2017 Arthroscopy
Medial patellar instability is a disabling condition that is often misdiagnosed. In 1988, Hughston and Deese described medial patellar instability as a complication of a lateral retinacular release procedure and reported that patients had increased pain and instability after a lateral retinacular release. Several studies have since reported on patients with medial patellar instability after lateral retinacular release, but traumatic and spontaneous cases have also been reported.
Lateral retinacular release was historically a popular procedure for treatment of lateral patellar instability, anterior knee pain, and patellar chondromalacia. Several studies reported low complication rates with this procedure,6 which may explain its widespread use. In case of an aggressive lateral retinacular release, some of the important patellar stabilizers on the lateral side of the knee, such as lateral patellotibial ligament and the lateral epicondylopatellar ligament, can be damaged. This is believed to be an important pathomechanism of iatrogenic medial patellar instability.
Several techniques have been described including direct lateral ligament repair, arthroscopic medial retinacular release, lateral retinacular reconstruction with soft tissue augmentation, lateral patellofemoral ligament reconstruction and lateral patellotibial ligament reconstruction. Given the paucity of literature on the outcomes and complications after treatment of medial patellar instability, the purpose of this study was to perform a systematic review of literature reporting on outcomes and complications after surgical treatment of medial patellar instability. It was hypothesized that good to excellent outcomes would be observed in most patients after surgery for medial patella instability. Moreover, it was hypothesized that medial patellar surgery would result in good to excellent outcomes in patients who underwent a prior lateral release.
Full Article: Medial Patellar Instability: A Systematic Review of the Literature of Outcomes After Surgical Treatment