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Adult Reconstructive
Surgery of the
Hip and Knee I
I
[
I
Answer Book
,Question 1
During the course of a revision total knee arthroplasty via a medial parapatellar exposure, the
surgeon does a complete intra-articular release and synovectomy but exposure is still inadequate. A
quadriceps snip is performed and, at the end ofthe procedure, the knee is stable throughout a range
of motion and the postoperative radiographs show acceptable alignment of the components. The
patient's postoperative physical therapy regimen should include which of the following?
1. No restriction in range of motion or weight bearing after surgery.
2. Limit flexion to 30 degrees postoperatively, progressing 10 degrees per week
3. Limit flexion to 90 degrees for the first 6 weeks postoperatively
4. Limit to active flexion only with no passive flexion or active extension for 6 weeks
5. Use of a hinged knee brace for 6 weeks
postoperatively PREFERRED RESPONSE: 1
DISCUSSION: A quadriceps snip is performed by extending a medial parapatellar approach
superiorly and laterally across the quadriceps tendon. It is then repaired primarily at the end of the
procedure. The primary advantage of this technique over other surgical maneuvers that improve
exposure at the time of revision total knee arthroplasty is that the postoperative regimen for physical
therapy does not need to be altered.
REFERENCES: Younger AS, Duncan CP, Masri BA: Surgical exposures in revision total knee
arthroplas- ty. J Am Acad Orthop Surg 1 998;6:55 -64.
Della Valle CJ, Berger RA, Rosenberg AG: Surgical exposures in revision total knee arthroplasty.
Clin Orthop Relat Res 2006;446 : 59-68.
Barrack RL , Smith P, Munn B, et al: The Ranawat Award. Comparison of surgical approaches in total
knee arthropl asty. Clin Orthop Relat Res 1998;356: 16- 21 .
Question 2
A healthy 72-year-old woman is seen 14 days after cemented total knee arthroplasty. She reports
increasing pain and swelling for the last 4 days accompanied by 4 days of wound drainage. Examination
reveals that she is afebrile, and has erythema and moderate serosanguinous drainage from the wound.
The knee is moderately swollen. Aspiration of the knee reveals no organisms on Gram stain. Culture
results are expected back in 48 hours. Optimal management should consist of
1. initiation of a first-generation cephalosporin while awaiting culture results.
2. initiation of broad-spectrum antibiotics while awaiting culture results.
3. ultrasound to evaluate for fluid collection around the knee.
4. surgical debridement of the knee before culture results are available.
5. inpatient observation and no antibiotics until culture results are available.
PREFERRED RESPONSE: 4
,8 • American Academy of Orthopaedic Surgeons
DISCUSSION: Increased pain, swelling, erythema, and drainage 2 weeks removed from the primary
arthroplasty are all signs of a probable infection. Erythrocyte sedimentation rate and C-reactive protein
may not be helpful as they are elevated postoperatively even in the absence of infection. Even in the
absence of infection, persistent wound drainage is an indication for surgical debridement to prevent
subsequent infection. When a postoperative infection is easily recognized by clinical examination, there
is no need to wait for a positive culture before proceeding with debridement.
REFERENCES: Weiss AP, Krackow KA: Persistent wound drainage after primary total knee
arthroplasty. J Arthroplasty 1 993;8 :285-289 .
laberi FM, Parvizi J, Haytmanek CT, et al: Procrastination of wound drainage and malnutrition affect the
outcome of joint arthroplasty. Clin Orthop Relat Res 2 0 0 8 ; 46 6 :1 3 68 - 1 3 7 1 .
Insall IN, Windsor RE, Scott, WN: Surgery ofthe Knee, ed 2. New York, NY, Churchill
Livingstone, 1 993, pp 959-964.
Figure 3a Figure 3b
Question 3
A 72-year-old woman underwent a primary total hip arthroplasty 14 months ago. She states that the
hip has now dislocated four times when rising from a low chair, requiring closed reduction. A
radiograph is shown in Figure 3a and a CT scan of her pelvis is shown in Figure 3b. What is the most
re1iable method for rectifying her instability?
1. Use of an abduction orthosis for 6 weeks
2. Modular exchange of the femoral head to a 36-mm head and a longer neck
3. Modular exchange ofthe polyethylene liner to a constrained acetabular insert
4. Revision and repositioning of the acetabular component and use of a 36-mm
femoral head
5. A physical therapy program stressing abductor
strengthening PREFERRED RESPONSE: 4
DISCUSSION: The radiograph shows well-fixed components without evidence of loosening. The CT
scan shows severe retroversion of the acetabu1ar component. Revision of the component into the correct
amount of anteversion will most reliably rectify the instability in the face of severe component
malposition.
, 2010 Adult Reconstmctive Surgery ofthe Hip and Knee Examination Answer Book· 9
REFERENCES: Parvizi J, Pidnic E, Sharkey PF: Revision total hip arthroplasty for instability:
Surgical techniques and principles. J Bone Joint Surg Am 2008;90: 1134- 1 142.
