Menu

Surgical Anatomy & Approaches MCQs

Practice Set 21 of 102

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 401

Topic: Surgical Anatomy & Approaches

What is the most common neurologic problem associated with a simple shoulder dislocation? Review Topic

. A neurapraxic brachial plexus injury
. A neurapraxic axillary nerve injury
. A neurapraxic musculocutaneous nerve injury
. A neurotmetic axillary nerve injury
. An axonotmetic musculocutaneous nerve injury

Correct Answer & Explanation

. A neurapraxic brachial plexus injury

Explanation

The most common nerve injury associated with dislocation of the shoulder involves the axillary nerve. This is typically a stretch injury, or neurapraxia, that occurs with anterior displacement of the humeral head out of the glenoid. The suspected diagnosis can be confirmed with neurodiagnostic testing after the first 2 to 3 weeks. A gradual return to normal function is the expected result, though mild deficits may remain. A neurotmetic injury, in which there is complete disruption of the entire nerve, would show no return of function. This type of injury is more likely associated with a penetrating injury, a laceration secondary to a fracture fragment, or occasionally with a direct blow of sufficient force.

Question 402

Topic: Surgical Anatomy & Approaches
When performing a Kocher approach to the radial head for open reduction internal fixation, the forearm is held in pronation. What structure is this maneuver attempting to protect?
. Median nerve
. Brachial artery
. Anterior interosseous nerve
. Radial nerve
. Posterior interosseous nerve

Correct Answer & Explanation

. Posterior interosseous nerve

Explanation

DISCUSSION: Dilberti et al quantified the dimensions of a surgically safe zone (with respect to the posterior interosseous nerve) when using the posterolateral approach to the radial head between the anconeus and the extensor carpi ulnaris. They found that the safe zone increased with pronation and decreased with supination.

Question 403

Topic: Surgical Anatomy & Approaches
Which of the following muscles has dual innervation?
. Pronator teres
. Flexor digitorum superficialis
. Coracobrachialis
. Latissimus dorsi
. Brachialis

Correct Answer & Explanation

. Brachialis

Explanation

DISCUSSION: The brachialis muscle typically receives dual innervation. The major portion is innervated by the musculocutaneous nerve. Its inferolateral portion is innervated by the radial nerve. The others listed have single innervation. The anterior approach to the humerus, which requires splitting of the brachialis, capitalizes on this dual innervation. REFERENCE: Mahakkanukrauh P, Somsarp V: Dual innervation of the brachialis muscle. Clin Anat 2002;15:206-209.

Question 404

Topic: Surgical Anatomy & Approaches

During a direct anterior approach for a total hip arthroplasty, the surgeon dissects through the superficial internervous plane. Which two nerves supply the muscles that define this specific interval?

. Femoral nerve and inferior gluteal nerve
. Femoral nerve and superior gluteal nerve
. Obturator nerve and superior gluteal nerve
. Sciatic nerve and femoral nerve
. Lateral femoral cutaneous nerve and obturator nerve

Correct Answer & Explanation

. Femoral nerve and inferior gluteal nerve

Explanation

The direct anterior (Smith-Petersen) approach utilizes a true internervous plane. Superficial dissection occurs between the sartorius (innervated by the femoral nerve) and the tensor fasciae latae (innervated by the superior gluteal nerve). The deep interval is between the rectus femoris (femoral nerve) and the gluteus medius (superior gluteal nerve).

Question 405

Topic: Surgical Anatomy & Approaches

During a standard posterior approach to the hip for a THA, the short external rotators are tagged and reflected over the posterior capsule. Which of the following structures is most at risk of iatrogenic injury if a retractor is placed too aggressively deep and posterior to the acetabulum?

. Femoral nerve
. Obturator nerve
. Sciatic nerve
. Superior gluteal nerve
. Inferior gluteal artery

Correct Answer & Explanation

. Femoral nerve

Explanation

The sciatic nerve lies posterior to the external rotators. Retractors placed deep and posterior to the acetabulum, especially without the protection of the reflected external rotators, place the sciatic nerve at direct risk of compression or laceration.

Question 406

Topic: Surgical Anatomy & Approaches
What neurovascular structure is most at risk when performing an inside-out repair of the posterior horn of the medial meniscus?
. Popliteal artery
. Peroneal nerve
. Saphenous nerve
. Tibial nerve
. Sciatic nerve

Correct Answer & Explanation

. Saphenous nerve

Explanation

DISCUSSION: The saphenous nerve is located on the posterior medial aspect of the knee and must be protected when performing an inside-out repair of the medial meniscus. The peroneal nerve is most at risk with lateral meniscal repairs. The other structures usually are not at risk with meniscal repair. REFERENCES: Cannon WD Jr, Morgan CD: Meniscal repair: Arthroscopic repair techniques. Instr Course Lect 1994;43:77-96. Scott GA, Jolly BL, Henning CE: Combined posterior incision and arthroscopic intra-articular repair of the meniscus: An examination of factors affecting healing. J Bone Joint Surg Am 1986;68:847-861.

