Change in CT-measured acetabular bone density following total hip arthroplasty: a systematic review and meta-analysis

Background and purpose - Assessing peri-acetabular bone quality is valuable for optimizing the outcomes of pri- mary total hip arthroplasty (THA) as preservation of good quality bone stock likely affects implant stability. The aim of this study was to perform a meta-analysis of peri-acetabular bone mineral density (BMD) changes over time measured using quantitative computer tomography (CT) and, second, to investigate the influence of age, sex, and fixation on the change in BMD over time.Methods - A systematic search of Embase, Scopus, Web of Science, and PubMed databases identified 19 studies that measured BMD using CT following THA. The regions of interest (ROI), reporting of BMD results, and scan protocols were extracted. A meta-analysis of BMD was performed on 12 studies that reported measurements immediately postop- eratively and at follow-up.Results - The meta-analysis determined that peri- acetabular BMD around both cemented and uncemented components decreases over time. The amount of BMD loss increased relative to proximity of the acetabular component. There was a greater decrease in cortical BMD over time in females and cancellous BMD for young patients of any sex.Conclusion - Peri-acetabular BMD decreases at differ- ent rates relative to its proximity to the acetabular component. Cancellous BMD decreases more in young patients and cor- tical bone decreases more in females. Standardized reporting parameters and suggested ROI to measure peri-acetabular BMD are proposed, to enable comparison between implant and patient variables in the future.