What Is Gerdy's Tubercle?

Gerdy's tubercle is the area where the iliotibial band and the fascia lata go into the tibia. The feature is named after Pierre Nicolas Gerdy, the 19th-century French surgeon who first described it. The tibia, also known as the shankbone or the shinbone, is one of the two bones of the lower leg, which is the part below the knee; the other lower leg bone is the fibula. The tibia is the bigger and stronger of the two and is known as the body's sturdiest weight-bearing bone. Gerdy's tubercle is located at the tibia right below the knee joint.

Above Gerdy's tubercle is the fascia lata, which is attached to the knee-joint's major points. The fascia lata is a layer of fibrous, connective tissue found in the thigh. It is a deep fascia, which means that it surrounds and separates individual muscles. The fascia lata does this to create compartments of muscles.

Extending toward the Gerdy's tubercle and inserting itself in the protuberance is the iliotibial band. Also known as the iliotibial tract or IT band, it is a longitudinal fibrous thickening of the fascia lata. The iliotibial band starts at the iliac crest of the pelvis, or, more specifically, at the crest's iliac tubercle, which is the structure's widest point.

The iliotibial band travels downward at the thigh's outside part to the lateral area of the tibia's upper extremity called the lateral condyle. The iliotibial band is responsible for stabilizing and extending the knee, as well as giving it flexion. An alternative term, Maissiat's band, is named for the person who discovered it, French anatomist Jacques Maissiat.

The clinical significance of Gerdy's tubercle concerns the tibia's big oblong-shaped elevation. Known as tibial tuberosity, it is located at the tibia's proximal end, which is where the lateral and medial portions of the bone's upper extremity end. Also, it marks the place where the ligament of the patella, or kneecap, attaches. This area can be fractured, as evidenced by cases involving injured basketball players.

French surgeon Pierre Nicolas Gerdy, who lived between 1797 and 1856, is credited with first describing this tibial projection. A Faculty of Medicine in Paris professor known for his contributions to the fields of pathology and physiology, Gerdy had several other anatomical features named after him in addition to Gerdy's tubercle.