1. General Principles & Basic Science MCQs

When performing an ilioinguinal approach for an acetabular fracture, the middle window is defined by which of the following boundaries?

In the modified Stoppa approach for anterior intrapelvic access, which of the following structures must often be identified and ligated on the superior pubic ramus to prevent catastrophic bleeding?

During a deltopectoral approach to the shoulder, the conjoined tendon is identified attaching to the coracoid process.

Which of the following structures makes up the conjoined tendon, and what nerve is most at risk if retractors are placed aggressively medial to it?

The posterolateral approach to the distal tibia (often used for posterior malleolus fractures) exploits the internervous plane between which two muscle groups?

A surgeon uses the medial approach to the knee to perform an opening wedge high tibial osteotomy. The superficial medial collateral ligament (sMCL) is located deep to which of the following structures?

During a Smith-Petersen (anterior) approach to the hip,

the deep dissection involves working between the rectus femoris and the gluteus medius/minimus. Which blood vessels typically cross this field and require ligation to mobilize the rectus femoris safely?

A posterior approach to the humerus is selected for open reduction and internal fixation of a distal third humerus fracture. The radial nerve is identified in the spiral groove. Approximately how far proximal to the lateral epicondyle does the radial nerve piece the lateral intermuscular septum to pass from the posterior to the anterior compartment?

In the Kaplan approach (anterolateral) to the proximal radius,

the internervous plane is developed between the extensor digitorum communis (EDC) and the extensor carpi radialis brevis (ECRB). Why is this approach considered to have a higher risk of neurologic injury compared to the Kocher approach?

An anterolateral (Watson-Jones) approach is utilized. The deep dissection requires identification of the capsule. During this deep dissection, which muscle must frequently be detached from the anterior aspect of the greater trochanter to optimize exposure of the femoral neck?

A surgeon performs the Ludloff (medial) approach to the hip for an open reduction of a pediatric developmental dysplasia of the hip.

What is the deep internervous plane utilized in this approach?

A 15-year-old boy presents with right thigh pain that is worse at night and dramatically improves with ibuprofen. Radiographs and CT show a cortically based lesion with a 1 cm radiolucent nidus surrounded by reactive sclerosis.

What is the primary molecular mediator responsible for this patient's characteristic pain?

A neonate is evaluated for short-limbed dwarfism, a 'hitchhiker' thumb, clubfeet, and swelling of the external ear (cauliflower ear). This condition is inherited in an autosomal recessive manner. What is the underlying pathophysiologic defect?

A 12-year-old girl is noted to have excessive shoulder mobility, allowing her to touch her shoulders together anteriorly. She also has delayed eruption of secondary teeth. A mutation in which of the following transcription factors is responsible?

A 35-year-old woman presents with a large, lytic, epiphyseal lesion of the distal femur that extends to the subchondral bone. Biopsy confirms a Giant Cell Tumor of bone. Medical management with denosumab is planned. Denosumab targets which of the following?

A 32-year-old female presents with knee pain. Radiographs show an eccentric, lytic lesion in the distal femoral epiphysis reaching the subchondral bone. Biopsy confirms Giant Cell Tumor of Bone. When utilizing Denosumab for unresectable disease, what is the specific molecular target?

A 10-year-old boy with severe Hemophilia A complains of progressive right knee pain and swelling following recurrent hemarthroses. What is the primary pathophysiologic mechanism driving irreversible cartilage destruction in hemophilic arthropathy?

A 7-year-old boy presents with a waddling gait, bilateral knee pain, and mild short stature. Lateral knee radiographs demonstrate a classic "double-layer" patella. A diagnosis of Multiple Epiphyseal Dysplasia (MED) is suspected. A mutation in which gene is most commonly implicated?

A newborn presents with severe short-trunk dwarfism, a cleft palate, and bilateral rigid clubfeet. Radiographs reveal delayed ossification of the epiphyses and platyspondyly. A diagnosis of Spondyloepiphyseal Dysplasia Congenita (SEDC) is established. This condition is caused by a defect in which type of collagen?

A 10-year-old boy with severe Hemophilia A presents with a chronically swollen, boggy right knee and significantly restricted range of motion. Radiographs show advanced joint space narrowing and epiphyseal overgrowth. What is the primary cellular mechanism driving joint destruction in this condition?

An 8-year-old girl is referred for evaluation of unusually delayed tooth eruption. On examination, she is noted to have a large head, delayed closure of cranial sutures, and she is able to easily bring her shoulders together anteriorly. Which genetic mutation is highly characteristic of this condition?