Dynamic hip screws versus cephalocondylic intramedullary nails for unstable extracapsular hip fractures in 2021: A systematic review and meta-analysis of randomised trials

Background: Extracapsular hip fractures comprise approximately half of all hip fractures and the incidence of hip fractures is exponentially increasing. Extramedullary fixation using a dynamic hip screw (DHS) has been the gold standard method of operative treatment for extracapsular fractures, however, in recent years, intramedullary nails (IMN) have become a popular alternative. Intramedullary versus extramedullary fixation is continuously discussed and debated in literature therefore, the purpose of this systematic review and meta-analysis is to directly compare the peri-operative and post-operative outcomes for DHS versus IMN to provide an up-to-date analysis as to which method of fixation is superior. Methods The MEDLINE/Pubmed, Embase and Web of Science Database were searched for eligible studies, from 2008 to August 2021, that compared peri- and post-operational outcomes for patients undergoing IMN or DHS operations for fixation of unstable extracapsular hip fractures (PROSPERO registration ID:CRD42021228335). Primary outcomes included mortality rate and re-operation rate. Secondary outcomes included operation time, blood loss, transfusion requirement, complication, and failure of fixation rate. The risk of bias and quality of evidence were assessed using the Cochrane RoB 2.0 tool and GRADE analysis tool, respectively. Results Of the 6776 records identified, 22 studies involving 3151 patients, were included in the final review. Our meta-analysis showed no significant different between mortality rates (10 studies, OR 0.98; 95% CI 0.80 to 1.22, p = 0.88), and similarly, no significant difference for re-operation rates (10 studies, OR 1.03; 95% CI 0.64 to 1.64, p = 0.91). There was also no significant difference found between complication or failure of fixation rates (17 studies, OR 1.29; 95% CI 0.79 to 2.12, p = 0.31) and (14 studies, OR 1.32; 95% CI 0.74 to 2.38, p = 0.35). Mean blood loss was not included in the meta-analysis but was demonstrated to be significantly greater in those undergoing DHS in 12 out of 13 studies. Conclusion Overall, based on the outcomes assessed, this review has demonstrated no significant difference in the peri- or post-operative outcomes for DHS vs IMN. Future studies should investigate DHS vs IMN for different types of unstable fractures as well as investigating different types and generations of fixation devices.