Comparison of Techniques Utilising External Fixation to Motorised Intramedullary Nails in the Treatment of Lower Limb Discrepancy: Systematic Review and Meta-analysis

Aim: This systematic review and meta-analysis compares the clinical outcomes of motorised lengthening intramedullary nails (MLNs) with techniques utilising external frames for lower limb discrepancy (LLD) treatment. Materials and methods:The systematic review was conducted under the guidance of PRISMA guidelines and reported to the PROSPERO registry in December 2022.Out of 3,422 articles, only six eligible studies were identified from PubMed, Scopus, and EMBASE, meeting inclusion criteria.Meta-analysis was conducted for total lengthening, time to union, and incidence of reoperations.Results: Pooled MD for total lengthening was -0.50 (95% CI: -0.93, -0.08), showing a slightly better outcome (statistically significant) for the comparison treatment.For time to union, pooled MD was -0.12 (95% CI: -1.38, 1.14), indicating no statistically significant difference between the treatments.Lastly, with the reoperation rates, the overall log odds ratio (OR) was 0.91 in favour of MLN and statistically significant (95% CI: -1.77, -0.04). Conclusion:This study suggests that techniques that incorporate external fixators have a greater potential for the amount of total lengthening over the use of motorised lengthening MLN but may increase complications requiring reoperation.There is no significant difference in time to union.Clinical significance: This is the first systematic review and meta-analysis comparing MLN with other techniques utilising external frames.Finite conclusions cannot be drawn owing to the use of a small number of observational studies with relatively small numbers in each study.Further studies should be developed to support the suggested conclusions, and this study may serve as a foundation for future studies.