Adult Reconstruction HenFord Ortho by MikeJenny

VIEWS: 103 PAGES: 63

									  2010 Adult
Reconstruction
7.) Figure 7 shows the radiograph of a 82-year-old woman returning for
annual follow-up after undergoing total hip arthroplasty 12 years ago.
She denies pain and has no pain on examination.
Treatment should consist of

1- acetabular revision.
2- follow-up in 1 year.
3- initiation of alendronate sodium therapy.
4- femoral and acetabular revision.
5- femoral head/liner exchange with retroacetabular bone grafting.
                              Answer: 5


   Indications for surgical intervention for periprosthetic osteolysis
    include (1) first-time presentation of advanced osteolysis in the
    presence of an identifiable cause of wear particle production or in
    the presence of associated bone loss that places the structural
    integrity of the bone or fixation of the components at risk, (2) bearing
    surface wear in the presence of impending wear-through or related
    mechanical symptoms, (3) progressive osteolysis in an active
    individual, and (4) symptoms of wear debris–related synovitis that
    are refractory to conservative treatment.




                                                                      Elbanna
    1,4- Acetabular revision, femoral and acetabular revision: Despite extensive loss of
     bone in the pelvis, the porous-coated acetabular component can remain rigidly fixed by
     so-called pods of bone. Removal of a stable shell often leads to destruction of these
     pods, further compromising the reconstruction. Similarly, removal of a socket stabilized
     by bone ingrowth can result in a defect of the medial wall of the acetabulum; extensive
     damage to the anterior and posterior columns; and, in some cases, pelvic discontinuity.
     If the metal shell has been markedly damaged by the femoral head, the locking
     mechanism for the polyethylene liner is not intact, or a satisfactory replacement liner is
     not available, then revision of the porous-coated acetabular component is Indicated.

    2- Follow-up in 1 year: Neglect of wear and significant osteolysis only delays the need
     for what may become more difficult surgery, as lesions progress in size and/or complete
     failure of the bearing with metal-on metal contact precludes simple bearing exchange.

    3- Initiation of alendronate sodium therapy: This will not reverse the cause of the
     osteolysis, which is a biological reaction to wear debris.




Recommended Reading(s):
Maloney WJ, Herzwurm P, Paprosky W, Rubash HE, Engh CA. Treatment of pelvic osteolysis associated with a stable acetabular component inserted without cement as part of
      a total hip replacement. J Bone Joint Surg Am. 1997 Nov;79(11):1628-34. PubMed PMID: 9384421.

Maloney W, Rosenberg A; Implant Wear Symposium 2007 Clinical Work Group. What is the outcome of treatment for osteolysis? J Am Acad Orthop Surg. 2008;16 Suppl
      1:S26-32. PubMed PMID: 18612010.
                                                                                                                                                              Elbanna
15- Which of the following is the strongest independent risk factor for
dislocation after total hip arthroplasty?

1- Female gender
2- Diabetes mellitus
3- Height of over 6 feet
4- BMI of greater than 35
5- Age greater than 75 years
           15) A: 1- Female gender
             Approximately 60-70% of dislocations occur in the first 6 weeks after surgery. Most
            studies have found a 2:1 to 3:1 higher risk of dislocation in women, with the greatest
            discrepancies in first time dislocators after 5 years. One large review study found an
            overall relative risk of 2.1 in women.
           Patient ager great than 75 years is often referred to as a known risk factor for
            dislocation but the evidence for age as an independent risk factor for instability is
            rather weak. RR in patients > 70 was 1.3 in a large series study compared to those
            <70.
           Obese patient may develop soft tissue impingement sooner because of increased
            limb girth contacting the prominent abdomen leading to greater ease of dislocation.
            Tall patient with longer limbs have a greater lever arm that increases forces at the
            hip, which may affect the tendency to dislocate.
           The most significant preexisting risk factor for dislocation is prior hip surgery. Most
            likely due to impaired muscle strength or dysfunction, damaged soft tissue
            attachments to the proximal femur and the adverse impact these factors have on soft
            tissue tension and dynamic control of the joint.




Masri BA, Davidson D, Duncan CP, et al. Total hip arthroplasty complications. In: Barrack RL, Booth RE Jr, Lonner JH, McCarthy JC, Mont MA, Rubash HE, eds. Orthopaedic
Knowledge Update: Hip and Knee Reconstruction 3. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2006:475-503
                                                                                                                                                                  Ghacham
                            Question 26


A 66-year-old woman falls 2 weeks after undergoing primary total hip
arthroplasty and sustains a Vancouver B2 periprosthetic fracture.
What is the preferred treatment?

1) Protected weight bearing for 6-8 weeks
2) Fixation with a locking-cable plate system
3) Fixation with an allograft strut and cables
4) Revision with a long stem implant
5) Revision with a proximal femoral allograft and a long stem implant
4. Revision with a long stem
          implant




            NEEMS
                                            4) Revision with a long stem implant


          Non  operative treatment is only for type A
          Fixation with locking cable and plate system is most likely b1

          Fixation with an allograft strut and cable- could be B3



          The  technique proposed in the reference article is for the treatment of
          B2 fractures, using cerclage wires to reconstruct the fractures, then
          implantation of a longstem uncemented femoral component followed by
          cable attachment of femoral allograft struts to reconstruct the
          biomechanical properties of the proximal part of the femur.

