Outcomes and Challenges of Limb Lengthening Using Motorized Intramedullary Nails: A Retrospective Analysis of 129 Consecutive Lengthenings

Limb lengthening using a motorized intramedullary nail is a relatively new technique. The aim of this study was to evaluate whether lengthening nails are a reliable and safe method for femoral and tibial lengthening. We analyzed data from a prospective database of all limb lengthening procedures performed at our hospital. The primary outcomes were achieved lengthening, lengthening index (healing rate), and complications. We identified data from 129 lengthening procedures performed with motorized intramedullary nails on 119 patients with a mean age of 20 years (range 9–61); 64 were male and 55 were female. Seven patients underwent bilateral lengthening for short stature. The most common diagnoses were congenital short femur (n=29), post-traumatic shortening (n=18), and idiopathic leg length discrepancy (n=14). The procedures included 116 femoral lengthenings (90 antegrade, 26 retrograde) and 13 tibial lengthenings. The mean operative time was 134 minutes (range 49–300), and 16 cases involved multiple procedures under the same anesthesia. The average lengthening achieved was 39 mm (range 20–80). Complications led to 13 unplanned secondary surgeries (10%), including five cases of early removal of a blocking screw. Additionally, three cases of nonunion required secondary surgical intervention. Retrograde femoral and tibial lengthening were associated with higher complication rates compared to antegrade femoral lengthening. The results demonstrate that motorized intramedullary nails are effective for limb lengthening, achieving consistent results in terms of lengthening and healing. However, the higher complication rates observed with retrograde femoral lengthening and tibial lengthening highlight the need for careful patient selection and surgical planning. Retrograde approaches, especially when combined with angular correction, may introduce additional technical challenges and mechanical stress, increasing the risk of complications. For femoral angular deformities, a staged approach with initial angular correction followed by antegrade lengthening may reduce complications. In tibial lengthening, external fixation (e.g., Ilizarov or TSF) remains a viable alternative in selected cases, offering better control over alignment and healing in complex deformities. Further studies are needed to refine surgical techniques and identify patient-specific factors influencing outcomes. Limb lengthening using motorized intramedullary nails is a reliable and safe method, but complications are more frequent in retrograde femoral and tibial procedures. Optimized surgical strategies are essential to improve outcomes and reduce risks in these cases.