Copyright 2009
Author John Udall MD
Definition
The lateral patellar retinaculum is a fibrous expansion of the tendon of the vastus lateralis muscle.
Its unique structural features include the layer of tissue which stabilizes the patella from dislocating or translating medially.
Its origin is the fibrous extension of the vastus lateralis and its insertion is the lateral margin of the patella, the patellar tendon, and the tibial condyle.
It is supplied by the geniculate arteries
The nerve supply is the femoral nerve.
The function or action of the lateral retinaculum is to provide lateral support to the patella so that it won’t dislocate medially. It also plays a role in transfer of force from the vastis lateralis in extension of the knee
Common diseases include tear of the retinaculum with patella fractures, and tightness of the lateral structures. A tight lateral retinaculum will lead to tilting of the patella andis one of the common causes of adolescent knee pain (patellofemoral pain).
Commonly used diagnostic procedures include applying a rotatory load to the patella to determine if the patella can be inverted. This can help in determinig if the retinaculum is too tight.
It is usually treated with physical therapy. The goal of physical therapy is to stretch the lateral retinaculum and strengthen the vastus medialis which will give better balance to the patella.
References
http://www.springerlink.com/content/ut68570424516740/