Femur lengthening with a telescopic intramedullary nail ISKD--method presentation and early clinical results

INTRODUCTION: Limb discrepancy over 4 cm is an indication for limb lengthening. Surgical techniques rely on osteotomy, external stabilisation and gradual distraction. The ISKD (Intramedullary Skeletal Kinetic Distractor) nail allows distraction osteogenesis and no external fixator is required. AIM OF PAPER: Aims of paper are: presentation of limb elongation method with the ISKD device, and presentation of early own results. MATERIAL AND METHODS: Material consists of 5 patients, age 14-16 years, 3 boys and 2 girls, who underwent femur lengthening with the ISKD nail between 2005 and 2007. We evaluated: initial shortening, surgical procedure, complications, amount of lengthening, lengthening rate, distraction index, time of treatment and mobility of adjacent joints. RESULTS: Initial shortening was 4-11 cm. No surgical complications were observed, mean time of surgery was 145 minutes, mean blood loss--200 ml. In three patients difficulties with initial distraction required manipulations under general anaesthesia. Distraction was complicated in 3 cases--in two patients premature consolidation was noted; in one case the distraction rate was too high. Mean lengthening rate in the study group was 0.7 mm/day (0.6-0.7 mm/day). Mean distraction index was 41.7 days/cm (26.2-55 days/cm). Full weight bearing was allowed after mean 234 days (210-275 days). Transient decrease of adjacent joint mobility was observed. CONCLUSION: The fully implantable, telescopic ISKD eliminates the need of external fixation and associated complications. Early results of limb lengthening with ISKD are encouraging. Careful patient selection and preoperative planning is required. Further studies and longer follow-up periods are needed.