Functional outcomes and complications of tibial lengthening using the lengthening over nail technique in leg length discrepancy patients in a low-resource setting

OBJECTIVE: To evaluate the functional outcomes, complications, and cost-effectiveness of tibial lengthening using the Lengthening Over Nail (LON) technique with locally available implants in a resource-limited setting. MATERIALS AND METHODS: A prospective case series was conducted from January 2012 to January 2023. The study included skeletally mature patients diagnosed with leg length discrepancy who underwent tibial lengthening using the LON technique. The construct consisted of a standard unlocked intramedullary nail (SIGN® nail) combined with a locally manufactured external fixator. Outcome measures included the External Fixation Index (EFI), Bone Healing Index (BHI), range of motion (ROM), and complications. Functional outcomes were evaluated using the Lower Extremity Functional Scale (LEFS) and the ASAMI criteria. RESULTS: A total of 51 patients were included. The mean lengthening achieved was 5.69 ± 1.52 cm (3.2–9 cm). The mean EFI was 13.74 ± 1.89 days/cm, and the mean BHI was 44.13 ± 5.48 days/cm. Bone union was achieved in 100% of cases. Complications included 31 cases of pin tract infection and 29 cases of transient equinus contracture, all successfully managed with non-operative or minor operative measures. At final follow-up, knee and ankle ROM were fully restored. The mean LEFS score was 74 ± 3.6. According to the ASAMI score, excellent or good results were achieved in 100% of patients. CONCLUSION: The LON technique using simple, cost-effective hardware is a safe and reliable method for treating leg length discrepancy. It significantly reduces external fixation time compared to traditional methods and offers a scientifically valid and economically viable alternative to expensive motorized lengthening nails, particularly in low- and middle-income healthcare systems. LEVEL OF EVIDENCE: Level IV.