Induced membrane technique for large bone defects A systematic review and individual participant data meta-analysis

Aims: The aim of this study was to evaluate the efficacy of induced membrane technique (IMT), and to analyze the relationships between patient factors and surgical parameters as well as their impacts on achieving bone union and complication rates. Materials and methods: A comprehensive, computerized search of PubMed, Embase, and The Cochrane Library was conducted, and articles published from January 1, 1978 to February 1, 2021 were included. Clinical trials matching the following inclusion criteria were included: 1. published as a case series, case-controlled studies, or cohort study; 2. IMT was performed for more than 10 cases within the study. Univariate and multivariate logistic regression were performed with random intercepts to determine the association of specific predictor variables with nonunion rate, postoperative infection, the need for additional procedures, and time to union. Results: Seventy eight trials were included in the study with a total of 3840 patients managed with IMT. Mean age was 38.6 (0.8-88) years, mean size of bone defects was 6.4 (0-25) cm primarily distributed in the tibia (n= 1814, 60.9%), and overall union rate was 87.6%. Multivariate analysis showed the odds of nonunion were significantly increased in patients with an interval between two stages from 8 to 12weeks and >= 12 weeks. Patients with preoperative infection and addition of antibiotic to bone cement during IMT had significantly decreased odds of longer union time, but preoperative infection caused increased odds of additional surgery. External fixation throughout 2 stages had significantly increased odds of postoperative infection and additional surgery. Conclusions: We recommend that the timing of the second stage should be delayed until 6 to 8 weeks after the first stage. Bone cement with antibiotics can control the infection rate and shorten the healing time. Furthermore, there is no need to avoid using internal fixation due to possible concerns about causing postoperative infection.