DeWal H, Su E, DiCesare PE: Instability following total hip arthroplasty. Am J Orthop 2003;32: 377-
382. Barrack RL, Booth RE Jr, Lonner lH, et al (eds) : Orthopaedic Knowledge Update: Hip and Knee
Reconstruction 3. Rosemont, IL, Amelican Academy of Orthopaedic Surgeons, 2006, pp 475-503.
Question 4
A patient with a history of rheumatoid arthritis reports a painful total hip arthroplasty 3 years after
the index procedure. Radiographs reveal loosening of the femoral component. Preoperative blood
work shows an erythrocyte sedimentation rate (ESR) of 38 mmlh (nOlmal 0-29 mmlh) and a C-
reactive protein (CRP) of 8.9 (0.2-8.0). W hat is the most appropriate action at this time?
1. Technetium bone scan
2. Hip aspiration for culture
3. FDG-PET scan
4. Surgery with no further investigations
5. Revision surgery and obtain an intraoperative frozen
section PREFERRED RESPONSE: 2
DISCUSSION: The question centers on the appropriate work-up for a failed total hip arthroplasty
prior to revision surgery. The preoperative ESR is elevated and the CRP is at the upper end of
normal. If either the ESR or CRP is elevated, further investigations are required to exclude
infection as a cause of loosening, particularly in a patient only 3 years after the index procedure. A
technetium scan alone is nonspecific and will show increased uptake because of the loose femoral
component. An intraoperative
frozen section is a helpful confirmatory investigation, but whenever possible the diagnosis should be
made preoperatively to allow for appropriate surgical planning. Recently, investigators have shown the
value of FDG-PET scanning as a useful investigation for diagnosing infection; however, it is no more
accurate than the combined use of an ESR and CRP, and does not allow for identification of an
infecting organism. At this point, a hip aspiration for culture is the most appropriate investigation.
REFERENCES: Bauer TW, Parvizi J, Kobayashi N, et al: Diagnosis of periprosthetic infection. J
Bone Joint Surg Am 2006;88:869-882.
Pill SG, Parvizi J, Tang PH, et al: Comparison offiuorodeoxyglucose positron emission tomography
and ( 11 1)indium-white blood cell imaging in the diagnosis of periprosthetic infection of the hip. J
Arthroplasty 2006;21:91-97.
Spangehl MJ, Masri BA, O'Connell JX, et al: Prospective analysis of preoperative and intraoperative
investigations for the diagnosis of infection at the sites of two hundred and two revision total hip
arthroplasties. J Bone Joint Surg Am 1999;8 1:672-683.
Adult Reconstructive
Surgery of the
Hip and Knee I
I
[
I
Answer Book
,Question 1
During the course of a revision total knee arthroplasty via a medial parapatellar exposure, the
surgeon does a complete intra-articular release and synovectomy but exposure is still inadequate. A
quadriceps snip is performed and, at the end ofthe procedure, the knee is stable throughout a range
of motion and the postoperative radiographs show acceptable alignment of the components. The
patient's postoperative physical therapy regimen should include which of the following?
1. No restriction in range of motion or weight bearing after surgery.
2. Limit flexion to 30 degrees postoperatively, progressing 10 degrees per week
3. Limit flexion to 90 degrees for the first 6 weeks postoperatively
4. Limit to active flexion only with no passive flexion or active extension for 6 weeks
5. Use of a hinged knee brace for 6 weeks
postoperatively PREFERRED RESPONSE: 1
DISCUSSION: A quadriceps snip is performed by extending a medial parapatellar approach
superiorly and laterally across the quadriceps tendon. It is then repaired primarily at the end of the
procedure. The primary advantage of this technique over other surgical maneuvers that improve
exposure at the time of revision total knee arthroplasty is that the postoperative regimen for physical
therapy does not need to be altered.
REFERENCES: Younger AS, Duncan CP, Masri BA: Surgical exposures in revision total knee
arthroplas- ty. J Am Acad Orthop Surg 1 998;6:55 -64.
Della Valle CJ, Berger RA, Rosenberg AG: Surgical exposures in revision total knee arthroplasty.
Clin Orthop Relat Res 2006;446 : 59-68.
Barrack RL , Smith P, Munn B, et al: The Ranawat Award. Comparison of surgical approaches in total
knee arthropl asty. Clin Orthop Relat Res 1998;356: 16- 21 .
Question 2
A healthy 72-year-old woman is seen 14 days after cemented total knee arthroplasty. She reports
increasing pain and swelling for the last 4 days accompanied by 4 days of wound drainage. Examination
reveals that she is afebrile, and has erythema and moderate serosanguinous drainage from the wound.
The knee is moderately swollen. Aspiration of the knee reveals no organisms on Gram stain. Culture
results are expected back in 48 hours. Optimal management should consist of
1. initiation of a first-generation cephalosporin while awaiting culture results.
2. initiation of broad-spectrum antibiotics while awaiting culture results.
3. ultrasound to evaluate for fluid collection around the knee.
4. surgical debridement of the knee before culture results are available.
5. inpatient observation and no antibiotics until culture results are available.
