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Surgical Anatomy & Approaches MCQs

Practice Set 10 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 181

Topic: Surgical Anatomy & Approaches

The image below illustrates the medial window of the ilioinguinal approach. During the development of this window, which anatomical variant must be anticipated and carefully managed to prevent significant hemorrhage?

. Aberrant course of the lateral femoral cutaneous nerve
. High bifurcation of the femoral artery
. The 'corona mortis' anastomosis
. Accessory obturator nerve branch
. Deep circumflex iliac artery

Correct Answer & Explanation

. The 'corona mortis' anastomosis

Explanation

Correct Answer: CDuring the development of the medial window, meticulous dissection is performed along the superior pubic ramus, deep to the pubic tubercle. In this region, the 'corona mortis' (crown of death) is an anatomical variant involving an anastomosis between the obturator and external iliac/inferior epigastric vessels. This vascular connection crosses the superior pubic ramus in 10-30% of cases and can cause significant, life-threatening bleeding if inadvertently injured. Therefore, careful identification and either ligation and division or protection of these vessels are critical. The lateral femoral cutaneous nerve is relevant to the lateral aspect of the incision, not the medial window. A high bifurcation of the femoral artery or an accessory obturator nerve branch are not specific to this region or associated with the same risk of massive hemorrhage. The deep circumflex iliac artery is typically encountered more laterally along the iliac crest.

Question 182

Topic: Surgical Anatomy & Approaches

The image below demonstrates the middle window of the ilioinguinal approach. Which of the following structures, located deep to the external iliac vein in this region, requires meticulous protection to prevent iatrogenic injury during dissection and retraction?

. Ilioinguinal nerve
. Lateral femoral cutaneous nerve
. Femoral nerve
. Obturator nerve and vessels
. Superior gluteal nerve

Correct Answer & Explanation

. Obturator nerve and vessels

Explanation

Correct Answer: DThe middle window of the ilioinguinal approach involves the careful medial retraction of the femoral neurovascular bundle (femoral artery, vein, and nerve) along with the iliopsoas muscle. Deep to the external iliac vein, the obturator nerve and vessels cross the medial aspect of this window. Injury to these structures is rare but can lead to adductor weakness (obturator nerve) or significant hemorrhage (obturator vessels). Therefore, meticulous dissection and careful retraction are essential to protect the obturator nerve and vessels in this critical area. The ilioinguinal and lateral femoral cutaneous nerves are more superficial and lateral, respectively. The femoral nerve is part of the bundle being retracted. The superior gluteal nerve is located more posteriorly, exiting the pelvis through the greater sciatic notch, and is not directly exposed or at risk in the ilioinguinal approach.

Question 183

Topic: Surgical Anatomy & Approaches

A 45-year-old male sustains a posterior wall acetabular fracture with a posterior hip dislocation. Closed reduction is performed in the emergency department. Which of the following findings is the most definitive indication for operative fixation of the posterior wall fragment?

. Fragment size comprising 15% of the posterior articular surface
. Displacement of the fragment by 1 mm
. Dynamic instability of the hip joint in flexion and internal rotation under anesthesia
. Concomitant partial sciatic nerve palsy present before reduction
. Presence of marginal impaction on CT scan

Correct Answer & Explanation

. Dynamic instability of the hip joint in flexion and internal rotation under anesthesia

Explanation

Dynamic stress fluoroscopy under anesthesia is the most definitive method to assess hip stability. Hip instability is an absolute indication for operative fixation, even if the fragment size is considered borderline.

Question 184

Topic: Surgical Anatomy & Approaches

A trauma surgeon is performing an ilioinguinal approach for a complex anterior column acetabular fracture. The middle window is developed to access the pelvic brim. What structure defines the medial boundary of this middle window?

. Iliopectineal fascia
. External iliac vessels
. Symphysis pubis
. Spermatic cord
. Rectus abdominis muscle

Correct Answer & Explanation

. Iliopectineal fascia

Explanation

The middle window of the ilioinguinal approach is bounded laterally by the iliopectineal fascia and medially by the external iliac vessels. It allows direct access to the pelvic brim and quadrilateral plate.

Question 185

Topic: Surgical Anatomy & Approaches

During the distal portion of a volar (Henry) approach to the radius for fracture fixation, the surgeon develops an internervous plane. Which two structures define this distal interval?

