A meta-analysis of the relationship between foot local characteristics and major lower extremity amputation in diabetic foot patients

ObjectiveTo clarify and quantify risk factors among local characteristics of the foot for major amputation in diabetic foot patients. MethodsArticles published before January 2018 on PubMed and Embase were conducted observational studies about risk factors for major amputation in patients with diabetic foot were retrieved and systematically reviewed by using Stata 12.0 statistical software. ResultsA total of 4668 major amputees and 65 831 controls were reported in 18 observational studies. Across the studies, the overall odds ratios (ORs) and 95% confidence intervals (CIs) of significant risk factors are ulcer reaching bone (OR, 11.796; 95% CI, 6.905-20.152), gangrene (OR, 6.487; 95% CI, 4.088-10.293), hindfoot position (OR, 3.913; 95% CI, 2.254-6.795), decreased ankle-brachial index (ABI) (OR, 2.522; 95% CI, 1.805-3.523), infection (OR, 2.516; 95% CI, 1.708-3.706), peripheral arterial disease (PAD) (OR, 2.114; 95% CI, 1.326-3.372). While there is no significant difference in the size of the ulcer, neuropathy, Charcot foot, osteomyelitis and intermittent claudication (OR, 1.15; 95% CI, 0.85-1.54). ConclusionFactors among local characteristics of the foot associated with major amputation in patients with diabetic foot are the ulcer reaching bone, gangrene, hindfoot position, decreased ABI, infection, and PAD, a negative risk factor for the risk of amputation. Further studies are required to provide more details of foot local characteristics.