progressive im-
Macrodystrophia Lipomatosa -        relatively long ulna & radial-ulnar   provement w growth
eventually becomes staight w        prob w minimal herniation           shortening
minimal shortenening                Short pedicles & narrow intrape-    Premature DJD, short palanges,
                                    dicular distance MUST be pre-       auto rec w NO shortened life-
                                    sent                                span
       Skeletal Dysplasias          Flattened Acetabular Angle & Il-    minimal spine effects DDx from
SKELETAL DYSPLASIAS                 iac wings                           Spondyloepiphyseal dysplasias
Disturbance of bone growth                                              DDx - stippled epiphysis also
Rhizomelic Dwarfism - proximal      Spondyloepiphyseal Dysplasia        seen w cretinism & warfarin em-
limbs, humerus & femur, achon-      - Auto dom, dwarfism from spine     bryopathy
droplasia                           & hips
Mesomelic Darfism - shortened       DDx - Morquio's, several distin-    Metaphyseal Chondrodyspla-
intermediate seg                    guishing features                   sia - severe short limbed dwarfs
Acromelic Darfism - distal short-   presents at birth, morquio's seen   all have Erlenmeyer flask de-
ening, asphyxiating thoracic dys-   at end of first year                formity extending to diaphysis
plasia                              deficient ossification of pubic
Micromelic Dwarfism - shortened     bones & narrow pelvic angle, not    Schmid Type - most common,
entire limb, jeune syn, thanato-    flared                              AutoDom
phoric                              varus deformity of hips, Mor-       widened epiphysis, cupped
                                    quio's has valgus                   metaphysis & coxa vara
Achondroplasia - Rhizomelic         NO involvement of the hands         mimics Vit D refractory Rickets
Shortening (prox long bones)        Corneal detachment rather than
Scalloped post vert bodies as       corneal clouding                    Metaphyseal Dysplasia - Pyle
seen in acromegaly                                                      Dz, often tall & asymptomatic
Foramen Magnum small - Hy-          Multiple Epiphyseal Dysplasia       effects long bones esp in hand &
drocephalus causes lg head          - irreg mottled calc of epiphysis   medial clavicle, genu valgum
Narrow dist spinal canal - causes   late onset of dwarfism, mild limb   splaying of ends w thinned cortex
                                     Demineralization but dense ver-      1st then stress during flexion &
Chondroectodermal Dysplasia          tebral margins                       adduction
- Ellis-van Creveld Syn              Calvarial thickening, caxa vara,     Transverse view - head centered
Accelerated Skeletal maturation      wedge vert bodies in adulthood       over & touching triradiate carti-
Polydactyly & congenital heart       NO skeletal change w adult on-       lage
Dz freq, Septal defects #1           set                                  femoral metaphysis inferior & is-
Nails, hair & teeth ALWAYS in-                                            chium superior make cup for
volved                               Angiovenous Dysplasia - AVM,         head
Cleidocranial Dysotosis - delayed    hemangioma or venous malfor-         Coronal view - gluteal muscles
ossification of midline structures   mation                               will be seen lat to iliac bone &
large head w Wormian bones,          most asym, may cause over-           head
hypoplastic sinuses, bossing, lg     growth of affected limb due to inc   Abduction will demonstrate if hip
mandible                             flow                                 is reducable
hypoplastic chest, medial & lat      can cause focal bone errosions,      MRI - may show iliopsoas tendon
portions of clavicle don't fuse      look for phleboliths                 within joint if dislocated
delayes ossification of symphysis                                         Inverted Limbus - labrum hyper-
pubis                                Hip Dysplasia - femoral head         trophies & turns inward to joint
spina bifida occulta, varus hip,     cartilage <50% covered by ace-       prevents relocation, arthrography
short radius                         tabulum                              shows loss of "rose thorn" pg760
                                     usually displaced post & lat, will   ACR37
Cretinism - congenital Hypothry-     eventuall migrate superior           Femoral head ischemia - head
roidism, Delayed skeletal matu-      1) seated at rest, lax w stress,     rotates superior causing valgus
ration                               2)subluxated, 3)dislocated           deformity
Stippled Epiphysis, may remain       Most important is to determine if    occurs at younger age than
open indefinetly, wide sutures &     it is reducible or not               Legg-Perthes
fontanelles                          Dynamic US Scanning - neutral        look for shallow acetabulum &
widened "teardrop" seen w             acetabulum shallow or absent         tilage deposits on synovium
