3. Adult Reconstruction (Hip & Knee) MCQs

A 71-year-old man complains of persistent knee pain 2 years after a TKA. Aspiration of the joint reveals a synovial white blood cell (WBC) count of 4,200 cells/uL with 88% neutrophils. Serum CRP is 18 mg/L. What is the most appropriate definitive management for this chronic condition?

A 65-year-old man presents with progressive groin pain 5 years after a primary total hip arthroplasty (THA) utilizing a titanium stem, cobalt-chromium modular head, and highly cross-linked polyethylene liner. Radiographs show a well-fixed stem and cup with no osteolysis. Aspiration yields dark, turbid fluid with 500 WBCs/mcL and negative cultures. Serum cobalt is markedly elevated compared to chromium. What is the most likely diagnosis?

A 72-year-old woman presents with an inability to perform a straight leg raise 4 weeks after a primary total knee arthroplasty (TKA). Examination reveals a palpable defect at the inferior pole of the patella. Surgical exploration confirms a massive patellar tendon rupture with severely attenuated, retracted tissue that cannot be approximated. What is the most reliable reconstructive option?

A 68-year-old male is 3 weeks post-primary THA and presents with 3 days of increasing pain, erythema, and incisional drainage. CRP is 150 mg/L. Joint aspiration yields 45,000 WBCs/mcL with 95% polymorphonuclear cells. What is the optimal surgical management?

A 60-year-old woman is 1-year post-posterior stabilized TKA. She complains of a painful catching and popping sensation in her anterior knee as she actively extends her knee from a flexed position. What implant design factor most significantly contributes to this specific complication?

A 75-year-old woman sustains a periprosthetic femur fracture around a cemented polished taper slip stem. Radiographs show a fracture line propagating just distal to the tip of the stem. The stem has subsided 10 mm and the cement mantle is fragmented, but the proximal femur bone stock remains robust. According to the Vancouver classification, what is the most appropriate treatment?

A 45-year-old woman complains of groin pain 6 months after an uncomplicated direct anterior approach THA. Pain is reproducible with active straight leg raise and resisted hip flexion. Radiographs demonstrate a neutral acetabular component with 8 mm of anterior overhang over the bony rim. Initial management should consist of?

Squeaking in a ceramic-on-ceramic total hip arthroplasty is most strongly associated with which of the following biomechanical phenomena?

During a primary TKA utilizing a gap balancing technique, the surgeon finds that the extension gap is perfectly symmetric and rectangular. However, the flexion gap is tight medially and loose laterally. What is the most appropriate adjustment to the femoral component to balance the flexion gap?

Which of the following describes the primary biomechanical mechanism by which a dual mobility cup decreases the risk of dislocation compared to a standard unconstrained THA?

A 68-year-old woman undergoes a primary TKA for an end-stage 25-degree valgus knee deformity. In the PACU, she has a complete foot drop and sensory loss over the dorsum of the foot. Pulses are symmetric and palpable. What is the immediate recommended management?

Which of the following patient factors is widely considered an absolute contraindication to metal-on-metal hip resurfacing arthroplasty?

A 65-year-old man is 8 weeks post-TKA and presents with an active and passive range of motion of 10 to 75 degrees despite aggressive, daily physical therapy. Radiographs confirm properly sized and positioned components without loosening. What is the most appropriate next step in management?

A 32-year-old man with a history of systemic lupus erythematosus and high-dose corticosteroid use presents with groin pain. Radiographs demonstrate mixed sclerosis and cysts in the superior femoral head, but the articular surface is perfectly spherical with no subchondral radiolucent crescent sign. MRI confirms osteonecrosis involving 25% of the weight-bearing surface. What is the most appropriate joint-preserving surgical intervention?

A 68-year-old woman with a severe valgus deformity undergoes a total knee arthroplasty using a lateral parapatellar approach. During trial reduction, the knee is tight in extension laterally but balanced in flexion. Which of the following structures should be released next?

A 65-year-old man presents with a painful total knee arthroplasty 3 years after the index procedure. His ESR is 45 mm/hr and CRP is 22 mg/L. Joint aspiration yields a WBC count of 2,500 cells/uL with 75% PMNs. Which of the following tests would be most definitive in confirming the diagnosis of periprosthetic joint infection?

An 80-year-old woman sustains a fall 8 years after a cementless total hip arthroplasty. Radiographs show a periprosthetic fracture around the femoral stem. The fracture extends into the diaphysis, and the stem is demonstrably loose. The patient has good remaining proximal bone stock. What is the most appropriate surgical management?

A 70-year-old man presents with a complete patellar tendon rupture 4 years after a total knee arthroplasty. He has an active extension lag of 45 degrees. Primary repair is attempted but cannot be opposed without severe tension. What is the most reliable reconstructive option?

A 60-year-old man complains of groin pain 6 years after a metal-on-polyethylene total hip arthroplasty utilizing a large diameter cobalt-chromium head. Radiographs show a well-fixed implant with no osteolysis. Aspiration is negative for infection, but MARS MRI reveals a solid pseudotumor adjacent to the joint. What is the most likely etiology?

During a posterior-stabilized total knee arthroplasty, the surgeon notes the knee is well-balanced and symmetric in extension, but symmetrically tight in flexion. Which of the following is the most appropriate next step?