Patellofemoral Instability in the Pediatric and Adolescent Population: From Causes to Treatments.

Background: Patella instability is one of the most common knee injuries in the adolescent patient. There are several pathoanatomic risk factors which should be assessed via several modalities, including X-rays, magnetic resonance imaging (MRI), or even CT scan.

Objectives: We intend to review these risk factors along with the nonsurgical and surgical techniques used to prevent recurrent dislocations.

Methods: We completed an extensive review of the recent literature concerning pediatric and adolescent patellar dislocation and subsequent treatment modalities.

Results: We review in detail the risk factors such as patella alta, trochlear dysplasia, lateralization of the tibial tubercle or medialization of the trochlear groove (increased tibial tubercle to trochlear groove (TT-TG) distance), lower limb malalignment, excessive femoral anteversion and/or tibial torsion, and hyperlaxity. There are classification systems for dislocators, and a natural progression of instability that patients often proceed through. Only after a patient has continued to dislocate after bracing and physical therapy is surgical treatment considered. Surgical techniques vary, with the workhorse being the medial patellofemoral ligament (MPFL) reconstruction. However, there are a variety of other techniques which add onto this procedure to address other anatomic risk factors. These include the tibial tubercle osteotomy to address a large TT-TG distance or trochleoplasty to address the lack of a trochlear groove.

Conclusions: Nonsurgical and surgical treatments for patella dislocators are tailored to the pathoanatomic risk factors in each patient.