MCQs – Anatomy 3

Modern Study Review (AI-Generated)

High-Yield Summary

This topic is a staple of the Royal College exam, focusing heavily on surgical anatomy and vascular considerations during approaches to the hip and tendon vascularity. The single most important trade-off in clinical scenarios is preserving the medial circumflex femoral artery during the medial Ludloff approach to prevent avascular necrosis of the femoral head. The examiner often forces a choice between adequate exposure and vascular preservation. While classic teaching emphasizes careful dissection to avoid nerve injury, modern practice increasingly uses intraoperative nerve monitoring and minimally invasive techniques to reduce morbidity.

High-Yield Decision Matrix

Active Recall Q&A

Q: During the medial Ludloff approach, which structure is most endangered?
A: The medial circumflex femoral artery.
Related Pearl: Injury to this artery risks femoral head avascular necrosis, a devastating complication that can lead to collapse and arthritis.

Q: Which nerves are exposed during the medial Ludloff approach and at what depths?
A: The anterior branch of the obturator nerve during superficial exposure, and the posterior branch during deep exposure.
Related Pearl: Obturator nerve injury causes medial thigh sensory loss and adductor weakness, which can impair gait and hip stability.

Q: What is the anatomical relationship of the sciatic nerve to the ischial tuberosity?
A: The sciatic nerve lies anterior and lateral to the ischial tuberosity.
Related Pearl: This relationship is critical during hamstring repairs to avoid iatrogenic sciatic nerve injury.

Q: What are the boundaries of the femoral triangle?
A: Superiorly by the inguinal ligament, medially by pectineus and adductor longus, laterally by sartorius and iliopsoas.
Related Pearl: The femoral artery, vein, and nerve lie within this triangle, making it a key landmark for vascular access and nerve blocks.

Q: What are the sources of blood supply to tendons?
A: Vessels in the perimysium, periosteal insertion, and surrounding tissue via vessels in the paratenon or mesotenon.
Related Pearl: Preserving these vascular sources during surgery optimizes tendon healing and reduces risk of necrosis.

Q: How does the vascularity differ between tendons surrounded by paratenon and those surrounded by a tendon sheath?
A: Tendons with paratenon are vascular; tendons with a tendon sheath are avascular.
Related Pearl: This explains why flexor tendons within sheaths rely on specialized structures like vincula for nutrition.

Q: In tendons surrounded by paratenon, how do vessels enter?
A: Vessels enter from many points along the tendon.
Related Pearl: Multiple vessel entry points provide redundancy, reducing ischemic risk during injury or surgery.

Q: What is the primary blood supply source for flexor tendons within a tendon sheath?
A: Blood supply is mostly from the mesotenon, specifically via vincula.
Related Pearl: Damage to vincula impairs tendon nutrition and healing, increasing risk of rupture or adhesions.

Classic Clinical Notes

• Therefore, during the medial Ludloff approach, the most endangered structure is the medial circumflex femoral artery. Also exposed are both the anterior branch of the obturator nerve (during superficial exposure) and the posterior branch of the obturator nerve (during the deep exposure).

• The sciatic nerve is anterior and lateral to the ischial tuberosity (the origin of the hamstrings).

• The femoral triangle – inguinal ligament, pectineus and adductor longus medially, sartorius and iliopsoas laterally.

• Tendon blood supply – from vessels in the perimysium, the periosteal insertion, the surrounding tissue via vessels in the paratenon or mesotenon.

• Tendons surrounded by paratenon have been referred to as vascular tendons and those surrounded by a tendon sheath, as avascular tendons.

• In tendons surrounded by a paratenon, vessels enter from many points.

• The vascular pattern of a flexor tendon within a tendon sheath is quite different – here the mesotenons are reduced to vincula.

• So in the flexor tendons – blood supply is probably mostly from mesotenon.

Last Updated on January 25, 2026 by Christian Veillette