A heterotopic autoinnervated urinary neosphincter.

Twenty-six female adult New Zealand white rabbits underwent surgical denervation of a gracilis muscle to study the possibility of developing an autologous neosphincter innervated by the pudendal nerve. The study was conducted in 2 phases. In both Phase I and Phase II, the study group had the motor nerve to the gracilis, a branch of the obturator nerve and the pudendal nerve coapted in the perineum. The control group was left denervated. In Phase I, all muscle flaps were wrapped around the urogenital sinus. In Phase II, the muscle flaps were returned to their anatomic location. With bulbocavernosus reflex testing, 89% of the reinnervated group and 60% of the denervated group from Phase I and 86% of the reinnervated group and none of the denervated group from Phase II had a contractile response in the muscle flap. In Phase II, histologic examination of the gracilis muscle was suggestive of an early change in muscle myofiber physiology from fast twitch to slow twitch in the reinnervated group only. In the rabbit, a transplanted vascularized muscle flap, cross-innervated by the pudendal nerve has a reproducible response to bulbocavernosus reflex testing. This suggests that a transplanted muscle might be able to assume some of the characteristics of the voluntary urinary sphincter. The rabbit is a useful model in which to investigate the potential of the heterotopic neosphincter.

Military nordic skiing injury profiles with two different types of NATO ski bindings.

Two different types of NATO ski bindings were compared during military-nordic ski training of a Marine Corps infantry battalion of 534 men, who sustained 26 injuries (3.75 injuries per 1,000 skier days). Twelve injuries occurred with the 224 subjects using the NATO 100 bindings. Fourteen injuries occurred with the 310 subjects using the NATO 120 bindings. A total of 133 days were lost from training in the NATO 100 cohort and 121 days from training in the NATO 120 cohort, a statistically significant difference. It is concluded that the NATO 120 binding is safer.