The medial (inner aspect) and lateral (outer aspect side) retinacula are the bands of fibrous tissue that help to support the patella in its position in relation to the femur bone below it.

Laterally and medially to the patellar ligament, the lateral and medial patellar retinacula connect fibers from the vastus lateralis and medialis muscles to the tibia. Some fibers from the iliotibial tract radiate into the lateral retinaculum, and the medial retinaculum receives some transverse fibers arising on the medial femoral epicondyle.