This practice set contains high-yield board review questions covering key concepts in 3. Adult Reconstruction (Hip & Knee). Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 1041
Topic: Total Knee Arthroplasty (TKA)
A complication unique to computer navigation of total knee arthroplasty (TKA) is
Correct Answer & Explanation
. femoral shaft fracture.
Explanation
DISCUSSIONThreaded pins are frequently inserted into the femoral shaft and tibial shafts or proximal tibia to attach arrays for tracking devices. There have been case reports of fractures propagating through the pin tracks, which is a complication unique to computer navigation. Intercondylar fractures can occur following posterior stabilized TKA. Vascular injury, ligament disruption, and nerve palsy are rare complications following TKA performed with or without computer navigation.CLINICAL SITUATION FOR QUESTIONS 111 THROUGH 113Figure 111 is the anteroposterior radiograph of a 79-year-old woman with a presurgical diagnosis of osteonecrosis who sustained a periprosthetic tibia fracture following her total knee arthroplasty (TKA).
Question 1042
Topic: 3. Adult Reconstruction (Hip & Knee)
A patient has pain 2 years after undergoing a metal-on-metal (MOM) left total hip arthroplasty (THA). Which test(s) best correlate with prognosis in the setting of reaction to metal debris?
Correct Answer & Explanation
. Erythrocyte sedimentation rate, C-reactive protein, and white blood cell count
Explanation
Figures 1 and 2 are the recent radiographs of an 82-year-old man with rheumatoid arthritis who underwent total knee arthroplasty (TKA) 18 years ago. These radiographs reveal osteolysis with loosening of the tibial component. Aspiration and laboratory study findings for infection are negative. During the revision TKA, treatment of tibial bone loss should consist of
Question 1043
Topic: 3. Adult Reconstruction (Hip & Knee)
A 65-year-old man has a painful and often audible crepitus after undergoing a total knee arthroplasty 8 months ago. His symptoms are reproduced with active extension of about 30°. Examination reveals no effusion or localized tenderness, a stable knee, and a range of motion of 5° to 120°. Radiographs are shown in Figures 37a and 37b. Management should consist of
Correct Answer & Explanation
. revision of all components to ensure patellar tracking.
Explanation
DISCUSSION: This is a typical presentation of the patellar clunk syndrome. The syndrome usually follows implantation of a posterior stabilized prosthesis. It is thought to be the result of femoral component design and altered extensor mechanics. The condition usually resolves with arthroscopic debridement of the suprapatellar fibrous nodule. Arthrotomy or revision is seldom warranted.REFERENCES: Beight JL, Yao B, Hozack WJ, Hearn SL, Booth RE Jr: The patellar “clunk” syndrome after posterior stabilized total knee arthroplasty. Clin Orthop 1994;299:139-142.Lintner DM, Bocell JR, Tullos HS: Arthroscopic treatment of intra-articular fibrous bands after total knee arthroplasty: A follow-up note. Clin Orthop 1994;309:230-233.
Question 1044
Topic: 3. Adult Reconstruction (Hip & Knee)
Compared with retention of the native patella in primary total knee arthroplasty, routine patellar resurfacing is associated with
Correct Answer & Explanation
. a reduced risk for revision surgery.
Explanation
DISCUSSION:Despite concerns regarding fracture, osteonecrosis, and patellar clunk, the routine retention of the native patella during primary total knee replacement is associated with a 20% to 30% increased revision risk inlarge joint registries. In addition, the retention of the native patella results in a 5.7% revision surgery rate in patients with anterior knee pain.
Question 1045
Topic: 3. Adult Reconstruction (Hip & Knee)
What is the most likely explanation for the change between the initial intraoperative radiograph (Figure 11a) and the radiograph taken 4 weeks after surgery (Figure 11b) in an 87-year-old man who underwent primary hip replacement for osteoarthritis?
Correct Answer & Explanation
. Initial implant stability
Explanation
DISCUSSIONThe image demonstrates subsidence of the femoral implant. The implant subsided because it did not have good initial stability. The tapered femoral implant was placed after initial preparation for an anatomic femoral stem. A limited, nondisplaced femoral neck fracture was encountered during the procedure and treated. Two advantages of tapered stems are the efficient transfer of stress to the proximal femur and the ability to accommodate some subsidence to achieve enhanced stability. Although subsidence of a tapered stem to a more stable position can produce a good result, quality of metaphyseal bone should be considered. Attention to surgical technique remains important to optimize component stability for biological fixation.RECOMMENDED READINGSSavory CG, Hamilton WG, Engh CA Sr, Della Valle CJ, Rosenberg AG, Galante JO.15Hip designs. 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; 2006:345-368.Blaha JD, Borus TA. Press-fit femoral components. In: Callaghan J, Rosenberg A, and Rubash H, eds The Adult Hip. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2007:1036-1043.