chronic process                       due to dysplastic femoral head       Calcium deposits in cartilage,
Weberg Angle - adult head             Apert's Syndrome - Acrocephalo-      Knee, hips & elbows #1
should be centered in acetabu-        syndactyly
lum                                   Craniosynostosis of coronal su-      Pigmented Villonodular Syno-
angle between vertical & line to      ture resulting in brachiocephaly     vitis
upper margin of acetabulum            also hypoplastic ant fossa,          hemosiderin deposited causing
both lines originate in center of     prominent sella turcica & choroid    fibrosis & Synovial prolif
femoral head, 20-46deg N,             calcification                        Monarticular degeneration of
smaller bad                           midface hypoplasia, hypertelo-       knee #1, hip #2
                                      rism, hydrocephalus                  most commonly effects extraar-
Proximal Focal Femoral Defi-          Syndactyly - results in "mitten      ticular tendon sheaths
ciency - dysgenesis of prox fe-       hand" & "sock foot"                  Periarticular cystic degeneration
mur                                   Symphalangism - progressive          in hands & feet freq
probably II' to in utero vasc acci-   obliteration of interphalangeal      85% have osseous lytic lesions &
dent, most unilat, isolated anom-     joints                               cortical errosions
aly                                   fusion of other joints as well in-   Lg subchondral cysts w NO joint
70% have ipsilat fibular agenesis     cluding tarsals & carpals            space narrowing typical
prob due to same vasc accident                                             NO CALC & NO Osteoperosis,
present as unilat short limb, no                                           articular cartilage preserved until
pain                                    Arthritis and Benign Joint         late
US - shows a cartilage connec-                   Processes                 Resembles nonossified synovial
tion between head & shaft in mild     BENIGN JOINT PROCESSES               osteochondromatosis
form                                  Synovial Osteochondromatosis -       DDx - Synovioma, sim distribu-
severe form has no connection         usually monoarticular                tion & ST mass
or no femoral head                    Metaplasia of the synovium - car-    errosions more smooth & no pe-
riosteal rxn                         H. flu in infant, S. aureus in child   giomatous tissue, crosses joints
                                     present w fever and immobile           & disk
Sudec's Atrophy - Reflex Sym-        joint, X-ray N initially               effects children & young adults,
pathetic Dystrophy, shoulder-        Effusion displaces med aspect of       any bone involved
hand syn                             head >1mm relative to opposite         no pain or expansile mass assoc,
1) onset of painful & stiff shoul-   Aspirtation for Dx, Emergent ar-       no Tx effective.
der or hand joints, lasts 6mo        throtomy & open drainage for Tx
2) Shoulder improves but hand        high risk of cartilage destruction,
continues to burn, ST wasting        15% assoc w head osteomyelitis           Collagen Vascular Disease
3) last stage may be 3-6mo or        X-ray - <35% sensitivity, 1mm is
chronic, contractures, skin atro-    sig for poss infection, need of        NO joint destruction
phy                                  aspiration
Nucs - shows inc flow & uptake,      US - 90% sensitive for effusion,       Scleroderma - Tight overlying
plain film shows osteopenia P        best in sagittal plane                 skin causes calcinosis cutis
6wks                                 echogenicity of the fluid does not     Dist phalangeal resorb - pencil-
Trauma is often intial event, se-    relate to need for aspiration          ing & acroosteolysis
verity does not influence out-                                              ST calc but less than dermato-
come                                 Lyme Disease - JRA type pres-          myositis
Tx w corticosteroids & sympa-        entation possible if no Tx             NO osteoperosis
thetic block w meds or surg          Erythema Migrans rash at site of
Aggressive Osteoporosis is hall-     deer tick bite, Spirochet              Dermatomyositis - nonsuppura-
mark                                                                        tive inflam myopathy
DDx - dissuse osteoporosis, no       Gorham's Vanishing Bone -              Onset 4-11yrs, Edema of SubQ
ST wasting or skin atrophy assoc     massive osteolysis II' to hema-        tissues first Sx
                                     giomatosis                             Muscle also presents w edema &
Septic Hip - B strep in neonate,     bone resorbed & replaced by an-        loss of fat-musc planes
Eventual fibrosis, calc & contrac-   Mixed connective tis Dz -          Rotary fixation of the atlantoaxial
ture                                 sclero, SLE, polymyositis & RA     joint - follows mild tra
ST calc in linear confluent pat-     Osteoporosis & soft tissue wast-   C1-C2 move en mass, lat spaces
