3. Adult Reconstruction (Hip & Knee) MCQs

A 55-year-old female presents with groin pain 5 years after a metal-on-metal THA. Labs show elevated cobalt and chromium. MARS MRI shows a large cystic mass. What histologic finding is most characteristic of this condition?

A 72-year-old female undergoes revision THA. Intraoperatively, she is found to have complete separation of the superior and inferior hemi-pelvis with severe bone loss. What is the most appropriate acetabular reconstruction strategy?

A 55-year-old active male undergoes THA with a ceramic-on-ceramic bearing. At 2 years postop, he complains of a squeaking noise with deep flexion. Radiographs show a well-fixed cup. What is the most significant risk factor for this phenomenon?

A 65-year-old woman presents with chronic hip pain 3 years after a primary total hip arthroplasty. Serum ESR and CRP are elevated. Aspiration yields a synovial fluid WBC of 2,500 cells/uL with 60% PMNs. Which of the following synovial fluid biomarkers provides the highest specificity for confirming periprosthetic joint infection in this scenario?

A 62-year-old man presents with progressive groin pain and swelling 5 years after a metal-on-polyethylene THA utilizing a modular titanium neck. Aspiration yields cloudy fluid with a normal cell count but elevated cobalt and chromium ions. MRI demonstrates a solid pseudotumor. What is the most likely etiology?

During a primary total hip arthroplasty via a posterolateral approach, increasing the femoral offset without changing the leg length will have which of the following biomechanical effects?

A 35-year-old man with a history of corticosteroid use presents with hip pain. MRI reveals a well-demarcated area of osteonecrosis in the anterosuperior femoral head, involving 25% of the head. Radiographs show no subchondral collapse or joint space narrowing. What is the most appropriate initial surgical management?

A 70-year-old woman experiences recurrent posterior dislocations of her total hip arthroplasty. Radiographs demonstrate a well-fixed acetabular component with 20 degrees of anteversion and 45 degrees of abduction. The femoral stem is well-fixed with 15 degrees of anteversion. What is the most appropriate surgical intervention?

A 78-year-old man sustains a fall 8 years after a primary cementless THA. Radiographs show a spiral fracture around the tip of the femoral stem. The stem is radiographically loose with subsidence, but the bone stock is well-preserved. According to the Vancouver classification, what is the most appropriate treatment?

Evaluate the clinical image provided:

A 45-year-old man presents with worsening hip pain. He has a history of childhood hip disease. If total hip arthroplasty is planned, which anatomic challenge is most characteristic when templating for a high hip dislocation (Crowe IV)?

A 55-year-old woman undergoes a primary total hip arthroplasty via a direct anterior approach. Postoperatively, she reports numbness and a burning sensation over the anterolateral aspect of her thigh, with normal hip abductor and quadriceps motor function. Injury to which of the following structures is the most likely cause?

After a successful closed reduction of a first-time, uncomplicated posterior dislocation occurring 4 weeks following a primary total hip arthroplasty, what is the most widely recommended initial management?

Compared to highly cross-linked polyethylene, the use of ceramic-on-ceramic bearing surfaces in primary total hip arthroplasty is uniquely associated with an increased risk of which of the following phenomena?

A 75-year-old active, community-ambulating woman sustains a displaced intracapsular femoral neck fracture. Compared to internal fixation, treating this patient with a total hip arthroplasty (THA) provides which of the following distinct advantages?

A 50-year-old patient presents with groin pain 12 years after a primary total hip arthroplasty. A radiograph is provided.

Assuming eccentric wear of a standard polyethylene liner and extensive radiolucent lines around the components without signs of infection, what is the fundamental biologic mechanism causing the bone loss?

A 60-year-old man presents with a painful total hip arthroplasty 6 years after index surgery. He has a metal-on-polyethylene bearing with a 36-mm titanium head on a cobalt-chrome stem. Aspiration is negative for infection, but serum cobalt levels are markedly elevated. What is the most likely diagnosis?

A 65-year-old woman presents with persistent lateral hip pain and a severe Trendelenburg gait 1 year after a THA via a lateral (Hardinge) approach. MRI demonstrates a chronic, full-thickness, completely retracted tear of the gluteus medius and minimus with severe fatty infiltration. What is the most appropriate surgical management?

Despite advancements in implant design, what remains the most common complication and cause for late revision surgery following anatomic total shoulder arthroplasty (aTSA)?

A 68-year-old woman sustains a displaced proximal humerus fracture. According to Hertel's criteria for ischemia, which of the following radiographic findings is the strongest predictor of subsequent avascular necrosis of the humeral head?