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 121
Topic: Surgical Anatomy & Approaches
During a dorsal (Thompson) approach to the proximal third of the radius, the surgeon identifies the internervous plane. Which of the following describes the appropriate plane for this approach?
Correct Answer & Explanation
. Extensor carpi radialis brevis and extensor digitorum communis
Explanation
The Thompson approach utilizes the internervous plane between the extensor carpi radialis brevis (radial nerve) and the extensor digitorum communis (posterior interosseous nerve). It allows exposure of the proximal and middle thirds of the radius.
Question 122
Topic: Surgical Anatomy & Approaches
A surgeon elects to utilize the dorsal (Thompson) approach for open reduction and internal fixation of a proximal third radial shaft fracture. This surgical approach exploits an internervous plane between which of the following two muscle groups?
Correct Answer & Explanation
. Extensor Carpi Radialis Brevis and Extensor Digitorum Communis
Explanation
The Thompson approach utilizes the internervous plane between the extensor carpi radialis brevis (supplied by the radial nerve) and the extensor digitorum communis (supplied by the posterior interosseous nerve).
Question 123
Topic: Surgical Anatomy & Approaches
A 24-year-old male presents to the emergency department after a football injury, complaining of severe right shoulder pain. His arm is held in slight abduction and external rotation. On inspection, the anterior aspect of his shoulder appears prominent, and there is a palpable void beneath the acromion. Which of the following physical exam findings is MOST concerning for an associated neurovascular injury in this patient?
Correct Answer & Explanation
. Absent radial pulse
Explanation
Correct Answer: DAn absent radial pulse is a critical finding indicating potential compromise of the brachial artery, which is a surgical emergency. While axillary nerve injury (loss of sensation over the lateral deltoid, weakness in abduction) is the most common nerve injury with anterior shoulder dislocations, it is rarely an acute limb-threatening condition unless it's a traction injury without spontaneous recovery. Weakness in wrist extension would suggest radial nerve involvement, which is less common. Ecchymosis is a common finding but not acutely life- or limb-threatening.
Question 124
Topic: Surgical Anatomy & Approaches
A 68-year-old woman falls directly onto her shoulder. She presents with severe pain and an inability to move her arm. On exam, the shoulder appears abducted, and a prominent hard mass is palpable inferior to the glenoid, consistent with a Luxatio Erecta. Which neurovascular structure is at highest risk of injury in this type of dislocation?
Correct Answer & Explanation
. Axillary artery
Explanation
Correct Answer: CLuxatio Erecta (inferior dislocation) involves extreme abduction, forcing the humeral head inferiorly. The head can impinge upon or stretch the neurovascular bundle in the axilla. The axillary artery is at significant risk due to its proximity and the severe displacement. While the axillary nerve and brachial plexus are also at risk, arterial compromise (axillary artery) is a more acute and limb-threatening complication associated with the extreme force and direction of displacement in luxatio erecta, often leading to intimal tears or thrombosis.
Question 125
Topic: Surgical Anatomy & Approaches
When performing antegrade humeral intramedullary nailing, which specific nerve is most at risk during the proximal locking screw placement?
Correct Answer & Explanation
. Axillary nerve
Explanation
Correct Answer: ADuring proximal locking screw placement for an antegrade humeral intramedullary nail, the axillary nerve is most vulnerable. It courses around the surgical neck of the humerus, deep to the deltoid, and is susceptible to injury, particularly with excessively long screws or imprecise drilling techniques in the superolateral aspect of the proximal humerus. The radial nerve is at risk more distally, especially with distal locking or in the spiral groove. The ulnar, musculocutaneous, and median nerves are typically not at high risk with proximal humeral locking screws.
Question 126
Topic: Surgical Anatomy & Approaches
During a Latarjet procedure, the coracoid process is osteotomized and transferred to the anterior glenoid. Which two nerves are at the highest risk of iatrogenic injury during the coracoid mobilization and subsequent screw fixation?
Correct Answer & Explanation
. Musculocutaneous and axillary nerves
Explanation
The musculocutaneous nerve enters the conjoint tendon distally and is at risk during retraction. The axillary nerve courses inferiorly along the joint capsule and is at risk during inferior glenoid preparation and screw placement.
Question 127
Topic: Surgical Anatomy & Approaches
A 33-year-old overhead athlete undergoes an arthroscopic labral repair. Post-operatively, he notes new-onset numbness over the lateral aspect of his deltoid. Which arthroscopic portal placement is most strongly associated with this specific iatrogenic nerve injury?
