Combined trochleoplasty and medial patellofemoral ligament reconstruction for patellofemoral instability

Abstract

Combined anatomical reconstruction of the MPFL and deepening trochleoplasty to improve the stability of the patellofemoral joint in patients with severe trochlear dysplasia. Confirmed patellofemoral instability with recurrent dislocations and high-grade trochlear dysplasia. Open distal femoral physis, degenerative changes of the patellofemoral joint grade ICRS III-IV. Diagnostic arthroscopy, exposure of the femoral trochlea through a lateral parapatellar arthrotomy and preparation of an osteochondral flake were carried out. The aim was to create a recentralized, deepened groove. Fixation of the flake in the newly formed groove was achieved with a Vicryl band and bone anchors. Closure of the capsule followed. Via the same skin incision the quadriceps tendon was exposed. The most superficial layer of the quadriceps tendon with a width of 12 to 15 mm was elevated from the deeper tendon. The graft was dissected superiorly at a length of 8-9 cm. The pedicled slip of the tendon remained distally, leaving the patellar attachment intact. The interval between the capsule and the vastus medialis obliquus was developed to the femoral insertion of the MPFL. The graft was then secured with an interference screw under fluoroscopic control with the knee flexed to 30°. Closure of the aponeurosis of the tendon and the capsule concluded the procedure. Partial weight-bearing of 20 kg, using crutches, is allowed. Physical therapy with flexion and extension exercises of the knee, and strengthening of the vastus medialis muscle follow. Full weight-bearing is permitted at 6 weeks and earliest return to sport is 3 months postoperatively. Since 2006 a total of 86 patients with patellofemoral instability have undergone trochleoplasty. In 26 patients combined trochleoplasty and anatomical reconstruction of the MPFL with a distal pedicled quadriceps tendon graft was performed. No recurrent dislocation occurred postoperatively, knee scores improved statistically significantly. Ninety-five percent of the patients were satisfied or very satisfied with the result.