The lateral retinaculum and lateral release

The lateral retinaculum is the sheet of fibrous material on the outer (lateral) side of the kneecap. It supports the patella in a central position.

The lateral retinaculum may become tight if the forces around the kneecap are not in balance - for example, if the vastus medialis muscle (part of the quads) is weak or if the medial retinaculum is stretched.

A tight lateral retinaculum may cause the patella to tilt to one side, and this may trigger pain in the front of the knee. A tight lateral retinaculum may be released surgically by cutting it along its length in a procedure known as 'lateral retinacular release' or 'lateral release'.