For surgical treatment of hallux rigidus many different procedures have been described. Resection arthroplasty (‘Keller procedure’) is a surgical procedure mostly used for older patients suffering from severe osteoarthritis of the first metatarsophalangeal joint. As a modification of this procedure, resection arthroplasty is combined with cheilectomy and interposition of the dorsal capsule and extensor hallucis brevis tendon, which are then sutured to the flexor hallucis brevis tendon on the plantar side of the joint (capsular interposition arthroplasty, IA).

Capsular interposition arthroplasty was performed on 22 feet of 14 patients (six male, eight female) suffering from osteoarthritis of the 1st MTP-joint were included in this study (group 1). These results were compared to the outcome of 30 feet of 22 patients (12 male, 10 female) treated with resection arthroplasty (group 2). The indication for resection arthroplasty were the same as for IA. The mean age was 55.3 years (37.6 to 71.2) in group 1 and 57.8 (43.5 to 75.6) in group 2. The age distribution of our patients at surgery did not differ significantly between both groups (p=0.633). The mean follow-up period was 15.1 month, range 6 to 27 months and did not differ between both groups (group 1: 16.5 month, group 2: 14.1 month; p=0.143).

The mean follow-up period was 15 months. No statistically significant difference was found between both groups concerning patient’s satisfaction, clinical outcome and increase in range of motion of the first metatarsophalangeal joint. At follow-up, patients who had undergone interposition arthroplasty did not show statistically significant better AOFAS forefoot-scores compared to the Keller procedure group. A high rate of osteonecrosis of the first metatarsal head was found in both groups. These radiological findings did not correlate with the clinical outcome at follow-up.

There is no benefit in clinical or radiological outcome for capsular interposition arthroplasty compared to the Keller procedure.