Fulkerson Osteotomy For The Treatment Of Patellofemoral Instability

Objectives: To evaluated the results of Fulkerson osteotomy in patients with chronic patellofemoral instability.Methods: Fulkerson osteotomy (anteromedial tibial tubercle transfer) was performed in 14 knees of 12 patients (7 females,5 males; mean age 27.4 years; range 19 to 45 years)in the orthopeadic department of China-Japan union hospital,Jilin university. The patellofemoral congruence angle and lateral patellofemoral angle were measured pre- and postoperatively on tangential radiograms obtained at 45°knee flexion. All patients had severe osteoarthrosis in the patellar articular surfaces preoperatively.There were 8 knees with lateral patellar tilt, three with lateral patellar subluxation. Femoral dysplasia was observed in 1 knees of subluxation and planovalgus accompanying external tibial torsion was found in 1 women. The Q-angle average measured in about 15°flexion of knee was 25.4°(19-33°)。This average was 25.3°in males and 25.6°in female patients. The surgical procedure was performed according to the standart technique of Fulkerson. The cut extends distally about 6 cm, with the medial tip of the cut being more superficial. Drill holes perforate the cortex distally so that the fragment can be hinged. Proximally, an osteotome is used to complete the osteotomy just deep and just proximal to the insertion of the patellar tendon and to pry the tuberosity medially so that the Q angle is corrected to between 10 and 15 degrees. This usually requires moving the tuberosity anteriorly 8 to 10 mm. The transferred tuberosity is secured by placing a drill bit proximally through the tuberosity and tibia with the knee in 90 degrees of flexion to prevent damage to neurovascular structures. The knee is then moved through a range of motion, and patellar tracking is evaluated. If tracking is satisfactory, the tuberosity is secured with two countersunk, low-profile, bicortical screws. The medial retinaculum is closed in a pants-over-vest fashion, thus plicating the medial side. The lateral retinaculum is not closed.In all patients, the operated leg was placed in a plaster cast and kept at rest until the third postoperative day. Then the patient was allowed to walk with partial weightbearing. Cast immobilization was usually maintained for four weeks. Full weightbearing was allowed after the six postoperative week.The patients were assessed according to the criteria of Fulkerson et al. pre- and postoperatively. The mean follow-up was 23 months (range 15 to 58 months).Results: According to the criteria of Fulkerson et al., the results were excellent, very good, or good in 12 knees (85.7%). Pain and instability scores showed significant improvement (p<0.05). On final radiographic assessment, the mean patellofemoral congruence angle were -6.5 (range -15°to 9°), 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=3). Wound-related problems, peroneal nerve palsy, or proximal tibial fracture were not encountered. Conclusion: Successful results are obtained by Fulkerson osteotomy in the treatment of chronic patellofemoral instability with severe articular degeneration .