FMGE 2004

Question 1: In meniscus injury, 'Locking'-that is sudden inability to extend the knee fully is a feature of:

• A. Anterior horn tear
• B. Bucket handle tear (Correct Answer)
• C. Horizontal tears
• D. Posterior horn tear

Explanation: ***Bucket handle tear*** - A **bucket handle tear** is a specific type of **longitudinal tear** where a large segment of the meniscus is displaced into the intercondylar notch, physically blocking knee extension and leading to **locking**. - This tear typically affects the **medial meniscus** and is a classic cause of **mechanical locking** where the knee cannot be fully straightened. *Anterior horn tear* - Tears of the **anterior horn** are less common than posterior horn tears and rarely cause **locking** unless they are extensive and displace significantly. - While they can cause pain and instability, they are not the primary cause of acute, complete mechanical **locking**. *Horizontal tears* - **Horizontal tears** separate the meniscus into superior and inferior halves and are often degenerative. - They typically cause pain and swelling but are less likely to cause a distinct mechanical **locking** sensation compared to displaced bucket handle tears. *Posterior horn tear* - **Posterior horn tears** are the most common type of meniscus injury and can cause pain, swelling, and sometimes catching. - While they can impede movement, they usually do not cause the complete, irreversible **locking** characteristic of a displaced bucket handle fragment.