Total knee arthroplasty in a patient with neglected congenital patellar dislocation.

Late presentation of congenital patellar dislocation with advanced osteoarthritis is rare. This article presents a case of 56-year-old woman with advanced osteoarthritis due to right neglected congenital patellar dislocation treated with total knee arthroplasty (TKA) with release of the lateral retinaculum and proximal extensor mechanism realignment. One year later, the patient had improvement of her Knee Society scores and painless function, stability, and better extensor strength. A literature search revealed a limited number of similar cases in which congenital patellar dislocation was treated with TKA. Total knee arthroplasty provides a valid treatment option for adults with congenital patellar dislocation who have absence of the femoral sulcus and associated osteoarthritis. Total knee arthroplasty has the ability to correct the pathologies seen with congenital patellar dislocation, eg, external tibial rotation, absence of femoral groove, and patellar hypoplasia. Realignment of extensor mechanism restores quadriceps strength, normal knee biomechanics, and may prevent complications such as dislocation.