tern                                 ing                                unequal even w/o rotation
seen in hands, axilla, inguinal &    No erosions
chest wall                                                              Clay Shoveler's fx - avulsion of
Bone undergoes dissuse resorb-                     Trauma               lower spinous process
tion                                 CERVICAL SPINE                     excesive force to the su-
NO terminal tuft resorbtion, malig   Prevertebral soft tissue - 3mm     peraspinous ligaments
joint contracture assoc              from C1-C4, smooth contour
Fever, rash, lymphadenopathy,        Anterior vertebral bodies - in-    Hangman's fx - bilat neural arch
splenomegaly & death assoc           teruption indicates serious inj    fx of C2, ant Sublux of C2 on C3
Atony & dilation of the esopha-      Spinolaminal line - disruption     hyperextention & extraction in-
gus                                  could indicate cord injury         jury, unstable but cord decomp
                                     C1 ant arch should be no more      prevertebral ST swelling but NO
Systemic Lupus Erythemato-           than 2.5mm from dens (5mm          facet dilocation
sus - Alignment changes, NO          kids)                              ant inf corner fx of C2
ERROSIONS                            Nerve Root Avulsion - most
Boutoneire Deformity - lax joint     common in dist cerv spine          Hyperextention Teardrop Fx -
capsules esp at MCP joints                                              avulsion of ant inf corner by ant
reducable ulnar deviation typical    Jefferson's fx - split C1, CT to   long lig, C2 #1
Nonerrosive peripheral polyar-       demonstrate all fx points          Usually no displacement of vert
thritis w sim distribution as RA     Unstable only if Trans lig dis-    body
Calc of tendenous insertions         rupted, seen if >7mm spread
poss                                 rarely assoc w an odontoid fx      Hyperflextion Teardrop Fx - ant
                                                                        inf corner crushed anteriorly,
body retropulsed                       Smith's fx - fx of post body          Rolando's fx - com fx at base of
one of the most severe & unsta-                                              1st met w joint involed
ble, cause ant cord syn - quad &       Chance fx - results from flexion,
loss of pain                           10% assoc w bowel damage              Mallet Finger or Baseball Finger -
                                       failure of the post & middle spinal   avul at dorsal base of dist phal
Unilateral locked facet - apo-         columns                               extensor digitorum insertion
physeal ligaments rupture              ant failure also poss                 makes surg fix mandatory
flexion & rotation inf, facets                                               flexs w/o opposition due to loss
overide, rarely bilat                  Spondylolysis - fx of the pars in-    of extensor
                                       terarticularis of lamina
Ant Subluxation - hyperextention,      fx in neck of scottie dog on obl      Volar Plate Fx - fx at the base of
20% have delayed instability           view                                  the mid phalanx along the volar
kyphotic angulation w narrowed         often occurs in toddler yrs, not      aspect
ant disk space, wide post              always significant
                                                                             Gamekeeper's thumb - avul of
Instability - inability to withstand   Spondylolisthesis - bilat pars fx,    ulnar side of 1st prox phalanx
physiologic loads                      sup sublux ant to inf
Intervertebral space widened,                                                WRIST
horiz displacement >3.5mm              HAND                                  80% of axial loading force on ra-
angulation >11deg, disruption of       Bennett's fx - fx at base of 1st      dius
facets, mult fx's                      metacarpal into carpomet joi          any radial fx can result in positive
                                       thumb adductors cause sliding,        ulnar variance
LUMBAR SPINE                           must be surgically fixed
Seat belt injury - ant compres-        psuedo-bennett's fx - no in-          Lunate/Perilunate Dislocation -
sion of L1 or L2                       volvement of the joint                ligaments to capitate disrupt
                                                                             Dorsal perilunate dislocation -
capitelum & carpals dorsal            of lunate                            AP film - often shows widening of
3x more common than lunate            assoc w negative ulnar variance,     scapholunate joint
disloc, 75% assoc w Fx                short ulna                           Lat Film - key to diagnosis of
                                                                           dorsiflexion instability
Lunate dislocation - lunate           Hook of Hamate Fx - need carpal      shows volar angulation of lunate
pushed volar to radius                tunnel view, parralel to palm        & capitate displaced volar (post)