          Revision                with a long stem implant and allograft is for B3


Greidanus NV, Mitchell PA, Masri BA, Garbuz DS, Duncan CP. Principles of management and results of treating the fractured femur during and after total hip arthroplasty. Instr
Course Lect. 2003;52:309-22. Review. PubMed PMID: 12690859.
Masri BA, Davidson D, Duncan CP, Lewallen DG, Noiseux NO, Ranawat CS, et al. Total hip arthroplasty complications. In: Barrack RL, Booth RE Jr, Lonner JH, McCarthy JC,
Mont MA, Rubash HE, eds. Orthopaedic Knowledge Update: Hip and Knee Reconstruction 3. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2006:475-503.
Sledge JB 3rd, Abiri A. An algorithm for the treatment of Vancouver type B2 periprosthetic proximal femoral fractures. J Arthroplasty. 2002 Oct;17(7):887-92. PubMed PMID:
                                                                                                                                                                                 NEEMS
12375248.
39 Use of a metal-on-metal bearing compared with use
of a metal-on-cross linked polyethylene bearing of the
 same diameter will result in which of the following?
1 smaller wear particles
2 increased volumetric wear
3. decreased incidence of dislocation
4 lower serum metal ion concentration
5 a higher incidence of early soft tissue sarcoma
         39 Use of a metal-on-metal bearing compared with use of a metal-on-cross linked
         polyethylene bearing of the same diameter will result in which of the following?

         Response # 1

           1 smaller wear particles
           2 increased volumetric wear
           3. decreased incidence of dislocation
           4 lower serum metal ion concentration
           5 a higher incidence of early soft tissue sarcoma




Recommended Reading(s):
Heisel C, Silva M, Schmalzried TP: Bearing surface options for total hip replacement in young patients. J Bone Joint Surg Am 2003;85:1366-1379.
Amstutz HC, Campbell P, McKellop H, Schmalzreid TP, Gillespie WJ, Howie D, Jacobs J, Medley J, Merritt K. Metal on metal total hip replacement workshop consensus document. Clin Orthop
Relat Res. 1996 Aug;(329 Suppl):S297-303. PubMed PMID: 8769344.
39 Use of a metal-on-metal bearing compared with use
of a metal-on-cross linked polyethylene bearing of the
 same diameter will result in which of the following?
1 smaller wear particles
~24nm(.024um) in metal-metal vs. .27 um in UHMWPE

2 increased volumetric wear
-There would be reduced volumetric wear with the lack of the PE

3. decreased incidence of dislocation
-No increase in dislocation rate

4 lower serum metal ion concentration
-There is the potential for increased serum metal ion concentration due
to the contact b/w metal surfaces

5 a higher incidence of early soft tissue sarcoma
- Inconclusive evidence thus far for long term increased risk of Ca. No
increased risk of early sarcoma.




                                                                          T. North
                                   54

Compared with a static antibiotic spacer, an articulating antibiotic
spacer inserted following resection of a septic total knee arthroplasty
demonstrates

1. A greater chance of infection recurrence
2. A greater retention of host bone
3. An improved rate of infection eradication
4. Decreased exposure time during reimplantation
5. Decreased wound healing complications
                                                                                              54
      Answer 4. Decreased exposure time during reimplantation
               1. Although you are able to use larger doses of antibiotics with static spacers they have
                been shown to have similar rates of infection recurrence
               2. Static Spacers have also been found to have increased not decreased bone loss
                compared to mobile spacers
               3. Rates of eradication are statistically similar with either static or mobile
               4. Exposure at the time of the second stage of the revision is made easier due to retained
                joint motion, this may also lead to better ROM after the final surgery
               5. Wound healing complications can be higher with mobile spacers




Recommended Reading(s):
Jacobs C, Christensen CP, Berend ME. Static and mobile antibiotic-impregnated cement spacers for the management of prosthetic joint infection. J Am Acad Orthop Surg.
2009 Jun;17(6):356-68. Review. PubMed PMID: 19474445.
Fehring TK, Odum S, Calton TF, Mason JB. Articulating versus static spacers in revision total knee arthroplasty for sepsis. The Ranawat Award. Clin Orthop Relat Res. 2000
Nov;(380):9-16. PubMed PMID: 11064968.
                                            54


   Mobile Cement spacers
       Come in three flavors
            Cement on Cement, Cement on Poly, Cement on Metal

       Benefits: Limited ability for patient to use leg, able to do PT with spacer, better
        final ROM, less bone loss, easier reimplantation surgery
       Drawbacks: Possibility of cement fracture, problems with wound healing




                                                                                       Sunderland
62) Following a total knee arthroplasty for a varus knee,
    a patient is unable to extend her toes and cannot
 dorsiflex or evert her ankle. Plantar flexion strength is
 intact. What is the most likely cause of the weakness?
1- Aberrant retractor placemen
2- Ischemia from a prolonged tourniquet time

3- Correction of a preoperative flexion contracture

4- Peroneal nerve transection

5- Excessive medial release
                          Placement
   All answers are correct, just pick most common.
    3 is most common in valgus not varus knee.
    Could not find any information on aberrant
    retractor placement incidence, probably why
    question got tossed.

