1. General Principles & Basic Science MCQs

A 60-year-old male undergoes a lumbar laminectomy. Six hours postoperatively, he complains of significant lower abdominal discomfort and has not voided. A bladder ultrasound reveals 500 mL of urine. What is the next most appropriate step in management?

A 25-year-old male is rescued after being trapped under a collapsed building for 12 hours with severe crush injuries to both lower extremities. His urine is dark brown, and serum creatine kinase is 45,000 U/L. What is the primary mechanism of his expected acute kidney injury?

According to Perren's strain theory, absolute stability is required for primary bone healing. Primary bone healing occurs without visible callus formation when the interfragmentary strain is maintained below what threshold?

Articular cartilage is divided into distinct structural zones. Which zone is responsible for resisting the highest amount of shear stress and contains densely packed collagen fibers oriented parallel to the articular surface?

For operative management of this navicular body fracture, the surgeon plans an open reduction and internal fixation. Which surgical approach is most commonly utilized for direct visualization and reduction of a navicular body fracture, as described in the case?

A 29-year-old female undergoes operative fixation for a displaced, comminuted navicular body fracture. Which of the following is an early complication specifically mentioned in the context of operative management for this injury?

A 32-year-old female has a large, eccentric lytic lesion in the distal femur epiphysis confirmed by biopsy to be a Giant Cell Tumor (GCT). If medical therapy is considered to downstage the tumor prior to surgery, which mechanism of action is utilized?

A 30-year-old female undergoes intralesional curettage and cementation for a giant cell tumor of the distal femur. Two years later, she presents with recurrence. She is started on denosumab therapy prior to re-operation. What is the specific mechanism of action of this medication?

A patient with suspected lateral epicondylitis has undergone a corticosteroid injection at the common extensor origin. They return three months later with recurrent, slightly worse pain. What is the MOST appropriate next step in management, assuming initial non-operative treatment (PT, NSAIDs) was also attempted without success?

A 40-year-old female undergoes open reduction and internal fixation of a comminuted mid-diaphyseal radial fracture using the volar (Henry) approach. During the deep dissection to expose the proximal and middle thirds of the radius, the surgeon must be particularly vigilant about protecting a specific nerve. Which of the following describes the most critical nerve to protect and its anatomical relationship during this approach?

A 55-year-old male presents with a comminuted fracture of the proximal third of the radial diaphysis. The surgeon opts for a dorsal (Thompson) approach for open reduction and internal fixation. During the deep dissection, after incising the fascia and developing the interval between the ECRB and EDC, the supinator muscle is exposed. What is the most crucial step to prevent iatrogenic nerve injury during the subsequent exposure of the radial shaft?

A surgeon utilizes the dorsal (Thompson) approach for open reduction and internal fixation of a proximal-third radial shaft fracture. Between which two muscles is the internervous plane developed?

A 45-year-old man undergoes ORIF of a diaphyseal radius fracture via the volar (Henry) approach. The internervous plane for the proximal portion of this surgical approach lies between which two nerves?

A 55-year-old male sustains an isolated ulnar shaft fracture and is treated non-operatively in a functional brace. At 14 weeks, radiographs demonstrate a hypertrophic nonunion. What is the most appropriate management?

A surgeon is using the posterolateral (Kocher) approach to access the radial head for an arthroplasty. To prevent denervation and safely expose the joint, the superficial internervous plane is developed between which two muscles?

When utilizing the volar (Henry) approach to the forearm for fixation of a distal radius diaphyseal fracture, which internervous plane is utilized?

A surgeon is choosing an intramedullary nail for a young, active patient with a tibia fracture. They are considering two options: one made of stainless steel and another of titanium alloy. From a biomechanical perspective, which material property is most relevant to minimizing long-term stress shielding of the bone?

A 40-year-old patient with a transverse mid-diaphyseal tibia fracture is initially treated with a statically locked IM nail. After 8 weeks, there is evidence of delayed union. The surgeon decides to dynamize the nail by removing one of the distal interlocking screws. What is the primary biomechanical objective of this intervention?

A 4.5 mm cortical screw is primarily designed with which thread characteristic compared to a 6.5 mm cancellous screw?