Roentgenographic and mathematical analysis of first metatarsal osteotomies for metatarsus primus varus: a comparative study.

The operative effectiveness of five different first metatarsal osteotomies for nonarthritic hallux valgus and metatarsus primus varus were objectively evaluated roentgenographically. The series consisted of 120 feet (75 patients) seen over a 5-year period. The osteotomies were biplanar neck, Chevron, biplanar basilar, basilar concentric, and basilar concentric combined with a lateral closing wedge. All the osteotomies except for the Chevron had varying degrees of plantar displacement of the distal fragment and crossed Kirschner wire fixation. The operative techniques and failures are discussed. Special x-ray studies confirmed misleading pseudocorrections caused by bandage compression and intraoperative and early postoperative roentgenographic distortion. The Chevron gave the least correction, 2 degrees, and did not permit plantar displacement to obviate late metatarsal transfer lesions. The biplanar neck osteotomies were technically the simplest, giving 86% satisfactory corrections, averaging 4.3 degrees. The biplanar basilar osteotomies yielded the most erratic results. The poor results were due to medial tilt during fixation, thereby negating any correction. The technical difficulties with the basilar concentric osteotomy were overcome by the addition of a small lateral closing wedge. This procedure gave by far the most consistently good results with corrections of up to 12 degrees, averaging 7.9 degrees.