Patellar Instability and Dislocation: Optimizing Surgical Treatment and How to Avoid Complications.

Patellar instability is a common problem seen by the orthopedic surgeon. Surgery is indicated in recurrent dislocation to improve patellar tracking and ligamentous restraint in order to decrease risk of recurrence, osteochondral injury, and eventual progression to arthritis. Preoperative imaging studies identify anatomic risk factors that increase risk of patellar dislocation to inform surgical decision making. Surgical management starts with medial patellofemoral ligament reconstruction, which is effective in many cases. Tibial tubercle osteotomy realigns the extensor mechanism and is useful in cases of lateralized tibial tubercle or patella alta. For patients with trochlear dysplasia, both tibial tubercle osteotomy and trochleoplasty are options to prevent recurrent dislocation. Chondral lesions are common and, depending upon symptomology and size, can be addressed with débridement, structural grafting, or cell-based treatment. To maximize outcomes, comprehensive preoperative diagnosis and planning must be combined with meticulous surgical technique. Unfortunately, there is minimal evidence to guide when a soft-tissue ligament reconstruction is sufficient versus when is it necessary to correct and alter the bony anatomy. This chapter covers the individualized decision making and surgical pearls for these techniques to improve outcomes and minimize perioperative complications.