Question 1046
Topic: 3. Adult Reconstruction (Hip & Knee)
Which of the following medicolegal relationships between an attending surgeon and a resident assistant applies when a patient files a malpractice suit relating to surgical complications following a total knee arthroplasty?
Correct Answer & Explanation
. Respondeat superior
Explanation
“Let the master answer”. A resident has been authorized to act for or represent the supervising physician. As an agent for the supervisor, all acts of the resident are considered to be under the direction of the supervisor. This is the definition for respondeat superior. Hold harmless agreement attempts to shift liability from company to physician. Comparative negligence refers to the % of involvement. Contributory negligence is where the resident is accused of contributing to a negligent act.
Question 1047
Topic: 3. Adult Reconstruction (Hip & Knee)
When planning revision of a total hip arthroplasty where an acetabular reconstruction will be required, what prerequisite is important to ensure long-term success of a cementless component?
Correct Answer & Explanation
. Presence of at least 50% host bone
Explanation
DISCUSSION: In bone defects where host bone support is less than 50%, the failure rate is 70% at 5.1 years. The presence or absence of columns or hip position is of relatively little importance if the supportive bone is not present in at least 50% of the surface area around the future acetabular implant.REFERENCE: Gross AE, Allan DG, Catre M, et al: Bone grafts in hip replacement surgery: The pelvic side. Orthop Clin North Am 1993;24:679-695.
Question 1048
Topic: 3. Adult Reconstruction (Hip & Knee)
A 35-year-old construction worker has developed isolated lateral compartment arthritis. He has lost 50 pounds, now has a body mass index of 30, and still has pain that limits his activities of daily living and work despite receiving a 4-month course of nonsteroidal anti-inflammatory medications and 2 intra-articular cortisone injections. His range of motion is 5 to 110 degrees, and his mechanical axis is 18 degrees of valgus. What is the most appropriate surgical treatment for this patient?
Correct Answer & Explanation
. Proximal tibial varus osteotomy
Explanation
DISCUSSIONKnee arthritis in a young laborer is challenging to address. A surgeon could perform an arthroplasty, but there is concern for early failure and the subsequent need for multiple revisions during this patient’s lifespan. Indications for distal femoral varus osteotomy include at least a 12- to 15-degree valgus mechanical axis and range of motion of at least 15 to 90 degrees. Contraindications for this procedure include inflammatory arthritis and restricted knee motion.RESPONSES FOR QUESTIONS 138 THROUGH 141Acute periprosthetic infectionChronic periprosthetic infectionJoint dislocationPeriprosthetic fracturePseudotumorFemoral nerve palsySciatic nerve palsyAseptic prosthetic looseningSelect the total hip arthroplasty (THA) complication listed above that most commonly is associated with the clinical scenario described below.
Question 1049
Topic: 3. Adult Reconstruction (Hip & Knee)
Following insertion of a cementless femoral component into the total hip arthroplasty construct, the amount of femoral stress shielding is most associated with
Correct Answer & Explanation
. presurgical bone mineral density.
Explanation
DISCUSSIONAlthough material modulus, characteristics of surface, and extent of coating all contribute to stress shielding, poor bone quality is the most important factor associated with stress shielding.
Question 1050
Topic: 3. Adult Reconstruction (Hip & Knee)
An 82-year-old woman reports right buttock pain after a car trip. Laboratory studies show an erythrocyte sedimentation rate of 30 mm/h and WBC of 4,600/mm 3 . Figure 34a shows a plain AP radiograph of the pelvis, and Figure 34b shows a delayed technetium Tc 99m bone scan. Management should consist of
Correct Answer & Explanation
. bed rest and pain medication.
Explanation
DISCUSSION: The radiograph shows bilateral cemented total hip arthroplasties. The acetabular components are loose bilaterally, but there has been no acute change. Therefore, it is unlikely that the acetabular loosening is contributing to the patient’s pain. The bone scan is consistent with a sacral insufficiency fracture. This is best treated with bed rest and pain medication. Activity can be increased as the pain allows. Revision will not address the pain.REFERENCES: Newhouse KE, el-Khoury GY, Buckwalter JA: Occult sacral fractures in osteopenic patients. J Bone Joint Surg Am 1992;74:1472-1477.Marmor L: Stress fracture of the pubic ramus simulating a loose total hip replacement. Clin Orthop 1976;121:103-104.
