David R. Diduch, MD

COLORADO SPRINGS, Colo. — Results presented here showed patients who underwent medial patellofemoral ligament repair for patellar instability had a higher failure rate compared with MPFL reconstruction at long-term follow-up.

A combination of bony and dynamic and static soft tissue stabilizers provides for stability of the patellofemoral joint. Therefore, the etiology of patellar instability is multifactorial and often includes trochlear dysplasia, patella alta, coronal malalignment, torsional abnormalities and incompetent medial soft tissue constraints. Recent studies have indicated that trochlear dysplasia is the key anatomic risk factor leading to persistent patellar instability. Though trochlear dysplasia is frequently present in patients with patellar instability, correction of this dysplasia through deepening trochleoplasty is only indicated in a subset of patients. This article describes the sulcus-deepening trochleoplasty, including indications and technical pearls.

In most traumatic patellar dislocations, the medial patellofemoral ligament is either torn or attenuated to the point where it is functionally incompetent. Unfortunately, as the medial patellofemoral ligament is the primary static restraint to lateral patellar translation from 0° to 30°, this injury leaves the patient susceptible to subsequent dislocations. Secondary patellar stabilizers are not substantial enough to compensate for the loss of this powerful restraint, and thus, surgery is often needed for recurrent instability.