[Ankle arthrodesis with four cancellous lag screws].

OBJECTIVE: Arthrodesis of the ankle at 90 degrees and perfect axial alignment for restoration of a painless function. Early functional postoperative care.

INDICATIONS: Painful posttraumatic or idiopathic osteoarthritis of the ankle either unresponsive to conservative measures or where these measures are not expected to be successful. Posttraumatic malalignment of the ankle, paralysis or instability, that cannot be improved or eliminated by joint-preserving measures. Joint destruction after infection. Failure of total joint replacement.

CONTRAINDICATIONS: Acute osteitis. Poor skin or soft-tissue conditions. Severe peripheral arterial occlusive disease.

SURGICAL TECHNIQUE: Anterior approach, judicious resection of the remaining articular cartilage. Freshening of the zones of sclerosis. Preservation of the anatomic shape of the mortise. Correction of malalignments in the sagittal and frontal planes and placement of the talus in line with the tibial axis. Tibiotalar stabilization with four 7.3-mm self-cutting cannulated cancellous lag screws or with four 6.5-mm cancellous lag screws.

RESULTS: Between January 1, 1994 and December 31, 1998 this technique was performed in 50 ankles of 48 patients. 40 patients could be followed up for an average of 5.6 years (4.8-7.6 years). No serious complications. The average compensatory movement of the Chopart joint amounted to 26 degrees . Osteoarthritis of the subtalar joint was seen in 13%, and of the talonavicular joint in 12.5% of patients. Preexisting osteoarthritis of these joints remained in general unchanged. The AOFAS Score was assessed pre- and postoperatively. Preoperatively, 17.5% of patients showed a satisfactory and 82.5% a poor score. Postoperatively, 52.5% had an excellent, 30% a good, 10% a satisfactory, and 7.5% a poor outcome.