Inferior subtendinous bursa of biceps femoris muscle

The inferior subtendinous bursa of the biceps femoris muscle is anatomically located lateral to the distal quarter of the fibular collateral ligament. It forms an inverted "J" shape around the anterior and anteromedial portions of the ligament. The bursa's most distal margin is just proximal to the fibular head, where the fibular collateral ligament inserts. Its more proximal aspect is at the superior edge of the anterior arm of the long head of the biceps femoris muscle. This structure was consistently found in all 50 knees dissected in the study by LaPrade and Hamilton, indicating a constant anatomic location. [1]

The bursa has a mean width of 8.4 mm and a mean height of 18 mm, which may be relevant for clinicians in the differential diagnosis of lateral knee pain.[1]