Question 1051
Topic: 3. Adult Reconstruction (Hip & Knee)
You are interested in learning a new technique for minimally invasive total knee arthroplasty. The Keyhole Genuflex system seems appealing to you because the instrumentation comes with wireless controls. Which of the following represents an acceptable arrangement?
Correct Answer & Explanation
. Keyhole will pay your expenses to attend a workshop, in Phoenix at their company headquarters, to learn how to implant the Genuflex knee and to see how the implant is manufactured and tested.
Explanation
DISCUSSION: Both the AAOS and AdvaMed, the medical device manufacturer's trade organization, have written guidelines that address potential conflicts of interest regarding interactions between physicians and manufacturer's representatives when it comes to patients' best interest. The AAOS feels that the orthopaedic profession exists for the primary purpose of caring for the patient and that the physician-patient relationship is the central focus of all ethical concerns. When an orthopaedic surgeon receives anything of significant value from industry, a potential conflict of interest exists. The AAOS believes that it is acceptable for industry to provide financial and other support to orthopaedic surgeons if such support has significant educational value and has the purpose of improving patient care. All dealings between orthopaedic surgeons and industry should benefit the patient and be able to withstand public scrutiny. A gift of any kind from industry should in no way influence the orthopaedic surgeon in determining the most appropriate treatment for his or her patient. Orthopaedic surgeons should not accept gifts or other financial support with conditions attached. Subsidies by industry to underwrite the costs of educational events where CME credits are provided can contribute to the improvement of patient care and are acceptable. A corporate subsidy received by the conference's sponsor is acceptable; however, direct industry reimbursement for an orthopaedic surgeon to attend a CME educational event is not appropriate. Special circumstances may arise in which orthopaedic surgeons may be required to learn new surgical techniques demonstrated by an expert or to review new implants or other devices on-site. In these circumstances, reimbursement for expenses may be appropriate.REFERENCES: AAOS Standard of Professionalism -Orthopaedist -Industry Conflict of Interest (Adopted 4/18/07), Mandatory Standard numbers 6, 9, 12-15. http://www3.aaos.org/member/profcomp/SOPConflictsIndustry.pdfThe Orthopaedic Surgeon’s Relationship with Industry, in Guide to the Ethical Practice of Orthopaedic Surgery, ed 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2007. http://www.aaos.org/about/papers/ethics/1204eth.aspAdvaMed Code of Ethics on Interactions with Health Care Professionals 2005. http://www.advamed.org/MemberPortal/searchresults.htm?query=Advamed%20Code%20of%20Ethics%20on%20Interactions%20with%20Health%20Care%20Professionals%202005
Question 1052
Topic: 3. Adult Reconstruction (Hip & Knee)
Figures 14a and 14b show the plain radiographs of an 85-year-old woman who has had severe pain in the right knee for the past 4 months. Management should consist of
Correct Answer & Explanation
. total knee arthroplasty.
Explanation
DISCUSSION: The patient has osteonecrosis of the lateral femoral condyle with collapse of the articular surface. Because there is already collapse of the articular surface, a total knee arthroplasty is the treatment of choice. The results of total knee arthroplasty in these patients are usually excellent. However, knee replacement is only a resurfacing procedure, and some patients with global osteonecrosis of the distal femur may have residual pain after knee replacement. High tibial osteotomy may be indicated in younger patients who have a varus deformity and localized osteonecrosis. Arthroscopic surgery would provide minimal relief for this patient because there is already collapse of the articular surface. A hinged knee brace will not adequately unload the joint. An osteochondral allograft should be considered only for younger patients with localized osteonecrosis.REFERENCES: Bergman NR, Rand JA: Total knee arthroplasty in osteonecrosis. Clin Orthop 1991;273:77-82.Lotke PA, Abend JA, Ecker ML: The treatment of osteonecrosis of the medial femoral condyle. Clin Orthop 1982;171:109-116.
Question 1053
Topic: 3. Adult Reconstruction (Hip & Knee)
A 45-year-old man has a draining sinus and recurrent infection of his right total knee arthroplasty. He has had two prior revision surgeries after the primary procedure and three other surgeries before his initial replacement, including a proximal tibial osteotomy and subsequent hardware removal. On clinical examination, he has a draining sinus in the mid portion of his surgical scar and a range of motion of 5° to 85°. AP and lateral radiographs of the right knee are shown in Figures below. During surgery, the femoral component is found to be grossly loose, but the tibial component is well fixed. What is the most appropriate extensile approach that would provide adequate exposure and aid in tibial component extraction?
