Which ligament of the hip joint is the strongest and prevents excessive abduction of the thigh?

Explanation

## Hip Joint Ligaments **Key Point:** The iliofemoral ligament is the strongest ligament of the hip joint (and indeed the strongest ligament in the entire body) and is a primary restraint to both hyperextension and excessive abduction of the thigh. ### Anatomy of Hip Ligaments | Ligament | Origin | Insertion | Primary Function | | --- | --- | --- | --- | | **Iliofemoral** | Anterior inferior iliac spine & acetabular rim | Intertrochanteric line | Prevents hyperextension & excessive abduction **(strongest)** | | Pubofemoral | Superior pubic ramus | Intertrochanteric fossa | Assists in preventing abduction and external rotation | | Ischiofemoral | Ischial part of acetabular rim | Greater trochanter (medial surface) | Prevents internal rotation & hyperextension | | Ligamentum teres | Acetabular notch / transverse acetabular ligament | Fovea capitis of femoral head | Carries blood supply (obturator artery branch) to femoral head | ### Why Iliofemoral is Correct The **iliofemoral ligament** (also called the **Y-ligament of Bigelow**) is shaped like an inverted Y and is the thickest, strongest ligament of the hip joint. It reinforces the anterior capsule and: - **Prevents hyperextension** of the hip (most important function) - **Limits excessive abduction** of the thigh - Plays a key role in maintaining the upright posture with minimal muscular effort The **pubofemoral ligament** is a weaker structure located on the inferior and medial aspect of the capsule; it assists in limiting abduction and external rotation but is NOT the strongest ligament. **High-Yield:** Gray's Anatomy and Clinically Oriented Anatomy (Moore) consistently identify the iliofemoral ligament as the strongest ligament in the human body, capable of withstanding tensile forces exceeding 350 kg. **Clinical Pearl:** Anterior hip dislocations (rare) occur when the iliofemoral ligament is disrupted, allowing the femoral head to displace anteriorly. Posterior dislocations (more common) involve the posterior capsule and ischiofemoral ligament. **Mnemonic:** **IHA** = **I**liofemoral → **H**yperextension & **A**bduction (strongest); **P**ubofemoral → assists **A**bduction; **I**schiofemoral → **I**nternal rotation.