Intra-uterine and juxtanatal repair of syndactyly in foetal mice

39 foetal mice with genetic syndactyly were identified in utero at 17 days of gestation, and the right hindfoot extruded through the uterus. The syndactylous digits were separated by simple incisions. In one group (n=25) digit separation was maintained during wound healing by the interdigital application of a silver microclip. Digit separation was also assessed in a second group of newborn mice less than 24 hours old (juxtanatal population, n=24). Two foetuses (5%) and six newborns (25%) developed digital necrosis following microclip application. In the remaining microclipped animals (23 intrauterine and 10 juxtanatal), microclip application maintained digit separation, allowing wound healing to occur with epithelialization of the separated digits. No inflammation or scar formation occurred. In the third group (n=22) without microclip application, the digital skin reapproximated and webbing recurred during wound healing. These studies demonstrate the need to maintain digit separation during wound healing following intra-uterine or juxtanatal syndactyly repair.