This practice set contains high-yield board review questions covering key concepts in Surgical Anatomy & Approaches. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 541
Topic: Surgical Anatomy & Approaches
A 38-year-old female sustains a coronal shear fracture of the capitellum and lateral trochlea. Operative fixation via an extensile lateral approach (Kocher interval) is planned.
During distal extension of this approach, the surgeon must be careful to protect which nerve within the substance of the supinator muscle?
Correct Answer & Explanation
. Posterior interosseous nerve
Explanation
The Kocher approach exploits the interval between the extensor carpi ulnaris (ECU) and the anconeus. When extending this approach distally to expose the proximal radius and lateral elbow joint, the supinator muscle is elevated. The posterior interosseous nerve (PIN), a branch of the radial nerve, courses through the two heads of the supinator (arcade of Frohse) and is at significant risk of injury during distal dissection.
Question 542
Topic: Surgical Anatomy & Approaches
A 26-year-old overhead athlete undergoes shoulder arthroscopy for chronic pain. A Type II Superior Labrum Anterior to Posterior (SLAP) tear is identified. The surgeon places a suture anchor at the 12 o'clock position on the superior glenoid rim. If the drill or anchor is placed too deeply and medially into the glenoid neck, which neurological structure is at greatest risk of injury?
Correct Answer & Explanation
. Suprascapular nerve
Explanation
The suprascapular nerve courses through the suprascapular notch and then through the spinoglenoid notch at the base of the coracoid process, passing approximately 1 to 2 cm medial to the superior glenoid rim. When placing suture anchors at the 12 o'clock position for a SLAP repair, drilling too deeply or angling too medially puts the suprascapular nerve at high risk of iatrogenic injury.
Question 543
Topic: Surgical Anatomy & Approaches
A 35-year-old man is involved in a high-speed motor vehicle collision. Judet views demonstrate a both-column acetabular fracture. Based on the fracture characteristics, which of the following features most strongly indicates the need for an anterior ilioinguinal approach rather than a posterior Kocher-Langenbeck approach?
Correct Answer & Explanation
. Anterior column displacement predominating over posterior displacement
Explanation
The choice of surgical approach in acetabular fractures is largely dictated by the column with the maximal displacement. An anterior ilioinguinal approach is classically indicated for anterior column, anterior wall, and associated anterior-predominant fractures. A Kocher-Langenbeck approach is chosen when posterior wall/column displacement predominates.
Question 544
Topic: Surgical Anatomy & Approaches
A 19-year-old overhead athlete with multidirectional instability (MDI) of the shoulder has failed a 6-month trial of physical therapy. He undergoes an open inferior capsular shift procedure. During the release of the inferior capsule from the humeral neck, which neurological structure is at greatest risk of iatrogenic injury?
Correct Answer & Explanation
. Axillary nerve
Explanation
The axillary nerve runs inferior to the glenohumeral joint capsule as it passes through the quadrangular space. During an inferior capsular shift, release of the capsule from the humeral neck (particularly inferiorly) places the axillary nerve at significant risk. It must be carefully identified and protected, often by leaving a small cuff of capsule on the humerus.
Question 545
Topic: Surgical Anatomy & Approaches
A 28-year-old female sustains a crush injury to her dominant right hand. She develops a complete radial nerve palsy at the forearm level. After 6 months of observation and physical therapy, there is no evidence of motor recovery, and electrodiagnostic studies confirm a complete nerve transection. What is the MOST appropriate next surgical step to restore hand function?
Correct Answer & Explanation
. Nerve grafting of the radial nerve.
Explanation
The patient has a complete radial nerve palsy from a crush injury, with no recovery after 6 months and electrodiagnostic evidence of transection. For a complete nerve transection, surgical intervention is necessary. Given 6 months have passed, primary repair is likely not feasible due to nerve gap and retraction. Tendon transfers are typically considered if nerve repair/grafting is not possible or has failed, and sufficient time has passed for reinnervation to occur or fail (usually 12-18 months post-injury).For a complete nerve transection with a gap, nerve grafting is the appropriate reconstructive technique. This involves harvesting a nerve graft (e.g., sural nerve) and coapting the ends to bridge the gap in the radial nerve. The goal is to provide a conduit for regenerating axons to cross the defect.Rationale for options:A. Nerve grafting of the radial nerve is the most appropriate surgical intervention for a complete radial nerve transection with a nerve gap, especially after 6 months where primary repair is unlikely due to retraction. This is the correct answer.B. Primary repair of the radial nerve would be ideal if performed acutely after injury with minimal gap. After 6 months, significant retraction makes primary repair without tension highly improbable.C. Tendon transfers are typically considered if nerve reconstruction (repair or graft) is not feasible, has failed, or if the time for reinnervation (usually 12-18 months) has passed without functional recovery. It is a salvage procedure, not the primary choice for an acute transection with a potentially reconstructible nerve.D. Dynamic splinting is supportive care; continued observation for a complete transection after 6 months is inappropriate without surgical intervention.E. Exploration and neurolysis are for nerve compression or scarring, not for complete transection.
