3. Adult Reconstruction (Hip & Knee) MCQs

A 30-year-old active female sustains a posterior hip dislocation with an associated femoral head fracture that extends cephalad to the fovea capitis (Pipkin Type II). Following closed reduction of the hip joint, the displaced fracture is noted to have a 3mm step-off. What is the most appropriate definitive management?

A 68-year-old female undergoes a revision total hip arthroplasty for aseptic loosening. Preoperative dual-energy x-ray absorptiometry (DEXA) scanning confirms severe osteoporosis. During impaction of a cementless acetabular component, a non-displaced medial wall acetabular fracture occurs. The component is stable. What is the most appropriate intraoperative management?

Placement of a screw in the anterosuperior quadrant of the acetabulum (Wasielewski zones) during total hip arthroplasty places which of the following structures at greatest risk of injury?

A 65-year-old man receives a ceramic-on-ceramic total hip arthroplasty. Two years later, he complains of a reproducible squeaking noise during gait. What is the most common biomechanical or radiographic finding associated with this phenomenon?

A 75-year-old woman sustains a periprosthetic femur fracture around a cemented polished taper-slip stem. Radiographs demonstrate a fracture near the tip of the stem with obvious cement mantle fragmentation and stem subsidence. What is the most appropriate classification and treatment?

A 60-year-old man with a metal-on-polyethylene total hip arthroplasty presents with new-onset groin pain and a palpable mass 5 years postoperatively. Blood work reveals elevated serum cobalt and chromium. Aspiration yields sterile, cloudy fluid. What is the most likely etiology?

Histologic evaluation of a successful, well-fixed porous-coated cementless titanium acetabular component retrieved 5 years postoperatively for an unrelated cause typically demonstrates bone ingrowth into approximately what percentage of the available porous surface?

A 60-year-old male is scheduled for a revision total hip arthroplasty. He has a history of severe Brooker class III heterotopic ossification following his index procedure. What is the most effective prophylactic regimen to prevent recurrence?

During a posterior approach to the hip, excessive retraction or release of the short external rotators close to the intertrochanteric crest endangers the primary blood supply to the femoral head. These critical retinacular vessels are terminal branches of which artery?

A 55-year-old active woman undergoes primary total hip arthroplasty with a ceramic-on-ceramic bearing. At her 2-year follow-up, she complains of a squeaking noise coming from the hip during deep flexion, though she is pain-free. What is the most significant risk factor for this phenomenon?

A 64-year-old man presents with painful swelling in his groin three years after undergoing a metal-on-metal total hip arthroplasty. Blood work reveals significantly elevated serum cobalt and chromium ion levels. A MARS MRI demonstrates a large cystic pseudotumor. If revision surgery is undertaken, histologic evaluation of the periprosthetic tissue will most likely show:

During surgical dislocation of the hip using the Ganz trochanteric flip approach for a femoral head fracture, the blood supply to the femoral head is protected by maintaining the integrity of which of the following structures?

A 72-year-old female presents with a periprosthetic femur fracture around a cementless, proximally porous-coated femoral stem.

Radiographs reveal a fracture extending just distal to the tip of the stem. The stem is radiographically loose with subsidence, but the proximal bone stock is highly comminuted while the diaphyseal bone is intact. According to the Vancouver classification, what is the most appropriate management?

During a primary total hip arthroplasty using a posterior approach, the surgeon decides to use a 'high offset' femoral stem instead of a standard offset stem. Assuming the neck angle remains the same, how does this stem primarily affect hip biomechanics?

A 68-year-old man underwent a right total hip arthroplasty 5 years ago with a modular cobalt-chromium femoral head on a titanium stem. He now presents with persistent thigh pain. Inflammatory markers are normal, and joint aspiration is negative for infection. Radiographs show no loosening. Serum cobalt is disproportionately elevated compared to chromium. What is the most likely diagnosis?

A patient is undergoing revision of a failed metal-on-metal total hip arthroplasty due to severe trunnionosis. The well-fixed titanium femoral stem will be retained, but the trunnion is macroscopically damaged. Which of the following head component combinations is most appropriate to place on the damaged trunnion?

A 45-year-old man presents with a Pipkin type II femoral head fracture associated with a posterior hip dislocation. The dislocation is successfully reduced in the emergency department, but the large fracture fragment remains displaced superior to the fovea capitis. What is the recommended surgical management?

A 60-year-old highly active man undergoes a primary total hip arthroplasty using a ceramic-on-ceramic bearing. Two years postoperatively, he complains of a reproducible, audible squeaking sound from the hip during deep flexion. Radiographs show a well-fixed implant but with a steeply positioned acetabular component. What is the most likely biomechanical cause of the squeaking?

In the evaluation of a painful total hip arthroplasty, synovial fluid is aspirated and sent for an alpha-defensin test to rule out periprosthetic joint infection (PJI). Which of the following best describes the biologic function and source of alpha-defensin?

The widespread use of highly cross-linked polyethylene (HXLPE) in total hip arthroplasty has significantly reduced volumetric wear rates compared to conventional ultra-high-molecular-weight polyethylene. Which of the following biomechanical properties is typically DECREASED as a direct result of the high irradiation cross-linking process?