3. Adult Reconstruction (Hip & Knee) MCQs

A 55-year-old male who underwent a metal-on-metal (MOM) total hip arthroplasty 6 years ago presents with progressive fatigue, shortness of breath, and bilateral hearing loss. His local hip examination is relatively benign, but laboratory studies reveal elevated metal ion levels. Toxicity from which of the following metal ions is most directly responsible for his systemic presentation?

When counseling patients on metal-on-metal (MOM) hip resurfacing, the orthopedic surgeon must consider patient-specific and implant-specific risk factors for early failure. Which of the following profiles represents the highest risk for developing adverse local tissue reactions (ALTR) and early failure?

A 49-year-old female is 5 years status post metal-on-metal hip resurfacing. She reports new-onset groin pain and a mechanical clicking sensation. Radiographs show optimally positioned components with no lucencies. Serum cobalt is 11 ppb. What is the most appropriate next step in evaluation?

During revision of a failed metal-on-metal hip resurfacing for an extensive pseudotumor, tissue samples are sent for histopathological analysis. Which of the following findings is most characteristic of an Aseptic Lymphocytic Vasculitis-Associated Lesion (ALVAL)?

A 45-year-old active male underwent a total hip arthroplasty with a ceramic-on-ceramic bearing. Two years postoperatively, he complains of a new-onset squeaking noise from the hip during gait, without pain. What is the most significant risk factor for this phenomenon?

According to the Musculoskeletal Infection Society (MSIS) and International Consensus Meeting (ICM) criteria, which of the following findings is considered a definitive major criterion for diagnosing a periprosthetic joint infection (PJI)?

A 70-year-old female presents with her third posterior dislocation 4 weeks after a primary total hip arthroplasty (THA). Radiographs and CT demonstrate the acetabular component is placed in 10 degrees of retroversion and 40 degrees of abduction. The femoral component is well-fixed with 15 degrees of anteversion. What is the definitive management?

During an ABOS oral exam, you are presented with a 65-year-old female who is 8 years status post a metal-on-metal total hip arthroplasty. She complains of new-onset groin pain and a palpable mass. Laboratory studies show significantly elevated serum cobalt and chromium levels. Which of the following imaging modalities is MOST appropriate to evaluate the extent of the suspected adverse local tissue reaction (ALTR)?

Six months after a total knee arthroplasty, a 70-year-old patient presents with a draining sinus tract communicating with the joint. What is the gold standard surgical management for this presentation?

A 40-year-old man presents with a chronic, rigid mallet deformity of his index finger 2 years after an untreated injury. He complains of pain and difficulty performing fine motor tasks. Radiographs demonstrate advanced osteoarthritis of the DIP joint with joint space narrowing and osteophytes. What is the most reliable surgical option for this patient?

A 55-year-old male presents with severe, bilateral knee pain, worse with activity and stair climbing. Radiographs reveal tricompartmental osteoarthritis with significant joint space narrowing, subchondral sclerosis, and osteophytes. He has failed extensive conservative management including NSAIDs, physical therapy, and intra-articular injections. His BMI is 32. He is otherwise healthy. What is the most appropriate next step in management?

A 68-year-old female presents with a painful total knee arthroplasty 2 years postoperatively. Serum CRP is 15 mg/L and ESR is 35 mm/hr. Synovial fluid aspiration yields a WBC count of 3,500 cells/uL with 75% PMNs. Which of the following synovial fluid biomarkers is most specific for confirming a periprosthetic joint infection (PJI)?

A 72-year-old male falls and sustains a periprosthetic femur fracture around a cemented polished taper-slip stem placed 8 years ago. Radiographs show a spiral fracture around the tip of the stem. The stem is radiographically loose with subsidence. What is the Vancouver classification and appropriate treatment?

A 60-year-old male with a metal-on-polyethylene total hip arthroplasty presents 5 years postoperatively with groin pain. Radiographs show no loosening. Aspiration is negative for infection. Serum cobalt levels are highly elevated, while chromium levels are only mildly elevated. What is the most likely etiology?

A 65-year-old female undergoes a primary total hip arthroplasty via a posterior approach. Six weeks later, she experiences a posterior dislocation while sitting in a low chair. Which of the following component malpositions most likely contributed to this specific type of instability?

During a primary total knee arthroplasty, the surgeon notes poor patellar tracking with a tendency for lateral subluxation. Which of the following technical errors most commonly causes this complication?

A 72-year-old female sustains a fall and presents with a periprosthetic fracture around her cemented total hip arthroplasty. Radiographs demonstrate a fracture around the stem, which is visibly loose, but the proximal femoral bone stock remains adequate. According to the Vancouver classification, what is the most appropriate surgical management?

A 68-year-old male presents with a painful total knee arthroplasty 3 years postoperatively. Serum ESR is 45 mm/hr and CRP is 25 mg/L. Joint aspiration yields a synovial WBC count of 4,500 cells/uL with 85% polymorphonuclear neutrophils, and the alpha-defensin test is positive. According to the current consensus criteria, what is the most appropriate next step?