Primary or secondary wound healing of the Pin Sites After Removal of the External Fixator: Study Protocol for a Prospective, Randomized Controlled Mono-center Trial

Abstract

Background: Temporary fixation with an external fixator is used for numerous indications in orthopedic trauma surgery. It is unclear whether primary wound healing or the secondary open wound healing after removal of the external fixator should be advocated for the pin site. This study compares primary wound closure with secondary wound healing for the pin sites. The primary aim is to compare the infections rates of the pin site. Secondary aim is to compare time to wound healing and esthetic outcome. The hypothesis was that primary wound closure does not lead to more infections than secondary wound healing. Methods: This is a prospective, randomized, controlled and blinded monocenter study based on a non-inferiority design. To obtain an equal patient population and groups, all pin entry sites of the patients are treated alternately at the time of removal of the external fixator with primary wound closure and secondary wound healing. Patients are randomized whether the proximal pin entry site is treated with wound closure or by secondary open wound healing, from which the further sequence develops. The pre- and postoperative protocol is standardized for all pin entry sites. A photo documentation of the pin entry sites takes place 2 and 52 weeks postoperatively during the routine clinically follow-up visits. Further controls take place after 6, 12 and 26 weeks after the removal. The primary outcome was to demonstrate the non-inferiority of primary wound closure compared to secondary wound healing in terms of postoperative wound infections according to center of disease control (CDC). The secondary outcomes are time to complete wound healing (days) and esthetical outcome (Subjective preference of patients and Vancouver scar scale). Discussion: This study aims in answering how to deal with the pin site after removal of the external fixator. To date, no routine and generally accepted protocol exists for the management of pin sites after removal of the external fixator. This prospective, randomized, blinded monocenter trial will answer if primary wound closure or secondary wound healing should be advocated after removal of the external fixator.