1. General Principles & Basic Science MCQs

Mixing titanium and stainless steel in surgical implants can lead to galvanic corrosion. Which of the following factors primarily determines the severity of corrosion between these two metals in vivo?

A 68-year-old man presents with increasing hat size, bowing of the tibiae, and hearing loss. Radiographs show mixed lytic and sclerotic lesions. Which of the following serum parameters is most likely to be isolated and significantly elevated?

A 35-year-old farmer sustains a severe open tibia fracture after being run over by agricultural machinery. In addition to standard broad-spectrum coverage, which antibiotic is classically recommended to specifically cover for Clostridium species due to soil contamination?

During a prolonged lower extremity orthopedic surgery, a pneumatic tourniquet is utilized. What is the generally accepted maximum safe continuous tourniquet inflation time before a deflation 'breathe' period is required?

When comparing various orthopedic implant materials, which of the following possesses a modulus of elasticity that most closely approximates that of human cortical bone, thereby reducing stress shielding?

A 5-year-old boy sustains a completely displaced extension-type supracondylar humerus fracture. On examination, he is unable to make an 'A-OK' sign. Which nerve is most likely injured?

Which of the following correctly describes the cellular mechanism of action of nitrogen-containing bisphosphonates such as alendronate?

During the Smith-Petersen (anterior) approach to the hip, an internervous plane is utilized to protect dynamic stabilizers. Which of the following defines the superficial internervous plane of this approach?

Which of the following organisms is most notoriously associated with early and robust biofilm formation on orthopedic implants, frequently resulting in indolent, chronic periprosthetic joint infections?

In orthopedic hardware selection, mixing certain metals can lead to destructive galvanic corrosion. Which of the following implant combinations in direct physical contact poses the highest risk for severe galvanic corrosion?

Following a closed midshaft humerus fracture, a patient demonstrates a profound radial nerve palsy. An electromyogram (EMG) performed at 4 weeks demonstrates abundant fibrillation potentials but no voluntary motor unit action potentials. What is the minimum grade of nerve injury sustained according to Seddon's classification?

Venous thromboembolism (VTE) prophylaxis is a standard of care following major joint arthroplasty. Which of the following oral anticoagulants exerts its effect by acting as a direct thrombin inhibitor?

When a diaphyseal fracture is fixed with a rigid dynamic compression plate (DCP) resulting in absolute stability and less than 2% interfragmentary strain, which specific process of bone healing predominates?

A surgeon applies a long, locked bridging plate to a highly comminuted midshaft femur fracture, leaving the fracture site undisturbed. This specific fixation construct relies on which biomechanical principle to promote healing?

Denosumab is an antiresorptive medication used for treating severe osteoporosis. What is its specific molecular mechanism of action?

Bone morphogenetic proteins (BMPs) induce osteogenesis by signaling through transmembrane receptors. Which intracellular signaling pathway is primarily activated by BMPs to promote osteoblast differentiation?

Teriparatide is an anabolic pharmacological agent utilized in the treatment of severe osteoporosis. What is its specific mechanism of action and the maximum FDA-approved duration for continuous lifetime use?