A Case Report of Spontaneous Second Toe Varus Deformity Correction after Hallux Valgus Deformity Correction by a Non-osteotomy Technique: Syndesmosis Procedure.

INTRODUCTION: Crossover deformity of the first and second toes is not uncommon of a severe hallux valgus (HV) deformity. It can be corrected by adequate realignment of the hallux. However, the crossover deformity may be complicated by also a concomitant varus deformity of the second toe. Although the pathoanatomy of second toe varus deformity has been well described, its pathogenesis is still unclear. Consequently, its treatment has been mostly symptomatic and notspecific to its pathogenesis. This is a 1-year follow-up report of spontaneous correction of the second toe varus deformity after a soft tissue procedure for HV and metatarsus primus varus (MPV) deformities correction. CASE REPORT: A patient had bilateral HV and crossover deformities of her feet. She opted for a bilateral surgical treatment when conservation management failed to be helpful anymore. A soft tissue non-osteotomy technique called syndesmosis procedure was chosen for her deformities correction. Her crossover deformity was caused mainly by varus deformity of the second toe. Intraoperatively, the second toe varus deformity was found to correct itself spontaneously once the first metatarsal was realigned by a non-osteotomy intermetatarsal cerclage suture technique to correct the MPV deformity. Only themore severe second toe deformity of right foot required additional soft tissue release to help correct its mild residual varus deformity. The patient enjoyed excellent cosmetic and functional results. The possible pathogenesis of second toe varus deformity and its unexpected spontaneous correction is discussed.
CONCLUSION: The pathogenic deforming force of second toe varus deformity may originate from the first ray HV deformity complex. Consequently, the satisfactory anatomical correction of her HV deformity and also function restoration of the first ray by the syndesmosis procedure might have been the mechanism of spontaneous correction of the second toe varus deformity and its recurrence prevention.