Question 407

Topic: Surgical Anatomy & Approaches
An adult patient has a closed humeral fracture that was treated nonsurgically and a concomitant radial nerve injury. Six weeks after injury, electromyography shows no evidence of recovery. Management should now consist of:
. exploration and neurolysis/repair.
. MRI of the arm.
. functional electrical stimulation.
. radial nerve tendon transfers.
. observation.

Correct Answer & Explanation

. observation.

Explanation

In patients with radial nerve injuries with closed humeral fractures, it has been reported that 85% to 95% spontaneously recover. Based on this premise, most surgeons favor expectant management of these injuries. Even if there is no evidence of recovery at 6 weeks, repeat electromyography at 12 weeks is advocated. If there are no clinical or electromyographic signs of recovery at 6 months, exploration is recommended.

Question 408

Topic: Surgical Anatomy & Approaches

A 16-year-old girl sustains the closed injury shown in Figure 1. On physical examination, she is found to have a complete radial nerve palsy. Her fracture is treated nonsurgically, and her nerve palsy is followed clinically for improvement. What muscle is most likely to improve last as her nerve recovers?

. Brachioradialis (BR)
. Extensor carpi radialis brevis (ECRB)
. Extensor carpi ulnaris (ECU)
. Extensor indicis proprius (EIP)The incidence of radial nerve palsy after a humeral shaft fracture has been estimated as being between 7% and 22%. Controversy remains regarding the need for early exploration in a patient presenting with a closed humerus fracture and concurrent radial nerve palsy, because approximately 77% of patients treated without explorationhave spontaneous recovery of radial nerve function. Within 3 to 4 months of the injury, the BR and extensor carpi radialis longus (ECRL) should begin to show signs of reinnervation. Anatomic studies have demonstrated a relatively consistent order of the radial nerve motor branches in the forearm (proximal to distal): BR, ECRL, supinator, ECRB, extensor digitorum communis, ECU, extensor digit quinti, abductor pollicis longus, extensor pollicis longus, extensor pollicis brevis, and EIP. Because the EIP is the last motor branch from the radial nerve, it is likely to be the last to recover following a high radial nerve palsy.

Correct Answer & Explanation

. Brachioradialis (BR)

Explanation

A 35-year-old man reports ulnar sided wrist pain. Radiographs show ulnar positive variance with cystic changes in the ulnar head and lunate. His body mass index (BMI) is 22, and he has had a 1.5-pack-per-day smoking history for the past 10 years. He undergoes an oblique ulnar shortening osteotomy with volar placement of the plate. Nine months after surgery, he reports continued pain, and radiographs reveal a nonunion. Of the factors cited for this patient, which has been shown to most likely increase the risk of nonunion?

Question 409

Topic: Surgical Anatomy & Approaches
A 25-year-old male presents to the emergency department with a mangled lower extremity that is not salvageable. He undergoes transfemoral amputation. Three months later the patient presents to the office with the limb sitting in an abducted position. What important step was forgotten during the amputation?
. Beveling the distal femur
. Saving the patella
. Allowing the sciatic nerve to retract deep into the soft tissue
. Myodesis of the adductors
. Timely fitting of orthosis

Correct Answer & Explanation

. Myodesis of the adductors

Explanation

DISCUSSION: Prior to the late 80’s, techniques for transfemoral amputation sacrificed the hip adductor muscles resulting in unopposed abductor forces. Amputation with an abducted femur leads to an increase in side lurch and higher energy consumption. Gottschalk in ’99 showed that myodesis of the adductor magnus through drill holes in the lateral femur preserved maximum muscle force and provided a mechanical advantage for the adductors of the thigh. This resulted in maintenance of the normal anatomic alignment of the femur and a balance between the abductor and adductor mechanisms of the hip, thus providing patients with improved control and easier prosthesis fit.

Question 410

Topic: Surgical Anatomy & Approaches
On average, the radial nerve travels from the posterior compartment of the arm to the anterior compartment at which of the following sites?
. Spiral groove of the humerus
. At the arcuate ligament of Osborne
. 10 cm distal to the lateral acromion
. 10 cm proximal to radiocapitellar joint
. At the origin of the deep head of the triceps

Correct Answer & Explanation

. 10 cm proximal to radiocapitellar joint

Explanation

DISCUSSION: The radial nerve enters the anterior compartment through the intercompartmental fascia on average 10 cm proximal to the radiocapitellar joint. It has never been found to remain in the posterior compartment within the distal arm.

