1. General Principles & Basic Science MCQs

A 32-year-old competitive weightlifter feels a sudden pop in his anterior axilla while bench pressing. Examination reveals loss of the anterior axillary fold and weakness in internal rotation. MRI confirms a complete rupture of the pectoralis major at the sternocostal head insertion. What is the optimal timing and treatment?

A 19-year-old male is brought to the ER after a high-speed motor vehicle collision. He has severe pain over his medial clavicle, shortness of breath, and mild dysphagia. Examination shows a depression over the medial clavicle. What is the most appropriate initial diagnostic imaging to confirm the suspected diagnosis?

A 26-year-old elite volleyball player complains of vague posterior shoulder pain and fatigue with overhead activities. Physical exam reveals isolated atrophy of the teres minor. An MRI shows isolated fatty infiltration of the teres minor and a cystic structure in the quadrilateral space. Which vascular structure is most likely compressed alongside the affected nerve?

A 30-year-old male weightlifter felt a sudden 'pop' in his anterior axilla while performing a heavy bench press. Examination reveals loss of the anterior axillary contour and weakness in internal rotation. If surgical repair is undertaken, which of the following describes the normal anatomic footprint of the ruptured structure?

An 18-year-old high school football player sustains a posterior sternoclavicular (SC) joint dislocation. He presents to the emergency department with mild dysphagia and a feeling of fullness in his throat. Which of the following is the most appropriate next step in management?

A 30-year-old male weightlifter felt a distinct "pop" in his anterior axilla while bench pressing. Examination reveals loss of the normal anterior axillary fold contour and weakness in internal rotation. MRI confirms a sternal head avulsion of the pectoralis major from the humerus. What is the recommended treatment?

A 32-year-old male weightlifter felt a 'pop' in his anterior axilla while performing a heavy bench press. Examination reveals an asymmetric axillary fold and weakness in internal rotation. MRI confirms a pectoralis major rupture. Which portion of the muscle is most commonly torn in this scenario?

A 50-year-old active construction worker is undergoing surgery for a symptomatic SLAP II tear and degenerative long head of the biceps tendon. He wishes to avoid any cosmetic asymmetry of his arm. Which procedure carries the highest risk of postoperative 'Popeye' deformity?

A 28-year-old male weightlifter feels a "pop" in his anterior axilla while bench pressing. Examination reveals ecchymosis, a loss of the anterior axillary fold, and weakness in internal rotation. MRI confirms an acute avulsion of the pectoralis major tendon from its humeral insertion. Which of the following best describes the anatomical arrangement of the native pectoralis major tendon insertion?

A 32-year-old male weightlifter feels a pop in his anterior axilla while performing a heavy bench press. Examination reveals loss of the anterior axillary fold and weakness in internal rotation. Surgical repair is planned. Where does the sternocostal head of the pectoralis major insert in relation to the clavicular head?

Which of the following cell types and cytokines are most directly responsible for the capsular fibrosis seen in the proliferative stage of adhesive capsulitis?

A 19-year-old male sustains a severe blow to the medial clavicle during a football game. He presents to the ED with a posterior sternoclavicular dislocation, dyspnea, and dysphagia.

A closed reduction is attempted in the OR. If closed reduction fails, which specialist is most critical to have available during the open reduction?

A 65-year-old woman is evaluated for osteoporosis. She is started on denosumab. What is the precise mechanism of action of this medication?

A 35-year-old man sustains a midshaft humerus fracture resulting in an isolated radial nerve palsy. Electromyography at 4 weeks shows fibrillation potentials in the brachioradialis but no voluntary motor unit action potentials. What is the underlying pathophysiological process occurring at the distal axon?

Articular cartilage has a complex hierarchical structure that allows it to withstand compressive and shear forces. In the superficial zone of articular cartilage, what is the primary orientation of type II collagen fibers and what is its biomechanical function?

A 45-year-old patient undergoes an open reduction and internal fixation of a diaphyseal forearm fracture using absolute stability techniques (lag screw and neutralization plate). Which type of bone healing is expected, and what is the primary biological mediator initiating this process?

Aseptic loosening is the most common cause of late failure in total joint arthroplasty. The biological cascade leading to periprosthetic osteolysis is primarily initiated by the phagocytosis of wear debris. Which cell type is the principal driver of this initial inflammatory response, and what is the primary cytokine released?

A 60-year-old man develops a chronic prosthetic joint infection 2 years after a total knee arthroplasty. Intraoperative cultures grow Staphylococcus epidermidis. The organism's ability to persist on the implant surface despite appropriate systemic antibiotic therapy is primarily due to:

During tensile testing of a human anterior cruciate ligament (ACL) graft, a load-elongation (stress-strain) curve is plotted. What does the non-linear 'toe region' of this curve represent physiologically?

A patient is diagnosed with familial hypophosphatemic rickets (X-linked dominant). The underlying pathophysiology involves an overproduction of Fibroblast Growth Factor 23 (FGF23). What is the primary renal effect of excessive FGF23 in this condition?