Ilizarov fixator pin site care: the role of crusts in the prevention of infection.

Pin site infection is one of the most common local complications after procedures using the Ilizarov fine wire fixator. In this study, the rate of infection was investigated in two groups of patients, representing two consecutive case series, undergoing fracture stabilisation or lower limb reconstruction using an Ilizarov fine wire fixator. Both groups received identical Russian-style pin site care, except in the first Group A where the crusts of dried exudate were removed at the time of pin site cleaning; while in the subsequent Group B, the adherent crusts were retained during cleaning. Pin site infection was diagnosed if the site was painful and inflamed or discharging. The first infected pin site while the fixator remained in situ was considered the outcome of interest. Group A consisted of 59 patients and Group B of 33 patients. A lower proportion of patients in Group B (12/33 - 36%) developed a pin site infection compared to Group A (36/59 - 61%) (p=0.023). However, once infection had developed, a greater proportion of patients in Group B required more than one course of antibiotics to treat the infection when compared to patients in Group A (p=0.005). No patient required hospitalisation for intravenous antibiotics or wire change in Group B (0/33), whereas 3/59 patients required hospitalisation in Group A; but this did not reach statistical significance (Chi-squared test, p=0.18). Retention of adherent crusts during Ilizarov fixator pin site care significantly protects against the development of pin site infection, but renders subsequently infected pin sites more refractory to treatment. This study therefore suggests that crusts should be retained as long as a pin site remains uninfected. Retained crusts may act as a physical barrier to bacterial contamination ('biological dressing').