Question 411

Topic: Surgical Anatomy & Approaches
In the anterior approach (Smith-Petersen) to the hip, dissection is carried out between muscles innervated by the
. superior gluteal nerve laterally and the obturator nerve medially.
. superior gluteal nerve laterally and the femoral nerve medially.
. superior gluteal nerve medially and the femoral nerve laterally.
. superior gluteal nerve medially and the inferior gluteal nerve laterally.
. femoral nerve laterally and the obturator nerve medially.

Correct Answer & Explanation

. superior gluteal nerve laterally and the femoral nerve medially.

Explanation

In the Smith-Petersen approach to the hip, dissection is carried out between the tensor fascia lata laterally (supplied by the superior gluteal nerve) and the sartorius and rectus femoris medially (both supplied by the femoral nerve).

Question 412

Topic: Surgical Anatomy & Approaches
A 25-year-old patient presents with a posterior wall/posterior column acetabular fracture. She is scheduled for open reduction internal fixation through a posterior approach. What position of the leg exerts the least amount of intraneural pressure on the sciatic nerve?
. hip flexion, knee extension
. hip extension, knee extension
. hip flexion, knee flexion
. hip extension, knee flexion
. the pressure does not vary based on position

Correct Answer & Explanation

. hip extension, knee flexion

Explanation

DISCUSSION: In the cited study, researchers measured tissue fluid pressure within the sciatic nerve in cadaveric specimens using a pressure transducer. The hip and knee were taken through a combination of ranges and found that the clinically relevant increase in pressure happened with the hip flexed at 90 degrees and the knee fully extended. They concluded that increased intraneural pressure was related to excursion of the nerve as linear distance between the greater sciatic notch and the distal leg increase. Hence, according to the question stem, to avoid traction injury, the reverse position should be implemented (hip extension and knee flexion).

Question 413

Topic: Surgical Anatomy & Approaches
A 35-year-old male sustains a posterior column/posterior wall acetabular fracture. Which of the following is the preferred approach for open treatment of this injury?
. Modified Stoppa approach
. Extended iliofemoral approach
. Kocher-Langenbach approach
. Ilioinguinal approach
. Combined

Correct Answer & Explanation

. Kocher-Langenbach approach

Explanation

DISCUSSION: Operative treatment is indicated for most displaced acetabular fractures to allow early ambulatory function and to decrease the chance of post-traumatic arthritis. Among the various surgical approaches, the Kocher-Langenbach allows direct exposure of both the posterior column and posterior wall. Indications for using this exposure include posterior wall fractures, posterior column fractures, combined posterior wall/posterior column fractures, and simple transverse fractures.

Question 414

Topic: Surgical Anatomy & Approaches
A patient sustains a displaced scapular neck fracture. What is the internervous plane for a posterior approach to the glenohumeral joint?
. lateral pectoral-axillary
. subscapular-musculocutaneous
. suprascapular-axillary
. long thoracic-spinal accessory
. suprascapular-subscapular

Correct Answer & Explanation

. suprascapular-axillary

Explanation

DISCUSSION: Surgical fixation of a scapular neck fracture is performed via the Judet approach, a posterior approach to the scapula/glenoid. The internervous plane is between the infraspinatus (suprascapular nerve) and the teres minor (axillary nerve). As outlined by Ball et al, the posterior branch of the axillary nerve has intimate association with the inferior aspects of the glenoid and shoulder joint capsule, which may place it at particular risk during a posterior approach to the shoulder.

Question 415

Topic: Surgical Anatomy & Approaches
What structure is 7cm from the acromion and at greatest risk of injury during a deltoid splitting approach for a proximal humerus fracture?
. Radial nerve
. Suprascapular nerve
. Axillary nerve
. Axillary artery
. Axillary vein

Correct Answer & Explanation

. Axillary nerve

Explanation

DISCUSSION: The axillary nerve is located approximately 7cm from the tip of the acromion. The axillary nerve comes off the brachial plexus (middle trunk, posterior division, posterior cord) carrying fibers from C5 and C6. The axillary nerve travels through the quadrangular space with the posterior circumflex humeral artery and vein to innervate the teres minor and deltoid muscles and supply sensation over the lateral shoulder. Based on the knowledge of the course of the axillary nerve, and potential complications regarding the vascular supply to the humeral head with the delto-pectoral approach, some authors are suggesting deltoid-splitting approach to the proximal humerus for reduction and fixation of proximal humeral fractures.