   Peroneal Nerve Palsy post TKA

   Peroneal Nerve (L2-S2, branch of sciatic)
      Motor: CPN (short head biceps), SPN
        (peroneals), DPN (EHL, TA, EDL, EDB)
      Sensory: Sural n. (lateral leg), SPN (lateral
        leg and dorsal foot), DPN (1st dorsal
        webspace)

   Incidence: 0.3-1.3% may be underdiagnosed

   Prognosis: Most studies show >50% achieve full
    recovery

   Treatment
      Removal of restrictive dressings
      Knee flexion
      EMG if no improvement in 1 mo
      Chronic: Dropfoot brace and ROM exercises
      Delayed exploration and decompression at
        3-4 mo                                         SPN
          Also possible nerve graft of Post tib
           transfer
                             62) Answer 1: Aberrant retractor placement
              Predisposing factors for Peroneal Nerve Palsy
                      Valgus Deformity > 10 - 15 ° and Flexion Contracture > 20 °
                        Traction injury: axon damage seen with 4 - 11 % elongation and microcirculatory damage
                          with 8% elongation
                        More extensive soft tissue dissection
                      Postop Epidural Anesthesia
                        Usually delayed presentation
                      Previous Neuropathy or Spinal Surgery
                        “Double-crush” phenomenon. Secondary insult to already diseased nerve. Can be central
                          (stenosis, radiculopathy) or peripheral
                        Diabetes not shown to have association
                      Rheumatoid Arthritis
                        Slowed motor n. conduction velocity and abnormal sensory conduction in superficial
                          peroneal n. distribution seen in asymptomatic pts
                      Tourniquet > 120 min
                        Linked, but not proven. EMG changes shown in studies, plus lots of bad things can
                          happen with extended tourniquet time so use with caution
                      Hematoma (Theoretical)
                      Constrictive Dressing (Theoretical)
                      Previous Proximal Tibial Osteotomy: stretch/traction/scarring



Recommended Reading(s):                                                                                                                                    Assenmacher
Idusuyi OB, Morrey BF. Peroneal nerve palsy after total knee arthroplasty. Assessment of predisposing and prognostic factors. J Bone Joint Surg Am. 1996
     Feb;78(2):177-84. PubMed PMID: 8609107.
Nercessian OA, Ugwonali OF, Park S. Peroneal nerve palsy after total knee arthroplasty. J Arthroplasty. 2005 Dec;20(8):1068-73. Review. PubMed PMID:
     16376265.
 Question 75


Failure to restore the femoral offset during routine total hip arthroplasty may
result in which of the following?

1- Increased body weight lever arm
2- Increased bone to bone impingement
3- Decreased joint reactive force
4- Increased component to component impingement
5- Improved abductor moment
 Question 75 - Answer

Preferred response: 2- Increased bone to bone impingement

Decreased offset places the hip at risk of femoral bone impinging against the pelvis at the
extremes of motion. Decreased offset can be created in THA by excessive medialization of
the acetabular component or a low neck cut.

Decreased femoral offset would decrease the body weight level arm and result in a
decreased abductor moment. Decreased head-neck ratio leads to cam type component on
component impingement.
Recommended Reading(s):
Malik A, Maheshwari A, Dorr LD. Impingement with total hip replacement. J Bone Joint Surg Am. 2007 Aug;89(8):1832-42. Review. PubMed PMID: 17671025.

Kristiansen B, Jorgensen L, Holmich P. Dislocation following total hip arthroplasty. Arch Orthop Trauma Surg; 1985;103:375-377.




    Joints                                                                                                                                             Charters
                                   108


Allograft strut fixation is most appropriately indicated as an adjunct to a
lateral plate for what type of periprosthetic femoral fracture associated
with a total hip arthroplasty?

1. Trochanteric fracture (Vancouver type A)
2. Shaft fracture at the tip of the stem with a well-fixed stem
(Vancouver type B1)
3. Shaft fracture at the tip of a loose stem (Vancouver type B2)
4. Shaft fracture at the tip of a loose stem associated with bone loss
(Vancouver type B3)
5. Fracture distal to the stem (Vancouver type C)




                                                                 Tao
              Question 108 - Preferred answer: 4

Type AG (fracture in greater trochanter) - treat symptomatically with
  protected weight bearing; limit abduction. Consider ORIF if fracture
  is displaced > 2.5 cm or if there is pain, instability, or abductor
  weakness due to trochanteric nonunion.

Type AL (fracture in lesser trochanter) - treat symptomatically with
  protected weight bearing even if fracture is displaced. Treat
  surgically only if a large portion of the medial cortex is attached.

