1. General Principles & Basic Science MCQs

A 32-year-old weightlifter feels a 'pop' in his anterior axilla while performing a heavy bench press. MRI confirms a complete rupture of the pectoralis major tendon. During surgical repair, an understanding of the insertional anatomy is critical. Which of the following best describes the normal footprint of the pectoralis major on the humerus?

A 32-year-old elite weightlifter feels a sudden "pop" in his anterior axilla while bench pressing. He presents with extensive ecchymosis and loss of the anterior axillary fold. An acute rupture of the pectoralis major is suspected. At its normal humeral insertion, what is the anatomical relationship of the sternal head relative to the clavicular head?

During an ilioinguinal approach to the acetabulum for a transverse fracture, the surgeon encounters massive bleeding over the posterior aspect of the superior pubic ramus. This bleeding is most likely originating from an anastomosis between which of the following vascular systems?

Historically, the anterior humeral circumflex artery was thought to be the primary blood supply to the humeral head. Based on modern quantitative perfusion studies, which vessel actually provides the majority of the blood supply to the humeral head?

A 65-year-old woman on alendronate for 12 years presents with insidious lateral thigh pain. Radiographs reveal lateral cortical thickening and a transverse radiolucent line in the subtrochanteric femur. What is the primary cellular mechanism leading to this atypical femur fracture?

A 72-year-old female with severe osteoporosis has a T-score of -3.5 and a recent fragility fracture of the lumbar spine. Her endocrinologist recommends romosozumab. What is the primary mechanism of action of this medication?

A 65-year-old female on alendronate for 8 years presents with progressive, activity-related lateral thigh pain. Radiographs of the femur demonstrate lateral cortical thickening and a transverse, incomplete radiolucent line in the subtrochanteric region. What is the most appropriate next step in management?

Which of the following laboratory profiles is most characteristic of severe osteomalacia, helping to differentiate it from primary postmenopausal osteoporosis?

A 74-year-old female on denosumab therapy for 5 years suddenly discontinues the medication due to a planned dental procedure. Eight months later, she presents with severe back pain, and radiographs reveal three new acute vertebral compression fractures. What is the primary pathophysiological mechanism for this rapid deterioration?

During a direct anterior approach (DAA) to the hip, a consistent crossing arterial branch is routinely encountered within the internervous plane and must be ligated to prevent postoperative hematoma. This vessel is a branch of which major artery?

A 68-year-old female with severe hip osteoarthritis and severe osteoporosis is scheduled for an elective total hip arthroplasty (THA). She is currently on denosumab therapy, receiving subcutaneous injections every 6 months. Her last injection was 3 months ago. What is the most appropriate recommendation regarding her denosumab therapy and the timing of surgery?

A 74-year-old female with severe postmenopausal osteoporosis is started on romosozumab. What is the specific mechanism of action of this medication?

A 75-year-old female presents with an atraumatic dull ache in her left thigh. She has been taking alendronate for 9 years for osteoporosis. Plain radiographs of the left femur reveal localized lateral cortical thickening in the subtrochanteric region with a subtle transverse radiolucent line, consistent with an incomplete atypical femur fracture (AFF). What is the most critical next step in her imaging workup?

Bisphosphonates are the most commonly prescribed first-line therapy for osteoporosis. By which of the following specific cellular mechanisms do nitrogen-containing bisphosphonates (e.g., alendronate) primarily exert their antiresorptive effect?

The direct anterior approach (DAA) to the hip utilizes the internervous plane between the tensor fasciae latae (TFL) and the sartorius. During the superficial dissection, careful retractor placement is necessary to avoid injury to a nerve that typically courses distally over the sartorius muscle. Which of the following nerves is at greatest risk during this part of the exposure?

A 71-year-old male with a T-score of -3.5 and multiple recent fragility fractures requires aggressive medical management for osteoporosis. You are considering starting teriparatide. Which of the following elements in his past medical history represents an absolute contraindication to teriparatide therapy?

An 80-year-old female with severe osteoporosis and a recent femoral neck fracture is placed on romosozumab. What is the precise mechanism of action of this medication?

A 72-year-old female on alendronate for 10 years presents with 3 months of progressive anterior thigh pain. Radiographs reveal focal lateral cortical thickening and a transverse radiolucent line involving 30% of the lateral cortex of the subtrochanteric femur. There is moderate varus bowing of the femur. What is the most appropriate next step in management?

Which of the following combinations of implant characteristics confers the highest risk for mechanically assisted crevice corrosion (trunnionosis) at the head-neck junction in total hip arthroplasty?

A 68-year-old female sustains a fragility fracture of the pelvis. A DXA scan reveals a T-score of -3.2 at the femoral neck. An incidental finding on the pelvic radiograph is an asymptomatic area characteristic of Paget's disease involving her right hemipelvis. Which of the following medical treatments for her osteoporosis is strictly contraindicated?