An anatomic study of the iliotibial tract

Purpose: To identify the structure of the iliotibial tract at knee level, as well as its insertions, layer arrangement, and relationship with other structures of the lateral region of the knee and to compare the findings with available literature. Methods: Ten detailed anatomic dissections were performed by using incisions as recommended by the literature in fresh cadaver knees identifying the iliotibial tract components. Results: The authors observed an iliotibial tract arrangement in superficial, deep, and capsularosseous layers. Insertions have been described as follows: at linea aspera, at the upper border of the lateral epicondyle, at the patella, and at Gerdy's fibial tuberculum and across the capsular-osseous layer. Conclusions: The iliotibial tract (ITT) has important interconnections to the femur, the patella, and the lateral tibia; the iliopatellar band joins the ITT to the patella through the superficial oblique retinaculum and the lateral femoropatellar ligament, and the ITT capsular-osseous layer presents differentiated fibers in an arched arrangement that borders the femoral condyle and inserts laterally to the Gerdy's tubercle. Clinical Relevance: The iliotibial tract can be considered as an anterolateral knee stabilizer, particularly its capsular-osseous layer, which, together with the anterior cruciate ligament, constitutes a functional unit forming a spatial "horseshoe" form. The detailed description of the structures forming iliotibial tract plays an important role in the study of knee instabilities. Its important tibial, femoral, and patellar conections are described so that better understanding of fibial femoral instability on the lateral side as well as patellofemoral instability can be achieved and mechanisms of repair can be conceived.