PREFERRED RESPONSE: 4
,8 • American Academy of Orthopaedic Surgeons
DISCUSSION: Increased pain, swelling, erythema, and drainage 2 weeks removed from the primary
arthroplasty are all signs of a probable infection. Erythrocyte sedimentation rate and C-reactive protein
may not be helpful as they are elevated postoperatively even in the absence of infection. Even in the
absence of infection, persistent wound drainage is an indication for surgical debridement to prevent
subsequent infection. When a postoperative infection is easily recognized by clinical examination, there
is no need to wait for a positive culture before proceeding with debridement.
REFERENCES: Weiss AP, Krackow KA: Persistent wound drainage after primary total knee
arthroplasty. J Arthroplasty 1 993;8 :285-289 .
laberi FM, Parvizi J, Haytmanek CT, et al: Procrastination of wound drainage and malnutrition affect the
outcome of joint arthroplasty. Clin Orthop Relat Res 2 0 0 8 ; 46 6 :1 3 68 - 1 3 7 1 .
Insall IN, Windsor RE, Scott, WN: Surgery ofthe Knee, ed 2. New York, NY, Churchill
Livingstone, 1 993, pp 959-964.
Figure 3a Figure 3b
Question 3
A 72-year-old woman underwent a primary total hip arthroplasty 14 months ago. She states that the
hip has now dislocated four times when rising from a low chair, requiring closed reduction. A
radiograph is shown in Figure 3a and a CT scan of her pelvis is shown in Figure 3b. What is the most
re1iable method for rectifying her instability?
1. Use of an abduction orthosis for 6 weeks
2. Modular exchange of the femoral head to a 36-mm head and a longer neck
3. Modular exchange ofthe polyethylene liner to a constrained acetabular insert
4. Revision and repositioning of the acetabular component and use of a 36-mm
femoral head
5. A physical therapy program stressing abductor
strengthening PREFERRED RESPONSE: 4
DISCUSSION: The radiograph shows well-fixed components without evidence of loosening. The CT
scan shows severe retroversion of the acetabu1ar component. Revision of the component into the correct
amount of anteversion will most reliably rectify the instability in the face of severe component
malposition.
, 2010 Adult Reconstmctive Surgery ofthe Hip and Knee Examination Answer Book· 9
REFERENCES: Parvizi J, Pidnic E, Sharkey PF: Revision total hip arthroplasty for instability:
Surgical techniques and principles. J Bone Joint Surg Am 2008;90: 1134- 1 142.
DeWal H, Su E, DiCesare PE: Instability following total hip arthroplasty. Am J Orthop 2003;32: 377-
382. Barrack RL, Booth RE Jr, Lonner lH, et al (eds) : Orthopaedic Knowledge Update: Hip and Knee
Reconstruction 3. Rosemont, IL, Amelican Academy of Orthopaedic Surgeons, 2006, pp 475-503.
Question 4
A patient with a history of rheumatoid arthritis reports a painful total hip arthroplasty 3 years after
the index procedure. Radiographs reveal loosening of the femoral component. Preoperative blood
work shows an erythrocyte sedimentation rate (ESR) of 38 mmlh (nOlmal 0-29 mmlh) and a C-
reactive protein (CRP) of 8.9 (0.2-8.0). W hat is the most appropriate action at this time?
1. Technetium bone scan
2. Hip aspiration for culture
3. FDG-PET scan
4. Surgery with no further investigations
5. Revision surgery and obtain an intraoperative frozen
section PREFERRED RESPONSE: 2
DISCUSSION: The question centers on the appropriate work-up for a failed total hip arthroplasty
prior to revision surgery. The preoperative ESR is elevated and the CRP is at the upper end of
normal. If either the ESR or CRP is elevated, further investigations are required to exclude
infection as a cause of loosening, particularly in a patient only 3 years after the index procedure. A
technetium scan alone is nonspecific and will show increased uptake because of the loose femoral
component. An intraoperative
frozen section is a helpful confirmatory investigation, but whenever possible the diagnosis should be
made preoperatively to allow for appropriate surgical planning. Recently, investigators have shown the
value of FDG-PET scanning as a useful investigation for diagnosing infection; however, it is no more
accurate than the combined use of an ESR and CRP, and does not allow for identification of an
infecting organism. At this point, a hip aspiration for culture is the most appropriate investigation.
REFERENCES: Bauer TW, Parvizi J, Kobayashi N, et al: Diagnosis of periprosthetic infection. J
Bone Joint Surg Am 2006;88:869-882.
Pill SG, Parvizi J, Tang PH, et al: Comparison offiuorodeoxyglucose positron emission tomography
and ( 11 1)indium-white blood cell imaging in the diagnosis of periprosthetic infection of the hip. J
Arthroplasty 2006;21:91-97.
Spangehl MJ, Masri BA, O'Connell JX, et al: Prospective analysis of preoperative and intraoperative
investigations for the diagnosis of infection at the sites of two hundred and two revision total hip
arthroplasties. J Bone Joint Surg Am 1999;8 1:672-683.
