Modified Fulkerson osteotomy in recurrent patellofemoral dislocations

Abstract

Objectives: We evaluated the results of a modified Fulkerson technique performed for the treatment of recurrent patellofemoral dislocations. Methods: The study included 17 knees of 16 patients (11 males, 5 femalesmean age 25 yearsrange 15 to 43 years) who were operated on by the same surgeon for patellofemoral alignment disorders. The mean duration of complaints was 3.4 years (range 1 to 12 years). Preoperatively, the number of recurring dislocations were 1 to 5 in three knees, 6 to 10 in five knees, and more than 10 in nine knees, and all the patients had a positive apprehension test and a Q angle exceeding 15 degrees. All the knees were assessed by preoperative and postoperative radiographs and computed tomography, which showed both subluxation and patellar tilt in all the knees, and trochlear dysplasia in two knees preoperatively. During surgery, diagnostic arthroscopy was performed in all the patients. The skin incision consisted of two horizontal incisions for cosmetic reasons. Surgical treatment was comprised of lateral patellar release to correct patellar tilt, and a modified Fulkerson osteotomy to correct patellofemoral malalignment, and medial plication in three knees. The patellofemoral congruity following lateral release, and the position of the patella following osteotomy and anteromedialization of the tibial tuberosity were checked arthroscopically. On control examinations, the patients were administered functional scoring questionnaires developed by Kujala et al. and Crosby and Insall. Radiographic grading of osteoarthritis was made according to the classification developed by Iwano et al. and modified by Palmer et al. The mean follow-up period was 2.6 years (range 24 to 53 months). Results: During arthroscopy, eight knees had severe (Outerbridge grade III-IV) and nine knees had moderate (grade I-II) retropatellar cartilage damage. Follow-up evaluations showed effusion in two knees, subluxation in two knees, and a positive apprehension test in three knees. The mean flexion loss was 8 degrees (range 0 degrees to 20 degrees). One patient who had an extension loss of 10 degrees regained full extension following a six-week physical therapy program. Postoperative computed tomography scans showed that patellar tilt and subluxation were corrected in all but two knees. Preoperative radiographies showed degenerative arthritis in the tibiofemoral joint in one knee (5.9\%), and in the patellofemoral joint in seven knees (41.2\%). The number of knees with degenerative changes increased postoperatively to three knees (17.3\%) in the tibiofemoral joint, and to 11 knees (64.7\%) in the patellofemoral joint. According to the Crosby-Insall scoring system, five knees had excellent, seven knees had good, and five knees had moderate scores. The mean Kujala score was 82.6 (range 44 to 100) postoperatively. Conclusion: Our results show that, with appropriate indications, the modified Fulkerson method is associated with successful results in the treatment of recurrent patellofemoral dislocations.