1. General Principles & Basic Science MCQs

A 35-year-old male sustains a closed diaphyseal fracture of the humerus. On initial evaluation, he is unable to actively extend his wrist or fingers. He undergoes closed reduction and functional bracing. At 12 weeks, there is no clinical or electromyographic (EMG) evidence of radial nerve recovery. What is the most appropriate next step in management?

A 32-year-old woman undergoes primary repair of a lacerated flexor digitorum profundus (FDP) tendon in Zone II. To optimize healing and minimize adhesions, which of the following postoperative rehabilitation protocols is most strongly supported by current evidence?

A 30-year-old professional bodybuilder feels a tearing sensation in his anterior axilla while performing heavy bench presses. Examination reveals loss of the anterior axillary fold contour and weakness in internal rotation. In this mechanism of injury, where does the pectoralis major most commonly rupture?

An 18-year-old football player presents after a pile-up tackle with shortness of breath, dysphagia, and severe pain over the medial clavicle. Examination shows a palpable depression of the medial clavicle. What is the most appropriate initial diagnostic step?

A 30-year-old bodybuilder feels a "pop" in his anterior axilla while bench pressing. He exhibits ecchymosis and loss of the anterior axillary fold. MRI confirms a complete pectoralis major tear. Normal anatomy dictates that the sternal head of the pectoralis major inserts in what relation to the clavicular head?

A 65-year-old woman sustains an intra-articular distal humerus fracture (AO/OTA type 13-C3). During open reduction and internal fixation utilizing a transolecranon osteotomy, the surgeon must routinely identify and protect which of the following structures?

A 29-year-old elite volleyball player presents with poorly localized posterior shoulder pain and paresthesias over the lateral deltoid. An MRI demonstrates isolated atrophy of the teres minor. He is diagnosed with quadrilateral space syndrome. Which artery and nerve traverse this anatomical space?

A 30-year-old cyclist undergoes open reduction and internal fixation of a displaced midshaft clavicle fracture utilizing an anterior-inferior plating technique. Postoperatively, he complains of a well-demarcated area of numbness over his anterosuperior chest wall, just inferior to the surgical incision. Which nerve was most likely injured during the surgical exposure?

Sclerostin is a key regulatory glycoprotein secreted by osteocytes to inhibit bone formation. Its mechanism of action involves directly antagonizing which of the following intracellular signaling pathways?

A trauma surgeon is comparing different implant materials for a diaphyseal fracture fixation. Which of the following lists correctly orders materials by decreasing Young's modulus (stiffness)?

According to Perren's strain theory of fracture healing, which of the following tissues can tolerate the highest level of interfragmentary strain before mechanical failure?

An infant presents with diffuse osteosclerosis and recurrent fractures. Genetic testing reveals a mutation in the CLCN7 gene. This condition primarily affects which of the following cellular mechanisms?

Bone morphogenetic protein 2 (BMP-2) stimulates osteoblast differentiation. Upon binding to its serine/threonine kinase receptor, which intracellular signaling molecules are directly phosphorylated to translocate to the nucleus?

Fibroblast growth factor 23 (FGF-23) plays a critical role in mineral homeostasis. Which of the following accurately describes its primary cellular source and its main renal effect?

On a load-deformation (stress-strain) curve of a bone specimen, the total area under the entire curve before the point of failure represents which specific mechanical property?

Denosumab is highly effective in the management of osteoporosis and giant cell tumors of bone. It exerts its therapeutic effect by mimicking the physiological function of which endogenous molecule?

A polymeric orthopedic implant subjected to a constant physiological load over a prolonged period exhibits progressive, slow deformation. This viscoelastic behavior is known as:

Regarding the normal ultrastructure of articular cartilage, which zone contains the highest concentration of water and features collagen fibers oriented parallel to the joint surface?