Correct Answer & Explanation
. Anterior inferior portal (5 o'clock portal)
Explanation
The anterior inferior portal places the axillary nerve at risk due to its close proximity to the inferior capsular recess and axillary pouch. Injury causes numbness over the lateral deltoid (axillary nerve distribution).
Question 128
Topic: Surgical Anatomy & Approaches
An 18-year-old gymnast sustains an anterior shoulder dislocation. After successful closed reduction, she complains of decreased sensation over the lateral aspect of her deltoid muscle. Which of the following nerve roots primarily contributes to the injured nerve?
Correct Answer & Explanation
. C5, C6
Explanation
The axillary nerve is the most commonly injured nerve in anterior shoulder dislocations, presenting with lateral deltoid numbness. The axillary nerve arises from the posterior cord of the brachial plexus and carries fibers primarily from the C5 and C6 nerve roots.
Question 129
Topic: Surgical Anatomy & Approaches
During a posterior approach to the shoulder, the surgeon must carefully navigate the quadrangular space to avoid injury to the axillary nerve and posterior circumflex humeral artery. Which muscle forms the superior border of this anatomic space?
Correct Answer & Explanation
. Teres minor
Explanation
The quadrangular space is bordered superiorly by the teres minor, inferiorly by the teres major, medially by the long head of the triceps, and laterally by the surgical neck of the humerus. It transmits the axillary nerve and posterior circumflex humeral vessels.
Question 130
Topic: Surgical Anatomy & Approaches
During a posterior approach to the hip (Kocher-Langenbeck), the surgeon divides the short external rotators. Which specific tendinous structure is typically tagged and reflected posteriorly over the sciatic nerve to protect it during the procedure?
Correct Answer & Explanation
. Obturator internus
Explanation
During the posterior approach to the hip, the conjoined tendon of the obturator internus and the gemelli is tenotomized at its femoral insertion and reflected posteriorly. This creates a soft-tissue sling that protects the sciatic nerve from retractors during the operation.
Question 131
Topic: Surgical Anatomy & Approaches
A 65-year-old female undergoes a total hip arthroplasty utilizing the direct anterior approach (Smith-Petersen interval). Postoperatively, she reports a distressing patch of numbness and burning pain over the anterolateral aspect of her proximal thigh. Which nerve was most likely stretched or injured during the exposure?
Correct Answer & Explanation
. Lateral femoral cutaneous nerve
Explanation
The lateral femoral cutaneous nerve (LFCN) is highly vulnerable during the direct anterior approach to the hip due to its variable course near the anterior superior iliac spine (ASIS) and sartorius muscle. Injury results in anterolateral thigh numbness or meralgia paresthetica.
Question 132
Topic: Surgical Anatomy & Approaches
A 28-year-old male sustains a shoulder injury during a recreational wrestling match. Based on the likely diagnosis shown in the representative radiograph, which of the following is the most commonly associated nerve injury?
Correct Answer & Explanation
. Axillary nerve
Explanation
The most common nerve injury associated with an anterior shoulder dislocation is an axillary nerve neuropraxia. Patients should be carefully evaluated for altered sensation over the lateral shoulder (regimental badge area) and weakness in the deltoid muscle.
Question 133
Topic: Surgical Anatomy & Approaches
A 35-year-old male undergoes open posterior glenohumeral stabilization for recurrent posterior instability with significant glenoid retroversion. The surgeon plans a posterior deltoid-splitting approach to access the joint. During the approach, careful attention is paid to the internervous plane and nerve protection. The image below depicts a posterior shoulder approach.
Which of the following statements accurately describes the internervous plane utilized in this approach and a critical nerve to protect?
Correct Answer & Explanation
. The interval between the infraspinatus and teres minor, protecting the axillary nerve.
Explanation
Correct Answer: CThe case content explicitly describes the open posterior approach: 'The approach utilizes the interval between the infraspinatus (innervated by the suprascapular nerve) and the teres minor (innervated by the axillary nerve).' It also highlights that 'Care must be taken to identify and protect the axillary nerve, which typically courses horizontally approximately 5-7 cm distal to the acromial angle' and that 'The split should not extend more than 5 cm distally from the acromion to avoid injury to the axillary nerve.' Therefore, the interval between the infraspinatus and teres minor is the internervous plane, and the axillary nerve is a critical structure to protect.Option A describes an anterior approach and an incorrect nerve.Option B describes an incorrect interval and nerve.Option D describes an incorrect interval and nerve.Option E describes muscles involved in scapular stabilization, not the direct glenohumeral approach, and an incorrect nerve for this context.
