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Aim: To investigate the effect of femoral head size on blood metal-ion levels caused by taper corrosion in metal-on-polyethylene total hip arthroplasty, comparing 36- to 44-mm heads with 32-mm heads. Methods: In a randomised, controlled, single-blinded trial, 96 patients were allocated to receive either a 32-mm metal head or the largest possible metal head (36–44 mm) that could be accommodated in the thinnest available vitamin E, cross-linked polyethylene insert. Blood metal ion levels were collected at 1- and 2-year follow-ups. Results: At 1-year, metal-ion levels did not differ between the groups. The median (interquartile range) blood-ion levels for the 32-mm versus the 36- to 44-mm group were 0.11 µg/L (0.08–0.15) versus 0.12 µg/L (0.08–0.22), p = 0.546, for cobalt, 0.50 µg/L (0.50–0.59) versus 0.50 µg/L (0.50–1.20), p = 0.059, for chromium and 1.58 µg/L (1.38–2.05) versus 1.48 µg/L (1.14–1.87), p = 0.385, for titanium. At 2 years, there was no difference either and the corresponding values were 0.15 µg/L (0.12–0.24) versus 0.18 µg/L (0.12–0.28), p = 0.682 for cobalt, 0.50 µg/L (0.50–0.50) versus 0.50 µg/L (0.50–0.57), p = 0.554, for chromium and 1.54 µg/L (1.16–1.87) versus 1.42 µg/L (1.01–1.72), p = 0.207 for titanium. Conclusions: The use of the largest possible metal head (36–44 mm) compared to a 32-mm head in metal–on-polyethylene bearings does not appear to elevate blood metal-ion levels up to 2 years postoperatively. As taper corrosion is probably time-dependent, longer-term reports are needed to evaluate the association between large metal heads and blood metal ion levels. Trial registration: ClinicalTrials.gov (reg. ID NCT0231 6704)

Background Despite existing studies favoring cemented fixation for patients older than 75 years, a trend toward increased use of uncemented fixation has been described in a 2013 study that used arthroplasty registry data from 2006 to 2010. Updated summarized data are needed beyond 2010 to investigate contemporary trends in the usage of uncemented fixation, especially in patients older than 75 years, and to draw attention to a potential continuing conflict between trends in fixation choice and reported revision risk. Thus, healthcare policy and practice can change and surgeons can make better implant fixation choices. Questions/purposes (1) Has the percentage of primary THAs performed with uncemented fixation changed since 2010? (2) Has the percentage of primary THAs performed in patients older than 75 years performed with uncemented fixation changed since 2010? (3) After stratifying by age, which fixation strategy (cemented versus uncemented and hybrid versus uncemented) is associated with the lowest risk of revision? Methods National annual reports from hip arthroplasty registers were identified, and data were extracted from registers published in English or a Scandinavian language, with at least 3 years of reported data in the period from 2010 to 2017. These included Australia, Denmark, England-Wales, Finland, the Netherlands, New Zealand, Romania, Norway, Sweden, and Switzerland, which are all countries with high completeness rates. Data regarding rates of revisions (all causes) related to fixation methods and secondary to different age groups, were taken directly from the registers and no re-analysis was done. The risk estimates were presented as either hazard ratios, rate per 100 component years or as Kaplan-Meier estimates of revision. The age groups compared for Denmark were younger than 50, 50-59, 60-69,70-79, and older than 80 years, and for Australia, New Zealand, England-Wales, and Finland, they were younger than 55, 55-64, 65-74, and older than 75 years. No data were pooled across the registers. Results The current use of uncemented fixation in primary THAs varies between 24% (Sweden) and 71% (Denmark). Increasing use of uncemented fixation has been reported in Norway, Denmark, and Sweden, whereas decreasing use of uncemented fixation has been reported in England-Wales, Australia, New Zealand, and Finland. Examining the group of patients older than 75 years, we found that the use of uncemented fixation has been stable in Netherlands, Sweden, New Zealand, and England-Wales. The use of uncemented fixation is still increasing in Denmark and Australia. In Finland, the use of uncemented fixation has decreased (from 43 % to 24 %) from 2010 to 2017. When compared with uncemented fixation, the risk of revision for hips using cemented fixation was lower in patients older than 75 years for all registers surveyed, except for the oldest males in the Finnish register. In this group, no difference was found between cemented and uncemented fixation. Conclusion Our findings should be used in healthcare policy as feedback on current THAs being performed so as to direct surgeons to choose the right implant fixation, especially in patients older than 75 years, thereby reducing revision risk and increasing the long-term survival of primary THAs. It appears that femoral stem fixation may be the most important revision risk factor in older patients, and future studies should examine this perspective. Level of evidence Level III, therapeutic study.

