Hoveda Mufti M.D.
• Also known as
disease or “wear and
• Progressive loss of
subchondral bone and
of the joint (s).
• Cartilage destruction
may be a result of a
variety of etiologies
Prevalence and epidemiology
• Over 20 million affected in U.S.
• About 60-90% of people over age 65
• Under 45 yrs it is equally common in men
• Over 55 yrs its more common in women
• Nodal OA involving DIP and PIP joints is
more common in women and their first
degree female relatives
• Premature OA associated with gene mutations
that encode collagen types 2, 9, 10
• OA of knee is more common in African American
• Commonest cause of long-term disability
• Large economic impact as a result of medical
• OA cost the U.S. economy nearly $125 billion
per year in direct expenses and lost wages and
• It is not an inevitable part of aging, some
people are more susceptible than others
• A combination of different factors are
• Both mechanical and biologic destructive
processes play a role in OA.
• Metabolic (hemachromatosis)
• Inflammatory (RA, infection)
• genetic factors
• Primary • Secondary
• Idopathic • Post-traumataic
• Localized or • Congenital or
• Local: knee, hip,
spine, hands • Localized or
• Generalized: large
joints and spine • Calcium deposition
• Small peripheral joints disease
and spine • Other:
• Mixed and spine • Inflammatory
• Avascular necrosis
• OA is generally a non-inflammtory arthritis.
• Increasing evidence for inflammatory type:
caused by cytokines, metalloproteinase release.
• This erosive inflammatory type may have flares
but later acts like typical OA.
• Primarily in women
• May be suspected from evidence of active
synovitis, chondrocalcinosis on x-rays, morning
stiffness greater than 30 mins, history of
swelling and night pain.
Overview of the process
• Articular cartilage
• Damage progresses
• Fragments of
cartilage released into
• Matrix degenerates
• Eventually there is
complete loss of
• Bone is exposed
Normal knee anatomy
• left: Normal x-ray
• Right: worn away cartilage reflected by
decreased joint space
The process – at a cellular level
• Cartilage matrix has increased water content and
• This is different from the changes that occur with aging
cartilage dries up.
• Increased activity of proteinases compared to inhibitors
• Breakdown products of cartilage cause inflammatory
reaction of synovium
• Cytokines cause matrix degeneration. Where do they
• Cycle of destruction starts
• Compensatory bone overgrowth occurs - subchondral
bone increases in density
Left: View of normal elbow cartilage through an
arthroscope - white, glistening, smooth
Right: severe elbow osteoarthritis - cartilage is lost
and the bone underneath is exposed
The process cont’d
• Bony proliferations at joint margins form,
what are they called?
• Thought to be new bone formation in
response to degenerating cartilage
• They cause joint motion restriction
What to look for in an x-ray
• Radiographic changes visible relatively late
in the disease
• Subchondral sclerosis
• Joint space narrowing esp where there is
• Subchondral cysts
• Bone mineralization should be normal
• Joint space narrowing
where there is more
• Subchondral bone has
• bony overgrowth
significant joint space narrowing as well as proliferative
bone formation around the femoral neck (arrows)
Left: normal hip
Right: There is some joint space medially but the superior portion is
completely destroyed. Supralateral aspects affected most because
the weight is transfered through the roof of the acetabulum.
Note the sclerosis and oseophyte formation (arrow).
painful bone on bone contact at the CMC joint and the large bone
spurs -- osteophytes.
X-ray shows lateral osteophytes, varus deformity, narrow joint space in
a 70 yr old female with OA
• Are crystals found in osteoarthritic joints?
• Calcium pyrophosphate dihydrate and
• Are of unknown significance and
Clinical features and diagnosis
– Joint effusion and stretching of the joint capsule
– Torn menisci
– Inflammation of periarticular bursae
– Periarticular muscle spasm
– Psychological factors
• Deep, aching localized to the joint
• Slow in onset
• Worsened with activity in initial stages
• Occurs at rest with advanced disease
• May be referred eg hip pain referred to
the thigh, groin, knee.
• Pain may be aggravated with weather
• Joint line tenderness
• Bony enlargement of
• +/- effusion
• Decreased range of
• Joint line pain can
indicate tear of the
lining of the capsule
or the meniscus.
