Adding stability to the crescentic basilar first metatarsal osteotomy.

Crescentic basilar osteotomies for metatarsus primus varus and hallux valgus allow for substantial correction of the first intermetatarsal angle and the hallux valgus angle. Crescentic osteotomies have two well-documented pitfalls: sagittal plane instability and difficulty in fixation. We describe the addition of a plantar shelf to crescentic basilar osteotomy that allows for easier fixation and less risk of elevation of the first metatarsal postoperatively. This plantar shelf is made in the metaphyseal portion of the first metatarsal, which provides the benefit of better bone healing. In 20 patients, we found an average reduction in the intermetatarsal angle of 9.3 degrees and an average reduction in the hallux valgus angle of 21.8 degrees. Eight weeks postoperatively, only one patient showed elevation of the first metatarsal.