American Board of Internal Medicine (ABIM) Certification Practice Exam

What is a key characteristic of pes anserine bursitis?

1. Lateral tenderness

2. Point tenderness at pes anserine bursa

3. Swelling above the knee

4. Fluid accumulation in the knee joint

The correct answer is: Point tenderness at pes anserine bursa

Pes anserine bursitis is characterized by point tenderness specifically at the site of the pes anserinus, which is located on the medial aspect of the knee, just below the joint line. This condition involves inflammation of the bursa that lies beneath the tendons of the sartorius, gracilis, and semitendinosus muscles. Point tenderness is a hallmark of this condition, as patients typically experience pain when direct pressure is placed on this area. It is often exacerbated by activities that increase tension on these muscles and the associated bursa, such as climbing stairs or running. The other options describe symptoms or conditions that are less specific to pes anserine bursitis. For example, lateral tenderness would suggest involvement of structures on the outer side of the knee, potentially indicating a different issue, such as iliotibial band syndrome or lateral collateral ligament injury. Swelling above the knee or fluid accumulation in the knee joint typically suggest intra-articular problems, such as osteoarthritis or meniscal tears, rather than isolated bursitis. Therefore, the point tenderness at the pes anserine bursa is the characteristic finding that confirms the diagnosis of pes anserine bursitis.