Lower limb lengthening and deformity correction using the Fitbone motorized nail system in the adolescent patient

Leg lengthening by an external fixation is associated with various difficulties. Pin-tract infections are commonly encountered, and muscle contractures and joint stiffness are additional complications associated with this method. Several researchers explored a purely intramedullary solution for leg lengthening since the 1970s. The purpose of this study was to evaluate the results of 10 adolescent patients who underwent leg lengthening with a motorized intramedullary lengthening device (the Fitbone System). We aimed to evaluate the effectiveness of the Fitbone system in deformity correction and lengthening of the femur and tibia in the pediatric and adolescent patients looking at whether the incidence of complications commonly associated with external fixators could be reduced. We compared our preliminary results with those from other reports, with a focus on leg length achieved and rate of complications. Ten patients were included, nine femoral nails and five tibial nails were implanted. The average lengthening distance was 4.8 cm (range, 2.8-10 cm). In 10 patients, leg lengthening was combined with successful correction of the mechanical axis alignment in three patients. The consolidation index averaged 24 days/cm (range, 20-39 days/cm). The average hospital stay was 8 days. No bone or soft tissue infections were observed. Only one patient had irritation and pain from the antenna system after lengthening and recovered fully after antenna removal. Our results suggest that the difficulties commonly associated with external fixators can be reduced with this method. It also allows good angular correction in patients with mechanical axis deviation. These features combined with a short time of hospitalization make it a promising procedure for limb lengthening in adolescent patients.