The undersurface of the patella was evaluated using the Outerbridge Rating System [8] and the location of wear (medial or lateral facet or central ridge) was recorded. The Outerbridge Rating ...

It usually possesses a median ridge that divides the proximal patella into medial and lateral facets, and the medial facet is generally smaller. The patellar tendon is mainly composed of rectus ...

In addition, patellar derangements were described in 40 of the patients ... and consisted of the junction of the medial and lateral facets (n = 3), the lateral facet (n = 3), the medial facet (n = 2).

Anatomic variations, such as tendons with minimal increments in width in the proximal-distal direction, may be associated with an increasing amount of patellar arthrosis at the lateral facet ...