Percutaneous Distal Osteotomy of the Fifth Metatarsal for Correction of Bunionette

Abstract

Distal osteotomy of the fifth metatarsal is indicated in the surgical treatment of bunionette and varus deformities of the fifth toe in patients with a valgus deviation of the fifth metatarsal. The aim of this study was to evaluate the results of a subcapital percutaneous osteotomy of the fifth metatarsal in the treatment of this disorder. From 1996 to 2006, thirty consecutive percutaneous distal osteotomies of the fifth metatarsal were performed in twenty-one patients for the treatment of a painful prominence of the head of the fifth metatarsal. Combined procedures were performed, including a first metatarsal osteotomy in sixteen feet for hallux valgus treatment and a distal open osteotomy of the second metatarsal for painful dorsal dislocation of the second metatarsophalangeal joint in eight feet. The patients were assessed at a mean of ninety-six months with a radiographic and clinical protocol that made use of the American Orthopaedic Foot & Ankle Society (AOFAS) Lesser Toe Metatarsophalangeal-Interphalangeal Scale. The AOFAS score improved from a mean and standard deviation of 51.9 ± 10.2 points preoperatively to 98.4 ± 2.6 points at the time of final follow-up. In 73% of feet there was complete resolution of pain at the fifth metatarsophalangeal joint without any functional limitation (AOFAS score of 100). In 20% of the cases the AOFAS score was 95 points with some decrease in function and a need to use comfortable shoes. In the remaining 7% of patients the AOFAS score was 93 points with mildly asymptomatic malalignment. No nonunions or recurrences were observed. The percutaneous procedure described here is a reliable technique to perform a distal transverse osteotomy of the fifth metatarsal to correct a painful varus fifth-toe deformity with prominence of the fifth metatarsal head. The clinical results are comparable with those reported with traditional open techniques, with the advantages of a minimally invasive surgical procedure, substantially shorter operating time, and a reduced risk of complications.