Clinical Research Studies

This study is a multi-center prospective cohort study to determine the most effective treatment of patellar instability. The principal investigators have identified surgeons who treat a high volume of patellar instability cases at various centers across the country. Invitations to participate in the study will be extended to these surgeons, along with the original members of the JUPITER study group. Patellar instability encompasses patellar dislocation and patellar subluxation. For the study, patellar dislocation is defined as either (1) dislocated patella that required reduction or (2) convincing history of patellar dislocation, associated with full giving way and presence of knee effusion, medial sided tenderness and positive apprehension sign1. Patellar subluxation is defined as partial giving way episodes (symptom), positive apprehension test (sign) and lateral displacement of patella relative to trochlea (radiologic). The most vulnerable group with first-time dislocation is 10-17 years age group where pediatric orthopaedic surgeons or adult sports medicine orthopaedic surgeons may be involved in their care. Thus, the participating centers are combination of pediatric and adult institutions. It is also not currently known how recurrent patellar instability impacts the progression of osteoarthritis in the knee. This study will include patients of all ages to better assess long-term outcomes and osteoarthritis progression after patellar instability treatment.