Prevention of pin tract infection with iodine-supported titanium pins.

BACKGROUND Pin tract infection is one of the most common complications of external fixation. We developed techniques to coat titanium implant surfaces with iodine. This study clinically evaluated the infection-preventive effects and biological safety of iodine-coated external fixation pins. PATIENTS AND METHODS Iodine-supported pins were placed in 39 limbs of 38 patients. The mean age of the patients was 33.6 years. Twenty-six patients were men and 12 were women. In all patients, the iodine-coated pins were used to prevent infection. There were 476 pin insertion sites. Pin sites were classified according to the Checketts-Otterburn classification (grade 1-6). White blood cells (WBC) and C-reactive protein (CRP) were measured pre- and postoperatively in all patients. To confirm whether iodine from the implant affected physiological functions, thyroid hormone levels in the blood were monitored. The change in the amount of iodine deposited in the body over time was calculated by examining the removed pins. RESULTS External fixation was used for a mean duration of 6 months. Grade 1 infection was found in 2.5% of patients, and grade 2 infection in 1.1%. There was no patient with an infection of grade 3 or higher. Median WBC levels were in the normal range, and median CRP levels returned to <0.3 mg/dl within 3 weeks after surgery. Abnormalities of thyroid gland function were not detected. The amount of iodine was maintained for a long time, with approximately 40% remaining after 1 year. CONCLUSIONS Iodine-supported titanium pins were able to decrease the pin tract infection rate and had no impact on thyroid function. These results suggest that iodine-coated titanium pins are biologically safe and effective at preventing pin tract infections.