Ilizarov method and its combined methods in the treatment of long bone defects of the lower extremity: systematic review and meta-analysis
Authors: Xie Lijun , Huang Ye , Zhang Libi , Si Shuting , Yu Yunxian 
Published: November 2023

Abstract
Background
Ilizarov method has become one of primary methods for treating bone defects. Currently, there is growing trend in the application of modified Ilizarov methods (e.g., applying unilateral external fixators or with flap tissue) and its combined methods (e.g., Ilizarov method with antibiotic spacer or internal fixation) to manage bone defects. However, there is a lack of studies with systematical evaluation of the clinical effects of these evolving methods. This study aimed to conduct a systematic review and meta-analysis for overall evaluating the clinical effects on long bone defects of lower extremity in Ilizarov methods and its combined methods.

Methods
Studies were identified in three electronic databases (Pubmed, Embase and Cochrane Library) from the earliest indexing year through November 01, 2022, and relevant data were extracted subsequently. The total number of participants, number of participants with bone unions, bone result or functional result, and related complications including pin infection, pin loosening, pain, refracture, limb discrepancy, malalignment, joint stiffness, recurrent infection, and amputation were extracted in this study. Then, union rate (defined as the proportion of patients who achieved bone unions) and specific complication incidence rate (defined as the proportion of patients who experienced specific complication) were pooled estimated respectively. Relative risk (RR) was used for comparing the clinical effects among various Ilizarov technique.

Results
Sixty-eight case series studies, 29 comparative studies, and 3 randomized clinical trials were finally included. The union rate of Ilizarov methods was 99.29% (95% CI: 98.67% ~ 99.86%) in tibial defects and 98.81% (95% CI: 98.81% ~ 100.00%) in femoral defects. The union rate of Ilizarov method with antibiotic spacer and intramedullary nail in tibial defects was 99.58% (95% CI: 98.05% ~ 100.00%) and 95.02% (95% CI: 87.28% ~ 100.00%), respectively. Compared to the Ilizarov methods, the union rate of the Ilizarov method with antibiotic spacer in tibial defects increased slightly (RR = 1.02, 95% CI: 1.01 ~ 1.04). Meanwhile, compared to Ilizarov methods, we found lower excellent rate in bone result in Ilizarov method with antibiotic spacer, with the moderate to high heterogeneity. Compared to the Ilizarov method, lower rate of pin infection, higher rate of recurrent infection and amputation were observed in Ilizarov method with intramedullary nail, however, the findings about the comparison of pin infection and recurrent infection between the two groups were presented with high degree of statistical heterogeneity.

Conclusion
Our study confirmed the reliable treatment of Ilizarov methods and its combined technique on long bone defects, and founded there were significant differences on some complications rate between Ilizarov methods and its combined technique. However, the findings need to be confirmed by further studies.