3. Adult Reconstruction (Hip & Knee) MCQs

A 65-year-old male, 3 weeks status-post primary THA, presents with 3 days of increasing hip pain, erythema, and drainage from the incision. His CRP is 150 mg/L. Aspiration reveals an elevated WBC count with 95% PMNs. Radiographs show stable, well-fixed implants. What is the most appropriate management?

Which design modification in posterior-stabilized (PS) total knee arthroplasty components has most significantly reduced the incidence of patellar clunk syndrome?

During a total hip arthroplasty, the surgeon decides to switch from a standard neck stem (131-degree neck-shaft angle) to a high-offset stem (121-degree neck-shaft angle) of the exact same size. Assuming the depth of insertion remains identical, what is the primary biomechanical effect?

In a kinematically aligned total knee arthroplasty compared to a traditional mechanically aligned TKA, the femoral component is typically placed in what position relative to the mechanical axis?

A 62-year-old male with a metal-on-polyethylene THA placed 8 years ago presents with new-onset hip pain and swelling. A large periarticular cystic mass is noted on MRI. Joint aspiration is negative for infection. Bloodwork shows a markedly elevated serum cobalt level with a normal chromium level. What is the most likely diagnosis?

A 79-year-old patient sustains a periprosthetic femur fracture around a cemented total hip arthroplasty stem. Radiographs demonstrate the fracture extending from the mid-stem to just distal to the tip. The stem is radiographically loose, but there is excellent proximal femoral bone stock. According to the Vancouver classification, what is the fracture type and appropriate treatment?

A 65-year-old male is 8 weeks post-uncomplicated primary TKA and complains of significant stiffness. His range of motion is 15 to 75 degrees despite excellent compliance with aggressive physical therapy. Radiographs confirm appropriate component sizing and alignment without loosening. What is the most appropriate next step in management?

When balancing a total knee arthroplasty in a patient with a severe fixed valgus deformity, isolated release or 'pie-crusting' of the iliotibial (IT) band will primarily affect which gap?

A 78-year-old male with a history of recurrent posterior THA dislocations undergoes revision surgery. Intraoperative evaluation reveals an extremely deficient abductor mechanism. The acetabular shell is well-fixed and in appropriate anteversion and inclination. Which intervention will best restore stability in this patient?

During a total knee arthroplasty, 'overstuffing' the patellofemoral joint by using a patellar component that is too thick can predictably lead to which of the following postoperative complications?

A 65-year-old female presents with anterior knee pain and a reproducible "popping" sensation when extending her knee from a flexed position. She underwent a primary total knee arthroplasty (TKA) 18 months ago. Examination reveals a palpable catch at approximately 30 to 45 degrees of flexion as the knee extends. Which of the following implant design features is most strongly associated with this specific complication?

A 70-year-old male presents with progressively worsening anterior groin pain 5 years after an uncomplicated primary THA. He has a highly cross-linked polyethylene liner, a 36-mm cobalt-chromium femoral head, and a titanium alloy femoral stem. Radiographs show a well-fixed stem and cup. An MRI with metal artifact reduction sequence (MARS) reveals a 4-cm cystic periarticular mass. Serological workup is notable for elevated cobalt levels and normal chromium levels. What is the primary pathophysiologic mechanism for this failure?

During trialing in a primary posterior-stabilized total knee arthroplasty utilizing a measured resection technique, the surgeon finds that the knee is well-balanced and fully extends to 0 degrees symmetrically. However, upon testing flexion, the joint is symmetrically tight at 90 degrees and cannot achieve full flexion. What is the most appropriate next step to balance the knee?

Which of the following physical examination or radiographic findings is considered a strict contraindication to performing a medial unicompartmental knee arthroplasty (UKA) using standard traditional criteria?

Based on the 2018 International Consensus Meeting (ICM) criteria for Periprosthetic Joint Infection (PJI), which of the following findings is considered a definitive "Major Criteria," establishing the diagnosis of PJI independently?

A 78-year-old female sustains a periprosthetic femur fracture around her cemented total hip arthroplasty stem. Radiographs demonstrate a fracture located around the distal tip of the stem with extension into the diaphysis. The cement mantle is fractured, indicating a loose stem, and there is severe osteolysis and comminution of the proximal femur, leaving inadequate bone stock for proximal fixation. What is the correct Vancouver classification and the recommended treatment?

A 65-year-old female with severe rheumatoid arthritis presents for a primary THA. Preoperative radiographs demonstrate severe protrusio acetabuli (Kohler's line is crossed by the femoral head). When preparing the acetabulum during surgery, what is the most appropriate technique to achieve a stable, biomechanically sound reconstruction?

A 60-year-old female presents for a primary total knee arthroplasty. She has a documented severe hypersensitivity reaction to nickel, confirmed by a dermatologist via patch testing. Which of the following femoral component materials is the most appropriate alternative to minimize her risk of a delayed hypersensitivity reaction?

During a complex revision TKA, the surgeon notes that the joint line has been inadvertently elevated by 8 mm compared to its pre-disease anatomic location. If left uncorrected, which of the following complications is most likely to occur postoperatively?