Extramedullary versus intramedullary fixation of unstable trochanteric femoral fractures (AO type 31-A2): a systematic review and meta-analysis

Objective The aim of this systematic review was to compare extramedullary fixation and intramedullary fixation for AO type 31-A2 trochanteric fractures in the elderly, with regard to functional outcomes, complications, surgical outcomes, and costs. Methods Embase, Medline, Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar were searched for randomized controlled trials (RCTs) and observational studies. Effect estimates were pooled across studies using random effects models. Results are presented as weighted risk ratio (RR) or weighted mean difference (MD) with corresponding 95% confidence interval (95% CI). Results Fourteen RCTs (2039 patients) and 13 observational studies (22,123 patients) were included. Statistically superior results in favor of intramedullary fixation were found for Harris Hip Score (MD 4.09, 95% CI 0.91-7.26, p = 0.04), Parker mobility score (MD - 0.67 95% CI - 1.2 to - 0.17, p = 0.009), lower extremity measure (MD - 4.07 95% CI - 7.4 to - 0.8, p = 0.02), time to full weight bearing (MD 1.14 weeks CI 0.92-1.35, p < 0.001), superficial infection (RR 2.06, 95% CI 1.18-3.58, p = 0.01), nonunion (RR 3.67, 95% CI 1.03-13.10, p = 0.05), fixation failure (RR 2.26, 95% CI 1.16-4.44, p = 0.02), leg shortening (MD 2.23 mm, 95% CI 0.81-3.65, p = 0.002), time to radiological bone healing (MD 2.19 months, 95% CI 0.56-3.83, p = 0.009), surgery duration (MD 11.63 min, 95% CI 2.63-20.62, p = 0.01), operative blood loss (MD 134.5 mL, 95% CI 51-218, p = 0.002), and tip-apex distance > 25 mm (RR 1.73, 95% CI 1.10-2.74, p = 0.02). No comparable cost/costs-effectiveness data were available. Conclusion Current literature shows that several functional outcomes, complications, and surgical outcomes were statistically in favor of intramedullary fixation when compared with extramedullary fixation of AO/OTA 31-A2 fractures. However, as several of the differences found appear not to be clinically relevant and for many outcomes data remains sparse or heterogeneous, complete superiority of IM fixation for AO type 31-A2 fractures remains to be confirmed in a detailed cost-effectiveness analysis.