1. General Principles & Basic Science MCQs

When a diaphyseal fracture is treated with an interfragmentary lag screw and a neutralization plate to achieve absolute stability, which mode of bone healing predominates?

Which of the following common orthopedic implant metals has a modulus of elasticity that most closely approximates that of cortical bone?

What is the primary mechanism by which Denosumab inhibits bone resorption in the treatment of osteoporosis?

In the pathogenesis of periprosthetic joint infections, which phase of biofilm formation is characterized by the irreversible attachment of bacteria to the implant surface mediated by exopolysaccharides?

According to the Sunderland classification of nerve injuries, a third-degree injury is characterized by the disruption of which of the following structures?

A 55-year-old male presents with acute pain, swelling, and erythema in his first metatarsophalangeal joint. Joint aspiration yields synovial fluid with a WBC count of 35,000/µL. Under polarized light microscopy, what type of crystals are typically seen in this condition?

Absolute stability constructs, such as a compression plate for a transverse radius fracture, promote which type of bone healing?

Galvanic corrosion in orthopedic implants is most likely to occur under which of the following circumstances?

Demineralized bone matrix (DBM) is widely used in orthopedic surgery as a bone graft substitute. Which of the following properties does DBM inherently possess?

During the normal human gait cycle, which of the following muscles undergoes primarily eccentric contraction at heel strike to prevent the clinical phenomenon of 'foot slap'?

In Sunderland's classification of peripheral nerve injuries, a third-degree injury is characterized by the disruption of which of the following microscopic structures while leaving the perineurium intact?

A 7-year-old child presents with gingival bleeding, petechiae, and diffuse bone pain. Radiographs reveal generalized osteopenia and widened, dense zones of provisional calcification. The underlying nutritional deficiency impairs bone formation by disrupting which of the following cellular processes?

A 65-year-old man presents with increasing hat size, hearing loss, and bowing of his tibiae. Serum alkaline phosphatase is markedly elevated, but calcium and phosphate are normal. Genetic testing is most likely to reveal a mutation in which of the following genes, known to play a critical role in RANK-NF-kB signaling?

The biological incorporation of a massive cortical bone allograft used in tumor reconstruction relies primarily on the process of 'creeping substitution'. Which of the following sequences best characterizes this process?

A new biomarker test for periprosthetic joint infection is evaluated in a study of 1000 patients. The study includes 100 patients with true infections and 900 without. The new test correctly identifies 80 true infections and correctly rules out 810 true non-infections. What is the specificity of this new test?

Which of the following statements best describes the primary biomechanical advantage of utilizing a titanium alloy (Ti-6Al-4V) instead of a cobalt-chromium (Co-Cr) alloy for a femoral intramedullary nail?

Within the extracellular matrix of normal articular cartilage, which of the following molecules acts as the central unbranched backbone to which multiple aggrecan monomers attach via link proteins to form massive proteoglycan aggregates?

Which of the following molecules is primarily responsible for the boundary lubrication mechanism that protects the articular cartilage surfaces when a joint is subjected to high loads with low relative motion?

Following a primary surgical repair of a zone II flexor tendon injury, at what time point postoperatively does the biomechanical strength of the repair typically reach its lowest point?