. Flexor carpi radialis and palmaris longus
. Brachioradialis and flexor carpi radialis
. Flexor carpi ulnaris and flexor digitorum superficialis
. Pronator teres and flexor carpi radialis
. Extensor carpi radialis longus and brevis

Correct Answer & Explanation

. Brachioradialis and flexor carpi radialis

Explanation

The distal interval of the Henry approach is between the brachioradialis (innervated by the radial nerve) and the flexor carpi radialis (innervated by the median nerve). This true internervous plane provides safe access to the volar distal radius.

Question 186

Topic: Surgical Anatomy & Approaches

During a Kocher-Langenbeck approach for a posterior wall acetabular fracture, the surgeon must carefully protect the sciatic nerve. Which of the following patient positioning maneuvers most effectively decreases tension on the sciatic nerve during this approach?

. Hip flexion and knee extension
. Hip extension and knee flexion
. Hip flexion and knee flexion
. Hip extension and knee extension
. Hip abduction and knee extension

Correct Answer & Explanation

. Hip extension and knee flexion

Explanation

To minimize tension on the sciatic nerve during the Kocher-Langenbeck approach, the hip should be extended and the knee flexed. The peroneal division of the sciatic nerve is particularly vulnerable to stretch injury during retraction.

Question 187

Topic: Surgical Anatomy & Approaches

During the modified Stoppa approach for an anterior acetabular fracture, the surgeon must elevate a specific fascial layer to access the quadrilateral plate. Which of the following structures must be incised or elevated?

. Fascia lata
. Iliopectineal fascia
. Inguinal ligament
. Lacunar ligament
. Transversalis fascia

Correct Answer & Explanation

. Iliopectineal fascia

Explanation

In the modified Stoppa approach, the iliopectineal fascia must be divided to allow access to the true pelvis and the quadrilateral plate. Failure to divide this fascia prevents adequate medialization and visualization of the fracture.

Question 188

Topic: Surgical Anatomy & Approaches

A 45-year-old male undergoes open reduction and internal fixation of a posterior wall acetabular fracture via a Kocher-Langenbeck approach. Postoperatively, he exhibits a foot drop and inability to extend his great toe. Which anatomical characteristic best explains why the affected nerve division is disproportionately injured during this procedure?

. It is located medial to the tibial nerve division.
. It has a thicker epineurium than the tibial division.
. It is tethered at the greater sciatic notch and has less protective connective tissue.
. It courses anterior to the piriformis muscle in the majority of patients.
. It possesses a larger number of motor fibers overall.

Correct Answer & Explanation

. It is tethered at the greater sciatic notch and has less protective connective tissue.

Explanation

The peroneal division of the sciatic nerve is most commonly injured due to its lateral and superficial location within the nerve bundle. It also contains less protective epineurium and is tethered between the sciatic notch and fibular head.

Question 189

Topic: Surgical Anatomy & Approaches

During a modified Stoppa approach for an anterior column acetabular fracture, the surgeon dissects along the superior pubic ramus. Massive hemorrhage occurs from a vessel located approximately 5 cm lateral to the pubic symphysis. This structure represents an anastomosis between which two vascular systems?

. External iliac and internal pudendal
. External iliac and obturator
. Superior gluteal and inferior gluteal
. Internal iliac and femoral
. Deep circumflex iliac and obturator

Correct Answer & Explanation

. External iliac and obturator

Explanation

The corona mortis is a vascular anastomosis between the external iliac (or inferior epigastric) and the obturator vessels. It lies on the posterior aspect of the superior pubic ramus and is highly vulnerable during anterior intrapelvic approaches.

Question 190

Topic: Surgical Anatomy & Approaches

A 45-year-old male undergoes open reduction and internal fixation of a posterior wall acetabular fracture via a Kocher-Langenbeck approach. Post-operatively, he is noted to have a profound foot drop. Which specific lower extremity positioning maneuver during the surgical exposure most likely increased the risk of this iatrogenic complication?

. Hip extension and knee flexion
. Hip flexion and knee extension
. Hip flexion and knee flexion
. Hip abduction and internal rotation
. Hip extension and knee extension

Correct Answer & Explanation

. Hip flexion and knee extension

Explanation

During the Kocher-Langenbeck approach, the sciatic nerve is at high risk for stretch injury. Maintaining the hip in extension and the knee in flexion relaxes the sciatic nerve, whereas hip flexion combined with knee extension places the nerve under maximal tension.

