1. General Principles & Basic Science MCQs

When utilizing the direct anterior approach (DAA) for a primary total hip arthroplasty, the superficial surgical dissection utilizes an internervous plane. Which of the following pairs of muscles defines this interval?

A 30-year-old weightlifter feels a 'pop' in his anterior axillary fold during a heavy bench press. MRI confirms a rupture of the pectoralis major tendon at its insertion. In the anatomic footprint of the pectoralis major on the humerus, what is the spatial relationship of the sternal head relative to the clavicular head?

During an anterolateral approach for internal fixation of a proximal humerus fracture, the axillary nerve is at significant risk of iatrogenic injury. What is the average distance of the axillary nerve from the lateral edge of the acromion?

A 32-year-old powerlifter feels a sharp pop in his anterior chest while bench-pressing heavy weights. Examination reveals loss of the anterior axillary fold and weakness in internal rotation. If surgical repair of the completely avulsed tendon is performed, to which anatomic landmark should the tendon be reattached?

A 29-year-old weightlifter feels a pop in his anterior axilla while performing a heavy bench press. He presents with extensive bruising, loss of the anterior axillary fold, and weakness in internal rotation. MRI confirms a complete rupture of the pectoralis major. Where is the most common anatomic location for this tear?

A 42-year-old female sustains a Bryan and Morrey Type I capitellar fracture. During ORIF, headless compression screws are to be placed anterior-to-posterior. Which surgical approach provides the most direct anterior access while minimizing the risk to the lateral ulnar collateral ligament (LUCL)?

A 28-year-old weightlifter feels a pop in his anterior axilla while bench pressing. Examination reveals an asymmetric axillary fold and weakness in internal rotation. MRI confirms a complete pectoralis major rupture at the sternal head insertion. Which structure provides the most reliable surgical landmark to locate the anatomical insertion site?

A 28-year-old male weightlifter feels a sudden tear in his axilla while performing a heavy bench press. He is diagnosed with a pectoralis major rupture. Which portion of the pectoralis major typically ruptures first in this scenario, and why?

Proximal row carpectomy (PRC) is being considered for a 45-year-old laborer with a collapsed carpus. Evaluation of which of the following articulations is most critical to determine if PRC is an appropriate option?

To correct a severe humpback deformity in a scaphoid waist nonunion through a volar approach, what specific shape of bone graft is most frequently required to restore normal carpal kinematics?

A 28-year-old man presents with a 2-year-old scaphoid waist nonunion. CT imaging demonstrates a 'humpback' deformity with a lateral intrascaphoid angle of 65 degrees. Which of the following is the most appropriate surgical strategy to restore carpal kinematics?

During surgical treatment of a scaphoid waist nonunion, a tourniquet is used for initial dissection. After debridement of the nonunion site, what is the most reliable intraoperative macroscopic indicator of proximal pole viability?

A 5-year-old girl with a history of multiple fractures, blue sclerae, and dentinogenesis imperfecta presents with a new diaphyseal femur fracture. She is currently treated with intravenous pamidronate. What is the primary mechanism of action of this medication in her condition?

A 3-year-old girl is evaluated for multiple recurrent fractures with minimal trauma. She has blue sclerae and mild bowing of her femurs. Genetic testing confirms a mutation affecting type I collagen. Which of the following medical treatments is most commonly used to decrease fracture frequency in this condition?

A patient undergoes revision total hip arthroplasty. The retrieved femoral component demonstrates evidence of galvanic corrosion at the modular head-neck junction. Which of the following material combinations is most susceptible to this specific type of corrosion?

Secondary bone healing occurs via enchondral ossification.

According to Perren's strain theory, what is the maximum interfragmentary strain that allows for the formation of woven bone?

A 35-year-old woman presents with knee pain. Radiographs show an eccentric, lytic, expansile lesion in the epiphysis of the proximal tibia extending to the subchondral bone.

Biopsy demonstrates multinucleated giant cells in a stroma of mononuclear cells. The neoplastic stromal cells in this tumor are characterized by the excessive expression of which of the following?

On a standard stress-strain curve for an orthopedic biomaterial, what does the area under the curve in the elastic region represent?