Femoral Distraction Osteogenesis in Fibular Hemimelia: Risks and Advantages Using Magnetically Driven Antegrade Intramedullary Lengthening Nails.

Abstract

Fibular hemimelia (FH) is a rare congenital condition characterized by longitudinal lower limb deficiency with fibular hypoplasia or aplasia commonly associated with femoral and tibial shortening resulting in leg length discrepancy (LLD). Femoral distraction osteogenesis represents a well-established reconstructive approach in patients with LLD exceeding 2 cm. Twenty-three patients with FH were treated with antegrade femoral distraction osteogenesis between 2018 and 2021 using magnetically controlled motorized intramedullary lengthening nails (Precice P2 or Stryde, NuVasive/Globus Medical). The primary end points included accuracy, precision, reliability, distraction and consolidation index, and the complication profile. Radiographic and clinical outcomes were assessed over a median follow-up period of 39 (interquartile range [IQR], 26 to 52) months. The median preoperative LLD of 45 (IQR, 39 to 53) mm was reduced to 9 (IQR, 4 to 13) mm (P < 0.001) following a median distraction length of 40 (IQR, 34 to 44) mm. Planned lengthening was achieved with an accuracy of 91% ± 8% and a precision of 91%. The mean distraction index was 0.8 ± 0.2 mm/d, and a consolidation index of 36 ± 15 d/cm. At least one complication was observed in 70% of cases, including transient or persistent knee stiffness (39%) and pain (39%). Unplanned additional surgery related to complications was conducted in 17% of patients and all complications were successfully treated without permanent sequelae. The reliability of the treatment was 96%. No significant correlation was observed between distraction length and complications or revision surgery. Femoral distraction osteogenesis using magnetically driven intramedullary lengthening nails represents a precise and reliable treatment for LLD in FH. Despite favorable radiographic outcomes and high distraction accuracy, the notable complication rate underscores the necessity of rigorous patient selection and structured postoperative management.