1. General Principles & Basic Science MCQs

A 72-year-old man undergoes routine blood work which reveals an isolated elevated alkaline phosphatase level. Serum calcium and phosphorus are normal. Pelvic radiographs show coarse trabeculation and cortical thickening of the right ilium. The primary cellular abnormality initiating this disease process is characterized by which of the following?

A 66-year-old man with symptomatic, advanced Paget's disease of the left femur is scheduled for an elective total hip arthroplasty due to severe secondary osteoarthritis. Which of the following is the most appropriate preoperative intervention to minimize surgical blood loss?

A patient with active Paget's disease is treated with an intravenous nitrogen-containing bisphosphonate. At the cellular level, this medication achieves its primary therapeutic effect by inhibiting which of the following enzymes?

A 75-year-old woman treated with prolonged alendronate for Paget's disease presents to the ED after a low-energy fall. Radiographs demonstrate a transverse subtrochanteric femur fracture with a medial cortical spike and localized lateral cortical thickening. Following intramedullary nailing, which of the following medications is contraindicated for managing her fracture healing given her specific medical history?

A 45-year-old male sustains a comminuted diaphyseal tibia fracture. Which of the following factors is MOST critical in determining the rate of secondary fracture healing, assuming adequate reduction and stabilization?

A 70-year-old female falls directly onto her femur, sustaining a subtrochanteric fracture. Considering the primary load-bearing function of the femoral diaphysis, cortical bone is optimally designed to resist which type of force?

A 30-year-old patient is immobilized for 6 weeks following a complex ankle fracture. During this period of disuse, bone remodeling shifts towards resorption, contributing to localized osteopenia. Which bone cell type is primarily responsible for sensing the altered mechanical environment and initiating these remodeling changes?

A 65-year-old patient presents with knee osteoarthritis, characterized by progressive loss of articular cartilage. The primary proteoglycan responsible for the cartilage's ability to resist compressive loads, and whose degradation is central to osteoarthritis, is:

A 25-year-old carpenter sustains a laceration to the volar aspect of his index finger, severing the flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) in Zone II. Primary repair is performed. Which of the following rehabilitation protocols emphasizes early passive flexion and passive extension to minimize adhesions?

Aspirin is often used for deep vein thrombosis (DVT) prophylaxis following total joint arthroplasty. What is the primary mechanism of action of aspirin in this clinical context?

Recombinant human Bone Morphogenetic Protein-2 (rhBMP-2) is utilized in spine fusion and open tibia fractures. When an examiner asks about its cellular mechanism of action, you correctly state that BMP-2 initiates osteoinduction primarily by binding to cell surface receptors and subsequently activating which intracellular signaling pathway?

You are questioned about the physiology of fracture healing following the application of a dynamic compression plate (rigid internal fixation). This construct relies on which of the following mechanisms to achieve union?

A 32-year-old female presents with knee pain. Radiographs reveal an eccentric, lytic epiphyseal lesion extending to the subchondral bone of the distal femur. Biopsy confirms a Giant Cell Tumor of bone. If medical therapy is considered to facilitate joint-salvage surgery, which medication is most appropriate and what is its mechanism?

You are explaining the rationale for using a compression plate for a transverse radius fracture. Absolute stability constructs, such as compression plating, promote which type of bone healing, and what is the primary prerequisite?

Following a local anesthetic block, valgus stress testing was performed on the patient's right thumb metacarpophalangeal joint. In 30 degrees of flexion, the injured thumb demonstrated approximately 40 degrees of valgus angulation with a distinctly soft endpoint, compared to 10 degrees with a firm endpoint on the contralateral uninjured thumb. What is the most accurate interpretation of these findings?

A 33-year-old male presents with acute valgus instability of the thumb MCP joint. Clinical examination and stress radiographs confirm a diagnosis of a complete UCL rupture. According to established guidelines, what degree of absolute valgus laxity in 30 degrees of MCP flexion is generally considered an absolute indication for surgical intervention?

When examining a suspected ulnar collateral ligament (UCL) injury of the thumb, valgus stress testing is performed in both full extension and 30 degrees of flexion. Laxity detected exclusively in 30 degrees of flexion indicates an isolated tear of which structure?

Which structure anatomically links the PIP and DIP joints, contributing to the coordinated extension of the DIP joint when the PIP joint extends?