Correct Answer & Explanation
. Extended medial parapatellar approach
Explanation
DISCUSSION:Extended tibial tubercle osteotomy is an extensile approach to revision total knee arthroplasty that affords excellent exposure and can facilitate removal of tibial sleeves and cones. This patient has had multiple surgeries, including a proximal tibial osteotomy, as well as poor range of motion, patella baja, and a well- fixed metaphyseal sleeve component. Classically, an extended tibial tubercle osteotomy provides outstanding exposure for component removal in the setting of prior high tibial osteotomy and patella baja. For this patient, it is important to recognize the patella baja on the radiographs, as well as the tibial sleeve. In many of these cases the osteotomy provides access to the sleeve to help with extraction, because the stem will not pull through the sleeve or detach from the tray to allow visualization of the sleeve. The extended medial parapatellar approach is just a long medial approach that typically yields good exposurebut would not help with the patella baja or extraction of the tibial sleeve. The quadriceps snip would give good exposure to the knee but would not aid in tibial component removal. Lastly, the medial epicondyle osteotomy could help with exposure and tensioning of the medial complex of the knee but would not helpwith tibial component extraction.
Question 1054
Topic: 3. Adult Reconstruction (Hip & Knee)
Figure 4 shows the AP radiograph of a 28-year-old woman who has had moderate pain in the left hip for the past year. Nonsurgical management has failed to provide relief. She denies any history of hip pain, pathology, or trauma. Management should consist of
Correct Answer & Explanation
. a periacetabular osteotomy.
Explanation
DISCUSSION: The radiograph shows developmental dysplasia of the hip with the hip reduced and congruent. The treatment of choice is a periacetabular osteotomy because it can improve hip biomechanics and prolong the function of the hip joint. This procedure should be performed prior to the development of severe degenerative changes. Observation will not alter the patient’s natural history or the biomechanics of the hip. A total hip arthroplasty should be delayed until severe degenerative changes are present. A Chiari osteotomy is a salvage osteotomy used for a noncongruent subluxated hip. A Pemberton osteotomy requires an open triradiate cartilage; therefore, it is not an option in an adult.REFERENCES: Trousdale RT, Ekkernkamp A, Ganz R, Wallrichs SL: Periacetabular and intertrochanteric osteotomy for the treatment of osteoarthrosis in dysplastic hips. J Bone Joint Surg Am 1995;77:73-85.Pemberton PA: Pericapsular osteotomy of the ilium for the treatment of congenital subluxation and dislocation of the hip. J Bone Joint Surg Am 1965;47:65-86.
Question 1055
Topic: Total Hip Arthroplasty (THA)
The patient is given a blood transfusion. After starting the transfusion, nurses note that her temperature is 38.8°C and she has shaking and chills. What is the most likely cause of this problem?
Correct Answer & Explanation
. Blood transfusion incompatibility
Explanation
DISCUSSIONBlood management and venous thromboembolism prevention are important considerations in the perioperative management of THA. Recommendations now focus on presurgical optimization of hemoglobin, use of antifibrinolytics intrasurgically, and minimized use of transfusions. Current recommendations do not favor autologous blood donation for patients with hemoglobin levels higher than 13 g/dL. There is a move toward increased use of aspirin for venous thromboembolism prophylaxis, but this modality can cause GI bleeding that may necessitate blood transfusion. Transfusion reactions are rare, and the most common cause is administration of an incompatible unit because of clerical error.
Question 1056
Topic: 3. Adult Reconstruction (Hip & Knee)
An active 66-year-old man who underwent total shoulder arthroplasty 3 years ago now reports pain. Laboratory studies reveal an elevated erythrocyte sedimentation rate and C-reactive protein. Intraoperative frozen section reveals greater than 10 white blood cells per high power field on two slides and the Gram stain reveals gram-positive cocci in clusters. What is the most appropriate surgical treatment to eradicate the infection and maintain function? Review Topic
Correct Answer & Explanation
. Removal of the components and placement of an antibiotic spacer
Explanation
The prosthesis is grossly infected. Removal of the components and placement of an antibiotic spacer is necessary to eradicate the infection and allow for a second stage reimplantation. Resection arthroplasty is an option to treat the infection but the functional outcome would be limited. Bone grafting with concurrent infection is not likely to heal and should be delayed until the second stage. Humeral head exchange and debridement or arthroscopic debridement alone is unlikely to eradicate the infection.
