3. Adult Reconstruction (Hip & Knee) MCQs

A 65-year-old male with a 5-year history of a primary total hip arthroplasty presents with 4 days of acute severe hip pain, fevers, and chills following a dental extraction. Radiographs show well-fixed implants without lucencies. Aspiration yields 65,000 WBC/uL with 95% neutrophils. What is the most appropriate initial surgical management?

A 70-year-old female complains of persistent pain 2 years following a total knee arthroplasty. Aspiration yields synovial fluid with 2,500 WBC/uL and 75% PMNs. Serum CRP is 12 mg/L. Which of the following synovial fluid biomarkers offers the highest specificity for confirming a chronic periprosthetic joint infection?

During the workup of a painful total knee arthroplasty, a synovial fluid sample is sent for alpha-defensin testing. What specific cellular process does the presence of alpha-defensin primarily reflect in the context of periprosthetic joint infection (PJI)?

A 68-year-old female presents with an acutely painful total hip arthroplasty 14 days post-operatively. Her vitals are stable, but the wound is actively draining purulent fluid. Radiographs show well-fixed components. According to current guidelines, what is the most critical indication that supports a Debridement, Antibiotics, and Implant Retention (DAIR) procedure over a 2-stage revision?

During a revision total hip arthroplasty for a suspected chronic periprosthetic joint infection, the removed components undergo sonication in the microbiology lab. What is the primary purpose of utilizing sonication in this scenario?

A 65-year-old male presents with acute onset of severe right knee pain, swelling, and erythema 2 weeks after an uncomplicated primary total knee arthroplasty (TKA). Joint aspiration yields 45,000 WBC/uL with 92% neutrophils, and the implant appears well-fixed on radiographs. What is the most appropriate initial surgical management?

A 68-year-old man who underwent a total knee arthroplasty 2 years ago presents with new-onset knee pain. Aspiration of the knee yields synovial fluid. Which of the following synovial fluid analysis results is most predictive of the absence of a prosthetic joint infection?

During the tibial bone resection in a total knee arthroplasty, the surgeon must be mindful of the common peroneal nerve. At the level of the tibial resection, the common peroneal nerve is anatomically protected by lying superficial to which of the following structures?

During the tibial bone resection in a total knee arthroplasty, the common peroneal nerve is at risk of injury. At this specific level, which of the following structures lies directly deep to the common peroneal nerve, thereby offering it some protection?

A 55-year-old man undergoes an uncomplicated primary total hip arthroplasty. Three years later, he presents complaining of a high-pitched "squeaking" sound from his hip during certain movements. Which bearing surface combination was most likely utilized?

A 65-year-old woman presents with painful catching and a palpable 'clunk' in her knee when extending from a flexed position, one year after a posterior-stabilized total knee arthroplasty. Where is the fibrotic nodule responsible for this condition typically located?

Aseptic loosening is the most common mode of failure in total joint arthroplasty and is primarily driven by an inflammatory response to particulate wear debris. Which cell type is the primary effector of the subsequent osteolysis?

A 55-year-old woman with a history of a metal-on-metal total hip arthroplasty 10 years ago presents with groin pain and a palpable mass. Serum cobalt and chromium levels are significantly elevated. MRI with MARS shows a large cystic mass communicating with the joint. What is the predominant histologic finding expected in the periprosthetic tissue?

A 68-year-old female experiences her third posterior dislocation following a primary total hip arthroplasty. CT evaluation demonstrates the acetabular component is placed in 35 degrees of inclination and 5 degrees of anteversion. The femoral stem is in 15 degrees of anteversion. What is the most appropriate surgical intervention?

A 65-year-old female is 3 weeks post-operative from a primary total knee arthroplasty (TKA). She reports a sudden pop and is now unable to perform a straight leg raise. Examination reveals a high-riding patella and a palpable defect at the tibial tubercle. Direct repair is attempted but the tissue is highly friable. What is the best salvage option?

A 70-year-old woman experiences recurrent posterior dislocations following a posterior approach total hip arthroplasty. Imaging shows the acetabular cup at 45 degrees of abduction and 20 degrees of anteversion, and the stem at 15 degrees of anteversion. The abductor mechanism is intact. What is the most appropriate surgical intervention?

A 65-year-old man presents 3 weeks after a primary total knee arthroplasty with sudden onset severe pain, swelling, and erythema of the knee. Joint aspiration yields 65,000 WBC/hpf with 92% PMNs. What is the most appropriate surgical management?

The use of highly cross-linked polyethylene (HXLPE) in total hip arthroplasty significantly reduces volumetric wear. Which specific mechanism is primarily responsible for this reduction in wear?

A 65-year-old man presents with acute onset of knee pain, swelling, and erythema 3 weeks after a primary total knee arthroplasty. Aspiration yields synovial fluid with 45,000 WBC/mcL and 92% polymorphonuclear neutrophils. Which of the following is the most appropriate initial surgical management?