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Question 701

Topic: Surgical Anatomy & Approaches

The axillary nerve is at risk during inferior capsular release of the shoulder. It exits the axilla through the quadrangular space. What forms the superior border of this space?

. Teres major
. Teres minor
. Long head of the triceps
. Surgical neck of the humerus
. Subscapularis

Correct Answer & Explanation

. Surgical neck of the humerus


Explanation

The quadrangular space is bounded 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. The axillary nerve and posterior circumflex humeral artery traverse this space.

Question 702

Topic: Surgical Anatomy & Approaches

During a posterior approach to the hip, the surgeon must remember the anatomical relationship of the sciatic nerve to the short external rotators. In the majority of the population, the sciatic nerve exits the pelvis through the greater sciatic foramen in what relation to the piriformis muscle?

. Superior to the piriformis
. Inferior to the piriformis
. Through the belly of the piriformis
. Anterior to the obturator internus
. Medial to the sacrotuberous ligament

Correct Answer & Explanation

. Inferior to the piriformis


Explanation

In the majority of the population (approximately 80-85%), the entire sciatic nerve exits the pelvis inferior to the piriformis muscle. Variations exist where the common peroneal division pierces or passes superior to the piriformis.

Question 703

Topic: Surgical Anatomy & Approaches

During a posterolateral approach to the ankle for fixation of a posterior malleolar fracture, the internervous plane is developed between the flexor hallucis longus (FHL) and the peroneal muscles. Which nerve is at greatest risk during the superficial dissection of this approach?

. Sural nerve
. Saphenous nerve
. Deep peroneal nerve
. Tibial nerve
. Superficial peroneal nerve

Correct Answer & Explanation

. Sural nerve


Explanation

The sural nerve runs superficially with the small saphenous vein along the posterolateral aspect of the ankle. It is at significant risk during the superficial dissection in the posterolateral approach.

Question 704

Topic: Surgical Anatomy & Approaches

During the anterior (Smith-Petersen) approach to the hip, an internervous plane is utilized. Which of the following describes the correct muscular interval and their respective innervations?

. Sartorius (femoral n.) and tensor fasciae latae (superior gluteal n.)
. Rectus femoris (femoral n.) and gluteus medius (superior gluteal n.)
. Adductor longus (obturator n.) and gracilis (obturator n.)
. Gluteus maximus (inferior gluteal n.) and gluteus medius (superior gluteal n.)
. Tensor fasciae latae (superior gluteal n.) and rectus femoris (femoral n.)

Correct Answer & Explanation

. Sartorius (femoral n.) and tensor fasciae latae (superior gluteal n.)


Explanation

The Smith-Petersen approach utilizes the superficial internervous plane between the sartorius (innervated by the femoral nerve) and the tensor fasciae latae (innervated by the superior gluteal nerve). The deep plane is between the rectus femoris and gluteus medius.

Question 705

Topic: Surgical Anatomy & Approaches

During a posterior approach to the humerus, the radial nerve is identified. It passes from the posterior compartment to the anterior compartment through the lateral intermuscular septum. At what average distance proximal to the lateral epicondyle does this occur?

. 5 cm
. 10 cm
. 15 cm
. 20 cm
. 25 cm

Correct Answer & Explanation

. 10 cm


Explanation

The radial nerve pierces the lateral intermuscular septum to pass from the posterior to the anterior compartment at an average distance of 10 cm proximal to the lateral epicondyle. Identifying this landmark is critical during posterior plating of the humerus.

Question 706

Topic: Surgical Anatomy & Approaches

During an ilioinguinal approach for an acetabular fracture, significant hemorrhage occurs while dissecting near the superior pubic ramus. This is most likely due to an injury of an anastomotic vessel connecting which two vascular systems?

. Internal pudendal and inferior gluteal
. External iliac and obturator
. Internal iliac and superior gluteal
. Femoral and deep circumflex iliac
. Inferior epigastric and femoral

Correct Answer & Explanation

. External iliac and obturator


Explanation

The "corona mortis" is a vascular anastomosis between the obturator vessels (internal iliac system) and the external iliac or inferior epigastric vessels. It is located on the posterior aspect of the superior pubic ramus and is at risk during the ilioinguinal approach.

Question 707

Topic: Surgical Anatomy & Approaches

The volar (Henry) approach to the radius utilizes an internervous plane. Proximally, this plane is found between which of the following two muscles?