Question 1057
Topic: 3. Adult Reconstruction (Hip & Knee)
What is the most serious complication that may occur with a ceramic-on-ceramic bearing in a total hip prosthesis?
Correct Answer & Explanation
. Fracture
Explanation
Fortunately, due to improvements in strength and quality control, fracture of a modern ceramic hip bearing is very rare. However, when a ceramic bearing does fracture, numerous fragments may become embedded in the capsular tissues. During revision, the surgeon must make every reasonable effort to locate and remove these fragments. Among other complications, fragments that remain behind can become entrapped between the bearing surfaces of the new implant and initiate severe wear. In normal use, ceramic bearings have excellent wear resistance. Squeaking may be extremely annoying to the patient, but is not inherently dangerous and sometimes resolves spontaneously. Dislocation is a serious complication regardless of the type of bearing, but it sometimes may be treated without requiring a reoperation and, if revision is required, it typically is not as problematic as with a fractured ceramic bearing. Infection is to be avoided, but it is not a complication directly related to the use of a ceramic bearing.
Question 1058
Topic: 3. Adult Reconstruction (Hip & Knee)
03 A 64 year old man who underwent revision total knee arthroplasty 6 months ago has leg pain after walking. AP and lateral radiographs are shown in Figures 39a and 39b. The cause of pain is most likely related to
Correct Answer & Explanation
. prior patellecomy 2- tibial stem position.
Explanation
Barrack RL, Rorabeck C, Burt M. Sawhney J: Pain at the end of the stem after revision total knee arthroplasty. Clin Orthop 1999:367:216225.back to this question next question
Question 1059
Topic: 3. Adult Reconstruction (Hip & Knee)
below depict the radiographs obtained from a year-old woman with a painful total knee arthroplasty. She describes an uneventful recovery with no wound-healing issues and was pain free for the first 10 years. Although reporting no trauma or inciting event, she now describes pain in the entire knee that is most severe with her first few steps. She has begun to notice night pain and, more recently, constant swelling. What is the most appropriate work-up at this time?
Correct Answer & Explanation
. Knee aspiration with cell count/cultures, CRP, ESR
Explanation
DISCUSSION:An evaluation of the painful total knee must be supported by an understanding of the potential etiologies of pain. They may include, aseptic loosening, infection, osteolysis, gap imbalance, referred pain, stiffness, and complex regional pain syndrome. In this case, the patient demonstrates start-up pain and had no prior history of infections. Her radiographs show subsidence of the tibia, indicating a loose prosthesis. Knowing that the prosthesis is already loose precludes the need for a bone scan. It is, however, important to rule out infection in this case; therefore, CRP and ESR testing is essential. Aspiration is also recommended when going into knee arthroplasty, and infection is a concern.
Question 1060
Topic: 3. Adult Reconstruction (Hip & Knee)
Which of the following nutraceuticals has been associated with perioperative bleeding?
Correct Answer & Explanation
. Ginkgo biloba
Explanation
DISCUSSION: Ginkgo biloba is a popular nutraceutical for patients who have early dementia, intermittent claudication secondary to peripheral vascular disease, vertigo, and tinnitus. It is reported to improve mental alertness and cognitive deficiency. It has antiplatelet properties as a result of one of its components, ginkgolide B, which displaces platelet-activating factor from its receptor binding sight. Rowin and Lewis reported on spontaneous bilateral subdural hematomas associated with chronic ginkgo biloba ingestion. Vale also reported on subarachnoid hemorrhage associated with ginkgo biloba. Bebbington and associates reported on persistent postoperative bleeding after total hip arthroplasty secondary to ginkgo biloba usage. Furthermore, the use of ginkgo biloba with aspirin or other antiplatelet agents or anticoagulants represents a relative contraindication. Physicians should be aware not only of prescribed medications but also alternative nutraceuticals that are used by the patient.REFERENCES: Rowin J, Lewis SL: Spontaneous bilateral subdural hematomas associated with chronic ginkgo biloba ingestion. Neurology 1996;46:1775-1776.Vale S: Subarachnoid hemorrhage associated with ginkgo biloba. Lancet 1998;352:36.Bebbington A, Kulkarni R, Roberts P: Ginkgo biloba: Persistent bleeding after total hip arthroplasty caused by herbal self-medication. J Arthroplasty 2005;20:125-126.
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