3. Adult Reconstruction (Hip & Knee) MCQs

Which of the following bearing surface combinations in total hip arthroplasty is most closely associated with the phenomenon of "stripe wear"?

A 72-year-old man sustains a periprosthetic femur fracture around a cemented femoral stem. Radiographs demonstrate a fracture around the tip of the stem, with the stem remaining well-fixed and no cement mantle fracture. According to the Vancouver classification, what is the most appropriate surgical management?

A 45-year-old man with a metal-on-metal total hip arthroplasty presents with progressive groin pain and swelling. Blood metal ion testing shows elevated cobalt and chromium levels. MARS MRI demonstrates a large cystic mass communicating with the joint. What histologic finding is most characteristic of this condition?

A 30-year-old woman is diagnosed with Ficat stage II avascular necrosis (AVN) of the right femoral head. Radiographs show mixed sclerosis and cysts without subchondral collapse (crescent sign). What is the most appropriate initial surgical intervention if conservative management fails?

During templating for a total hip arthroplasty, increasing the femoral head neck length (e.g., using a +4 mm head instead of a +0 mm head) without changing the stem size or position will have what effect on hip biomechanics?

A 55-year-old man presents with an acute periprosthetic joint infection 2 weeks after a total hip arthroplasty. He is systemically well, and the implant is well-fixed. According to current guidelines, what is the most appropriate surgical treatment?

A 75-year-old woman with osteoporosis undergoes an uncomplicated cementless total hip arthroplasty. Six weeks postoperatively, she presents with severe thigh pain and inability to bear weight. Radiographs show a displaced, spiral fracture of the proximal femur originating at the distal tip of the stem. The stem has subsided by 2 cm. What is the appropriate Vancouver classification and treatment?

What is the primary advantage of utilizing a dual mobility articulation in total hip arthroplasty?

A 60-year-old male with a history of bilateral total hip arthroplasties presents with new-onset squeaking from his left hip during ambulation. He has a ceramic-on-ceramic bearing on the left. Radiographs reveal a well-fixed cup with an abduction angle of 65 degrees. What is the most likely cause of the squeaking?

In evaluating a painful total hip arthroplasty, an elevated synovial fluid alpha-defensin test is highly specific for:

A 58-year-old man presents with persistent lateral hip pain and a positive Trendelenburg sign one year after a total hip arthroplasty via a direct lateral (Hardinge) approach. MRI demonstrates a complete avulsion of the anterior third of the gluteus medius and minimus tendons without significant fatty infiltration. Management should consist of:

A 62-year-old man who underwent a metal-on-polyethylene total hip arthroplasty 5 years ago presents with spontaneous groin pain. Radiographs are unremarkable. Metal artifact reduction sequence (MARS) MRI shows a solid/cystic mass in the iliopsoas bursa. Serum cobalt levels are 8.5 ppb and chromium levels are 1.2 ppb. What is the most likely etiology?

The "safe zone" for acetabular cup placement in total hip arthroplasty, originally described by Lewinnek, suggests which of the following target angles to minimize dislocation risk?

A 65-year-old man presents with equivocal signs of periprosthetic joint infection 3 years after THA. Synovial fluid aspiration yields a WBC count of 2,500/uL with 75% PMNs. Which of the following synovial fluid biomarkers provides the highest specificity for diagnosing a periprosthetic joint infection in this scenario?

A 55-year-old man with a metal-on-polyethylene total hip arthroplasty presents with new-onset groin pain 6 years postoperatively. Radiographs show a well-fixed stem and cup. Serum cobalt is 12 ppb and chromium is 1.5 ppb. What is the most likely etiology of his pain?

A 65-year-old man presents with chronic pain 3 years after a total hip arthroplasty. His CRP is 45 mg/L and ESR is 50 mm/hr. Hip aspiration yields cloudy fluid with 4,500 WBCs/µL and 85% polymorphonuclear leukocytes. According to the 2018 ICM criteria, what is the most appropriate management?

A 78-year-old woman falls and sustains a periprosthetic femur fracture 8 years after a THA. Radiographs show a fracture around the distal aspect of the femoral stem. The stem is subsided by 1.5 cm and appears loose, but the medial and lateral diaphyseal cortices have excellent bone stock. What is the Vancouver classification and appropriate treatment?

A 32-year-old man presents with a 4-month history of groin pain. Radiographs demonstrate patchy sclerosis in the superolateral femoral head, but the contour of the head is perfectly spherical with no crescent sign. MRI confirms a localized area of osteonecrosis. What is the most appropriate initial surgical intervention?

A 45-year-old active man undergoes a total hip arthroplasty (THA). The surgeon selects a ceramic-on-ceramic bearing surface. Which of the following is a recognized unique complication associated with this specific bearing choice?