Painful bipartite patella following injury.

We report nine rare cases of painful bipartite patella following injury to the knee, in seven non-athletic adults. Patients suffered with persistent anterior knee pain and localized tenderness over the superolateral aspect of the patella for an average of 2 years following injury. The clinical, radiographic and arthroscopic findings are described. Excision of the accessory bipartite fragment resulted in satisfactory relief of pain and complete restoration of the knee function in all patients at a mean follow-up of 10 months (range 3-36 months). Although painful bipartite patella may be considered rare it should be recognized as a cause of post-traumatic anterior pain in the adult.