manipulation can change one to        usually due to fall onto an out-     lines drawn thru vert axis of lu-
the other                             streched hand                        nate & scaphoid angle >80deg
pie shaped lunate seen on AP          prof baseball, tennis, & golfers     (N 30-60)
view                                  can lever of hook                    Palmarflexion instability - Ant
permanent median nerve dam-           Ulnar Nerve which lies adjacent      displaced capitate & palmar an-
age can result from lunate            & outside tunnel often damaged       gulation of lunate
assoc w capitate, radial styloid, &   CT may be helpful
triquetrum fx                                                              Rotary sublux of Scaphoid - rup-
Can cause dorsal instability of       Fracture of Scaphoid - avasc nec     tured scapholunate lig, scaphoid
the wrist                             of prox frag common                  rotates volar
                                                                           lat view shows horizontal orienta-
Ulnolunate Impaction Syn - pos        Dorsal Instability of Wrist - dis-   tion of scaphoid
ulnar variance flattens med lu-       ruption of dorsal radiocarpal        gap between scaphoid and lu-
nate                                  ligaments                            nate on AP view - "Terry Thomas
triangular fibrocartilage thinned &   60% due to scaphoid fx, 10%          Sign"
often torn by long ulna               due to triquetral fx (dorsal chip
subchondral degen cyst devel-         seen)                                Triquetral fx - avul chip seen on
ops in lunate due to impaction        ligament inj such as rotary sublux   dorsum of wrist patognomonic
                                      of scaphoid or perilunate disloc     occurs at dorsum and may cause
Kienbock's Malacia - avasc nec        also                                 dorsal instability of the wrist
horizontal compresion assoc w       most in young female during lac-      fx w dislocation of dist radial ul-
perilunate diloc, capitate &/or     tation                                nar
scaphoid Fx
                                    FOREARM                               Barton Fx - Fx of the dorsal ar-
Carpal Tunnel - carries median &    Colle's fx - dorsal ang of dist       ticular margin of dist radius
ulnar N, Radial & Ulnar art         radius/ulnar styloid fx
Flexor digitorum Profunda deep                                            ELBOW
& superficialis over                Smith's fx - volar ang of dist        Fat pad displaced from post
Flexor dig Longus goes over         radius/ulna fx                        fossa following fx
flexor retinaculum, inserts to                                            child usually supracondylar, adult
palmar aponeurosis                  Plastic bowing deformity - bend       usually radial head
Carpal tunnel syndrome - most       but no break                          Children can have effusion with-
common in obese middle age          must be surgicaly broken & reset      out Fx - Dr. Ozonoff
women                               or lose sup & pronation
                                                                          CRITOE 1,5,7,10,10,12 - order &
Carpal-Ulnar Dislocation - ulna &   Monteggia's Fx - ulna fx, (90%        age of epiphysis ossification el-
triquetrum no longer aligned        proximal) & prox radius disloc        bow
                                    must examine prox radius or           Capitulum, Radius, Internal epi-
deQuervain's Stenosing Teno-        aseptic nec may result                condyle (med),Trochlea
synovitis - affects the extensors   Positive Ulnar Variance - can re-     Olecranon & External epicondyle
over radial styloid                 sult from any radial fx               (lat)
abductor pollicus longus & bre-                                           All but lat epi fuse by 16yrs, 18 -
vis, MRI shows fat planes in-       Galleazzi's Fx - radial fx w disloc   lat fused
flammed                             of distal ulna                        Come Rub My Tree Of Love -
pain occurs w thumb movement,                                             Erin Masada's pneumonic
                                    Essex-Lopressti Fx - radial head
Ligamentous Injuries                 defect in postlat articulation on      chondral injury to capitellum
Ulnar Collateral Lig - most impor-   MR                                     due to repeated valgus stress
tant, resists valgus stress          mistaken for osteochondral le-
Ant thick cordlike, middle apo-      sion or fx                             SHOULDER
neurotic, post thin & tran           True osteochonritis would be lo-       Neer Classifications for Fx's -
freq stressed in pitchers            cated more ant in cart                 based on # & angulation of frags
Annular Ligament - stabalizes                                               One Part - 80%, surgical neck fx
radial head in pronation & sup       Essex-Lopresti Fx - Radial head        w no displacement
