[Fulkerson osteotomy for the treatment of chronic patellofemoral malalignment].

Abstract

We evaluated the results of Fulkerson osteotomy in patients with chronic patellofemoral malalignment. Fulkerson osteotomy (anteromedial tibial tubercle transfer) was performed in 21 knees of 18 patients (10 females, 8 males; mean age 28.6 years; range 21 to 42 years). The patellofemoral congruence angle, lateral patellofemoral angle, and patellofemoral index were measured pre- and postoperatively on tangential radiograms obtained at 45 degrees knee flexion. Malalignment patterns were determined by computed tomography as lateral tilt (n=12), lateral patellar subluxation (n=4), and both (n=5). All the patients underwent arthroscopic examination preoperatively and all had severe osteoarthrosis in the patellar articular surfaces (Outerbridge type III-IV). The mean anteriorization was 10.5 mm (range 7 to 15 mm). The vastus medialis oblique muscle was advanced in seven knees. The patients were assessed according to the criteria of Fulkerson et al. pre- and postoperatively. The mean follow-up was 28 months (range 20 to 60 months). According to the criteria of Fulkerson et al., the results were excellent, very good, or good in 18 knees (85.7%), fair in two knees (9.5%), and poor in one knee (4.8%). Pain and instability scores showed significant improvement (p<0.05). On final radiographic assessment, the mean patellofemoral congruence angle and patellofemoral index were -6.8 degrees (range -26 degrees to 10 degrees ) and 1.4 (range 0.8 to 1.6), respectively (p<0.05). The lateral patellofemoral angle had a lateral orientation in all the knees. Complications included tibial tubercle avulsion (n=1), deep vein thrombosis (n=1), and slight knee flexion contractures (n=4). Wound-related problems, compartment syndrome, peroneal nerve palsy, or proximal tibial fracture were not encountered. Successful results are obtained by Fulkerson osteotomy in the treatment of chronic patellofemoral malalignment with severe articular degeneration (Outerbridge type III-IV) particularly in the lateral and distal regions of the patella.