American Board of Internal Medicine (ABIM) Certification Practice Exam

What physical examination finding is notorious for indicating a meniscal tear?

1. Positive Lachman test

2. Positive anterior drawer test

3. Joint line tenderness with swelling

4. Positive valgus stress test

The correct answer is: Joint line tenderness with swelling

A meniscal tear is often indicated by the presence of joint line tenderness, particularly when accompanied by swelling. This finding occurs because the meniscus, which serves as a cushion and stabilizer in the knee joint, often becomes injured during twisting motions or impact. When the meniscus is torn, it can lead to localized tenderness around the joint line where it is anatomically positioned. This tenderness is a direct result of injury to the meniscal tissue and inflammation in the surrounding area. Swelling can accompany joint line tenderness as a response to trauma and irritation, indicating that the body is reacting to the injury. The combination of these two signs is a strong indicator of a meniscal tear, particularly when the patient also experiences pain during activities that involve bending or twisting the knee. In contrast, other tests like the Lachman test and the anterior drawer test are primarily used to assess for anterior cruciate ligament (ACL) injuries, while the valgus stress test assesses the integrity of the medial collateral ligament (MCL). These tests, though significant in their own right, are not as specific for meniscal injuries as joint line tenderness with swelling. Thus, recognizing joint line tenderness in a clinical setting is crucial for identifying a potential meniscal tear.