The local soft tissue status and the prediction of local complications following fractures of the ankle region

Well-known risk factors (RF) for soft tissue complications following surgical treatment of fracture of the ankle region include diabetes, smoking, and the local soft tissue status. A weighted analysis might provide a risk profile that guides the surgical treatment strategy. The aim of this meta-analysis was to provide a risk profile for soft tissue complications following closed fractures of the ankle region. This review provides a meta-analysis of studies that investigate potential risk factors for complications in fractures of the ankle region. Inclusion criteria: Original articles that were published between 2000 and 2020 in English or German language that calculated odds ratios (OR) of RF for soft tissue complications. Further, this study only includes articles that investigated fractures of the ankle region including pilon fracture, calcaneal fractures, and fractures of the malleoli. This study excluded articles that provide exploratory analyses, narrative reviews, and case reports. RF were stratified as patient specific systemic RF (PSS), patient specific local RF (PSL), and non-patient specific RF (NPS). PSS RF includes comorbidities, American society of anaesthesiology (ASA), requirement of medication, additional injuries, and smoking or substance abuse. PSL RF includes soft tissue status, wounds, and associated complications. NPS RF includes duration of surgery, staged procedure, or time to definitive surgery. Random effect (RE) models were utilized to summarize the effect measure (OR) for each group or specific RF. Out of 1352 unique articles, 34 were included for quantitative analyses. Out of 370 complications, the most commonly assessed RF were comorbidities (34.6%). Local soft tissue status accounted for 7.5% of all complications. The overall rate for complication was 10.9% (standard deviation, SD 8.7%). PSS RF had an OR of 1.04 (95%CI 1.01 to 1.06, p = 0.006), PSL an OR of 1.79 (95% 1.28 to 2.49, p = 0.0006), and NPS RF an OR of 1.01 (95%CI 0.97 to 1.05, p = 0.595). Additional injuries did not predict complications (OR 1.23, 95%CI 0.44 to 3.45, p = 0.516). The most predictive RF were open fracture (OR 3.47, 95%CI 1.64 to 7.34, p < 0.001), followed by local tissue damage (OR 3.05, 95%CI 1.23 to 40.92, p = 0.04), and diabetes (OR 2.3, 95%CI 1.1 to 4.79, p = 0.26). Among all RFs for regional soft tissue complications, the most predictive is the local soft tissue status, while additional injuries or NPS RF were less predictive. The soft tissue da