Total Hip Arthroplasty (THA) MCQs

In metal-on-metal hip resurfacing, which of the following component malpositionings most significantly increases the risk of accelerated edge-loading and elevated serum metal ions?

Systemic toxicity from cobalt and chromium ions following metal-on-metal hip resurfacing can manifest with which of the following classic constellations of symptoms?

Which of the following patients is considered the ideal candidate for a metal-on-metal hip resurfacing?

What is the primary fluid lubrication regime under which a properly positioned metal-on-metal hip resurfacing bearing ideally operates during the steady-state phase?

Which surgical technical error is most highly associated with an early femoral neck fracture following a metal-on-metal hip resurfacing?

Which design feature of a metal-on-metal hip resurfacing relies on establishing an 'equatorial bearing' and is critical for generating optimal fluid-film lubrication?

A 55-year-old man presents with groin pain 4 years after a metal-on-metal (MOM) hip resurfacing. Blood work reveals elevated serum metal ions. According to major regulatory guidelines, serum cobalt levels above which of the following thresholds strongly indicate a poorly functioning bearing and warrant advanced imaging?

Metal-on-metal (MOM) hip resurfacing is considered for young, active patients with osteoarthritis, but stringent patient selection is required. Which of the following conditions is considered an absolute contraindication for a MOM hip resurfacing?

A 65-year-old female undergoes a primary total hip arthroplasty via a posterior approach. Six weeks later, she experiences a posterior dislocation while sitting in a low chair. Which of the following component malpositions most likely contributed to this specific type of instability?

When performing a posterior approach to the knee for a PCL avulsion, the surgeon makes a lazy S-shaped incision and identifies the neurovascular structures. Which of the following statements accurately describes the anatomical relationship of the major neurovascular structures in the popliteal fossa, as relevant to this approach?

The patient's radiographs show radiolucent lines at the bone–cement interface located circumferentially around all seven DeLee and Charnley zones in the acetabulum and lucencies in all seven Gruen zones around the femoral component. Based on the Harris and Barrack grading system for cement mantle quality, what grade would most accurately describe the femoral component's cement mantle in this scenario?

The patient requires an extended trochanteric osteotomy (ETO) for cement removal. When consenting the patient for this procedure, which of the following complications is *specifically* increased or unique to the use of an ETO compared to a standard revision THA without osteotomy?

During surgical planning for this patient's revision THA, the candidate states a preference for uncemented components. Given the need for an ETO to remove distal cement, what is the primary rationale for choosing an uncemented femoral implant in this specific scenario?

A 72-year-old male experiences his third posterior dislocation of a primary total hip arthroplasty initially performed via a posterior approach. Radiographs demonstrate that the acetabular component is well-fixed but positioned in 45 degrees of inclination and 5 degrees of retroversion. What is the most appropriate surgical strategy to establish stability?

A 55-year-old active male underwent a primary total hip arthroplasty with a ceramic-on-ceramic articulation 3 years ago. He now complains of a loud, audible squeaking sound from his hip during gait, though he denies pain. Radiographs demonstrate a well-fixed femoral stem and an acetabular cup positioned in 65 degrees of inclination. What is the primary mechanical cause of the squeaking?

A 72-year-old female presents with her third posterior dislocation of her total hip arthroplasty. A review of her postoperative CT scan evaluating component position is ordered. Which of the following cup positions is the most likely culprit for recurrent posterior instability?

A 70-year-old female undergoes a revision total hip arthroplasty via a posterior approach. Intraoperatively, the well-fixed acetabular component is noted to be retroverted by 10 degrees, but removal would result in massive bone loss. If the cup is retained, which adjustment to the modular femoral stem would best compensate for this acetabular malposition to prevent posterior instability?

In an oral viva setting, an examiner presents a radiograph of a healthy 75-year-old female with a displaced femoral neck fracture and asks the candidate to justify their choice of total hip arthroplasty (THA) over hemiarthroplasty. Which of the following responses demonstrates the best grasp of current orthopedic literature?

A candidate is asked to describe the surgical approach for a total hip arthroplasty in a dysplastic hip. The examiner repeatedly interrupts the candidate's description of the posterior approach to ask about the internervous plane. How should the candidate handle this?

In your oral examination, you are discussing a case from your collection where a patient experienced a major complication (e.g., foot drop after THA). The examiner presses you on what went wrong. What is the most successful tactic for defending your case?