3. Adult Reconstruction (Hip & Knee) MCQs

A 62-year-old female presents with groin pain and a palpable mass five years after a metal-on-metal total hip arthroplasty. Aspiration of the hip yields aseptic fluid, and serum cobalt and chromium levels are elevated. Histological examination of the periprosthetic tissue is most likely to show which of the following?

A 75-year-old male sustains a fall and suffers a periprosthetic fracture around his cemented total hip arthroplasty.

Radiographs demonstrate a fracture around the tip of the stem with evidence of cement mantle fragmentation and subsidence of the femoral component. Which of the following is the most appropriate management?

According to the 2018 International Consensus Meeting on Periprosthetic Joint Infection, which of the following synovial fluid profiles strongly supports the diagnosis of an acute periprosthetic joint infection (within 4 weeks of surgery)?

A 68-year-old male presents with a painful catching sensation and an audible clunk as his knee extends from 40 degrees of flexion to full extension, 18 months after a posterior-stabilized total knee arthroplasty. What is the most common cause of this phenomenon?

A surgeon is performing a total hip arthroplasty via the direct anterior approach. When preparing the femur, excessive retraction is applied to the medial soft tissues. Which of the following structures is at greatest risk of injury?

A 70-year-old female presents with an inability to actively extend her knee 3 years following a total knee arthroplasty. Evaluation confirms a chronic, massive rupture of the patellar tendon with severe tissue retraction and poor host tissue quality. Which of the following is the most reliable reconstructive option?

During a primary total knee arthroplasty, the surgeon finds the joint is perfectly balanced in flexion but tight in extension. Which of the following is the most appropriate surgical step to correct this mismatch?

A 65-year-old man presents with progressive groin pain 5 years after receiving a metal-on-polyethylene total hip arthroplasty. Aspiration is negative for infection. Blood tests reveal serum cobalt levels that are significantly higher than chromium levels. What is the most likely etiology of his symptoms?

A 78-year-old woman presents with thigh pain after a ground-level fall. Radiographs demonstrate a fracture around her cemented polished taper-slip femoral stem. The fracture occurs at the level of the stem tip, and the stem is clearly loose within the cement mantle, but the proximal bone stock remains adequate. According to the Vancouver classification, what is the most appropriate management?

A 60-year-old man presents with a painful total knee arthroplasty 3 years postoperatively. His ESR is 45 mm/hr and CRP is 25 mg/L. Joint aspiration yields a white blood cell count of 3,500 cells/uL with 85% neutrophils. Synovial alpha-defensin testing is positive. Based on the 2018 ICM criteria, what is the definitive diagnosis?

When converting a standard offset femoral stem to a high offset femoral stem of the exact same neck angle during total hip arthroplasty, what is the expected biomechanical effect on the hip joint?

During a trial reduction for a posterior-stabilized total knee arthroplasty, the surgeon notes significant lateral patellar subluxation. Which of the following component positioning errors is the most likely cause of this maltracking?

A 45-year-old active man with a ceramic-on-ceramic total hip arthroplasty reports an audible squeaking noise from his hip when bending over. Which of the following factors is most strongly associated with the development of this phenomenon?

A 70-year-old woman is 1 year status post a posterior-stabilized total knee arthroplasty. She reports a sensation of giving way, especially when descending stairs. On examination, the knee is completely stable in full extension but exhibits excessive anterior-posterior laxity at 90 degrees of flexion. What is the most likely intraoperative cause of her symptoms?

A 68-year-old woman is undergoing revision total hip arthroplasty for aseptic loosening. Preoperative imaging

demonstrates superior migration of the hip center by 4 cm and medial migration past Kohler's line. Severe osteolysis of the ischium and teardrop is noted. What is the Paprosky classification of this acetabular defect?

A 62-year-old man presents with acute onset of severe knee pain, swelling, and a low-grade fever exactly 3 weeks after an uncomplicated primary total knee arthroplasty. Joint aspiration reveals frankly purulent fluid. What is the most appropriate initial surgical management?

A 55-year-old woman with a metal-on-metal total hip arthroplasty presents with new-onset groin pain and a palpable soft tissue mass. Radiographs show well-fixed components.

Metal artifact reduction sequence (MARS) MRI reveals a large cystic fluid collection. What histologic finding is most characteristic of this condition?

Six months after a posterior-stabilized total knee arthroplasty, a patient reports a painful catching and popping sensation at the anterior knee when extending from a flexed position. The catch typically occurs around 30 to 45 degrees of flexion. What is the most definitive surgical management for this condition if conservative measures fail?

During revision total hip arthroplasty for a massive acetabular defect, the surgeon evaluates the remaining bone and notes that the superior hemipelvis moves completely independently from the inferior hemipelvis upon applied stress. Which of the following is an essential biomechanical requirement when reconstructing this specific defect?

A patient presents with lateral patellar subluxation following a primary total knee arthroplasty. Which of the following component malpositions is the most likely cause?