Surgical Anatomy & Approaches MCQs

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?

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 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?

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?

During an anterior intrapelvic (modified Stoppa) approach for a complex acetabular fracture involving the anterior column, the surgeon dissects along the posterior aspect of the superior pubic ramus. Brisk, pulsatile bleeding is encountered from an anomalous anastomotic vessel. This structure, classically known as the corona mortis, represents a potentially fatal communication between which two major vascular networks?

A 35-year-old man undergoes an ilioinguinal approach for an anterior column acetabular fracture. During the surgical exposure along the superior pubic ramus, severe bleeding is encountered from an injured vascular anastomosis. This structure represents an anastomosis between which of the following vascular systems?

A 28-year-old man sustains a closed anterior shoulder dislocation. After a successful closed reduction, he has persistent numbness over the lateral aspect of the shoulder and weakness in shoulder abduction. The nerve injured in this patient passes through a defined anatomic space in the posterior shoulder. Which of the following forms the inferior border of this space?

A 45-year-old man sustains a closed midshaft humerus fracture. Upon presentation, he is unable to extend his wrist or fingers and has numbness over the dorsal first web space. The nerve responsible for this deficit pierces the lateral intermuscular septum of the arm to cross from the posterior to the anterior compartment. At approximately what distance proximal to the lateral epicondyle does this nerve pierce the septum?

A 45-year-old male undergoes an open reduction and internal fixation for a proximal humerus fracture via a standard deltopectoral approach. To properly develop the internervous plane, the surgeon identifies the cephalic vein. Which of the following nerve pairs innervates the muscles that define the boundaries of this specific surgical interval?

A surgeon is performing an anterior approach to the hip (Smith-Petersen) for an uncemented total hip arthroplasty in a 65-year-old patient. The approach requires careful dissection through both a superficial and a deep internervous plane. Which of the following correctly identifies the muscles and corresponding innervations of the superficial internervous plane?