Abstract
Peripheral nerve injuries that are not acutely repaired may lead to a nerve gap because of the surrounding zone of injury and elastic recoil of nerve tissue after laceration. This can result in tension across the repair site during primary neurorrhaphy. Decades of basic science literature using in vivo models consistently demonstrate a relationship between increasing strain at a neurorrhaphy site and compromised microvascular blood flow. Clinical and laboratory data suggest tension-free repairs are associated with optimal outcomes; in the setting of a short segmental nerve gap, data suggest primary repair may continue to yield good functional results. In the case of high strain, nerve grafting or other methods should be considered given poor results of primary repairs performed under high tension because of local ischemia and fibrosis on a cellular level.