1. General Principles & Basic Science MCQs

A surgeon performs a THA using the direct anterior approach (DAA). This approach exploits a true internervous plane between which two muscles?

During a direct anterior (Smith-Petersen) approach to the hip for a primary total hip arthroplasty, the superficial surgical dissection passes between which of the following internervous muscle intervals?

Following a total hip arthroplasty via a posterior approach, a patient exhibits a foot drop and inability to extend the great toe, but plantar flexion and foot inversion remain intact. Which specific nerve division is most likely injured?

Highly cross-linked polyethylene was introduced to drastically reduce wear rates in total joint arthroplasty. Which of the following thermal processing steps is specifically performed to eliminate residual free radicals, but results in a slight decrease in the material's mechanical yield strength?

When performing a primary total hip arthroplasty via the direct anterior (Smith-Petersen) approach, the superficial internervous plane lies between muscles supplied by which of the following nerves?

Mechanically assisted crevice corrosion (MACC), or trunnionosis, is most frequently associated with which of the following total hip arthroplasty component combinations?

A 66-year-old man presents with new-onset groin pain 6 years after a primary total hip arthroplasty using a metal-on-polyethylene bearing. Serum metal ion testing reveals a cobalt level of 12 ppb and a chromium level of 1.5 ppb. Which of the following implant characteristics most increases the risk of this condition?

A surgeon utilizing the direct anterior (Smith-Petersen) approach for total hip arthroplasty enters the hip joint through a specific internervous plane superficially. This plane lies between which two muscles?

In the process of aseptic loosening due to particulate wear debris, macrophages phagocytose the particles and subsequently release cytokines that drive osteoclastogenesis. Which of the following cytokines is a primary mediator of this process?

A 50-year-old male with ankylosing spondylitis is scheduled for a total hip arthroplasty. To minimize his high risk of heterotopic ossification, which prophylactic regimen is most strongly supported by the literature?

A patient undergoes a complex revision total hip arthroplasty requiring an extended trochanteric osteotomy (ETO). Postoperatively, the ETO goes on to a fibrous nonunion with significant proximal migration. What is the most predictable clinical consequence?

During a TKA for severe varus deformity, standard bone cuts have been made, and the deep medial collateral ligament (MCL) has been released. The knee remains tight medially in both flexion and extension. What is the next most appropriate step in the soft tissue release sequence?

A 70-year-old man presents with a chronic prosthetic joint infection 2 years after THA. Aspiration grows methicillin-resistant Staphylococcus aureus (MRSA). You plan a two-stage exchange. What antibiotic should be predominantly mixed into the temporary polymethylmethacrylate (PMMA) spacer?

During a direct anterior approach for a total hip arthroplasty, the patient sustains a nerve injury resulting in localized numbness over the anterolateral aspect of the thigh. Which nerve was most likely injured?

The introduction of highly cross-linked polyethylene in total hip arthroplasty has significantly reduced volumetric wear rates. What mechanical trade-off results from the irradiation process used to cross-link the polyethylene?

In the production of highly cross-linked polyethylene for arthroplasty, what is the primary biomechanical consequence of remelting the plastic after irradiation?

Highly cross-linked polyethylene (HXLPE) is used in modern arthroplasty to reduce volumetric wear. During its manufacturing, irradiation is typically followed by a thermal treatment such as remelting or annealing. What is the primary purpose of the remelting process?

During a direct anterior approach for total hip arthroplasty, the surgeon develops the superficial surgical interval. Between which two nerve territories does this true internervous plane lie?

When utilizing the direct anterior approach for total hip arthroplasty, the internervous plane is established between muscles supplied by which of the following pairs of nerves?

Highly cross-linked polyethylene is utilized in THA to reduce wear rates. What is the primary purpose of the post-irradiation melting or annealing process during its manufacture?