The JUPITER group consists of high-volume patellofemoral surgeons across the United States, and was organized to facilitate the collection of clinical and radiographic outcomes following surgical and non-surgical treatment of patellar instability. With this study (JUPITER 4.0), the group aims to prospectively enroll a new cohort of consecutive patients with recurrent patellar instability that would undergo isolated MPFL reconstruction regardless of radiographic measurements or anatomic risk factors to address two specific aims - 1) what patient, injury, and surgical factors lead to recurrent instability following isolated MPFL reconstruction and 2) the creation of an instability severity index score, with the long-term objective of identifying preoperatively, patients with a high risk of failure of an isolated MPFL reconstruction who may be better served with concomitant bony procedure.
