Patellar Instability in Children and Adolescents

CPT Richard K. Hurley, MD; MAJ Jeremy K. Rush, MD


Curr Orthop Pract. 2015;26(5):458-465. 

In This Article

Abstract and Introduction


Patellar instability is a common occurrence in the skeletally immature patient population, and multiple treatment options exist. Nonoperative treatment is appropriate for patients without osteochondral injuries and includes bracing and physical therapy focusing on strengthening of the gluteals as well as the vastus medialis obliquus muscles. Risk factors for recurrent instability include patella alta, trochlear dysplasia, and age younger than 25 yr. Isolated reconstruction of the medial patellofemoral ligament is indicated in patients with recurrent instability with normal tibial tubercle-trochlear groove distances with or without trochlear dysplasia. Distal realignment procedures risk physeal injury and are thus not routinely used in the skeletally immature population. Long-term data on the effect that trochleoplasty has on chondral surface have not been established and it has thus been a procedure reserved primarily for skeletally mature patient populations with chronic patellar instability. Despite multiple operative treatment methods, knee pain, decreased knee flexion, and recurrent instability are the most common postoperative complications.


Patellar instability is a complex, multifaceted condition that can be the result of soft-tissue injury or laxity, muscle imbalance, or even variations in bony morphology. It can lead to changes in normal knee biomechanics and may ultimately lead to chronic recurrent instability if not properly diagnosed and treated. Recurrence of patellar subluxation events is common and presents the treating orthopaedic surgeon with the challenge of determining whether patients should have nonoperative or operative treatment.