Reaction to Intraarticular Allografts Sterilized with Ethylene Oxide

Abstract

Allografts represent an alternative to autogenous tissue for use in reconstructive surgery of the anterior cruciate ligament (ACL). There are many issues for the surgeon to consider when using these tissues. Among these issues is the effect of processing protocols used by the tissue bank supplying the allografts. Ethylene oxide-sterilized allografts for ACL reconstruction have been reported to be associated with an intraarticular reaction. This reaction has been characterized by a persistent effusion and graft fragmentation requiring removal of the graft. It has been suggested that two byproducts of ethylene oxide sterilization, ethylene chlorohydrin (EC) and ethylene glycol (EG), are possibly responsible for these reactions. Studies attempting to elicit this intraarticular reaction as seen in humans using a rabbit model were unsuccessful. These animal-model studies included intraarticular injections of solutions of EC and EG, ethylene oxide-sterilized patellar tendon particulates, and ACL reconstruction using ethylene oxide-sterilized patellar tendon. The intraarticular reactions described in this article have not been reported because most tissue banks now procure soft tissues aseptically and no longer sterilize them with ethylene oxide for use in transplantation.