Many surgical techniques have been reported for the treatment of patellofemoral instability. The authors performed follow-up evaluations in 40 knees (6 males, 34 females) for recurrent dislocation of the patella after Elmsli-Trillat procedure. The mean age of the patients at the surgery was 21.1 years (range: 13 to 42 years). An average follow-up of 69 months (range: 24—113 months) was examined. We evaluated all patients using the Fulkerson's functional knee scores, Q angle, and evaluated the period of the time from primary dislocation to primary operation, and the number of times of dislocation. Radiographs were taken before and after surgery in tangential projections. The average Fulkerson's functional knee score improved significantly from 41.5±14.6 before operation to 86.4±8.2 at follow-up (p<0.0001). The average Q angle improved significantly from 23.8±3.0 before operation to 5.0±3.6 at follow-up (p<0.0001). The average tilting angle improved significantly from 26.6±10.0 before operation to 15.6±4.3 at follow-up (p<0.0001). The average congruence angle improved significantly from 27.7±13.3 before operation to —9.1±9.3 at follow-up (p<0.0001). The average sulcus angle was 147.7±10.8 before operation. The 40 knees were divided into two groups according to long-term outcome; excellent or very good or good (32), or fair or poor (8). The mean age at the time of surgery for patients with good resutls was 19.8±4.7 years and for those with poor results was 27.4±7.5 years (p<0.05). The mean length of time between the first dislocation and surgery for patients with good results was 84.0±52.7 months and for those with poor results was 176.5±112.0 months (p<0.05). The mean number of times dislocation for patients with good results was 6.7±2.5 times and for those with poor results was 10.8±3.5 times (p<0.05). The mean number of Carter-index for those patients with good results was 3.8±0.5 and for those with poor results 4.7±0.4 (p<0.05).
Our study suggests that the Elmsli-Trillat procedure prevents recurring dislocation. The main cause of deterioration in the clinical results was aggravation of patellofemoral joint pain.