Magnetic Intramedullary Lengthening Nails for Complex Lower Extremity Reconstruction: Functional Outcomes, Bone Healing, and Complications

Background: Magnetically controlled intramedullary lengthening nails have become increasingly popular for lower extremity reconstruction because they reduce complications associated with external fixation and facilitate earlier rehabilitation. However, comprehensive data integrating deformity correction, bone healing, functional recovery, psychosocial outcomes, and complication-related analyses remain limited. This study aimed to evaluate the radiological, functional, psychosocial, and complication-related outcomes of magnetic intramedullary lengthening nails in patients undergoing complex lower extremity reconstruction. Methods: This retrospective case series included 34 patients who underwent 37 magnetic intramedullary lengthening procedures between 2015 and 2024. Radiological outcomes, bone healing indices, lower extremity alignment parameters, complications, and patient-reported outcomes were evaluated. Functional and psychosocial assessments included the Lower Extremity Functional Scale (LEFS), Short Form-36 (SF-36), and Rosenberg Self-Esteem Scale. Subgroup and correlation analyses were performed to investigate factors associated with regenerate maturation and postoperative complications. Results: The mean follow-up duration was 44.6 ± 19.8 months. Radiological union was achieved in all patients. The mean achieved lengthening was 4.8 ± 1.9 cm, while the mean consolidation and distraction indices were 57.6 ± 44.5 days/cm and 1.0 ± 0.02 mm/day, respectively. Tibial lengthening procedures demonstrated significantly higher maturation indices compared with femoral procedures (60.5 ± 37.3 vs. 45.0 ± 45.4 days/cm, p = 0.045). Complications occurred in 18.9% of procedures and were associated with significantly prolonged consolidation and maturation indices. Delayed union was the most common complication and was successfully managed with autologous bone grafting or conversion to a standard intramedullary nail when necessary. No implant-related mechanical failure, permanent neurological deficit, or failure of final bone union was observed. Increasing age demonstrated significant positive correlations with both consolidation and maturation indices. Functional and psychosocial outcomes were favorable, with a mean LEFS score of 81.5 ± 15.5% and satisfactory SF-36 and Rosenberg Self-Esteem scores at final follow-up. Conclusions: Magnetically controlled intramedullary lengthening nails provide reliable deformity correction, successful bone healing, and satisfactory functional and psychosocial outcomes in patients undergoing complex lower extremity reconstruction. Although complications may prolong regenerate maturation, favorable clinical and radiological outcomes can be achieved with appropriate patient selection, standardized rehabilitation, and timely secondary interventions.