Question 191

Topic: Surgical Anatomy & Approaches

During an ilioinguinal approach for an anterior column acetabular fracture, brisk arterial bleeding is encountered on the posterior aspect of the superior pubic ramus, roughly 5 cm lateral to the pubic symphysis. Which of the following anatomic descriptions best characterizes the vessel most likely injured?

. An anastomosis between the internal pudendal and external pudendal vessels
. An anastomosis between the obturator and inferior epigastric or external iliac vessels
. An anastomosis between the superior gluteal and internal iliac vessels
. A direct branch of the medial femoral circumflex artery
. An anastomosis between the iliolumbar and superior gluteal arteries

Correct Answer & Explanation

. An anastomosis between the obturator and inferior epigastric or external iliac vessels

Explanation

The bleeding is from the corona mortis, an anatomic variant anastomosis connecting the obturator system with the external iliac or inferior epigastric systems. It crosses the superior pubic ramus and is highly susceptible to iatrogenic injury during the ilioinguinal approach.

Question 192

Topic: Surgical Anatomy & Approaches

During surgical planning for a Lisfranc injury, the surgeon reviews the patient's CT scan, which confirms a fracture-dislocation involving the second and third tarsometatarsal joints. The surgical approach will involve two dorsal incisions. The dorsal incision for the second/third ray is typically placed between which two structures, and what neurovascular structure is at highest risk?

. Between the tibialis anterior and extensor hallucis longus tendons; the saphenous nerve.
. Between the extensor hallucis longus and extensor digitorum longus tendons; the deep peroneal nerve.
. Between the extensor digitorum longus and peroneus tertius tendons; the superficial peroneal nerve.
. Medial to the tibialis anterior tendon; the posterior tibial nerve.
. Lateral to the extensor digitorum longus tendons; the sural nerve.

Correct Answer & Explanation

. Between the extensor hallucis longus and extensor digitorum longus tendons; the deep peroneal nerve.

Explanation

Correct Answer: BThe case details the surgical approach: 'A dorsal incision (Second/Third Ray) is a longitudinal incision over the second TMT joint, often extending to expose the third TMT joint. This incision is placed between the extensor hallucis longus (EHL) and extensor digitorum longus (EDL) tendons, or specifically between the EHL and the tendon to the second toe.' It further states: 'Careful dissection is paramount to avoid neurovascular injury, protecting the dorsalis pedis artery and deep peroneal nerve, which typically lie laterally to the EHL.' Therefore, the deep peroneal nerve is the neurovascular structure at highest risk with this incision. The other options describe incorrect internervous planes or nerves not primarily at risk with this specific dorsal incision.

Question 193

Topic: Surgical Anatomy & Approaches

During a single-incision anterior repair of a distal biceps tendon rupture, the surgeon has retrieved the retracted tendon and is preparing the radial tuberosity for fixation. The image below depicts a surgical field during such a procedure.

. Maintaining the elbow in full extension
. Placing a deep retractor medially to protect the brachial artery
. Keeping the forearm in full supination
. Placing the forearm in full pronation and using a deep retractor laterally
. Identifying and dissecting the PIN proximally to the supinator muscle

Correct Answer & Explanation

. Placing the forearm in full pronation and using a deep retractor laterally

Explanation

Correct Answer: DThe 'Surgical Approach & Technique' section, under 'Protection of the Radial Nerve (PIN)', explicitly states:"With the forearm in full pronation, the posterior interosseous nerve (PIN)... moves away from the surgical field, typically posterior to the radial tuberosity and deep to the supinator muscle. This maneuver increases the distance between the PIN and the radial tuberosity. A deep, blunt Hohmann or cobra retractor is placed beneath the brachioradialis and supinator, hugging the anterior surface of the radius, retracting the muscle belly laterally to expose the radial tuberosity. This retractor acts as a physical barrier, protecting the PIN from drilling and reaming."Maintaining full extension or supination would place the PIN at greater risk. While protecting the brachial artery is important, it is done with careful medial retraction, not specifically for PIN protection. Identifying and dissecting the PIN proximally is not the primary protective maneuver during tuberosity preparation.