Question 134
Topic: Surgical Anatomy & Approaches
A surgeon is performing an open coracoclavicular ligament reconstruction. During the exposure of the coracoid process, the clavipectoral fascia is incised lateral to the conjoint tendon. Referring to the provided image and the neurovascular anatomy described in the case, which critical neurovascular structure is at risk if dissection extends too far distally and medially from the coracoid tip?
Correct Answer & Explanation
. Musculocutaneous nerve
Explanation
Correct Answer: CUnder the 'Neurovascular Anatomy' section, the case states: 'When performing coracoid dissection, surgeons must remain acutely aware of the musculocutaneous nerve, which enters the conjoint tendon approximately 3 to 5 centimeters distal to the coracoid tip, and the underlying brachial plexus, which sits posteromedial to the coracoid base.' Dissection extending too far distally and medially from the coracoid tip would directly endanger the musculocutaneous nerve as it enters the conjoint tendon. The axillary and suprascapular nerves are typically at risk more posteriorly or superiorly, respectively. The lateral pectoral nerve innervates the pectoralis major and is generally more superior and medial. The thoracoacromial artery is a vascular structure, not a nerve, and while important for hemostasis, the question specifically asks for a neurovascular structure at risk in this specific location, with the musculocutaneous nerve being the most prominent neural structure in that immediate vicinity.
Question 135
Topic: Surgical Anatomy & Approaches
A surgeon is performing an anterolateral (deltoid-splitting) approach for a greater tuberosity fracture. To minimize the risk of iatrogenic injury to the axillary nerve, the surgeon must limit the deltoid split to a specific distance distal to the acromial border. What is the approximate safe limit for the deltoid split?
Correct Answer & Explanation
. 5 cm
Explanation
Correct Answer: CThe case specifically highlights the importance of limiting the deltoid split to approximately 5 cm distal to the acromial border when using the anterolateral approach. This is because the axillary nerve typically courses horizontally around the humerus at this level, and extending the split beyond this limit significantly increases the risk of iatrogenic nerve injury, which could lead to deltoid weakness or paralysis.
Question 136
Topic: Surgical Anatomy & Approaches
A 48-year-old male sustains a Holstein–Lewis fracture. On initial presentation, he has an incomplete radial nerve palsy (weak wrist extension, intact sensation). After a closed reduction attempt, his radial nerve palsy progresses to a complete motor and sensory deficit.
What is the most appropriate next step in the management of this patient's radial nerve injury?
Correct Answer & Explanation
. C. Proceed with immediate surgical exploration of the radial nerve concurrently with open reduction and internal fixation (ORIF).
Explanation
Correct Answer: CThe case study explicitly states under 'Indications for Operative Management' that if a radial nerve palsy 'worsens or develops following closed reduction attempts,' immediate surgical exploration is mandatory. This scenario suggests iatrogenic injury or worsening entrapment of the nerve by fracture fragments. While many neuropraxias recover spontaneously, a worsening palsy after manipulation is a critical indication for immediate surgical intervention to decompress or repair the nerve and stabilize the fracture.Option A is incorrect because worsening palsy post-reduction is an absolute indication for exploration, not observation. Option B (NCS/EMG) is not an emergent study and would delay critical intervention. Option D (functional brace and early ROM) is part of post-operative care, not the immediate management for a worsening nerve palsy. Option E (gabapentinoids for CRPS) is for a different complication and not the immediate concern.
Question 137
Topic: Surgical Anatomy & Approaches
A 55-year-old patient with a displaced Holstein–Lewis fracture and a complete radial nerve palsy at presentation is scheduled for ORIF.
Which surgical approach is generally preferred for this fracture pattern, and what is the most critical step regarding radial nerve management during the procedure?
Correct Answer & Explanation
. B. Posterior approach (triceps-sparing); identifying the radial nerve proximally in the spiral groove and tracking it distally.
