Proximal Patellar Quadricepsplasty Realignment During Total Knee Arthroplasty for Irreducible Congenital Dislocation of the Patella: A Report of Two Cases

The etiology of congenital dislocation of the patella remains unknown. In adulthood, osteoarthritis of the knee may develop, and it usually affects the lateral compartment. Valgus malalignment of the lower extremity and a laterally dislocated patella are the typical physical findings. Various techniques to reconstruct a dislocated extensor mechanism have been described1-4. In the presence of severe osteoarthritis, total knee arthroplasty is a surgical option, which may be combined with realignment of the extensor mechanism. We report a new technique of total knee arthroplasty with proximal realignment of the extensor mechanism with use of a V-W quadricepsplasty (quadriceps turndown and medial advancement) in two patients. The patients were informed that data concerning the cases would be submitted for publication, and they consented. Case 1. A forty-nine-year-old man was evaluated for bilateral knee pain and reduced walking distance secondary to knee arthritis. At the age of six years, he was diagnosed with bilateral congenital patellar dislocation and was managed nonoperatively. On examination, standing lower-extremity alignment measured 15° of valgus bilaterally. The passive range of motion of both knees measured 0° to 135°, with painful crepitus noted in the lateral compartments. The patient had a 30° extensor lag. Lateral dislocation of the patella was present bilaterally. Radiographic examination revealed bilateral valgus deformity with complete loss of the lateral compartment joint space. The patellae were laterally dislocated. A lateral unicompartmental hemiarthroplasty of the right knee was performed when the patient was fifty years of age, and the dislocated patella was not addressed. Because of recurrent disabling pain, the hemiarthroplasty was revised to a posterior stabilized total knee arthroplasty with cement four years later, when the patient was fifty-four years of age. The extensor mechanism was reconstructed with use of a V-W quadricepsplasty technique, as described below. Ten years …