Question 194

Topic: Surgical Anatomy & Approaches

A 60-year-old male underwent a regional fasciectomy for a severe PIP joint contracture of his ring finger. Post-operatively, the surgeon decided to insert a temporary K-wire across the PIP joint. Based on the provided case information, what is the primary rationale for using a K-wire in this scenario, and what is a potential drawback?

. To prevent infection; however, it increases the risk of nerve injury.
. To maintain extension for 2-3 weeks; however, it may increase stiffness risk.
. To facilitate early active range of motion; however, it increases the risk of hematoma.
. To provide pain relief; however, it can lead to skin necrosis.
. To allow for immediate full weight-bearing; however, it can cause CRPS.

Correct Answer & Explanation

. To maintain extension for 2-3 weeks; however, it may increase stiffness risk.

Explanation

Correct Answer: BExplanation:Option B is correct.The 'Detailed Surgical Approach / Technique' section, under 'K-wire Fixation,' states: 'For severe PIP joint contractures (especially > 60-70 degrees) that are difficult to hold in extension post-operatively, a temporary K-wire (e.g., 0.035" or 0.045") can be inserted across the PIP joint to maintain extension for 2-3 weeks. This helps prevent early re-contracture but may increase stiffness risk.' This directly matches the rationale and potential drawback described in the option.Option A is incorrect.K-wires are not primarily used to prevent infection, although any foreign body can potentially introduce infection. They do not inherently increase the risk of nerve injury if placed correctly.Option C is incorrect.K-wires temporarily immobilize the joint, which restricts early active range of motion at that specific joint, rather than facilitating it. While they help maintain extension, they are not for immediate full weight-bearing and do not directly increase hematoma risk.Option D is incorrect.K-wires do not provide pain relief; in fact, they can be a source of discomfort. While skin issues around the pin site can occur, skin necrosis is not a primary or common direct complication of K-wire use in this context.Option E is incorrect.K-wires are not for immediate full weight-bearing. While CRPS is a potential complication of any hand surgery, K-wire use is not specifically highlighted as a direct cause of CRPS, nor is it related to weight-bearing.

Question 195

Topic: Surgical Anatomy & Approaches

A 6-year-old child falls on an outstretched hand and sustains an extension-type supracondylar humerus fracture. Radiographs demonstrate posteromedial displacement of the distal fragment. Which nerve is most at risk of injury in this specific displacement pattern?

. Ulnar nerve
. Radial nerve
. Anterior interosseous nerve
. Posterior interosseous nerve
. Musculocutaneous nerve

Correct Answer & Explanation

. Radial nerve

Explanation

With posteromedial displacement of the distal fragment, the proximal fragment displaces anterolaterally, putting the radial nerve at greatest risk. Posterolateral displacement places the anterior interosseous nerve (AIN) at risk.

Question 196

Topic: Surgical Anatomy & Approaches

A 25-year-old male sustains a C5-C6 brachial plexus avulsion injury. At 4 months post-injury, he has no spontaneous elbow flexion. An Oberlin nerve transfer is planned. Which of the following best describes this procedure?

. Transfer of the spinal accessory nerve to the suprascapular nerve
. Transfer of a redundant fascicle of the ulnar nerve to the biceps motor branch of the musculocutaneous nerve
. Transfer of the medial pectoral nerve to the musculocutaneous nerve
. Transfer of the intercostal nerves to the musculocutaneous nerve
. Transfer of the triceps motor branch to the axillary nerve

Correct Answer & Explanation

. Transfer of a redundant fascicle of the ulnar nerve to the biceps motor branch of the musculocutaneous nerve

Explanation

The classic Oberlin transfer involves taking a redundant motor fascicle from the ulnar nerve (typically one innervating the FCU) and transferring it to the biceps motor branch of the musculocutaneous nerve. This effectively restores elbow flexion in upper trunk injuries.

Question 197

Topic: Surgical Anatomy & Approaches

A 22-year-old male sustains a C5-C6 root avulsion injury. At 4 months post-injury, he has no active elbow flexion but retains fully intact hand and wrist function. Which of the following is the most appropriate nerve transfer to restore elbow flexion?