Type B1 (fracture is around or just distal to the femoral stem and the
  stem is well fixed) - ORIF with fixation in 2 planes (lateral and
  anterior).

Type B2 (fracture is around or just distal to the femoral stem, the stem
  is loose, and there is good bone stock in the proximal femur) - long-
                                                            Tao
  stem revision. Consider cortical strut grafts to improve stability and
  enhance bone stock.
                                108


Type C (fracture located well below the femoral stem) - ORIF. Manage
  with blade plate, condylar screw plate, or locking supracondylar
  plate (e.g. LISS). Overlap plate and stem to avoid creation of a
  stress riser. Use screws to secure plate distal to the stem. Use
  cerclage wires around the plate at the level of the stem. May
  consider treatment with a retrograde IMN, but this may create a
  stress riser between the femoral stem tip and the nail.




                                                        Tao
108: Vancouver Classification of
     periprosthetic fractures
                                  108


Recommended readings:

Ricci WM, Bolhofner BR, Loftus T, Cox C, Mitchell S, Borrelli J Jr.
   Indirect reduction and plate fixation, without grafting, for
   periprosthetic femoral shaft fractures about a stable intramedullary
   implant. Surgical Technique. J Bone Joint Surg Am. 2006 Sep;88
   Suppl 1 Pt 2:275-82. PubMed PMID: 16951099.

Ricci WM, Haidukeqych GJ. Periprosthetic femoral fractures. Instr
   Course Lect. 2009;58:105-15. PubMed PMID 19385524.
                                 109


The routine use of a continuous passive motion device following total
knee arthroplasty compared with a structured physical therapy program
results in which of the following?

1.   Increased length of hospitalization
2.   Decreased need for narcotic medication
3.   Equivalent early range of motion
4.   Improved range of motion at 1 year
5.   Improved knee society scores.




                                                             Tao
                                                     109 – Preferred answer: 3

            Leach et al. performed a randomized prospective study to study the effects of
             continuous passive motion on knee range of motion, pain levels, and analgesia use.
             Patients were evaluated at time of discharge from hospital, 6 weeks, 6 and 12
             months postoperatively. They concluded that continuous passive motion following
             total knee arthroplasty does not influence outcome of range of motion or reported
             pain.

      Bourne performed a review of various randomized controlled trials, controlled clinical
         trials, case-control studies, or cohort studies comparing CPM with placebo, no
         treatment, or active interventions. He concluded that in patients who have had total
         knee arthroplasty, CPM plus PT increases active knee flexion more than PT alone 2
         weeks after surgery and reduces hospital length of stay. Other range-of-motion
         outcomes are not significantly different between CPM and PT. Outcomes are also no
         different when comparing CPM with splinting (except for knee flexion) or comparing
         different CPM applications.
   Recommended Readings:
   MacDonald SJ, Bourne RB, Rorabeck CH, McCalden RW, Kramer J, Vaz M. Prospective randomized clinical trial of continuous passive motion after
    total knee arthroplasty. Clin Orthop Related Res. 2000 Nov;(380):30-5. PubMed PMID:11064970.

   Leach W, Reid J, Murphy F. Continuous passive motion following total knee replacement: a prospective randomized trial with follow-up to 1 year.
    Knee Surg Sports Traumatol Arthrsc. 2006 Oct;14(10):922-6. Epub 2006 Feb 18. PubMed PMID: 16489477.
                                                                                                                                                       Tao
   Bourne RB. Continuous passive motion improves active knee flexion and shortens hospital stay but does not affect other functional outcomes after
    knee arthroplasty. J Bone Joint Surg Am. 2005 Nov;87(11):2954. PubMed PMID: 16264143.
                                  111


What process is used to fabricate ultra-high molecular weight
polyethylene by directly molding the resin into the finished part?

1.   Net shape
2.   Ram extrusion
3.   Annealing
4.   Porosity reduction
5.   High-density branching
                      111. Preferred answer: 1

Net shape compression molding (AKA direct compression molding) the resin is
   directly molded into the finished part. One advantage of net shape
   compression molding is the extremely smooth surface finish obtained with a
   complete absence of machining marks at the articulating surface. Better
   wear of UHMWPE has been consistently achieved with the direct
   compression molding process.

In ram extrusion, the resin is extruded through a die under heat and pressure to
    form a cylindrical bar that in turn is machined into the final shape.

Annealing is the process of heating PE close to the melting point to remove
   free radicals. If the heating is kept below the melting point, there is little
   reordering of the PE structure. If the heating is taken above the melting
   point, there is structural reordering of the PE chains, which can increase the
   crystallinity of the PE with certain techniques.
              Porosity reduction is a process to decrease pore size in cement to
               200 to 400 micrometers, mostly via centrifugation or vacuum mixing.
               Controversy remains as to the benefit of porosity reduction. In vitro
               studies demonstrate increased fatigue strength with porosity
               reduction. However, clinical studies question the significance of
               porosity reduction in the face of surface irregularities.

              High density branching or cross-linking of UHMWPE improves
               resistance to adhesive and abrasive wear, which improves wear
               rates. UHMWPE treated with low-dose irradiation in an inert
               environment without oxygen favors cross-linking of PE.