Dislocation - radius & ulna to-      Fx w dilocation of dist radial ulnar   Two Part - Fx of surgical neck w
gether #1                            joint                                  displacement
Nursemaids - reduced w supina-                                              >45deg angulation or >1cm
tion & ext rotation                  Volkmann's Contracture - com-          apart, ORIF required
Radial head freq w ulnar Fx          plication of a supracondylar fx        Three Part - greater or lesser
Common Flexor Tendon - from          vascular compromise from bra-          tuberosity avulsed & displaced
med epicondyle, can avulse           chial art injury or swelling           Four Part - both greater & lesser
Extensor Tendon - inflam causes      muscle & nerve ischemia results        tuberosity displaced
Tennis Elbow, esp anconius           in flexion contracture of hand &       devascularization of humeral
muscle                               wrist                                  head

Olecranon Bursa                      Biceps Tendon Rupture - most           Ant dislocation - #1, ext rotation
Subcutaneous - freq assoc w          common tendinous injury                and abduction
housemaids elbow & trauma            pt unable to flex biceps, pain         head seen inf and medial to the
Subtendinous - assoc w pitcher       over radial tuberosity                 glenoid
injuries, chips in fossa                                                    Hill-Sachs deformity - Fx of
                                     Little Leaguer's Elbow - osteo-        postlat head of hum, 50%
Pseudodefect of the Capitulum -                                             caused by inf lip of glenoid, dis-
loc likely to recur                  PELVIS                               causeing labrum to flip down
Bankart deformity - frag off inf     Acetabulum - CT needed to            II' acetabular dysplasia follows if
glenoid, less common                 show free frags and subtle fx        not corrected
Axillary Nerve Injury assoc                                               Pavlik Harness - holds in flexion
                                     Sacrum - fx 50% of time w pelvis     & ext rotation
Post dislocation - more dif to Dx,   fx, dificult to see                  US - greater than 50% of fem
use scapular Y or Axillary veiw      look for interruption of the arcu-   head should be in acetab
AP view - may be N, lose overlap     ate lines
of glenoid & head, sm space          stress fx can appear sclerotic in    Femoral neck stress fx - dif to
seen                                 osteopenic pt, CT                    detect esp in elderly
look for lesser tuberosity avul or                                        type 1 - sclerosis w/o fx line evi-
Fx of post rim of glenoid            Malaigne Fx - SI diastasis assoc     dent, bedrest for tx
Reverse Hill-Sach's - trough Fx      w pelvic ring Fx                     type 2 - sclerosis w fx line evi-
of ant-medial aspect of humeral      60% chance of significant injury     dent, int fixation
head poss                            elsewhere in the body                type 3 - displaced fx evident

Traumatic hemarthrosis - blood       FEMUR                                Long Bone Stress Fx - may pre-
displaces head inf medially          Femoral Head Dysplasia - abn         sent as sclerosis, NO Bx
CT may be helpful in fully evalu-    fem head & acetabular relation-      repeat in 1-2 wks, CT & MRI
ating a joint fx                     ship                                 helpful
                                     Etiology - Familial or anatomic
Rotator Cuff Tear - narrowed         variance, crowding or breech         Femoral Muscle Avulsions
subacromial space when chronic       90% effect females                   Sartoius - ant sup iliac spine
Contrast to subacromion & sub-       Laxity of capsule allows head        Rectus Femoris - ant in iliac
deltoid bursa on arthrogram          Sublux & compress posst labrum       spine
                                     eventually may dislocate             Hamstrings - ischial tuberosity
KNEE                                     ment insertions                      occasionally causes entrapment
Collateral Ligaments - Medial at-        Humphry's lig - passes just ant to   of the peroneal nerve
tached to the meniscus, tears            PCL, inserts post lat meniscus       rupture can cause pain & swel-
more freq                                Wrisburg Lig - passes just post to   ling similar to thrombophebitis
Medial Collateral Ligament - tear        PCL, inserts post lat meniscus
assoc w segond & ACL injury              oblique form post horn of lat me-    Meniscal Cyst - comm w joint via
Lateral has 3 parts - fibular col-       niscus to med fem condyle            meniscus tear, usually lateral
lateral, iliotibial collateral & arcu-   Transverse Lig - connects the        gelatinous fluid prevents visuali-
ate                                      med & lat ant menisci                zation w arthrography
                                         Popliteus Tendon - inserts on lat    Inclusion Cyst - seen w an intact
Meniscul Tears - horiz Tears de-         fem condyle, passes postlat me-      miniscus
