Purpose: Since the pathomechanism of patellofemoral malalignment is complex, multifactorial and varies individually, the ideal treatment has been a matter of controversy. The purpose of this study was to demonstrate the clinical outcome and radiographic changes of knees with patellofemoral malalignment treated with Fulkerson osteotomy after a minimum follow-up of 24 months.
Materials and Methods: Sixty knees in 40 patients (32 female and 8 male) were examined with a mean of 55 20 (25 97) months after having undergone medialization of the tibial tubercle using Fulkerson osteotomy for patel-lofemoral malalignment. Mean age at surgery was 20 7 (12 42) years. Prior surgery of medial retinacular plication in 4 knees and lateral retinacular release in 1 knee had been performed. During surgery, amount of tibial tubercle transfer was determined by examining the patellar tracking over full range of knee motion. After Fulkerson osteotomy, proximal realignment procedures were added depending on arthroscopic appearance of the patellofemoral adaptation. The clinical outcome was evaluated using Fulkersons knee instability scale. The radiographic parameters including congruence angle, lateral patellofemoral angle, tilting angle and lateral shift ratio were measured in Merchant view.
Results: Mean distance of medial transfer of tibial tubercle was 12.8 3.1 (8 22) mm. Lateral retinacular release in 54 knees and adductor magnus tenodesis (Avikainen procedure) in 2 knees were simultaneously performed combined with Fulkerson osteotomy. All radiographic parameters at the final follow-up were significantly improved compared to the preoperative values (p <
0.05 in a paired t-test), that is, from 23.0 14.6 to 0.4 13.7 degrees in congruence angle, from −6.3 9.0 to 0.4 6.9 degrees in lateral patellofemoral angle, from 25.1 11.5 to 16.3 5.6 degrees in tilting angle and from 35 24 to 17 9% in lateral shift ratio. Mean score in Fulkersons knee instability scale was 96 5 points at the final follow-up. All knees except 3 were ranked as excellent, very good or good. Two knees with moderate osteoarthritis of the patellofemoral joint were ranked as fair. One knee that had postoperative recurrence of patellar subluxation underwent a revision surgery with Avikainen procedure.
Discussion: In the clinical study with a minimum 2-year follow-up, Fulkerson tibial tubercle osteotomy provided excellent or good overall outcome in 93% of patients in combination with proximal realignment surgeries. Although all radiographic parameters were significantly improved, it was found that the lateral shift of the patella was more effectively corrected compared to the lateral tilt. It was suggested that reconstruction of the medial patellofemoral structures might be more suitable than Fulkerson osteotomy for some knees characterized by significant lateral tilt.
