3. Adult Reconstruction (Hip & Knee) MCQs

A 72-year-old female presents with chronic right hip pain beginning 2 years following an uncomplicated total hip arthroplasty. Her ESR is 45 mm/hr and CRP is 2.5 mg/dL. A fluoroscopically guided hip aspiration yields synovial fluid with a white blood cell count of 4,500 cells/µL with 85% polymorphonuclear neutrophils. An alpha-defensin immunoassay is positive. According to the MSIS/ICM criteria, what is the most appropriate next surgical step in management?

A 60-year-old male presents with isolated medial compartment knee osteoarthritis and is being evaluated for a unicompartmental knee arthroplasty (UKA). According to classical indications (Kozinn and Scott), which of the following is considered an absolute contraindication to a fixed-bearing UKA?

A 65-year-old female is 6 months status post a posterior-stabilized total knee arthroplasty (TKA). She presents complaining of a painful "catching" or "popping" sensation at the anterior aspect of her knee specifically when she actively extends her knee from a flexed position. What is the most likely etiology of this complication?

A 65-year-old active male underwent a total hip arthroplasty utilizing a ceramic-on-ceramic bearing surface. Two years later, he complains of an audible 'squeaking' sound from his hip during ambulation. Which of the following factors is most strongly associated with this complication?

A 68-year-old female with severe valgus osteoarthritis of the knee undergoes a total knee arthroplasty with an extensive lateral soft tissue release.

Postoperatively, she exhibits a foot drop. Which structure is most likely compromised?

A 65-year-old female presents with a painful total knee arthroplasty 2 years post-operatively. Synovial fluid analysis shows a WBC count of 3,500 cells/µL with 75% PMNs. The alpha-defensin immunoassay is positive. What is the primary cellular source of alpha-defensin in this context?

A 55-year-old active male underwent a total hip arthroplasty using a ceramic-on-ceramic bearing.

He presents 2 years post-operatively complaining of a squeaking noise from the hip during walking. Which of the following component malpositions is most commonly associated with this phenomenon?

During a primary total knee arthroplasty using a measured resection technique, the surgeon utilizes trial components and finds that the knee is symmetric and balanced in full extension, but perfectly symmetric and overly tight in 90 degrees of flexion. Which of the following adjustments is the most appropriate to balance the knee?

A 70-year-old patient returns to the emergency department three weeks following an uncomplicated primary total hip arthroplasty (posterior approach) with complaints of sudden severe hip pain. Radiographs demonstrate a posterior dislocation of the femoral component. Closed reduction is successful. In evaluating the cause of this early instability, which of the following component malpositions is the most common etiology for posterior dislocation in THA?

In kinematic alignment for Total Knee Arthroplasty (TKA), the primary objective is to align the components to the:

The retrograde blood supply to the proximal pole of the scaphoid, which places it at high risk for avascular necrosis following fracture, is primarily derived from branches of which artery?

A 68-year-old female presents with recurrent posterior dislocations following a primary Total Hip Arthroplasty performed via a posterior approach. Intraoperative evaluation during revision surgery reveals a well-fixed femoral component with appropriate version and offset. The acetabular component is well-fixed and positioned in 45 degrees of inclination and 5 degrees of retroversion. Which of the following is the most appropriate surgical intervention?

During a primary Total Knee Arthroplasty (TKA), after the preliminary bony cuts have been made and trial components are placed, the surgeon evaluates the joint spaces.

The surgeon finds that the extension gap is excessively tight, while the flexion gap is perfectly balanced and stable. Which of the following is the most appropriate next step to balance the knee?

A 65-year-old male presents with groin pain and swelling 5 years after an uncomplicated total hip arthroplasty utilizing a dual-taper modular titanium stem and a large diameter cobalt-chromium femoral head. Aspiration yields cloudy fluid with negative cultures. Blood work shows elevated serum cobalt levels with normal chromium levels. What is the primary mechanism of failure?

During a total knee arthroplasty (TKA) for a severe varus deformity, the surgeon resects the distal femur and proximal tibia. With spacer blocks inserted, the knee remains tight medially in both flexion and extension. To balance the gaps symmetrically, which structure should be released next?

In modern total hip arthroplasty, the use of highly cross-linked polyethylene (HXLPE) compared to conventional ultra-high-molecular-weight polyethylene is associated with which of the following?

A 65-year-old man presents with anterior knee pain and a feeling of instability during stair climbing 1 year after a primary total knee arthroplasty.

Examination reveals a lateral patellar tilt. CT scan is performed to evaluate component rotation. Which of the following errors in component positioning is most likely responsible for his symptoms?

A 60-year-old highly active male undergoes a total hip arthroplasty using a ceramic-on-ceramic (CoC) bearing surface.

Two years postoperatively, he complains of a highly audible 'squeaking' sound emanating from his hip during ambulation. What is the most widely recognized biomechanical cause for squeaking in CoC articulations?

A 68-year-old female is undergoing a primary total knee arthroplasty for a severe fixed valgus deformity.

Intraoperatively, after the standard bone cuts, the trial components are placed, and the lateral side is found to be symmetrically tight in BOTH 90 degrees of flexion and full extension. Which lateral soft-tissue structure is the primary restraint to lateral opening in both flexion and extension, and should be released to balance the knee?

A 68-year-old female undergoes a total hip arthroplasty via a posterior approach. She subsequently sustains a posterior dislocation. Which of the following component positions most increases the risk of posterior dislocation?