generative, vert tears post trau-        niscus
matic                                    Ant medial meniscus is 1/2 the       Plica - adhesive band to dist fe-
Medial meniscus more likely to           size of the posterior medial         mur, seen best w effusion
tear than lat, posterior > anterior                                           Medial Patellar Plica - most likely
assoc w med collateral, ACL &            Synovial Cysts - extrusion of        to cause Sx
Segond injury                            synovium w no communiction           Superior plica - between supra-
Bucket Handle - inner portion of         seen                                 patellar tendon & femur
lat meniscus displaced intracon-         Ganglion Cyst - assoc w tendon-      lateral placa - between lat coll
dylar                                    ous synovial compartments            ligament & femur
Discoid Meniscus - more likely to        filled w gelatenous fluid, often
be lat, prone to tear                    appear intramuscular                 Pes Anserinus - attachment of
more common in children, ie lat          Bakers Cyst - between semimem        semitend, gracilic & saratorius
tears #1 in child                        tendon & med gastroc head            attaches to medial tibia, N bursa
                                         free communication to joint          should not be seen
Pitfalls of Meniscul Tears - liga-       space, seen on arthrography
ACL Tears - external rotation &       collateral lig tears must be re-      component placement or liga-
abduction                             paired to reduce laxity               ment laxity
Segond's Fx - longitudinal fx of      50% require open reduction &          Tibial loosens most often, tilts va-
post & lat tibia                      internal fixation                     rus w subsidence of med plateau
occurs just dist to tibial platue,                                          Patellar component is the most
always seen w ACL tear                Patella Alta - pattella subluxed      common site of arthroplasty
Deepening of the lateral femoral      superior due to pattellar ligament    complication
sulcus - 100% specific                disrup                                subsidence occurs in 15% but it
Medial Meniscus & Medial Col-                                               often stabalizes (ie infrequent
lateral lig complete triad            Knee Prosthesis - anatomic            "failure")
Tibial Platue Fx - assoc fibular fx   alignment crucial to stability        Infection - most serious compli-
tends to be adjacent to tibial fx     femoral component 7deg valgus         cation, occurs in <2%
rarely cause damage to popliteal      +/- 3deg, tibial 90deg to long axis   73% appear normal on plain film,
art, 5% get peroneal nerve palsy      tibial component also tilts 10deg     abscence of signs does not ex-
Types - compression, split, com-      post to allow complete flexion        clude infec
bined or bicondylar                   Normal Long Term Appearance -         Periprosthetic Fracture - assoc w
knee instability develops in 30%      two common changes                    osteopenia and rheumatoid ar-
within 2yrs, 50% get DJD in           Lucency bone prosthesis inter-        thritis
15yrs                                 face <2mm, esp at ant tibial re-      usually incomplete and appear
20% assoc w meniscal tear, may        gion                                  as sclerotic lines of impaction
interfer w reduction                  Stress Shielding of Femur - due       Particle Disease - granulomatous
Tx - if <4mm displaced use brief      to nonuniform load transfer           response to debris from wear &
immobilization & range of motion      linear band of inc bone density       tear
early                                 extending from portion of pros-
poor outcome assoc w >10deg of        thesis                                FOOT & ANKLE
varus angulation                      Failure - follows nonanatomic         Cavus - elevation of the arch of
the foot                                 metatarsal                            seen in kids, Tx w immobilization
Plantus - flattening of the arch of      occurs II' to inversion-adduction
the foot                                 also                                  Lisfanc's Fx - fx dislocation of the
                                                                               tarsometatarsals
Maisonneuve Fx - proximal fibula         Calcaneal Stress Fx - linear band     Med border of 2nd metatarsal
Fx which is often associated w           of sclerosis in post calca            aligns med border of 2nd cune
ankle fractures                          Boehler's angle - 30-40 deg N,        Bunkbed Fx - fx disloc of 1st
proximal films must always be            lines drawn post & ant                metatarsal & medial(1st) cunei-
obtained to rule this out                not the best predictor of out-        form
Dr. Abrahams asked me this               come, does not indicate ORIF
question during oral boards              Alignment of the post articular       Chopart Dislocation - talo-
