3. Adult Reconstruction (Hip & Knee) MCQs

A 32-year-old woman with systemic lupus erythematosus on chronic corticosteroids presents with severe groin pain. Radiographs reveal a crescent sign in the anterosuperior femoral head with mild flattening of the articular surface. Joint space is preserved. What is the most reliable treatment to relieve pain and restore function?

A 70-year-old man presents 3 weeks after an uncomplicated primary THA with a draining sinus tract, increasing erythema, and a fever of 101.5°F. Radiographs show well-fixed components. What is the most appropriate definitive management?

A 25-year-old unrestrained driver suffers a posterior hip dislocation in a motor vehicle collision. Closed reduction is performed in the emergency department within 4 hours. Post-reduction CT scan shows a concentric joint reduction but identifies a 6x6 mm osteochondral fragment incarcerated within the joint space. What is the next best step in management?

During a complex revision THA for a well-fixed extensively porous-coated stem, the surgeon decides to perform an extended trochanteric osteotomy (ETO). Which muscle attachments must be maintained on the osteotomized fragment to ensure viability and subsequent healing?

A 64-year-old man underwent closed reduction and percutaneous pinning of a displaced femoral neck fracture 14 months ago. He now complains of severe, progressively worsening groin pain and shortened leg length. Radiographs demonstrate profound varus collapse, screw cut-out into the joint, and severe secondary acetabular wear. What is the treatment of choice?

A 72-year-old woman presents with start-up thigh pain 12 years after an uncemented THA. A radiograph (Figure 12) demonstrates progressive radiolucent lines >2 mm in all Gruen zones around the femoral stem with obvious subsidence. Inflammatory markers are strictly normal. Hip aspiration yields clear fluid with a WBC count of 300 cells/mm3 and 20% PMNs. What is the most likely diagnosis?

During pre-operative planning for a primary total hip arthroplasty, a surgeon decides to use a high-offset femoral stem instead of a standard-offset stem. Assuming leg length remains unchanged, what effect will this design choice have on hip biomechanics?

A 78-year-old woman with a history of a metal-on-metal total hip arthroplasty performed 8 years ago presents with new-onset groin pain and a palpable mass. Laboratory testing shows elevated serum cobalt and chromium levels. Which of the following is the most appropriate next imaging modality to evaluate for an adverse local tissue reaction (ALTR)?

A 72-year-old man who underwent a right total hip arthroplasty 6 weeks ago presents with persistent hip pain, erythema, and a draining sinus tract. Which of the following is an absolute indication for a two-stage revision rather than a debridement, antibiotics, and implant retention (DAIR) procedure?

During an extensile surgical approach to the hip, preserving the blood supply to the femoral head is critical to prevent avascular necrosis. The main arterial supply to the adult femoral head is the deep branch of the medial femoral circumflex artery (MFCA). This artery courses posterior to which of the following structures?

A 55-year-old man undergoes a primary total hip arthroplasty. To optimize stability and minimize the risk of dislocation, what is the generally accepted "safe zone" for acetabular cup orientation as originally described by Lewinnek?

In total hip arthroplasty, successfully increasing the femoral offset without altering the leg length will have which of the following biomechanical effects?

A 45-year-old man presents with a posterior wall acetabular fracture associated with a posterior hip dislocation. CT imaging demonstrates a focal area of marginal impaction of the articular surface. During surgical fixation, what is the most appropriate management of the impacted segment?

Ceramic-on-ceramic bearings in total hip arthroplasty have excellent wear characteristics but are associated with a unique complication known as "squeaking". Which of the following is the most significant risk factor for this phenomenon?

According to the quadrant system described by Wasielewski for acetabular screw placement during THA, placing a screw into the anterior-superior quadrant places which of the following structures at greatest risk?

A 62-year-old female presents 5 years after a metal-on-metal total hip arthroplasty with new-onset groin pain and a cystic mass. Histologic evaluation of the periprosthetic tissue is most likely to demonstrate which of the following?

During a total hip arthroplasty via a posterior approach, the sciatic nerve is at risk of injury. Which specific division of the nerve is most susceptible to indirect injury (e.g., traction), and what is the anatomic reason?

In the manufacturing of highly cross-linked polyethylene (HXLPE) for use in total hip arthroplasty, what is the primary purpose of heating the polyethylene above its melting point (remelting) following irradiation?

Three months following an uncomplicated primary total hip arthroplasty, a patient complains that the operative leg feels longer. Clinical examination reveals equal tape measurements from the anterior superior iliac spine (ASIS) to the medial malleolus bilaterally. However, the distance from the umbilicus to the medial malleolus is greater on the operative side. What is the most appropriate initial management?

A cementless femoral stem design is chosen for a primary THA in a 60-year-old man. Compared to a fully porous-coated cylindrical stem, what is the primary biomechanical advantage of a proximally coated tapered wedge stem?