. Ulnar nerve fascicle to the musculocutaneous nerve (Oberlin transfer)
. Spinal accessory nerve to the suprascapular nerve
. Intercostal nerves to the musculocutaneous nerve
. Phrenic nerve to the axillary nerve
. Triceps branch to the axillary nerve

Correct Answer & Explanation

. Ulnar nerve fascicle to the musculocutaneous nerve (Oberlin transfer)

Explanation

The Oberlin transfer utilizes an expendable motor fascicle from the ulnar nerve (usually to the flexor carpi ulnaris) transferred to the biceps branch of the musculocutaneous nerve. It is highly effective for restoring elbow flexion in upper trunk injuries with intact lower roots.

Question 198

Topic: Surgical Anatomy & Approaches

Following the successful harvest and transposition of a reverse radial forearm flap, the donor site defect is 5 cm wide. The surgeon plans to close the donor site. Which of the following is the most appropriate method for donor site closure in this scenario, and what critical structure must be preserved?

. Primary closure with tension-free sutures, ensuring preservation of the superficial radial nerve.
. Application of a split-thickness skin graft, ensuring preservation of the paratenon of the flexor tendons.
. Application of a full-thickness skin graft, ensuring preservation of the radial artery.
. Local flap advancement from the ulnar forearm, ensuring preservation of the ulnar artery.
. Secondary intention healing, ensuring meticulous wound care.

Correct Answer & Explanation

. Application of a split-thickness skin graft, ensuring preservation of the paratenon of the flexor tendons.

Explanation

Correct Answer: BThe case states that for wider flaps (typically >3-4 cm), primary closure is not feasible, and the defect is covered with a skin graft. For a 5 cm wide defect, asplit-thickness skin graftis the most appropriate method. A critical aspect of successful skin graft take is a well-vascularized bed. Therefore, it is essential topreserve the paratenon of the flexor tendons, which provides the necessary vascularity for the graft to survive. Without intact paratenon, the tendons themselves would be exposed, leading to poor graft take, desiccation, and adhesion.Option A is incorrect; primary closure is typically only feasible for narrower flaps (<3-4 cm) to avoid excessive tension. While preserving the superficial radial nerve is important to minimize donor site morbidity, it's not the primary consideration for graft take.Option C is incorrect; while a full-thickness skin graft could be used, the primary concern for graft take is the bed, not the radial artery (which has already been harvested or preserved as the flap pedicle). The paratenon is the critical structure for graft viability.Option D is incorrect; local flap advancement from the ulnar forearm is not a standard method for closing a large RRFF donor site, and the ulnar artery is crucial for hand perfusion, not for donor site closure.Option E is incorrect; secondary intention healing for a 5 cm wide defect would be prolonged, lead to significant scarring and contracture, and is generally not preferred for such a large defect, especially over exposed tendons.

Question 199

Topic: Surgical Anatomy & Approaches

To minimize the most common postoperative complication at the donor site of a radial forearm fasciocutaneous flap, which technical step is critical before applying a split-thickness skin graft?

. Resection of the superficial branch of the radial nerve to prevent neuroma
. Immobilization of the wrist in 45 degrees of flexion
. Approximation of the flexor carpi radialis and brachioradialis muscle bellies over the exposed tendons
. Routine harvest of the flexor pollicis longus muscle belly
. Application of a negative pressure wound therapy device at 200 mmHg

Correct Answer & Explanation

. Approximation of the flexor carpi radialis and brachioradialis muscle bellies over the exposed tendons

Explanation

The most frequent complication at the donor site is delayed healing or partial loss of the skin graft over avascular exposed flexor tendons. Carefully approximating the paratenon and muscle bellies of the brachioradialis and flexor carpi radialis provides a vascularized bed for the graft.

Question 200

Topic: Surgical Anatomy & Approaches

What anatomical structure primarily dictates the distal-most safe pivot point for a reverse radial forearm flap?

. The superficial branch of the radial nerve bifurcation
. The location of the superficial palmar arch
. The communicating branch between the deep palmar arch and the radial artery
. The distal insertion of the brachioradialis tendon
. The origin of the abductor pollicis longus

Correct Answer & Explanation

. The communicating branch between the deep palmar arch and the radial artery

Explanation

The pivot point is typically situated 2 to 3 cm proximal to the radial styloid. This critical distance preserves the essential contribution of the radial artery to the deep palmar arch, ensuring adequate retrograde arterial flow to the flap.

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