                                         surface predicts outcome              navicular & calcaneo-cuboid
Inversion-Adduction Injury - Lat         Coronal thin section CT best for      joints dilocated
lig rupture or trans fx lat malleo-      assesment                             mid tarsal dislocation
lus                                      Essex-Lopresti classification for
angular forces from talus can            Fx's - tounge type or joint de-       Clubfoot - Usully Equinovarus,
cause obl fx of medial malleolus         pression type                         Navicular rotated med to talar
                                         result from forces at the angle of    head
Eversion Injury - Deltoid lig rup-       Gissane                               lat veiw shows talus & calcaneus
ture & med malleolus Fx                  75% have some intra-articular         parralel
Dist tibiofibular lig tear, fx of dist   component, all assoc w lumbar fx
fib including spiral type                                                      Flatfoot - hindfoot valgus, navicu-
does NOT cause trans fx of lat           Talar Neck fx - forced dorsiflexion   lar rotated lat to talar head
malleolus                                                                      Talus rotates downward in front
                                         Kohler's Malacia - avasc nec of       w navicular near dorsum
Jones Fx - trans thru base of 5th        tarsal navicular, poss N var
Halx Valgus - great toe turned lat     communicates w joint, eff may           joint
Subtalr Dislocation - dist foot dis-   migrate                                 Claw toe is flexion of dist inter-
locates from fall onto inverted        Ant Tibial Tendon - rupture rare,       phalangeal joint
foot                                   tenosynovitis in downhill hikers
talonavicular & talocalcaneal          Achilles - has no sheath so can         PEDIATRIC TRAUMA
joints disrupted, medial #1            be abn w no evidence of fluid on        Birth Trauma - Clavicle fx #1, fe-
calcaneocuboid joint & ankle in-       MRI                                     mur & humerus poss
tact                                                                           usually spiral fx of diaphysis II' to
poor outcome if assoc w talar Fx       Navicular Fx - avulsion of cortical     breech
                                       margin #1 midtarsal Fx                  Undetected metaphyseal &
Tillo Fx - lat epiphysis of distal     deltoid ligament attachment in          epiphyseal fx freq
tibia                                  mid upper margin                        Good prognosis, pseudoarthrosis
occurs in adolescence when             not significantly displaced, not a      very rare
fuseing from med to lat                significant portion of articular sur-
                                       face                                    Battered Child - Metaphyseal
Tendon Tear on MRI - degenera-                                                 avul or "Corner Fx" pathog
tion, partial tear & tendinitis ap-    Hallux Valgus Deformity - lat de-       may see squaring of metaphysis,
pear sim                               viation of entire 1st toe               "bucket handle"
inc signal in substance of tendon,     sesamoids not centered over             Perisoteal rxn exuberant, perios-
tendon enlargement seen w all 3        joint & medial 1st head promen-         teum easily pulled free
Peronius, Post Tibial & Flexor         ince                                    Visceral injury & subdural hem
Digitorum - fluid seen in sheath       Hallux Rigidus Deformity - DJD          assoc
Post Tibial - rupture in women w       causeing loss of dorsiflexion
rhuematoid, painful flat foot as-                                              Bowing Fracture in Child - due to
soc                                    Hammertoe - fixed flexion con-          longitudinal compressive force
Flexor Hallucis Longus - sheath        tracture at prox interphalangeal        assoc w fx of parralel bone, oc-
curs in naturaly bowing bone        True fx radius is not aligned w       met & epi, arrest & twist
forearm #1, leg #2, fix w manual    capitelum
manipulation                        Apophyseal injuries to elbow, sup     Type V - easiest to miss, only
                                    acetabulum & ischial tub              germinal cells crushed
Salter-Harris Fractures                                                   Type VI - periosteal only, not X-
any fx involving the growth plate   Type II - Fx thru metaphysis into     ray Dx
I-VI                                physis                                Type VII - Osteochondritis desi-
Zone of degen & transformation      Easy to reduce except at knee,        cans
weakest portion of plate            tends to hem
best place - no germ cells, sup-                                          Osteochondritis Dissecans -
ply from metaphysis                 Type III - Fx thru epiphysis into     Type VII Salter-Harris Fx
Epiphyseal blood supply critical    physis                                chip Fx in articular surface of
to germinal matrix growth           Offset of articular surface com-      epiphysis, growth plate Normal