Question 416

Topic: Surgical Anatomy & Approaches

A 22-year-old rugby player undergoes an open Latarjet procedure for recurrent anterior shoulder instability with 30% glenoid bone loss. Postoperatively, he exhibits profound weakness in elbow flexion and decreased sensation over the lateral forearm. Which of the following structures was most likely injured during the surgical approach?

. Axillary nerve
. Radial nerve
. Median nerve
. Musculocutaneous nerve
. Ulnar nerve

Correct Answer & Explanation

. Axillary nerve

Explanation

The musculocutaneous nerve is the most frequently injured nerve during the Latarjet procedure due to its proximity to the coracoid process and the conjoint tendon (which is mobilized and transferred). It pierces the coracobrachialis muscle on average 5-8 cm distal to the coracoid tip. Injury leads to biceps/brachialis weakness and numbness over the lateral cutaneous nerve of the forearm.

Question 417

Topic: Surgical Anatomy & Approaches

A 24-year-old female with developmental dysplasia of the hip undergoes a Bernese periacetabular osteotomy (PAO). Through the standard Smith-Petersen approach, which osteotomy is typically performed first and requires fluoroscopy to ensure it is incomplete and does not enter the joint?

. Incomplete ischial osteotomy
. Superior pubic ramus osteotomy
. Supra-acetabular iliac osteotomy
. Retroacetabular osteotomy

Correct Answer & Explanation

. Incomplete ischial osteotomy

Explanation

The incomplete ischial osteotomy is typically the first bone cut in a Bernese PAO. It is performed just distal to the acetabulum, leaving the posterior column intact, and requires fluoroscopy to avoid intra-articular penetration.

Question 418

Topic: Surgical Anatomy & Approaches

When performing hip arthroscopy, the hip should be placed in neutral to slight internal rotation to protect which of the following structures? Review Topic

. Femoral nerve
. Lateral femoral cutaneous nerve
. Ascending lateral femoral circumflex artery
. Ascending medial femoral circumflex artery
. Sciatic nerve

Correct Answer & Explanation

. Femoral nerve

Explanation

The sciatic nerve is at greatest risk for injury during hip arthroscopy with placement of a posterolateral (posterior paratrochanteric portal). It can be within 3 cm of this portal. Advancing the trocar with the hip in neutral to slight internal rotation helps to protect the sciatic nerve from iatrogenic injury. The two structures in closest proximity with placement of arthroscopy portals are the lateral femoral cutaneous nerve (anterior portal) and the ascending branch of the lateral femoral circumflex artery (mid-anterior portal). The femoral nerve and medial femoral circumflex arteries are located medial to these anterior portals. Rotation of the hip has not been associated with increased risk of injury to any of these additional structures.

Question 419

Topic: Surgical Anatomy & Approaches

The 'MESS' (Mangled Extremity Severity Score) is a historical clinical tool designed to help predict the necessity of primary amputation versus limb salvage in severe lower extremity trauma. Which of the following variables is NOT formally included in the calculation of the MESS?

. Patient age
. Limb ischemia time and severity
. Presence of shock (hypotension)
. Skeletal and soft-tissue injury energy mechanism
. Presence of a neurological motor deficit

Correct Answer & Explanation

. Patient age

Explanation

The MESS evaluates 4 parameters: Skeletal/soft-tissue injury mechanism (1-4 points), Limb ischemia (1-3 points, doubled if ischemia >6 hours), Shock (0-2 points), and Patient Age (0-2 points). While an absent plantar sensation or sciatic nerve deficit is highly clinically relevant in decision-making, neurological deficit is NOT a mathematically scored variable in the MESS.

Question 420

Topic: Surgical Anatomy & Approaches

During a volar approach (Henry approach) for open reduction and internal fixation of a distal radius fracture, the surgeon develops the internervous plane. Which two structures define this primary interval?

. Flexor carpi radialis (FCR) and the radial artery
. Brachioradialis and the radial artery
. Flexor carpi ulnaris (FCU) and the ulnar artery
. Flexor pollicis longus (FPL) and the median nerve
. Pronator quadratus and the interosseous membrane

Correct Answer & Explanation

. Flexor carpi radialis (FCR) and the radial artery

Explanation

The classic volar (Henry) approach to the distal radius utilizes the interval between the flexor carpi radialis (FCR) tendon (median nerve) and the radial artery. The FCR is retracted medially and the radial artery laterally to expose the deeper structures.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page