Question 546
Topic: Surgical Anatomy & Approaches
During the ilioinguinal approach for an acetabular fracture, significant hemorrhage is encountered upon dissecting over the superior pubic ramus. This bleeding is most likely originating from an anastomotic vessel connecting the obturator system and which of the following vessels?
Correct Answer & Explanation
. External iliac or deep inferior epigastric artery
Explanation
The vessel in question is the 'corona mortis' (crown of death), which is an anastomosis between the obturator artery/vein (from the internal iliac system) and the external iliac or deep inferior epigastric artery/vein. It crosses the superior pubic ramus and is highly vulnerable to iatrogenic injury during anterior pelvic approaches (like the ilioinguinal or Stoppa approaches), potentially leading to massive, life-threatening hemorrhage.
Question 547
Topic: Surgical Anatomy & Approaches
During a Kocher-Langenbeck approach for an acetabular fracture, the surgeon must be mindful of protecting the sciatic nerve. What is the optimal positioning of the lower extremity to minimize tension on the sciatic nerve during retraction?
Correct Answer & Explanation
. Hip extended and knee flexed
Explanation
Extending the hip and flexing the knee relaxes the sciatic nerve. This minimizes the risk of iatrogenic traction injury during posterior retractor placement.
Question 548
Topic: Surgical Anatomy & Approaches
A 24-year-old rugby player undergoes a Latarjet procedure for recurrent anterior shoulder instability with 25% glenoid bone loss. During the transfer of the coracoid process, which of the following nerves is at greatest risk of injury and must be carefully protected?
Correct Answer & Explanation
. Musculocutaneous nerve
Explanation
The musculocutaneous nerve enters the coracobrachialis approximately 5 cm distal to the coracoid tip. It is at significant risk during coracoid osteotomy and mobilization of the conjoint tendon.
Question 549
Topic: Surgical Anatomy & Approaches
A 55-year-old patient undergoes an open Bankart repair for recurrent anterior shoulder instability. Post-operatively, he develops difficulty with elbow flexion and sensation along the lateral forearm. What nerve is MOST likely injured?
Correct Answer & Explanation
. Musculocutaneous nerve
Explanation
The musculocutaneous nerve innervates the biceps brachii and brachialis muscles (primary elbow flexors) and provides sensory innervation to the lateral forearm (lateral cutaneous nerve of the forearm). It is at risk during anterior shoulder approaches, particularly with excessive retraction of the conjoined tendon (coracobrachialis and short head of biceps), which lies close to this nerve. Axillary nerve injury would affect deltoid and teres minor. Radial nerve affects wrist/finger extensors. Ulnar nerve affects intrinsic hand muscles and medial forearm sensation. Median nerve affects forearm pronation, thumb, and index/middle finger flexion, and sensation to the thumb/index/middle fingers.
Question 550
Topic: Surgical Anatomy & Approaches
A 28-year-old female falls onto her extended arm. Radiographs and CT show a capitellum fracture extending into the lateral trochlear ridge with significant posterior comminution (Dubberley Type 3B). What is the most appropriate surgical approach to achieve stable fixation?
Correct Answer & Explanation
. Lateral approach (Kocher) with posterior extension
Explanation
Dubberley Type 3 fractures involve both the capitellum and trochlea, and the presence of posterior comminution (Type B) frequently necessitates a lateral or combined approach. A lateral approach with posterior extension allows adequate visualization to address both anterior and posterior articular surfaces securely.
Question 551
Topic: Surgical Anatomy & Approaches
Which is the most common complication following excision of a dorsal wrist ganglion?
Correct Answer & Explanation
. Recurrence
Explanation
Despite successful surgical excision, recurrence remains the most common complication of dorsal wrist ganglion removal, with rates varying but generally quoted around 5-15%. While nerve injury (e.g., to the superficial radial nerve) and stiffness are potential complications, recurrence is reported most frequently. Infection and vascular injury are rarer.
Question 552
Topic: Surgical Anatomy & Approaches
A 42-year-old male sustains a transverse fracture of the acetabulum with a large posterior wall component. Which surgical approach provides the best direct access to address both the posterior wall and the posterior column?
Correct Answer & Explanation
. Kocher-Langenbeck approach
Explanation
The Kocher-Langenbeck is the workhorse posterior approach to the acetabulum. It provides excellent direct visualization for reduction and fixation of posterior wall, posterior column, and specific associated transverse fractures.
Question 553
Topic: Surgical Anatomy & Approaches
A 28-year-old male sustains a posterior hip dislocation and an associated posterior wall acetabular fracture. Following closed reduction, a new ipsilateral foot drop is noted. Which nerve division is most likely injured?
Correct Answer & Explanation
. Common peroneal division of the sciatic nerve
Explanation
The sciatic nerve is at high risk during posterior hip dislocations and posterior wall fractures. The common peroneal division is lateral and securely tethered at the fibular head, making it significantly more susceptible to stretch injuries than the tibial division.
