1. General Principles & Basic Science MCQs

During an ilioinguinal approach for open reduction and internal fixation of an anterior column acetabular fracture, brisk arterial bleeding is encountered while dissecting over the superior pubic ramus. The vessel injured is the 'corona mortis'. This vascular structure represents an anastomosis between which of the following arterial systems?

A surgeon is performing a volar (Henry) approach to the radius to plate a proximal third radial shaft fracture. To safely expose the proximal radius, an internervous plane must be developed. Which two muscles define this proximal internervous plane, and what are their respective innervations?

A trauma surgeon is using a minimally invasive deltoid-splitting approach to plate a proximal humerus fracture. To avoid iatrogenic denervation of the anterior deltoid, the inferior extent of the deltoid split must be strictly limited. The axillary nerve, running deep to the deltoid muscle, typically crosses the lateral border of the humerus at what average distance distal to the tip of the lateral acromion?

During a modified Stoppa approach for anterior pelvic ring fixation, massive hemorrhage is encountered while dissecting over the superior pubic ramus near the symphysis. The surgeon suspects injury to the corona mortis. This anatomical variant most commonly represents an anastomosis between which of the following vascular systems?

The sciatic nerve normally exits the greater sciatic foramen inferior to the piriformis muscle. However, variants exist that may predispose patients to piriformis syndrome. According to the Beaton and Anson classification, what is the most common anatomical variant of the sciatic nerve in relation to the piriformis muscle?

A surgeon is performing a Kaplan (lateral) approach to the elbow for open reduction and internal fixation of a comminuted radial head fracture. Which of the following best describes the internervous plane utilized in this surgical approach?

A lateral deltoid-splitting approach is utilized to access the subacromial space for a rotator cuff repair. To avoid catastrophic denervation of the anterior and middle deltoid, the split must not extend too far distally. The axillary nerve typically courses transversely across the deep surface of the deltoid at approximately what distance distal to the lateral edge of the acromion?

A surgeon is performing a volar (Henry) approach to the proximal radius for open reduction and internal fixation of a radial shaft fracture. To adequately expose the proximal third of the radius, the surgeon must mobilize the supinator muscle. Which of the following describes the correct internervous plane and the structure at greatest risk during this proximal dissection?

During an ilioinguinal approach for an anterior column acetabular fracture, significant hemorrhage is encountered upon dissection posterior to the superior pubic ramus, approximately 5 to 6 cm lateral to the symphysis pubis. This bleeding is most likely originating from an anastomotic vessel connecting which two vascular systems?

A 35-year-old man undergoes open reduction and internal fixation of a middle-third humeral shaft fracture via an anterolateral approach. During the approach, the brachialis muscle is split longitudinally to expose the bone. Which of the following accurately describes the innervation of the medial and lateral halves of the brachialis muscle, respectively?

A patient presents with medial midfoot pain and paresthesias radiating to the plantar aspect of the great toe. Surgical exploration of the midfoot is planned to address a suspected entrapment neuropathy near the 'Master Knot of Henry.' Which of the following describes the anatomic relationship of the tendons at this location?

During the harvesting of hamstring tendons for an anterior cruciate ligament (ACL) reconstruction, the surgeon dissects the superficial layer of the pes anserinus to locate the correct tendons. Which of the following tendons forms the most proximal and anterior/superficial layer of the pes anserinus insertion on the anteromedial tibia?

A spine surgeon is performing a lateral transpsoas approach to the L4-L5 disc space. Neuromonitoring is utilized to safely navigate the psoas major muscle and avoid the lumbar plexus. At the L4-L5 level, what is the most common location of the lumbar plexus within the psoas major muscle relative to its anteroposterior dimension?

A 28-year-old man requires open reduction and internal fixation for a displaced middle-third radius shaft fracture. The surgeon utilizes a volar (Henry) approach, developing the internervous plane between the brachioradialis and the flexor carpi radialis. During dissection in the middle third of the forearm, which of the following nerves must be carefully protected as it runs along the undersurface of the brachioradialis?

A pelvic trauma surgeon is performing an ilioinguinal approach for an anterior column acetabular fracture. While dissecting along the posterior aspect of the superior pubic ramus, approximately 4 to 5 cm lateral to the symphysis pubis, sudden massive arterial bleeding is encountered. This bleeding is most likely originating from an unrecognized anastomosis connecting which of the following vascular structures?

During the harvest of semitendinosus and gracilis tendons for an anterior cruciate ligament reconstruction, the surgeon inadvertently transects a nerve branch that crosses superficial to the gracilis tendon at the level of the pes anserinus. Which of the following clinical deficits will the patient most likely experience postoperatively?

A 62-year-old man undergoes a lateral lumbar interbody fusion (LLIF) at L4-L5 utilizing a transpsoas approach. In the recovery room, he is found to have profound weakness in hip flexion and knee extension, alongside diminished sensation over his anterior thigh. These findings are most likely due to injury of a neural structure located in which specific zone of the psoas major muscle at the L4-L5 level?

A 35-year-old male undergoes open reduction and internal fixation of a midshaft humerus fracture via a posterior triceps-splitting approach. To safely expose the posterior humerus without injuring the radial nerve, the surgeon must be aware of its predictable anatomical course. Which of the following best describes the relationship of the radial nerve to the posterior humerus?

A 55-year-old male is undergoing an anterior intrapelvic (modified Stoppa) approach for open reduction and internal fixation of a transverse acetabular fracture. During deep dissection along the posterior aspect of the superior pubic ramus, significant brisk hemorrhage is encountered. The bleeding is identified as originating from the 'corona mortis'. This structure represents a highly variable vascular anastomosis between which two systems?

A 28-year-old male undergoes open reduction and internal fixation of a proximal third radius fracture via an anterior (Henry) approach. The surgeon develops the internervous plane between the brachioradialis and the pronator teres. To fully mobilize the mobile wad laterally and expose the supinator, a cluster of crossing vessels must be identified and ligated. These crossing vessels originate directly from which of the following structures?