Histologic evidence of retinacular nerve injury associated with patellofemoral malalignment.

Patellofemoral malalignment is frequently accompanied by pain that may respond to conservative treatment or lateral retinacular release. Frequently, there is little or no evidence of chondromalacia patellae in these patients. This study presents consistent evidence of nerve damage (demyelination and fibrosis) in the lateral retinaculum of patients with intractable patellofemoral pain requiring lateral retinacular release or realignment of the patellofemoral joint. The changes observed in the retinacular nerves resemble the histopathologic picture of Morton's interdigital neuroma. It is likely that the lateral retinaculum itself is painful in many patients with patellofemoral malalignment.