3. Adult Reconstruction (Hip & Knee) MCQs

A 65-year-old male with a metal-on-polyethylene total hip arthroplasty (titanium stem, cobalt-chromium head) performed 7 years ago presents with worsening groin pain. Inflammatory markers are within normal limits. MRI with metal artifact reduction sequence (MARS) shows a large, mixed solid and cystic mass adjacent to the joint. Serum cobalt levels are significantly elevated, while chromium levels are normal. What is the most likely etiology of this presentation?

Highly cross-linked polyethylene (HXLPE) has significantly reduced the incidence of wear-related osteolysis in total hip arthroplasty. During the manufacturing process, irradiation generates free radicals that must be extinguished to prevent in vivo oxidation. Which of the following accurately describes the biomechanical consequence of using a remelting process rather than an annealing process to eliminate these free radicals?

A 40-year-old female with Crowe Type IV developmental dysplasia of the hip (DDH) is undergoing a complex total hip arthroplasty. The femoral head is completely dislocated and located superior to the true acetabulum. The surgeon plans a subtrochanteric shortening osteotomy. Which of the following nerve injuries is the primary reason for performing this osteotomy when attempting to reduce the hip into the true acetabulum?

A 60-year-old male presents with persistent hip pain and erythema 4 weeks following a primary total hip arthroplasty. An aspiration of the hip is performed. Which of the following synovial fluid analysis results is most diagnostic of an acute periprosthetic joint infection in this specific timeframe?

A 55-year-old male with a metal-on-polyethylene total hip arthroplasty utilizing a large 36 mm cobalt-chrome head on a titanium stem presents at 7 years postoperatively with vague groin pain. Radiographs reveal well-fixed components. A MARS MRI demonstrates a large cystic pseudotumor. What is the primary mechanism of failure?

An 82-year-old female sustains a fall and presents with a periprosthetic femur fracture around a cemented total hip arthroplasty. Radiographs reveal a fracture at the level of the stem tip with evidence of cement mantle fracturing and 2 cm of stem subsidence. Proximal and distal bone stock is adequate. What is the most appropriate surgical management?

A surgeon is evaluating operative variables to minimize dislocation rates after primary THA using a conventional posterior approach. Based on current orthopedic literature, which of the following surgical techniques most significantly reduces the rate of early postoperative posterior dislocation?

A 59-year-old male presents with deep thigh pain 12 years after receiving a cementless THA. Radiographs reveal progressive expansile osteolysis with extensive endosteal scalloping around the femoral stem, though the stem itself shows no subsidence and appears stable. What is the primary biologic initiator of this periprosthetic osteolysis?

A 52-year-old male with severe psoriatic arthritis on adalimumab (Humira) is scheduled for an elective total knee arthroplasty. According to current ACR/AAHKS guidelines, how should his biologic therapy be managed perioperatively?

Which of the following radiographic findings is most characteristic of psoriatic arthritis as opposed to rheumatoid arthritis?

A patient with a long-standing history of psoriasis presents with severe, deforming joint destruction of the hands resulting in "telescoping" fingers. Which severe subtype of psoriatic arthritis does this clinical picture represent?

A 38-year-old female presents with mechanical catching and recurrent effusions in her knee. Imaging and gross pathology are shown.

What is the definitive treatment for this symptomatic primary lesion?

A 50-year-old female with severe psoriatic arthritis is scheduled for a total knee arthroplasty (TKA). She is currently managed with secukinumab. What is the mechanism of action of this biologic agent?

When comparing outcomes of total joint arthroplasty in patients with psoriatic arthritis to those with primary osteoarthritis, patients with psoriatic arthritis are at an increased risk for which of the following complications?

A 38-year-old male presents with characteristic 'pencil-in-cup' deformities on hand radiographs. Which pathophysiologic process best explains this radiographic appearance in psoriatic arthritis?

A 52-year-old female diagnosed with Lipoma Arborescens of the suprapatellar pouch continues to have mechanical symptoms and massive effusions despite intra-articular corticosteroid injections. What is the recommended treatment?

A 52-year-old male with psoriatic arthritis is scheduled for a total hip arthroplasty. He is currently well-controlled on adalimumab (a TNF-alpha inhibitor). According to current ACR/AAHKS guidelines, what is the most appropriate perioperative management of his biologic medication?

Compared to patients with primary osteoarthritis, patients with psoriatic arthritis undergoing primary total knee arthroplasty have a significantly higher risk of which of the following postoperative complications?

When planning total knee arthroplasty for a patient with advanced psoriatic arthritis, the surgeon must counsel the patient on which of the following elevated post-operative risks compared to primary osteoarthritis?

A 50-year-old male presents with a painless, slowly enlarging, boggy swelling of the left knee. MRI demonstrates a frond-like synovial mass with signal intensity identical to subcutaneous fat on all sequences.

What is the best initial definitive surgical treatment for a highly symptomatic patient?