Meta-analysis of the safety and efficacy of flap reconstruction in the treatment of diabetic foot ulcers

OBJECTIVE: To systematically evaluate the safety and efficacy of flap reconstruction surgery and the associated influential factors in the treatment of diabetic foot ulcers (DFUs) and to provide an evidence-based basis for clinical flap selection and surgical strategies. METHODS: The PubMed, Embase, Web of Science, and Cochrane Library databases were systematically searched to identify studies on comparative or single-arm flap reconstruction for the treatment of diabetic foot ulcers (DFUs). Eligible study designs included randomized controlled trials (RCTs), cohort studies, and case series published between 1998 and 2025. Two investigators independently screened the literature, extracted relevant data, and assessed the risk of bias using the Cochrane Risk of Bias tool and the Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I) tool. Meta-analyses were performed using Review Manager (RevMan) 5.4. The primary and secondary outcome measures included total flap loss, limb loss rate, and flap failure rate. Subgroup analyses were conducted according to flap type and regional differences. RESULTS: A total of 45 studies were included. The results of the meta-analysis showed that patients undergoing flap reconstruction had higher postoperative total flap loss (HR = 5.83; 95% CI 3.65-9.31), limb loss (HR = 11.09; 95% CI 7.22-17.03), and flap failure rate (HR = 10.01; 95% CI 8.31-12.05) compared with reference populations or expected baseline risks. Subgroup analyses revealed that the risk of free flap limb loss was significantly greater than that of non-free flaps (HR = 17.86 vs. 1.94; P = 0.02); the risk of limb loss was greater in Europe (HR = 22.97) and North America (HR = 17.42) than in East Asia (HR = 5.85; P < 0.001), and there was no regional difference in total flap loss (P = 0.67). The results of the sensitivity analysis were robust, with heterogeneity arising mainly from differences in study design and patient characteristics. CONCLUSION: Flap reconstruction remains a viable option for DFU wound closure, but it is associated with elevated risks of postoperative total flap loss and limb loss. Individualized surgical protocols, prioritization of non-free flaps for low- and intermediate-risk patients, and enhanced multidisciplinary collaboration and postoperative management are recommended. More high-quality studies are needed to validate the long-term efficacy of different flap techniques. TRIAL REGISTRATION: Register with PROSPERP, Registration Information: ID: CRD420251075758. Date of first submission to PROSPERO: 25 June 2025. Upload data information: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251075758.