. Flexor carpi radialis and palmaris longus
. Brachioradialis and pronator teres
. Pronator teres and flexor carpi radialis
. Brachioradialis and flexor carpi radialis
. Extensor carpi radialis longus and brachioradialis

Correct Answer & Explanation

. Brachioradialis and pronator teres


Explanation

Proximally, the volar Henry approach exploits the internervous plane between the brachioradialis (radial nerve) and the pronator teres (median nerve). Distally, the plane shifts to run between the brachioradialis and the flexor carpi radialis.

Question 708

Topic: Surgical Anatomy & Approaches

Placement of an anterior shoulder arthroscopy portal typically requires passing lateral to the coracoid process. If the portal is placed medially to the coracoid by mistake, which structure is at greatest immediate risk of injury?

. Axillary nerve
. Musculocutaneous nerve
. Suprascapular nerve
. Radial nerve
. Long thoracic nerve

Correct Answer & Explanation

. Musculocutaneous nerve


Explanation

The musculocutaneous nerve enters the conjoint tendon approximately 3-5 cm distal to the coracoid process. Placing the anterior portal medial to the coracoid process significantly endangers this nerve and the major neurovascular bundle.

Question 709

Topic: Surgical Anatomy & Approaches

The anterolateral (Watson-Jones) approach to the hip joint utilizes the interval between the gluteus medius and the tensor fasciae latae. Since both are innervated by the superior gluteal nerve, what anatomical characteristic makes this approach viable?

. The superior gluteal nerve innervates both muscles distal to the greater trochanter
. The approach is an intermuscular plane and proximal dissection is limited to avoid the nerve
. The nerve branches enter strictly from the anterior border of the TFL
. The tensor fasciae latae receives dual innervation from the femoral nerve
. The approach completely detaches the muscles, negating the risk of denervation

Correct Answer & Explanation

. The approach is an intermuscular plane and proximal dissection is limited to avoid the nerve


Explanation

The Watson-Jones approach is an intermuscular (not internervous) plane since both muscles are innervated by the superior gluteal nerve. Dissection is safe as long as it does not proceed more than 4-5 cm proximal to the greater trochanter, which avoids injuring the nerve branches.

Question 710

Topic: Surgical Anatomy & Approaches

When performing a volar Henry approach to the proximal radius, which structure must be ligated to safely mobilize the brachioradialis laterally and the pronator teres medially?

. Radial artery
. Ulnar artery
. Recurrent radial artery
. Common interosseous artery
. Anterior interosseous artery

Correct Answer & Explanation

. Recurrent radial artery


Explanation

The recurrent radial artery forms a tether across the proximal interval of the Henry approach (brachioradialis and pronator teres). It must be identified and ligated to mobilize the mobile wad laterally.

Question 711

Topic: Surgical Anatomy & Approaches

During an ilioinguinal approach to the acetabulum, the surgeon encounters bleeding from the 'corona mortis.' This vascular structure represents an anastomosis between which two vascular systems?

. External iliac and internal iliac systems
. Obturator and internal pudendal systems
. Internal iliac and inferior mesenteric systems
. Deep circumflex iliac and inferior epigastric systems
. Femoral and external pudendal systems

Correct Answer & Explanation

. External iliac and internal iliac systems


Explanation

The corona mortis is a vascular anastomosis between the external iliac (or inferior epigastric) vessels and the internal iliac (obturator) vessels. It lies over the superior pubic ramus.

Question 712

Topic: Surgical Anatomy & Approaches

During a direct anterior approach (Smith-Petersen) for total hip arthroplasty, the superficial internervous plane is developed between which two muscles?

. Tensor fasciae latae and gluteus medius
. Sartorius and tensor fasciae latae
. Rectus femoris and vastus lateralis
. Gracilis and adductor longus
. Pectineus and adductor brevis

Correct Answer & Explanation

. Sartorius and tensor fasciae latae


Explanation

The superficial plane in the direct anterior approach is between the sartorius (femoral nerve) and the tensor fasciae latae (superior gluteal nerve). The deep plane is between the rectus femoris and gluteus medius.

Question 713

Topic: Surgical Anatomy & Approaches

During hip arthroscopy, a variety of portals are established. Which nerve is at greatest risk of iatrogenic injury during the placement of the anteroinferior portal?

. Sciatic nerve
. Superior gluteal nerve
. Lateral femoral cutaneous nerve
. Femoral nerve
. Obturator nerve

Correct Answer & Explanation

. Lateral femoral cutaneous nerve


Explanation

The lateral femoral cutaneous nerve is at highest risk during the establishment of anterior and anteroinferior portals in hip arthroscopy.