Question 554
Topic: Surgical Anatomy & Approaches
During the ilioinguinal approach for an anterior column acetabular fracture, severe hemorrhage is encountered near the superior pubic ramus. This is most likely due to an iatrogenic injury to the corona mortis, which represents an anastomosis between which two vascular systems?
Correct Answer & Explanation
. External iliac and obturator
Explanation
The corona mortis is an anatomical vascular variant connecting the external iliac system (usually via the inferior epigastric vessels) to the obturator system (internal iliac). Injury during pelvic approaches can cause massive, difficult-to-control hemorrhage.
Question 555
Topic: Surgical Anatomy & Approaches
During a surgical approaches viva, you are asked about the anterior (Smith-Petersen) approach to the hip. What is the internervous plane utilized in the superficial dissection of this approach?
Correct Answer & Explanation
. Between Sartorius (Femoral N.) and Tensor Fasciae Latae (Superior Gluteal N.)
Explanation
The superficial internervous plane for the Smith-Petersen approach is between the Sartorius (innervated by the femoral nerve) and the Tensor Fasciae Latae (innervated by the superior gluteal nerve). This preserves the neurovascular supply to both muscles.
Question 556
Topic: Surgical Anatomy & Approaches
A 35-year-old male sustains a closed fracture of the middle third of the humeral shaft. Following closed reduction and application of a U-slab, he develops a new-onset complete radial nerve palsy. What is the most appropriate management?
Correct Answer & Explanation
. Immediate surgical exploration of the radial nerve
Explanation
While primary radial nerve palsies associated with closed humerus fractures are usually observed, a secondary palsy that develops after a manipulation or reduction attempt strongly indicates nerve entrapment at the fracture site. This warrants immediate surgical exploration.
Question 557
Topic: Surgical Anatomy & Approaches
During the anterior intrapelvic (modified Stoppa) approach for an acetabular fracture, an aberrant vessel traversing the superior pubic ramus is encountered and ligated. This 'corona mortis' represents an anastomosis between which two vascular systems?
Correct Answer & Explanation
. External iliac (or inferior epigastric) artery and the obturator artery
Explanation
The corona mortis ('crown of death') is an important anatomical variant consisting of a vascular anastomosis between the external iliac (or its branch, the inferior epigastric) system and the internal iliac (obturator) system. It lies on the posterior aspect of the superior pubic ramus, approximately 4-9 cm from the pubic symphysis. It can be arterial, venous, or both, and is highly susceptible to injury during anterior pelvic approaches, necessitating careful identification and ligation.
Question 558
Topic: Surgical Anatomy & Approaches
A 24-year-old male presents with radial-sided wrist pain after a fall onto an outstretched hand. Imaging reveals a displaced fracture of the proximal pole of the scaphoid. Surgical fixation with a headless compression screw is planned. Which of the following surgical approaches is most appropriate for optimal screw placement and preservation of the scaphoid blood supply in this specific fracture pattern?
Correct Answer & Explanation
. Dorsal approach between the third and fourth extensor compartments
Explanation
The blood supply to the scaphoid is primarily retrograde, entering the distal pole and dorsal ridge via branches of the radial artery. The proximal pole relies entirely on intraosseous blood flow from distal to proximal. For proximal pole fractures, a dorsal approach (typically between the 3rd and 4th extensor compartments) is preferred because it avoids damage to the dominant volar/distal blood supply (the palmar radiocarpal branches), prevents division of critical volar ligaments (e.g., radioscaphocapitate ligament), and provides direct, collinear access to the proximal pole for screw trajectory along the central axis of the scaphoid.
Question 559
Topic: Surgical Anatomy & Approaches
A patient presents with an irreversible high radial nerve palsy following a humerus fracture. The surgeon elects to perform a tendon transfer to restore wrist, finger, and thumb extension. The classic Boyes transfer specifically utilizes which of the following tendon transpositions to restore finger extension (Extensor Digitorum Communis)?
Correct Answer & Explanation
. Flexor Digitorum Superficialis (middle finger) to Extensor Digitorum Communis
Explanation
The Boyes transfer relies on the flexor digitorum superficialis (FDS) of the middle finger transferred through the interosseous membrane to the EDC to restore finger extension. It also uses the FDS of the ring finger to the EIP and EPL. In contrast, standard transfers (like the modified Green transfer) use the FCU or FCR to EDC.
Question 560
Topic: Surgical Anatomy & Approaches
A surgeon is performing a total hip arthroplasty using an approach that exploits the internervous plane between the superior gluteal nerve and the femoral nerve. Which of the following describes the muscles defining this surgical interval?
Correct Answer & Explanation
. Tensor fasciae latae and sartorius
Explanation
The anterior approach to the hip (Smith-Petersen) uses the internervous plane between the sartorius (innervated by the femoral nerve) and the tensor fasciae latae (innervated by the superior gluteal nerve) superficially.
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