Explanation
Correct Answer: BThe case study states that the 'Posterior Approach (Triceps-Sparing or Triceps-Splitting)' is often the preferred approach for Holstein–Lewis fractures, particularly when radial nerve exploration is anticipated or required, as it provides excellent direct visualization of the fracture site and the radial nerve as it exits the spiral groove. The most crucial step is 'Radial Nerve Identification,' which involves identifying the nerve proximally in the spiral groove and tracking it distally to the fracture site, carefully inspecting it for injury or entrapment.Option A (Anterolateral approach) can be used but is less preferred when direct radial nerve exploration is the primary indication. The musculocutaneous nerve is not the primary concern in Holstein–Lewis fractures. Option C (Medial approach) is not the standard for Holstein–Lewis fractures, and while ulnar nerve protection is important, it's not the primary nerve at risk in this specific fracture. Option D (Deltopectoral approach) is for proximal humerus fractures. Option E (Lateral approach) is not the primary approach, and the posterior interosseous nerve is a distal branch of the radial nerve, not the main site of vulnerability in this fracture pattern.
Question 138
Topic: Surgical Anatomy & Approaches
A 40-year-old patient presents with a Holstein–Lewis fracture. On initial examination, he has no signs of radial nerve palsy. After successful closed reduction and application of a functional brace, he develops a complete radial nerve palsy 24 hours later.
This scenario represents a secondary radial nerve palsy. What is the critical implication for management compared to a primary palsy present at initial presentation?
Correct Answer & Explanation
. B. Secondary palsies require immediate surgical exploration, as they often indicate iatrogenic injury or worsening entrapment.
Explanation
Correct Answer: BThe 'Summary of Key Literature / Guidelines' section, under 'Immediate vs. Delayed Exploration,' clearly states: 'If a radial nerve palsy develops or worsens after attempts at closed reduction, or post-operatively,immediate surgical exploration is mandatory. This suggests iatrogenic injury or worsening entrapment.' This is a critical distinction from primary palsy (palsy at presentation), where immediate exploration is often recommended but sometimes observation is considered for incomplete palsies, though less common for classic Holstein-Lewis patterns due to high entrapment risk.Option A is incorrect; secondary palsies are a red flag for iatrogenic injury and require immediate exploration. Option C reverses the urgency; secondary palsies are often more concerning due to their iatrogenic nature. Option D (immediate tendon transfers) is a salvage procedure for chronic, non-recovering palsy, not acute management. Option E is incorrect as the timing of palsy onset significantly impacts the management strategy.
Question 139
Topic: Surgical Anatomy & Approaches
A 30-year-old patient with a Holstein–Lewis fracture sustained a complete radial nerve transection that was not amenable to primary repair during initial surgery. Despite secondary nerve grafting 6 months later, there is no evidence of recovery after 18 months.
Given the persistent complete radial nerve palsy after 18 months, what is the most appropriate long-term salvage strategy to restore functional wrist and finger extension?
Correct Answer & Explanation
. C. Tendon transfers (e.g., pronator teres to ECRB, FCR to EDC, palmaris longus to EPL).
Explanation
Correct Answer: CThe 'Complications & Management' section, under 'Radial Nerve Palsy (Persistent/New),' states: 'If palsy persists >3-6 months post-injury: Consider secondary surgical exploration (neurolysis, repair, or grafting).Chronic palsy (>1 year): Tendon transfers (e.g., pronator teres to ECRB, FCR to EDC, palmaris longus to EPL) for functional restoration.' After 18 months with no recovery following nerve grafting, the likelihood of spontaneous or further surgical nerve recovery is very low, making tendon transfers the definitive functional salvage procedure.Option A (repeat nerve grafting) is generally not indicated after 18 months of no recovery following a previous graft, as the window for nerve regeneration is typically considered closed or severely limited. Option B (chronic pain management) addresses symptoms but not the functional deficit. Option D (permanent immobilization) would result in a non-functional limb. Option E (electrical stimulation) is an adjunctive therapy, not a primary salvage strategy for a complete, chronic palsy.
Question 140
Topic: Surgical Anatomy & Approaches
A surgeon is performing an open reduction and internal fixation of an isolated, displaced greater tuberosity fracture using a direct lateral (deltoid-splitting) approach. To avoid iatrogenic nerve injury, the distal extent of the deltoid split must not exceed what distance from the lateral edge of the acromion?
Correct Answer & Explanation
. 5-7 cm
Explanation
The axillary nerve runs transversely across the deep surface of the deltoid approximately 5 to 7 cm distal to the lateral edge of the acromion. The deltoid split must stay proximal to this to prevent nerve injury.
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