3. Adult Reconstruction (Hip & Knee) MCQs

During a primary total knee arthroplasty, trial components are inserted. Evaluation reveals that the knee is perfectly stable and balanced in full extension, but demonstrates excessive medial and lateral laxity at 90 degrees of flexion. What is the most appropriate surgical adjustment to correct this imbalance?

A 65-year-old female undergoes a right total hip arthroplasty via a posterior approach. Postoperatively in the recovery room, she demonstrates a dense foot drop and diminished sensation over the dorsal aspect of her right foot and lateral leg.

Which of the following intraoperative factors is most commonly responsible for this specific nerve injury?

A 70-year-old male presents with severe anterior knee pain and a complete inability to actively extend his knee, occurring 3 years after a primary total knee arthroplasty. Imaging confirms a chronic, complete, and retracted patellar tendon rupture.

What is the most reliable reconstructive option given the chronic nature and poor tissue quality?

During the femoral preparation of a primary total knee arthroplasty, the surgeon is utilizing a posterior referencing sizing guide.

The patient's anatomy falls exactly between sizes on the guide. If the surgeon elects to downsize the femoral component, what is the most likely geometric consequence?

During a primary total knee arthroplasty, trial components are placed. The knee is symmetric and balanced in extension, but it is symmetrically tight in 90 degrees of flexion. Which of the following is the most appropriate intraoperative step to balance the knee?

A 78-year-old female presents with thigh pain and inability to bear weight after a mechanical fall. Radiographs demonstrate a periprosthetic femur fracture around the tip of her cemented total hip arthroplasty stem. The stem is grossly loose on imaging, and the proximal femoral bone stock is severely deficient with diaphyseal thinning.

What is the most appropriate surgical management?

A 45-year-old male who underwent a ceramic-on-ceramic total hip arthroplasty 4 years ago complains of a loud squeaking noise from his hip with every step. He denies pain or instability. Which of the following is the most significant risk factor for this phenomenon?

Postoperatively, a patient who underwent a primary total knee arthroplasty complains of anterior knee pain and a feeling of instability. Radiographs demonstrate lateral patellar tilt and subluxation. Which of the following errors during component positioning most likely contributed to this finding?

A 55-year-old female with a metal-on-metal total hip arthroplasty presents with new-onset groin pain and a palpable anterior mass. Laboratory evaluation shows normal CRP and ESR. An MRI with MARS sequencing reveals a large cystic pseudotumor. What is the primary pathophysiology underlying this complication?

A patient undergoes a primary total hip arthroplasty. Postoperative templating reveals that the femoral offset was decreased by 15 mm compared to the contralateral native hip. What is the most likely clinical consequence of this biomechanical alteration?

Revision of a 20-year-old total knee arthroplasty reveals severe destruction of the polyethylene insert. The implant records indicate the polyethylene was sterilized by gamma irradiation in air. Which of the following wear mechanisms is predominantly responsible for this failure?

Six months after a posterior-stabilized total knee arthroplasty, a patient complains of a painful catching sensation in the knee when extending from a flexed position, specifically between 30 and 40 degrees of flexion. What is the most likely etiology?

A 60-year-old patient presents for a 10-year follow-up after receiving a fully porous-coated, extensively fixed cylindrical stem total hip arthroplasty. Radiographs demonstrate excellent distal diaphyseal fixation but severe localized proximal medial bone resorption. The patient is entirely asymptomatic. What is the primary cause of this radiographic finding?

Fourteen days after an elective total hip arthroplasty, a patient returns with a fever of 101.5°F, escalating hip pain, and a draining, erythematous surgical wound. Radiographs show perfectly positioned, well-fixed components. What is the most appropriate initial surgical intervention?

A 68-year-old male is undergoing a total hip arthroplasty. The surgeon plans to use highly cross-linked polyethylene (HXLPE) to reduce wear. Which of the following manufacturing processes is critical to eliminate free radicals generated during the cross-linking process and prevent in vivo oxidative degradation?

During a primary posterior-stabilized total knee arthroplasty, the knee is balanced in extension but is found to be excessively tight in flexion, preventing full range of motion. The extension gap is symmetric and perfectly tensioned. Which of the following is the most appropriate step to correct this kinematic mismatch?

A 78-year-old female sustains a periprosthetic femur fracture around her cementless total hip arthroplasty after a fall. Radiographs demonstrate a fracture around the tip of the stem. The stem is radiographically loose, and there is significant proximal osteolysis with poor bone stock in the proximal metaphysis. Which of the following is the most appropriate management (Vancouver Type B3)?

Which of the following biomechanical changes most effectively decreases the joint reactive force across the hip during a single-leg stance following a total hip arthroplasty?