Cause of death following revision for periprosthetic joint infection or major aseptic revision in total hip and knee arthroplasty

<b>Background and purpose</b>: Periprosthetic joint infection (PJI) revisions for total knee arthroplasty (TKA) and total hip arthroplasty (THA) have increased all-cause mortality. It remains unclear whether specific causes of death contribute to this excess mortality. Our purpose was to compare the underlying causes of death in patients revised for PJI with aseptic failure and to compare THA and TKA causes of death. <b>Methods</b>: We used routinely collected data from Danish health registries. We identified 9078 patients undergoing first-time revision for PJI or aseptic failure in the Danish Hip and Knee Arthroplasty Register. PJI was primarily defined by intra-operative microbiological cultures. The causes of death were obtained from the Cause of Death Register. We used inverse probability of treatment weighting (IPTW) to adjust for confounding and calculated adjusted hazard ratios (aHRs) with a 95 % confidence interval (CI). Among 2755 deceased patients, 37 % had undergone revision for PJI and 63 % for aseptic failure. The PJI group had a higher comorbidity burden and more hip revisions but was similar in age and marital status compared to aseptic revisions. <b>Results</b>: Cancer, circulatory, and respiratory diseases were the most common causes of death in both groups. However, deaths from musculoskeletal diseases (aHR 3.04, 95 % CI: 1.67-5.56), infections (aHR 2.13, 95 % CI: 1.06-4.30), and age-related causes (aHR 2.05, 95 % CI: 1.22-3.45) were more frequent after PJI revision. <b>Conclusion</b>: The increased mortality after PJI revision appears to be multifactorial, involving a range of causes rather than a single dominant driver.