Clinical and Functional Outcome of Infected Non Union of the Femur Managed with Monolateral External Fixator: A Prospective Interventional Study

Introduction: The treatment of infected non unions of long bones is one of the most challenging tasks in modern orthopaedic trauma practice. With the increasing prevalence of Road Traffic Accidents (RTAs) and associated high-energy trauma, primary fractures are often presented with gross contamination, softtissue degloving, bone loss and vascular compromise. Infected non unions of the femur are managed through debridement, external fixation, bone grafting, microvascular composite tissue transfer, bone transport via an external fixator over a nail and Ilizarov circular or monolateral fixators. Aim: To evaluate the clinical and functional outcomes in infected non unions of the femur treated with a monolateral external fixator. Materials and Methods: This study was a prospective interventional study that included 17 males and one female patient, with a mean age of 35 years, who were treated at Dr. DY Patil Tertiary Care Hospital in Pune city, Maharashtra, India with a monolateral external fixator between January 2021 and January 2024. All patients had high-energy RTAs, compound fractures and gross contamination initially. Implant removal was performed, followed by radical debridement and stabilisation with the rail fixator. The mean duration of non union was 13 months (range: 4-24 months). The mean number of previous surgical procedures was 3.4 (range: 1-4). Corticotomy and bone transport were performed in six patients who had shortening or bone loss of more than 2 cm. Distraction of the corticotomy was initiated one week later at a rate of 1 mm per day until lengthening was achieved. Monthly outpatient department follow-ups, with X-rays, were conducted and the fixator was maintained until the healing of three cortices and eradication of infection were confirmed. The average follow-up duration was 2.3 years (range: 1-4 years). A paired t-test was used for statistical analysis during follow-up. Results: Union was achieved in 17 out of 18 patients, resulting in a union rate of 94.4%. The mean time to bony union was 7±2 months (range: 4-12 months). Infection was eradicated in all but one patient, who continued to experience a discharging sinus. The mean length achieved in the corticotomy and lengthening group was 4±0.75 cm. According to Paley’s bone and functional outcome scoring, all but one patient had excellent to good results at the one-year follow-up. Significant improvement was observed in the Lower Extremity Functional Score (LEFS) and in the Physical Component Score (PCS) of the 36-Item Short Form Health Survey questionnaire (SF-36) at the one-year follow-up (p-value <0.05); however, there was no improvement in the Mental Component Score (MCS) of the SF-36. Conclusion: A monolateral external fixator can provide stable fixation for the management of infected non unions of the femur and is an effective method for eradicating infection.