Delayed Onset Implant Associated Infections in United Closed Fractures - An Analysis of a Rare Phenomenon

Purpose: Implant related infections occurring for the first time in healed closed fractures are a poorly understood phenomenon. Very little is known about their exact incidence and the risk factors involved. We aim to address this issue by a retrospective analysis of a case series of delayed onset implant associated infections in healed closed fractures. Methods: Retrospective cohort study conducted in a tertiary care hospital. Patients with united fractures and implant in situ presenting with infection for the first time were included. Open fractures and routine implant removal surgeries were excluded. Diagnosis made by using Metsemakers et al diagnostic criteria for implant related infections. Patient factors, fracture and treatment related factors were recorded. Results: A total of 14 cases fulfilled the inclusion criteria. Ten were males (70 %) and four females (30 %). Mean age was 46 years with time to diagnosis of infection ranging from one year to 10 years (mean=51 months). The most common presenting complaint was discharging sinus (n=10) and the most common implant affected was Tibia ILN (n=6). Diabetes Mellitus was seen in eight patients and one developed it subsequently after initial presentation with impaired glucose tolerance. Radiological evidence of infection was seen in all patients. All patients recovered completely after implant removal and antibiotic therapy. Conclusion: The possibility of an implant related infection occurring any time after fracture union should be acknowledged and studied in further detail so that appropriate measures can be taken to reduce patient morbidity and health care costs.