20% of all childhood Fx, dist ra-   plicates reduction                    Adolescent males - 15-20yrs,
dius accounts for 50%               Tillo Fx - most common, lat           never seen before 10yrs or after
Dist femur & prox tibia 3%, but     epiphysis of distal tibia             50yrs
50% of growth arrest                occurs in adolescence when            present w locking, recurrent
                                    fuseing from med to lat               swelling or aym
Type I - growth plate shear, best                                         Osteochondral Fx from "nut-
prognosis                           Type IV - Fx thru all 3 structures,   cracker"
Hip injury can mimic disloc, ar-    difficult to align                    Medial femoral condyle lat por-
thro will show cart head            Triplane Fx - prox tibial epiphysis   tion in 75%, seen on tunnel view
dist Humerus Fx can sim disloc,     fx in sag plane                       talus & capitellum also, Lat femo-
epiphysis shifts en bloc            maetaphysis Fx in Coronal             ral condyle very rarely affected
Radius remains aligned to capi-     Plane, epi in horiz plane             predisposes to early osteoarthri-
telum oss center                    Bony bar - cross union between        tis
DDx - N ossification variant,        Hemorrhage - Susceptibility from       Fatty marrow sustains a higher
epiphyseal dysplasia                 Iron products also causes signal       signal intensity than conventional
                                     loss                                   Spin Echo
Chondromalacia Patella - pain,                                              increased difficulty distinguishing
errosion of cartilage in adoles-     STIR - Short Tau Inversion Re-         fatty from red marrow
cent                                 covery, starts w an initial 180        improved sensitivity using fat
due to mechanical stress, T1         a 90 is given when fat protons at      suppresion techniques
MRI best for evaluation              their "null point", approx
called osteoarthritis in an adult.   350msec                                Fat Suppresion Techniques -
                                     a second 180 then rephases the         use chemical shift between fat &
                                     protons                                water protons
  MRI of Bone Marrow Lesions         Increased marrow to lesion con-        they resonate at slightly diff fre-
MRI CHARACTERISTICS OF               spicuity results, esp in fatty mar-    quencies due to enviroment dif-
BONE MARROW LESIONS                  row                                    ferences
Gradient Recalled Echo Im-                                                  Fat is suppresed by using low
ages - partial flip angle followed   FSE - Fast Aquisition Spin Echo,       intensity RF centered on fat
by 180                               produces images w long TR in           resonance
effective trans relaxation (T2*)     short time                             fat magnîn is rotated mult times
instead of T2                        k-space filling is altered by aquir-   in the direction of the applied RF
Susceptibility differences cause     ing trains of 2-16 echoes after        This nulls the Z component of fat
irreversible dephaseing, shorten-    one 90 pulse                           magnetization & blocks fat signal
ing T2*                              the TE becomes a midline value         routine spin echo or FSE se-
Trabecula in marrow form inho-       instead of a fixed value               quence can then be performed
mogeneous susceptibilities           middle lines of k-space are assoc      on water
loss of marrow signal results, not   w the greatest signal & highest
seen in diaphyseal region            contrast
Marrow Distribution - Red is          borders, fibrous interface
intermediate T1 intensity, fatty is
bright                                Sickle Cell - frequently have ex-
Infant pattern - homogeneous in-      tensive cellular replacement
termediate intensity in all long      Infarcts are freq complication due
bones                                 to sickles
childhood pattern - intermediate      Radiation Therapy - diffuse fatty
metaphyseal intensity up to           replacement in field of port
10yrs                                 follows 2000-4000 rads, edema
Ossifying epiphyses always con-       & destruction of sinusoids intitally
tain high intensity FATTY marrow      DDx - anaplastic anemia, fatty
Adolescent Pattern - patchy           replacement also but more
transformation of metaphyseal         patchy
marrow
Adult Pattern - fatty marrow in all   Lymphoma - focal regions of
portions of long bone                 dec marrow signal due to cellu-
Red Marrow can be N in prox           larity
fem & humeral metaphysis
also seen in flat bones & axial       Leukemic Bone - can have dif-
skeleton, clivus is fatty though      fuse inc cellularity in active stage

Medullary Bone Infarct - occurs
II' to ischemia
Acute appear as intermediate T1
& high T2
Chronic shows more defined

				
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