Question 714

Topic: Surgical Anatomy & Approaches

The internervous plane for the Smith-Petersen (anterior) approach to the hip lies between muscles innervated by which of the following pairs of nerves?

. Superior gluteal nerve and femoral nerve
. Inferior gluteal nerve and femoral nerve
. Superior gluteal nerve and obturator nerve
. Femoral nerve and obturator nerve
. Sciatic nerve and superior gluteal nerve

Correct Answer & Explanation

. Superior gluteal nerve and femoral nerve


Explanation

The anterior approach utilizes the internervous plane between the sartorius (femoral nerve) and tensor fasciae latae (superior gluteal nerve) superficially. Deeply, the plane lies between the rectus femoris (femoral nerve) and gluteus medius (superior gluteal nerve).

Question 715

Topic: Surgical Anatomy & Approaches

During a volar Henry approach to the forearm, which of the following vascular structures must be mobilized and its recurrent branches ligated to safely expose the proximal radius?

. Superficial radial nerve
. Radial artery
. Median nerve
. Ulnar artery
. Posterior interosseous nerve

Correct Answer & Explanation

. Radial artery


Explanation

During the proximal exposure of the radius via the volar Henry approach, the radial artery must be identified and protected. Its recurrent branches (the "leash of Henry") must be ligated to safely mobilize the artery ulnarly and expose the supinator.

Question 716

Topic: Surgical Anatomy & Approaches

A 25-year-old male sustains a midshaft humerus fracture and is noted to have a profound wrist drop on examination. The nerve responsible for this deficit passes through which of the following anatomical spaces?

. Quadrangular space
. Triangular space
. Triangular interval
. Cubital tunnel
. Spinoglenoid notch

Correct Answer & Explanation

. Triangular interval


Explanation

The radial nerve and profunda brachii artery exit the axilla to enter the posterior compartment of the arm via the triangular interval. The radial nerve is frequently injured in midshaft humerus fractures (Holstein-Lewis variant).

Question 717

Topic: Surgical Anatomy & Approaches

During an Ilioinguinal approach to the acetabulum, the "lateral window" is bounded medially by which of the following anatomical structures?

. Iliopsoas muscle
. External iliac artery
. Iliopectineal fascia
. Rectus abdominis
. Symphysis pubis

Correct Answer & Explanation

. Iliopectineal fascia


Explanation

The ilioinguinal approach provides access via three distinct windows. The lateral window is bounded laterally by the ASIS/iliac crest and medially by the iliopectineal fascia.

Question 718

Topic: Surgical Anatomy & Approaches

A surgeon is performing a posterolateral (Kocher) approach to the radial head. Maximal pronation of the forearm during this approach is necessary to protect which of the following neural structures?

. Median nerve
. Ulnar nerve
. Anterior interosseous nerve
. Posterior interosseous nerve
. Superficial radial nerve

Correct Answer & Explanation

. Posterior interosseous nerve


Explanation

Pronation of the forearm translates the posterior interosseous nerve (PIN) further anteriorly and medially, away from the surgical field. This maneuver significantly decreases the risk of iatrogenic injury during a Kocher approach.

Question 719

Topic: Surgical Anatomy & Approaches

When performing an anterior (Smith-Petersen) approach for open reduction of a DDH, which structure is typically released at the pelvic brim rather than its insertion to protect the primary blood supply to the femoral head?

. Iliopsoas tendon
. Ligamentum teres
. Pectineus
. Transverse acetabular ligament
. Pulvinar

Correct Answer & Explanation

. Iliopsoas tendon


Explanation

During an anterior open reduction, the iliopsoas tendon is typically released at the pelvic brim rather than the lesser trochanter. This technique avoids injuring the medial circumflex femoral artery, which is the primary blood supply to the femoral head.

Question 720

Topic: Surgical Anatomy & Approaches

A surgeon is performing a primary total hip arthroplasty utilizing the direct anterior approach. Which of the following describes the internervous plane utilized in the superficial dissection?

. Between the sartorius and tensor fasciae latae
. Between the tensor fasciae latae and gluteus medius
. Between the gluteus medius and piriformis
. Between the rectus femoris and vastus lateralis
. Between the adductor longus and gracilis

Correct Answer & Explanation

. Between the sartorius and tensor fasciae latae


Explanation

The direct anterior (Smith-Petersen) approach exploits the superficial internervous plane between the sartorius (innervated by the femoral nerve) and the tensor fasciae latae (innervated by the superior gluteal nerve).