Recommended readings:
Wright TM, Maher SA. Biomaterials. In: Einhorn TA, O’Keefe RJ, Buckwalter JA, eds. Orthopaedic Basic Science: Foundations of Clinical Practice,
3rd ed. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2007:65-85.                                                                       Tao
Lieberman JR, ed. AAOS Comprehensive Orthopaedic Review. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2009:21-28.
116.
Which of the following is considered the most sensitive method for measuring wear or
migration in total hip arthroplasty?

1-   Acetabular teardrop technique

2-   Plain radiographic overlay technique

3-   Martell method (Hip Analysis Suite)

4-   Radiostereometric analysis (RSA)

5-   EBRA (Einzel-Bild-Roentgen-Analysis) single image radiographic analysis
            4-       Radiostereometric analysis (RSA)


          All in vivo techniques of measuring poly wear are on the basis of femoral head
          penetration relative to the acetabulum with penetration of the head being assumed to
          represent the true loss of poly material. It is difficult to distinguish between poly wear
          and bedding in or “creep” of the liner. Computer assisted edge detection techniques
          such as EBRA and the Martell method have been shown to have improved accuracy and
          precision compared to manual techniques (overlay) and are suited both retrospective and
           prospective evaluation of large groups of patients for intermediate and long term follow up.

          Radioisometric analysis , developed in the 1970s, involves implantation of tiny
          tantalum beads in the skeleton and around hardware. Postoperatively, the patient is
          positioned over a specialized calibration cage and two simultaneous radiographs
          are taken. The three dimensional position of the femoral head with respect to the
          beads can then be precisely determined. It has been widely validated to be the most
          accurate and precise method, but is expensive and can only be done prospectively.

          I could not find any mention of a “teardrop” technique for measuring poly wear in the literature.




Recommended Reading(s):Cleland
Bragdon CR, Greene ME, Freiberg AA, Harris WH, Malchau H. Radiostereometric analysis comparison of wear of highly cross-linked polyethylene
against 36- vs 28-mm femoral heads. J Arthroplasty. 2007 Sep;22(6 Suppl 2):125-9. Epub 2007 Jul 26. PubMed PMID: 17823030.

McCalden RW, Naudie DD, Yuan X, Bourne RB. Radiographic methods for the assessment of polyethylene wear after total hip arthroplasty. J       Cleland
Bone Joint Surg Am. 2005 Oct;87(10):2323-34. Review. PubMed PMID: 16203901.
Question #147
Figures 147a through 147d show the radiographs of a 71-year-old
woman who presents for a second opinion. She has a well-functioning
right total knee arthroplasty (TKA) and underwent left TKA 5 months ago.
Following surgery on the left knee, she reports severe pain with passive
range of motion from -5° to 105°. Work-up for infection is normal. What is
the most appropriate management?

1- Hinged knee orthosis
2- Aggressive physical therapy
3- Closed manipulation of the knee
4- Revision total knee arthroplasty
5- Arthroscopy and synovial débridement
•   Question #147 Images Page 1 of 2
•   1- Hinged knee orthosis
•   2- Aggressive physical therapy
•   3- Closed manipulation of the knee
•   4- Revision total knee arthroplasty
•   5- Arthroscopy and synovial débridement
•   Question #147 Page 2 of 2 Images
•   1- Hinged knee orthosis
•   2- Aggressive physical therapy
•   3- Closed manipulation of the knee
•   4- Revision total knee arthroplasty
•   5- Arthroscopy and synovial débridement
   •      Question #147:
   •      Answer: 4 Revision TKA
   •      There are lots of clues in the question without even looking at the
          picture. She has good (but painful) range of motion and there is no
          mention of instability. Three answers, physical therapy, manipulation,
          and arthroscopy and debridement are usually therapies for poor
          range of motion. This leaves an orthosis and revision, given no
          instability, a revision TKA would be the best choice. Images then
          confirm this, looking at the long leg she is in too much valgus.




Recommended Reading(s):
Gonzalez MH, Mekhail AO. The failed total knee arthroplasty: evaluation and etiology. J Am Acad Orthop Surg.
2004 Nov-Dec;12(6):436-46. Review. PubMed PMID: 15615509.


Saleh KJ, Mulhall KJ, Thongtrangan I, Barrack RL. Revision total knee arthroplasty. In: Barrack RL, Booth RE Jr,
Lonner JH, McCarthy JC, Mont MA, Rubash HE, eds. Orthopaedic Knowledge Update: Hip and Knee
Reconstruction 3. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2006:123-145.
                                                                                                                   Jagadish
   160. A patient perceives a limb-length discrepancy
 after undergoing a total hip arthroplasty. He feels that
the operated leg is too long. Aside from an actual limb-
   length difference, what is a possible cause of this
                      perception?


