What's up with patella alta?

Purpose of review: Patella alta, which describes an abnormally proximally positioned patella, has become of particular interest as it has been identified as a potential factor in patellofemoral instability (PFI) and other common pediatric orthopedic conditions. The purpose of this review is to describe the condition, measuring techniques, and its association with pediatric orthopedic conditions, and to evaluate methods of correction of patella alta.

Recent findings: Recent literature has explored the etiology of patella alta by investigating patellar height as age increases, with inconclusive findings as to whether the condition is congenital or acquired over time. Additionally, patella alta has been identified to be associated with several pediatric orthopedic conditions, including PFI, anterior knee pain, and cerebral palsy. As such, methods of correction for patella alta, including medial patellofemoral ligament reconstruction (MPFLR), tibial tubercle distalization, and patella tendon imbrication, have been studied.

Summary: Patella alta, defined by an abnormally high patellar height, is associated with patellofemoral instability, anterior knee pain, and cerebral palsy. Various indices have been developed to measure and define patellar height, including the Caton-Deschamps Index and Koshino-Sugimoto Index which are applicable to a pediatric population. Treatments include isolated or concomitant MPFLR, distalizing tibial tubercle osteotomy, and patella tendon imbrication, which have shown success in reducing patellar height and improving patella alta, though risks for complications do exist.