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

Objectives: We evaluated the results of Fulkerson osteotomy in patients with chronic patellofemoral malalignment.

Methods: 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).

Results: 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.

Conclusion: 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.