1.   Quadriceps weakness
2.   An external rotation contracture
3.   A hip flexion contracture
4.   A hip adduction contracture
5.   Weakness of the hip abductors
                                   5: Weakness of the hip abductors

         Hip abductors function to keep the pelvis level during stance
         When the abductors are weak the contralateral side of the pelvis
          drops (Trendelenburg Sign) giving the perception that the affected
          side is longer
         None of the other choices would give the perception that the
          operative side is longer
         A hip flexion contracture or adduction contracture may give the
          perception of the operative side being short




Recommended Reading(s):
Bhave A, Marker DR, Seyler TM, Ulrich SD, Plate JF, Mont MA. Functional problems and treatment solutions after total hip arthroplasty. J
Arthroplasty. 2007 Sep;22(6 Suppl 2):116-24. Epub 2007 Jul 26. PubMed PMID: 17823029.
Maloney WJ, Keeney JA. Leg length discrepancy after total hip arthroplasty. J Arthroplasty. 2004 Jun;19(4 Suppl 1):108-10. Review. PubMed
PMID: 15190563.
                                                                                                                                            Kusuma
  172. After a standard medial parapatellar approach to
     the knee with excision of the fat pad and lateral
    meniscus, what artery is likely the only remaining
                blood supply to the patella?




1- Superior lateral genicular
2- Inferior lateral genicular
3- anterior recurrent tibial
4- superior medial genicular
5- inferior medial genicular
    172 Preferred Response: 1) superior lateral genicular
    Medial vessels will likely be disrupted due to the initial approach.
    Superior and inferior lateral genicular arteries are important
     remaining vessels to the patella, but the anterior tibial recurrent
     passes superiorly along the patellar tendon and supplies it and
     mostly skin overlying patella
    Lateral retinacular release along with fat pad excision and lateral
     meniscus resection will likely disrupt the inferior lateral genicular
     artery, which anastamoses with the anterior tib recurrent artery. It
     passes deep to lateral collateral ligament at level of the joint passing
     superficial to the popliteus tendon and then passes over the lateral
     limb of the arcuate ligament and popliteal musculotendinous junction
     and the lateral meniscus
    This would leave superior lateral genicular as the last artery
     standing, and it does anastomose with the descending branch of
     lateral femoral circumflex artery
Hip/Knee, Anatomy
Recommended Reading(s):
Saleh KJ, Mulhall KJ, Thongtrangan I, Barrack RL. Revision total knee arthroplasty. In: Barrack RL, Booth RE Jr, Lonner JH, McCarthy JC, Mont MA,
                                                                                                                                                    Vasileff
       Rubash HE, eds. Orthopaedic Knowledge Update: Hip and Knee Reconstruction 3. Rosemont, IL: American Academy of Orthopaedic Surgeons;
       2006:123-145.
Kelly MA. Patellofemoral complications following total knee arthroplasty. Instr Course Lect. 2001;50:403-7. Review. PubMed PMID: 11372340.
                  #181 Adult Reconstruction


In total knee arthroplasty, appropriate femoral component rotation
      achieves which of the following?

1.   Creation of a rectangular extension gap
2.   Creation of a rectangular flexion gap
3.   Ensures appropriate tibial rotation
4.   Correction of a varus deformity
5.   Maximizes the amount of knee extension that can be obtained.
         #181 Answer: 2. Creation of a rectangular flexion gap

         This is a gap balancing question. When approaching these questions remember distal femoral
          cuts effect the extension gap only and femoral component size (the AP dimension of the
          component) effects only the flexion gap.
         Appropriate femoral component rotation creates a rectangular flexion gap (see figure below)
         Creation of a rectangular extension gap requires an appropriate distal femoral cut which is made
          parallel to the tibial cut (as well as soft tissue balance)
         Femoral component rotation will not correct a coronal plane deformity (varus/valgus)
         Achieving full knee extension has to do with the extension gap which is dependent on the distal
          femoral and tibial cuts (as well as soft tissue balancing)




    CW, Scott RD. The Ranawat Award. Femoral component rotation during total knee arthroplasty. Clin Orthop Relat Res. 1999 Oct;(367):39-42.
Olcott
PubMed PMID: 10546596.

Heesterbeek PJ, Jacobs WC, Wymenga AB. Effects of the balanced gap technique on femoral component rotation in TKA. Clin Orthop Relat Res. 2009
Apr;467(4):1015-22. Epub 2008 Oct 2. PubMed PMID: 18830793; PubMed Central PMCID: PMC2650044.
187.
Figure 187 shows the radiograph of a 48-year-old man who underwent a hip fusion at age
24
years following a motor vehicle accident; the procedure resulted in a 5-cm limb-length
discrepancy. He now reports increasing back pain and discomfort in his contralateral knee
and
hip. Treatment should consist of

1- decompressive laminectomy.
2- fusion takedown and conversion to total hip arthroplasty.
3- fusion takedown and revision in less abduction.
4- contralateral total hip arthroplasty.
5- femoral distraction osteogenesis.
                                                                                     Answer-2

   The patient’s pain is secondary to his limb length discrepancy (backpain) and overuse/altered
   kinematics at the contralateral hip and knee secondary to his hip fusion.

