Failure Modes in Ilizarov Limb Salvage: A Narrative Review of Technical, Biological, Patient-related and Systemic Determinants.

Aim and background: The Ilizarov circular external fixator remains a cornerstone of limb salvage for infected non-unions, segmental bone defects, limb-length discrepancies and severe deformities. Despite consistently high union rates, treatment is prolonged and associated with a substantial burden of Paley-defined problems, obstacles and complications. This narrative review examines the technical, biological, patient-related and environmental determinants of failure and suboptimal outcomes following Ilizarov reconstruction, with particular emphasis on resource-limited settings. Materials and methods: A narrative synthesis of evidence from meta-analyses, large retrospective cohorts and representative case series was performed. Failure mechanisms were categorised into four domains: Technical factors, biological factors, patient-related factors and environmental/systemic influences. Evidence from low- and middle-income countries (LMICs) was specifically evaluated. Results: Reported bony union rates ranged from 85 to 95%; however, adverse event rates must be interpreted within Paley's framework. Most reported events represent expected and largely reversible treatment-related problems or obstacles inherent to prolonged external fixation rather than reconstructive failure. Aggregate rates of 90-406 Paley-defined events per 100 cases therefore reflect treatment burden rather than failure. Clinically significant complications, including persistent non-union, refracture and secondary amputation, comprised a smaller subset of adverse outcomes. Technical shortcomings contributed to malalignment regenerate deformity and docking-site non-union. Biological factors, particularly pin-site and deep infection, impaired regenerate formation and prolonged treatment. Patient noncompliance, psychological intolerance, malnutrition, smoking and metabolic disease increased failure risk, while socioeconomic constraints and limited rehabilitation resources exacerbated complications in resource-constrained settings. Conclusion: Successful Ilizarov reconstruction depends on technical precision, biological viability, patient engagement and environmental context. Multidisciplinary planning, realistic counselling and context-specific preventive strategies are essential to optimise outcomes in complex limb salvage reconstructions. Clinical significance: Recognition of modifiable failure pathways may help surgeons anticipate complications, refine treatment strategies and improve functional outcomes.