INTRODUCTION: Due to inconsistent results and high failure rates, total knee arthroplasty (TKA) is more often used to treat isolated patellofemoral osteoarthritis (PFOA) despite the theoretical advantage of patellofemoral arthroplasty (PFA). It is perceived that second-generation PFA may have improved the outcomes of surgery. In this systematic review, the primary aim was to compare outcomes of second-generation PFA and TKA by assessment of patient-reported outcome measures (PROMs). METHODS: A systematic search was made in PubMed, Medline, Embase, Cinahl, Web of Science, Cochrane Library and MeSH to identify studies using second-generation PFA implants or TKA for treatment of PFOA. Only studies using The American Knee Society (AKSS), The Oxford Knee Score (OKS) or The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) to report on PROMs were included. RESULTS: The postoperative weighted mean AKSS knee scores were 88.6 in the second-generation PFA group and 91.8 in the TKA group. The postoperative weighted mean AKSS function score was 79.5 in the second-generation PFA group and 86.4 in the TKA group. There was no significant difference in the mean AKSS knee or function scores between the second-generation PFA group and the TKA group. The postoperative weighted mean OKS score was 36.7 and the postoperative weighted mean WOMAC score was 24.4. The revision rate was higher in the second-generation PFA group (113 revisions [8.4%]) than in the TKA group (3 revisions [1.3%]). Progression of OA was most commonly noted as the reason for revision of PFA, and it was noted in 60 cases [53.1%]; this was followed by pain in 33 cases [29.2%]. CONCLUSION: Excellent postoperative weighted mean AKSS knee scores were found in both the second-generation PFA group and in the TKA group, suggesting that both surgical options can result in a satisfying patient-reported outcome. Higher revision rates in the second-generation PFA studies may in part be due to challenges related to patient selection. Based on evaluation of PROMs, the use of second-generation PFA seems to be an equal option to TKA for treatment of isolated PFOA in appropriately selected patients. Hopefully, this can be considered by physicians in their daily clinical work. LEVEL OF EVIDENCE: IV.

Difficulty in identifying patients who are at risk for hepatitis B virus (HBV) reactivation makes it import-ant to screen for HBV before initiating immunosuppressive therapy. The aim of this study was to investigate screening procedures for HBV infection before initiation of immunosuppressive therapy and to explore HBV treatment strategies.All Danish units of haematology, oncology, dermatology, rheumatology and gastroenterology using immunosuppressive agents were invited to fill out a questionnaire for The Danish Database for Hepatitis B and C.A total of 28 (53%) of the 53 included units answered the questionnaire, of which 25 (89.3%) had a guideline regarding screening for HBV serological markers prior to immunosuppressive therapy, but only ten (37%) had a guideline that is in line with the joint guidelines from the national Danish Societies of Infectious Diseases and Gastroenterology and Hepatology. Nineteen (76%) units had a strategy regarding treatment for reactivation before initiating immunosuppressive therapy in case of positive HBV serology. It was not possible to determine the number of HBV reactivations as this was not registered in the ICD-10 system. The Danish Medicines Agency had one report of reactivation.A minority of the units had screening guidelines for HBV reactivation that were in line with the guidelines of the national scientific societies. Screening in accordance with these recommendations should be a goal for all Danish units in order to prevent HBV reactivation.none.not relevant.