   It is reasonable to restore his hip joint with a total hip arthroplasty, now that he is in his late 40’s,
   validated by the cited articles below.


   1- decompressive laminectomy. -Wrong b/c backpain is from LLD
   2- fusion takedown and conversion to total hip arthroplasty. -Correct
   3- fusion takedown and revision in less abduction. - This would exacerbate his LLD and altered
   kinematics at the contralateral hip/knee
   4- contralateral total hip arthroplasty. -does not address the primary problem
   5- femoral distraction osteogenesis -Limb lengthening would be inappropriate




Joshi AB, Markovic L, Hardinge K, Murphy JC. Conversion of a fused hip to total hip
arthroplasty. J Bone Joint Surg Am. 2002 Aug;84-A(8):1335-41. PubMed PMID: 12177262.
Hamadouche M, Kerboull L, Meunier A, Courpied JP, Kerboull M. Total hip arthroplasty for the
treatment of ankylosed hips : a five to twenty-one-year follow-up study. J Bone Joint Surg Am.
2001 Jul;83-A(7):992-8. PubMed PMID: 11451967.                                                     JFarbs
191.
A 67-year-old man has had persistent groin pain for the past 2 years
following total hip
arthroplasty for degenerative arthritis. The patient’s erythrocyte
sedimentation rate is 20 mm/h
with a C-reactive protein of 0.4. A technetium bone scan was normal. A
CT scan revealed 5° of
acetabular component anteversion. What is the most likely cause of the
persistent pain?

1- Trochanteric bursitis
2- Occult infection
3- Aseptic loosening
4- Anterior iliopsoas impingement
5- Insufficiency fracture
                                                                                   Answer-4

Iliopsoas impingement is highly suspicious when the prominence of the
anterior aspect of the acetabular component compared with the anterior
rim of the bony acetabulum is greater than 12mm, and other work up is
negative.

There is a nice review article in JAAOS tan journal, see below, they make
no mention of acetabular version specifically.

1- Trochanteric bursitis – no mention of trochanteric pain, only groin pain.
2- Occult infection – ESR of 20 and CRP of 0.4 is not suggestive of
infection
3- Aseptic loosening – possible but unlikely given no abnormality on bone
scan.
4- Anterior iliopsoas impingement – Correct, and apparently
underdiagnosed
5- Insufficiency fracture – No uptake on bone scan, normal ct scan would
suggest no fx.




Lachiewicz PF, Kauk JR. Anterior iliopsoas impingement and tendinitis after total hip
arthroplasty. J Am Acad Orthop Surg. 2009 Jun;17(6):337-44. Review. PubMed PMID:                                                               JFarbs
19474443.
Duffy P, Masri BA, Garbuz D, Duncan CP. Evaluation of patients with pain following total hip replacement. Instr Course Lect. 2006;55:223-32.
Review. PubMed PMID: 16958458.
201. Adult reconstruction
Figures 201a and 201b show the radiographs of a 62-year-old woman who has persistent
chronic pain and a feeling of instability in her knee arthroplasty that was performed 2 years
ago. Examination reveals anterior-posterior laxity of the knee. She is unable to rise from a
chair without using her arms and cannot climb stairs with a reciprocal motion. There is no
coronal instability. What is the most likely cause of her chronic pain?

1- Patellar instability
2- Quadriceps tendon disruption
3- Varus position of the tibial component
4- Flexion-extension mismatch
5- Rupture of the posterior cruciate ligament
                 Answer 5: Rupture of the PCL



   Figures show a CR knee
   From the vignette, patient has A/P laxity. Unable to rise from chair =
    quadriceps active test. Climbing stairs = flexion instability
   PCL-retaining TKAs with PCL insufficiency show a posterior
    tibial sag, a positive posterior drawer test, and a positive
    90° quadriceps active test.
   X-ray rules out quad tendon rupture (no patella alta) and varus
    malpositioning.
   Flexion/extension mismatch is a general term and could be a
    possible answer but she would have had the problem since surgery
   When the PCL is inadvertently cut or improperly balanced, flexion
    instability in the AP plane can occur. Delayed rupture of a PCL also
    can cause flexion instability
                                                                       Khalil
Joints


210.
A patient undergoing primary total knee arthroplasty with a valgus knee remains tight laterally
in both full extension as well as deep knee flexion. Release of what structure will help balance
the joint?


1- Iliotibial band
2- Popliteus
3- Posterior lateral capsule
4- Posterior cruciate ligament
5- Lateral collateral ligament
                                   210.
                      5- Lateral collateral ligament

   The most common structures on the lateral side of the knee to be
    released in a valgus knee
        iliotibial band
         posterolateral
         capsule
         lateral collateral ligament
        popliteal tendon
        lateral head of the gastrocnemius.
   Releasing the LCL, popliteus, lateral gastroc, and IT band give <5
    degrees of correction in extension. Addition of PCL release gets a
    total of 9-degrees of correction.
   Releasing the LCL first allows for a more gradual correction. If the
    other structures are released first with inadequate correction,
    subsequent release of the LCL may lead to over correction and
    instability.
   If lateral side tight
        In both extension and flexion = release LCL
        In only extension = release IT band or popliteus
        In only flexion = release posterolateral capsule and popliteofibular ligament Novak
#214.
The routine use of antibiotics in the bone cement for primary total
  joint arthroplasty is associated with which of the following risks?



