Surgical treatment of pelvic discontinuity a systematic review and meta-analysis

Background: Pelvic discontinuity is a rare condition that is treated with arange of implant constructs. However, surgical failure rates are high, andoutcome data are inconsistent. It is therefore difficult to gain a clear pictureof whether recently developed constructs (antiprotrusio cage [APC], cupcage, custom triflange, and porous metal) provide better outcomes interms of mechanical failure and complications in the short to long terms.This study investigated the failure and complication rates associated withcage constructs and porous metal technologies.Methods: A systematic review and meta-analysis were performedaccording to the Meta-analysis Of Observational Studies in Epidemiology(MOOSE) guidelines to evaluatethe studies showing pelvic discontinuity inrevision total hip arthroplasty. Data retrieved included the interventionperformed, length of follow-up, mechanical failure, and othercomplication rates (dislocation, infection, neurological, loosening,migration). Study quality was assessed with the Methodological Index forNon-Randomized Studies (MINORS) instrument. Pooled mechanical failureand complication rates were calculated using MetaXL 5.3.Results: None of the included 30 articles (n 5 585 hips) were of highquality. The meta-analyses revealed a mechanical failure rate of 14% for allconstructs combined. Custom triflange (5%) and cup-cage (7%) had thelowest mechanical failure rates compared with the commonly used APC(25%) and porous metal (12%). The overall other complication rate was28%, with cup-cage lower at 21% compared with APC (34%) and customtriflange (28%). Long-term evidence investigating both interventions andporous metal technology is limited.Conclusions: Mechanical failure rates for cup-cage and custom triflangewere lowest. The other complication rate for cup-cage was lower than thepooled average. The study quality was limited, indicating a need for betterstudies and/or a registry.Level of Evidence: Therapeutic Level IV. See Instructions for Authors for acomplete description of levels of evidence.