MINIMALLY INVASIVE ANKLE ARTHRODESIS WITH A RETROGRADE LOCKING NAIL AFTER FAILED FUSION

Abstract

Background: To correct deformity and achieve fusion after failed fusion a retrograde nail with posterior-to-anterior (PA) locking into os calcis, talus and tibia was used.

Methods: A variety of Methods: have been published to achieve union of the ankle and subtalar joint in a failed fusion situation. We have studied a retrograde locking nail technique through a 2.5 cm incision in the non-weigthbearing part of the sole of the foot. Remaining cartilage in the ankle joint, where necessary, was percutaneously removed through an anterior approach and the locking nail was inserted after reaming of os calcis, talus and tibia. Locking screw insertion was in the sagittal plane (p.a. direction), in talus os calcis and tibial diaphysis using a nail mounted jig. Ten patients were entered in the study (age 27–60 years). The initial aetiology for attempted fusion was posttraumatic in nine cases and rheumatic in one case. There were 25 previous operations in the cohort not leading to fusion. An additional temporary external fixator was used in four cases to reach and maintain the optimum position for the procedure. The intervention time was 30–75 minutes. Dynamization of the nail was performed after four months under local anaesthesia.

Results: The mean duration of follow-up was 4 years (3 to 5,5 years). Radiologically and clinically, fusion was achieved in 16 weeks (range, 12 to 20 weeks). There was no loosening of the implant nor implant failure. A leg length discrepancy was avoided using this technique. There was one complication with varus malunion in a heavy smoker which united after corrective osteotomy, revision nailing and bone grafting. Patient satisfaction was measured on a scale (not visual analog) of 0 (not satisfied) to 10 (completely satisfied), overall satisfaction averaged 9.5 points (range, 6 to 10 points). The postoperative ankle-hindfoot score of the American Orthopedic Foot and Ankle Society averaged 73,5 points (range, 61 to 81 points).

Conclusion: Retrograde locked nailing with locking in the sagittal plane is a reliable minimally invasive procedure to achieve fusion of the ankle and the subtalar joint after failed fusion.