1- Reduced risk of aseptic loosening
2- Reduced risk of aseptic loosening and infection
3- Increased risk of aseptic loosening
4- Increased risk of renal insufficiency
5- Increased risk of a resistant organism
      3. Increased chance of aseptic loosening

   Antibiotic cement has shown to decrease acute and chronic
    infections following total joint arthroplasty for up to 2 years following
    revision TKA

   Aseptic loosening is a complication of any cemented implant
    whether antibiotic cement or nonantibiotic cement is used.

   Reduction of aseptic loosening rates is incorrect, see above
   Reduction of aseptic loosening and infection is also incorrect. It has
    not been shown to reduce infection in primary total joint arthroplasty.
   Joints
   Chiu, Fang-Yao et al, Atibiotic-Impregnated Cement in Revision Total Knee Arthroplasty; JBJS, 2009;91-623-33.




                                                                                                                    Woods
                                  236


Hip precautions following the anterolateral approach to the hip for total
     hip arthroplasty would include avoiding

     1- flexion and internal rotation.
     2- flexion and external rotation.
     3- internal rotation in midflexion.
     4- extension and external rotation.
     5- extension and internal rotation.
          236      4 – extension and external rotation



   Postop hip precautions generally apply to posterior and
    anterolateral approaches for total hip arthroplasty. The references
    were not helpful for this question. In order to answer appropriately,
    you have to consider where the soft tissue structures are violated
    with the various approaches and then determine what hip position
    would put the femoral head at risk of dislocation.
   Anterolateral (Watson-Jones) approach to the hip utilizes the
    interval b/w tensor fasciae latae and gluteus medius. This
    approach has been shown to reduce postop dislocation rates.
    Postop hip precautions include avoiding extension and external
    rotation.
                                       236


       Posterior approach to the hip has no true internervous interval.
        Slightly higher dislocation rate than anterolateral approach. Post-op
        hip precautions involve avoiding flexion and internal rotation (1).




Iorio
                                     Question 248


A revision total knee arthroplasty is stable with a 10-mm trial in flexion yet lacks
    10° of extension. What is the most appropriate treatment?
1- Increase the tibial slope
2- Augment the distal femur
3- Augment the tibia
4- Augment both the tibia and the distal femur
5- Perform a posterior capsular release
Larkin
                                                                           Answer 5
     •       This is a straight forward gap balancing question
     •       There are a bunch of ways to think (or memorize these things), but the best way is to just
             think about it. Note that adjustments to the tibia affect both the flexion and extension gap
     •       For this patient, the knee is stable in flexion but lacks full extension
               •       As such, the problem is not cutting enough distal tibia or an insufficient posterior
                       capsular release
     •       Incorrect answers:
               1. Increase the tibial slope: this would work if extension is good and flexion is tight
               2. Augment the distal femur: this works if extension is loose and flexion is good
               3. Augment the tibia: this works for a symmetric looseness in flexion and extension
               4. Augment both the tibia and the distal femur: the tibia would address looseness in
                  extension and flexion and then adding to the femur would then tighten up your
                  extension even more
               5. Perform a posterior capsular release: correct answer



 Dennis DA, Berry DJ, Engh G, Fehring T, MacDonald SJ, Rosenberg AG, Scuderi G. Revision total knee arthroplasty. J Am Acad Orthop Surg. 2008 Aug;16(8):442-54. PubMed PMID:
 18664633.
 Ries MD, Haas SB, Windsor RE. Soft-tissue balance in revision total knee arthroplasty. Surgical technique. J Bone Joint Surg Am. 2004 Mar;86-A Suppl 1:81-6. Erratum in: J Bone Joint
 Surg Am. 2004 May;86-A(5):1038-9. J Bone Joint Surg Am. 2004 Sep;86-A Suppl 1;(Pt 2):210. PubMed PMID: 14996925.
259. (Joints) In total hip arthroplasty, what is the linear
     wear rate of conventional polyethylene that is
 considered the threshold above which osteolysis is
                      likely to occur?

1-   1 micrometer per year
2-   0.1 millimeter per year
3-   0.5 millimeter per year
4-   1 millimeter per year
5-   2 millimeters per year
                      2-     0.1 millimeter per year

   Fact. Just know this. It’s a commonly asked question on
    exams and by attendings.
   Osteolysis is a hystiocytic response to wear debris that incites
    macrophage activation, dissolution of bone from the
    prosthesis, micromotion, more wear debris, and loosening.
    Wear rate of less than 0.1mm/yr, as with UHMWPE, are
    believed to cause less osteolysis than conventional
    polyethylene.
   Other poly facts:
         Sterilization using gamma radiation in air crosslinks the poly, but
          generates free radicals that increases oxidative degradation and wear.
          Radiating in inert environments and remelting prevents formation of free
          radicals.
   Lin

								
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