Purpose: Bipolar osteotomy of the first metatarsal with lateral release of the first metatarsophalangeal joint was performed in 19 cases of hallux valgus. The distal metatarsal surface was misaligned in all cases (increased DMMA). The purpose of our work was to evaluate outcome after Schnepp bipolar osteotomy.

Material and methods: The series included eleven women and three men who underwent the procedure between 1992 and 2001. All patients were reviewed retrospectively by the same clinician. Mean patient age was 56 years. Before surgery, mean values were: metatarsophalangeal valgus 39.6°, metatarsal varus 17.8°, and DMMA 21.1°. Mean foot opening measured preoperatively was 30°.

Results: The Groulier criteria, taking into consideration correction of the deformity, static disorders and function were assessed at mean follow-up of three years. Radiographically mean metatarsophalangeal valgus was 20.7°, metatarsal varus 10.3°, and DMMA 5.3°. The metatarsal span was 23°. The metatarsophalangeal joint was congruent and free of any sign of degeneration in 52%. Overall outcome was excellent or good in 57.5%, fair in 32% and poor in 10.5%.

Discussion: These results are rather modest but were obtained in a series of patients with severe hallux valgus. Bipolar osteotomy enables simultaneous correction of the phalangeal valgus, the metatarsal varus, and the increased DMMA, an advantage not obtained with any other procedure. Indications would include patients with increased DMMA > 15° or major metatarsal varus. Our series show that poor results can be observed in the event of incongruent joints, signs of osteoarthritic degeneration, or revision surgery.

Conclusion: Bipolar osteotomy of the first metatarsal remains indicated for the treatment of severe hallux valgus with increased DMMA. Metatarsophalanygeal arthrodesis should be reserved as a salvage procedure for non congruent or degenerated joints.