• Where is the patella?
• In the evaluation of joint
line pain, perform a varus
or valgus stress test.
• Apply stress across the
joint, place fingers
directly over the joint line
to assess for pain, a clunk
may indicate a meniscal
tear, or crepitus may
• Have the patient to lie supine on the exam
table with leg muscles relaxed
• Press the patella downward and quickly
• the patella visibly rebounds.
• What does this mean?
• a large knee effusion
• Ballotable patella
• Have the patient lie supine
with leg muscles relaxed
• Compress the suprapatellar
pouch with your thumb, palm,
and index finger.
• "Milk" downward and laterally
so that any excess fluid
collects on the medial side.
• Tap gently over the collected
fluid and observe the effect on
the lateral side
• A fullness on the lateral side
indicates the presence small
• DIP, PIP
• 1st carpometacarpal
• cervical/lumbar facet joints
• 1st metatarsophalangeal
• Wrist, elbows, shoulders,
• 1st metatarso-phalangeal most commonly
affected in OA of the foot.
• Heberden’s nodes
• Bouchard’s nodes
Rt: varus deformity of the knee
• No proven medication-based disease modifying
• Analgesics (acetominophen)
Help pain symptoms but controversial for long
term use in non-inflammatory OA because of
risks vs benefits
• Intra-articular steroids
• Chondroprotective agents
• Reasonable evidence for
• Exercise – prevent disuse
atrophy of muscles
• Physical therapy:
• Weight loss
• Wedges shoe
• Refer to physiatrist for
• Acetominophen at doses of upto 4g per
• 2004 meta analysis of 10 trials showed
that acetominophen superior to placebo
but less efficacious in relieving pain than
• Do you worry about hepatotoxicity?
• Only seen in pts who are taking excessive
amounts of alcohol, underlying disease.
• Generally should be avoided for long term
• For short term rx they may be effective. A
study showed oxycodone to be synergistic
• In older pts use caution because of side
effects such as confusion, constipation,
• Can use tramadol with acetominophen, in
addition to NSAID/COX-2 inhibitor
• A controlled study showed codeine and
acetominophen combination to be
equivalent to to tramadol and
• Consider opiates if pt is not a candidate
for surgery, or is at high risk for side
effects from NSAIDS
• Useful in non-inflammatory OA when pain
is moderate to severe
• Topical preparations available
• PGE2 may contribute to local inflammation
and so there is a role for NSAIDS in
• There is variability amongst patients in
terms of side effects and efficacy of
• Non-acetylated salicylates have less renal
• Indomethacin has been associated with
accelerated joint destruction, so avoid it
for long term use in pts with hip OA
Selective COX-2 inhibitors
• They have 200-300 times selectivity for
COX-2 over COX-1.
• Less gastroduodenal toxicity
• But if used with ASA pts may be at
increased risk for GI bleeding.
• Use GI prophylaxis
• Avoid in pts with atherosclerotic CAD - use
traditional NSAIDS with a
• GI bleeding
• CNS dysfunction in elderly
• Impairment of renal/hepatic/platelet
function. How can NSAIDS lead to renal
• By interfering with vasodilator renal PG
and causing renal ischemia.
• May be used if NSAIDS are contraindicated,
persistent pain despite use of other medications.
• (not > 4 injections per year per joint)
• 2004 meta-analysis of controlled trials (w/
placebo) showed short term improvement in
knee pain, but efficacy in other joints is
• saline vs steroid injection?
• A study comparing the two in knee OA showed
no effect on joint space narrowing or significant
difference in pain at the end of the study, but
over a 2 yr period saline injections has less pain
• Evidence shows they have a small
advantage in terms of pain control,
compared to intra-articular placebos or
• No evidence for improvement in function
• Two studies comparing intra-articular
steroids to hyaluronans have come to
opposite conclusions-more trials are
• arthroscopy is not recommended for
nonspecific "cleaning of the knee“.
• Used to fix specific structural damage on
imaging (repairing meniscal tears,
removing fragments of torn menisci that
are producing symptoms).
• If all other rx
ineffective, and pain
• Loss of joint function
• Joints last 8-15 years