Lateral patellar instability: treatment with a combined open-arthroscopic approach.

Lateral patellar maltracking, subluxation, and dislocation could arguably be grouped together as varying degrees of lateral patellar instability. Besides common anatomical etiological factors, such as genu valgum, patella alta, tibial rotation, and others, the author has found that many of these patients exhibit patellar hypermobility, a seldom mentioned physical finding. Lateral retinacular release fails to address the hypermobility, whereas traditional, more extensive open operations often carry significant postoperative morbidity and disability. This article suggests a surgical approach that combines open medial tethering of the patellar tendon with arthroscopic lateral release. The procedure addresses both etiological factors of anatomical peculiarity and patellar hypermobility, with a relatively benign postoperative course. In a series of 29 cases with follow-up of 4-8 years, results appear encouraging so far.