Martin Resl

Outcomes after total hip arthroplasty (THA) remain limited by wear and wear particle reaction. Although highly cross-linked polyethylene (HXLPE) mitigated this issue, there are major differences among the various brands available. This study quantified, for the first time, the volumetric wear on the retrievals from various HXLPE brands, using an optical coordinate measuring machine. Patient- and implant-related factors and component orientation were considered. As of 30.06.2025, 104 HXLPE sockets were available, and 79 could be analysed, excluding those too severely deformed/damaged. The median (range) time in situ was 8.7 (2.1–22.1) years. Wear volume and volumetric wear rate were 91 (1–674) mm³ and 9 (0–130) mm³/year, respectively. Highcross (n = 56, Medacta) experienced approximately five times more wear (p < 0.001) than Durasul (n = 17, Zimmer Biomet). The other brands (n = 6) were too small in group size at this stage for statistical analysis. The correlation (R² = 0.94) between linear and volumetric wear was excellent, but high wearing retrievals had a strong impact on this analysis, whereas low wear retrievals showed high variability. Differences in wear were mostly driven by the brand, while other parameters had only a minor impact. This is the first retrieval study comparing volumetric wear among various brands of retrieved HXLPE bearings. Not all HXLPE bearings should be considered equal. As the cohort grows, further parameters and brands may be integrated.

C-reactive protein (CRP) is an established component of perioperative diagnostics in primary hip and knee arthroplasty; however, its clinical value and the validity of commonly used thresholds remain controversial. The aim of this study was to assess the pre- and postoperative handling of CRP at certified German arthroplasty centres (EPZ) and to critically appraise its clinical relevance. A 12-item internet-based questionnaire on the perioperative use of CRP was mailed to all 659 centres certified in April 2024; 134 centres participated anonymously. In 2023, these centres had performed a total of 91793 primary hip and knee arthroplasties. Preoperatively, 130 of 134 centres (97.0%) determined CRP routinely. The thresholds applied varied considerably (< 5 mg/l: 48 centres; < 10 mg/l: 69; > 10 mg/l: 11). When the threshold was exceeded, 78 centres primarily referred patients for external evaluation, whereas 39 performed the work-up themselves. Most centres considered the probability of identifying a treatable focus to be low; when no focus was found, 67 of 130 centres proceeded with surgery nonetheless. Postoperatively, 126 centres determined CRP, but only 93 considered this necessary. The timing varied markedly, with 40.5% measuring as early as the first postoperative day. Additional inflammatory parameters were rarely obtained. Only seven centres based the indication for revision primarily on the CRP value. CRP is used frequently but heterogeneously in perioperative diagnostics. Given its limited specificity, particularly for mildly elevated values, and the well-known physiological postoperative increase, routine postoperative CRP measurement appears dispensable in uncomplicated cases. A standardised checklist and a stronger clinical focus could render diagnostics more efficient.

Aims: This study investigates re-revision and mortality rates following septic revision of total knee arthroplasty (TKA) using registry data from Germany.Methods: An observational cohort study was conducted using data from the German Arthroplasty Registry (EPRD), consisting of 15,372 revision TKAs. Cumulative incidences of re-revision and mortality for septic and aseptic revision-TKAs were analyzed over a seven-year follow-up (2015 to 2022). Kaplan-Meier estimates were employed to determine re-revision rates and cumulative mortality probabilities after revision TKA.Results: The re-revision rate within the first year following septic revision TKA was 21.7% (95% CI 20.3 to 23.1), compared to only 7.1% (95% CI 6.6 to 7.6) for aseptic revisions. Notably, 74% of all re-revisions for septic revision TKA occurred within the first year. Cumulative mortality within the first year after septic revision TKA was 4.9% (95% CI 4.2 to 5.7), rising to 28.5% (95% CI 24.2 to 33.2) after seven years. In contrast, aseptic revision TKA had lower mortality rates, with 2% within the first year and 16% within seven years. After multiple previous knee revisions, re-revision rates increased to over 47%, and mortality to 30% for septic revisions.Conclusion: Registry data revealed nearly twice the re-revision rates for septic revision TKA compared to single-centre studies, reflecting real-world outcomes in Germany. Septic revision TKA has a threefold higher re-revision rate in the first year and double the mortality rate compared to aseptic revisions. Given the high risk in the first postoperative year, optimizing perioperative procedures is crucial to reducing the burden of septic revision TKA.Cite this article: Bone Joint J 2025;107-B(9):896–904.

Aims: This study compares the re-revision rate and mortality following septic and aseptic revision hip arthroplasty (rTHA) in registry data, and compares the outcomes to previously reported data.Methods: This is an observational cohort study using data from the German Arthroplasty Registry (EPRD). A total of 17,842 rTHAs were included, and the rates and cumulative incidence of hip re-revision and mortality following septic and aseptic rTHA were analyzed with seven-year follow-up. The Kaplan-Meier estimates were used to determine the re-revision rate and cumulative probability of mortality following rTHA.Results: The re-revision rate within one year after septic rTHA was 30%, and after seven years was 34%. The cumulative mortality within the first year after septic rTHA was 14%, and within seven years was 40%. After multiple previous hip revisions, the re-revision rate rose to over 40% in septic rTHA. The first six months were identified as the most critical period for the re-revision for septic rTHA.Conclusion: The risk re-revision and reinfection after septic rTHA was almost four times higher, as recorded in the ERPD, when compared to previous meta-analysis. We conclude that it is currently not possible to assume the data from single studies and meta-analysis reflects the outcomes in the ‘real world’. Data presented in meta-analyses and from specialist single-centre studies do not reflect the generality of outcomes as recorded in the ERPD. The highest re-revision rates and mortality are seen in the first six months postoperatively. The optimization of perioperative care through the development of a network of high-volume specialist hospitals is likely to lead to improved outcomes for patients undergoing rTHA, especially if associated with infection.Cite this article: Bone Joint J 2024;106-B(6):565–572.