3. Adult Reconstruction (Hip & Knee) MCQs

During a total knee arthroplasty (TKA), the surgeon aims to optimize patellofemoral tracking. Which of the following femoral component positioning errors is most likely to cause patellar maltracking and lateral subluxation?

A 72-year-old active female undergoes evaluation for hip pain 8 years after a primary total hip arthroplasty (THA).

Imaging reveals eccentric wear and significant osteolysis. During the revision surgery, bearing surface selection is discussed. Which of the following THA bearing surface combinations boasts the lowest volumetric wear rate, but carries a unique risk of catastrophic brittle failure?

During a measured resection primary total knee arthroplasty (TKA) for an osteoarthritic varus knee, the surgeon utilizes spacer blocks to assess the gaps. The knee is found to be excessively tight in full extension, but perfectly balanced in 90 degrees of flexion. Which of the following isolated bone resection steps is the most appropriate next maneuver to achieve a balanced knee?

A 65-year-old active female presents to the emergency department after a mechanical fall. She complains of severe right groin pain and inability to bear weight. A representative radiograph of her injury is shown below.

Assuming the image demonstrates a displaced (Garden IV) femoral neck fracture, which of the following is the most appropriate surgical intervention to maximize her functional outcome and minimize her lifetime revision rate?

During a primary posterior-stabilized total knee arthroplasty, after making the standard bone cuts and placing trial components, the surgeon assesses the gap kinematics. The knee is perfectly balanced and symmetrical in full extension. However, it is symmetrically tight at 90 degrees of flexion. Which of the following is the most appropriate intraoperative adjustment to achieve gap balance?

During a measured resection posterior-stabilized total knee arthroplasty, the surgeon checks the trial components and notes that the knee is perfectly balanced in full extension but is excessively tight in 90 degrees of flexion. Which of the following interventions will best address this isolated tight flexion gap?

A 55-year-old active female who underwent a ceramic-on-ceramic total hip arthroplasty 2 years ago presents with a loud, audible squeaking during hip flexion. Which of the following is most strongly associated with this complication?

A 68-year-old male presents with insidious onset of anterior thigh pain five years after a primary total hip arthroplasty using a dual-taper modular femoral stem and a cobalt-chromium head. Radiographs are unremarkable. Aseptic joint aspiration reveals cloudy fluid with a normal nucleated cell count but elevated cobalt and chromium ions. During revision surgery, black necrotic debris is noted exclusively around the head-neck junction.

What is the primary underlying electrochemical mechanism responsible for this finding?

A 68-year-old female presents with persistent anterior knee pain three years following a primary Posterior Stabilized (PS) Total Knee Arthroplasty.

She reports a distinct 'catching' and 'popping' sensation as her knee extends from roughly 40 degrees of flexion to full extension. What is the most likely pathophysiological cause of this phenomenon?

In the context of total hip arthroplasty (THA), the phenomenon of 'stripe wear' is a localized area of increased wear and surface roughness caused by edge loading during transient microseparation. This is most characteristic of which bearing surface combination?

During a primary total knee arthroplasty (TKA), the surgeon inadvertently places the femoral component in internal rotation relative to the surgical epicondylar axis. This specific technical error is most likely to result in which of the following postoperative issues?

In total hip arthroplasty (THA), which of the following bearing surface combinations is known to have the lowest volumetric wear rate, but carries unique risks of catastrophic squeaking and component fracture?

A 68-year-old female is evaluated 6 weeks after an uncomplicated primary total knee arthroplasty (TKA). Despite dedicated daily physical therapy, her range of motion remains stalled at 10 to 70 degrees. Radiographs reveal well-fixed and well-aligned components without signs of loosening. What is the most appropriate next step in her management?

You are reviewing the wear characteristics of total hip arthroplasty (THA) bearing surfaces.

The introduction of highly cross-linked polyethylene (HXLPE) has significantly reduced volumetric wear rates. Which of the following processing steps in HXLPE manufacturing is directly responsible for a decrease in the material's fracture toughness?

During a measured resection primary Total Knee Arthroplasty (TKA), the surgeon utilizes trial components and notes the knee is perfectly balanced in full extension but excessively tight in flexion.

Which of the following maneuvers is the most appropriate next step to achieve a balanced knee?

A 55-year-old active female undergoes a primary total hip arthroplasty. The surgeon opts for a ceramic-on-ceramic bearing surface to maximize longevity. Which of the following complications is uniquely associated with this specific bearing couple compared to metal-on-polyethylene?

During a posterior-stabilized total knee arthroplasty, the surgeon evaluates the gaps using trial components.

The assessment demonstrates that the extension gap is perfectly balanced and rectangular, but the flexion gap is excessively tight. What is the most appropriate isolated next step to balance the knee?

A 65-year-old male who underwent a cementless total hip arthroplasty (THA) 15 years ago presents with new-onset thigh pain. Radiographs reveal eccentric positioning of the femoral head within the acetabular shell and large retroacetabular and proximal femoral radiolucencies.

What is the primary biological mediator released by macrophages that directly stimulates osteoclastogenesis and is responsible for the observed bone loss?