Distal oblique osteotomy of the first metatarsal for the correction of hallux limitus and rigidus deformity.

The purpose of this study was to evaluate the effectiveness of the distal oblique osteotomy of the first metatarsal (a triplanar shortening decompression osteotomy) to correct stage I and II hallux rigidus. The osteotomy cut is performed from dorsal-distal to plantar-proximal with an angle ranging from 35 degrees to 45 degrees in the sagittal plane. The capital fragment is then displaced plantarly and proximally and fixed with two screws and the metatarsal head is remodeled. From January 1993 through December 1995, a total of 26 patients (21 females and 5 males) underwent 30 distal oblique osteotomies of the first metatarsal (22 unilateral and 4 bilateral). The mean age of the patients was 54 years and the mean follow-up was 21 months. Patient satisfaction and objective clinical and radiographic measurements were evaluated. Patients' satisfaction was measured postoperatively with a modification of the University of Maryland 100-Point Painful Foot Center Scoring System. The results were: 84% good to excellent; 7% fair; and 9% poor. Radiographic measurements included: intermetatarsal angle mean: preop = 12.2 degrees, postop = 8.6 degrees; proximal articular set angle mean: preop = 11.8 degrees; postop = 10.3 degrees. There was no evidence of avascular necrosis in any of the cases. Clinical findings were: dorsiflexion of the first metatarsophalangeal joint: preop = 22 degrees, postop = 45 degrees; plantarflexion of the first metatarsophalangeal joint: preop = 15 degrees, postop = 18 degrees; hallux purchase power: preop = 2.5, postop = 2.3; pain on the second and third metatarsophalangeal joints, associated with excessive pressure on the central metatarsal heads: preop--present in 10 patients, postop--present in 12 patients; forefoot supination angle: preop = 13 degrees, postop = 7 degrees.