1. General Principles & Basic Science MCQs

Fibroblast growth factor 23 (FGF-23) plays a critical role in mineral metabolism and is often significantly elevated early in the course of chronic kidney disease. What is the primary physiologic effect of FGF-23?

Following a reamed intramedullary nailing of a closed midshaft femur fracture, which type of bone healing predominantly occurs?

Which zone of articular cartilage contains the highest concentration of water and has collagen fibers oriented parallel to the articular surface to resist shear forces?

According to Perren's strain theory of fracture healing, what is the maximum strain tolerated by lamellar bone formation?

Which of the following Bone Morphogenetic Proteins (BMPs) is currently FDA-approved for use in acute, open tibial shaft fractures?

A 5-year-old boy presents with a limp, fever of 39.0°C, a WBC count of 14,000/mm3, an ESR of 50 mm/hr, and inability to bear weight. According to the Kocher criteria, what is the approximate probability of septic arthritis?

In articular cartilage, which zone is characterized by the highest concentration of proteoglycans and vertically aligned type II collagen fibers?

During an anterior intrapelvic (modified Stoppa) approach for a complex acetabular fracture, massive hemorrhage occurs while dissecting bluntly over the superior pubic ramus. This bleeding most likely originates from an anastomosis between which two vascular systems?

A 32-year-old unrestrained driver presents with a shortened, adducted, and internally rotated right leg following a motor vehicle accident. Post-reduction CT shows a 3 mm incarcerated intra-articular acetabular fragment. What is the most critical rationale for urgent surgical extraction?

A surgeon performs an anterolateral approach to the distal humerus to plate a shaft fracture. During deep dissection separating the brachialis from the brachioradialis, which nerve-artery combination must be carefully identified and protected?

During a minimally invasive plate osteosynthesis (MIPO) via an anterior approach for a humeral shaft fracture, the plate is passed submuscularly beneath the brachialis. Which structure is at greatest risk of impingement if the plate drifts excessively medial in the mid-arm?

During a lateral approach to the distal humerus, the surgeon must identify and protect the radial nerve. Anatomically, at what average distance from the lateral epicondyle does the radial nerve pierce the lateral intermuscular septum to enter the anterior compartment of the arm?

A patient undergoes an ilioinguinal approach for an anterior column acetabular fracture. Severe hemorrhage is encountered over the posterior aspect of the superior pubic ramus. This bleeding is most likely originating from the Corona Mortis, which is an anastomosis between which two vascular systems?

A 30-year-old male sustains a posterior hip dislocation. Post-reduction examination reveals complete weakness in ankle dorsiflexion and great toe extension, but normal ankle plantar flexion. Which specific nerve structure is injured, and what is its most common anatomic relationship to the piriformis muscle?

Which of the following vessels provides the primary blood supply to the adult femoral head and is most at risk during a posterior approach to the hip?

A patient presents to the emergency department after a motor vehicle collision with a right hip dislocation. The affected leg is shortened, flexed, adducted, and internally rotated. Which nerve is at highest risk of injury in this scenario?

Based on recent quantitative vascular studies, which artery is now recognized as providing the majority of the blood supply to the humeral head, challenging classic anatomical teaching?

The trochanteric anastomosis provides a crucial extracapsular collateral circulation to the hip joint. Which of the following sets of arteries primarily form this vascular ring?

In the posterior compartment of the arm, the profunda brachii (deep brachial) artery travels in intimate association with which of the following nerves?