Surgical Management of Patellofemoral Instability in the Skeletally Immature Patient

Lauren H. Redler, MD; Margaret L. Wright, MD


J Am Acad Orthop Surg. 2018;26(19):e405-e415. 

In This Article

Surgical Indications

Skeletally immature patients who sustain an initial, acute patellar dislocation without loose osteochondral fragments have not been shown to benefit from surgical treatment.[8,9] Current standard treatment includes activity restriction, patellar taping or bracing, and physical therapy focused on stretching the iliotibial band and strengthening the vastus medialis oblique (VMO), gluteal muscles, and core. Osteochondral injuries occur in as many as 75% of pediatric patients with acute patellar dislocation.[10] The osteochondral lesion is typically on the medial facet of the patella or lateral femoral condyle. Surgery is indicated in patients with loose osteochondral fractures to avoid a mechanical block to motion and development of early chondral wear. Lesions in non–weight-bearing portions of the knee or irreparable osteochondral fragments may be excised, but large fragments from weight-bearing surfaces have high healing capacity and should be repaired. There are also reports of large, chondral only fragments healing after fixation in adolescent patients, and these may benefit from fixation.[11]

Patellar stabilization is indicated in patients with recurrent instability; 49% of patients with recurrent instability who are treated nonsurgically will have further instability, as opposed to a 4% of those treated with MPFL reconstruction.[3,12] Eighty percent of patients return to their preinjury activity level after MPFL reconstruction compared to only 52% of patients treated nonsurgically or with MPFL repair.[8,13] Patients with recurrent instability have lower short- and long-term outcome scores than those treated with MPFL reconstruction, as well as increased progression of patellofemoral cartilage erosion compared to those without recurrence.[14–16] MPFL reconstruction alone can be performed successfully in pediatric patients who have recurrent instability associated with trochlear dysplasia and no other structural deformities.[17] It is important to recognize the features that affect the risk of failure of surgical intervention and recurrent instability, including patella alta, elevated TT-TG, and trochlear dysplasia. Although these factors guide patient counseling, they rarely affect surgical planning in this age group. Surgeons should ensure that children have reached skeletal maturity and physeal closure before considering tibial tubercle (TT) osteotomy.