Does choice of bearings influence the survival of cementless total hip arthroplasty in patients aged 20-55 years? Comparison of 21,594 patients reported to the Nordic Arthroplasty Register Association dataset 2005-2017.

BACKGROUND AND PURPOSE: The bearings with the best survivorship for young patients with total hip arthroplasty (THA) should be identified. We compared hazard ratios (HR) of revision of primary stemmed cementless THAs with metal-on-metal (MoM), ceramic-on-ceramic (CoC), and ceramic-on-highly-crosslinked-polyethylene (CoXLP) with that of metal-on-highly-crosslinked-polyethylene (MoXLP) bearings in patients aged 20-55 years with primary osteoarthritis or childhood hip disorders. PATIENTS AND METHODS: From the Nordic Arthroplasty Register Association dataset we included 1,813 MoM, 3,615 CoC, 5,947 CoXLP, and 10,219 MoXLP THA in patients operated on between 2005 and 2017 in a prospective cohort study. We used the Kaplan-Meier estimator for THA survivorship and Cox regression to estimate HR of revision adjusted for confounders (including 95% confidence intervals [CI]). MoXLP was used as reference. HRs were calculated during 3 intervals (0-2, 2-7, and 7-13 years) to meet the assumption of proportional hazards. RESULTS: Median follow-up was 5 years for MoXLP, 10 years for MoM, 6 years for CoC, and 4 years for CoXLP. 13-year Kaplan-Meier survival estimates were 95% (CI 94-95) for MoXLP, 82% (CI 80-84) for MoM, 93% (CI 92-95) for CoC, and 93% (CI 92-94) for CoXLP bearings. MoM had higher 2-7 and 7-13 years' adjusted HRs of revision (3.6, CI 2.3-5.7 and 4.1, CI 1.7-10). MoXLP, CoC, and CoXLP had similar HRs in all 3 periods. The 7-13-year adjusted HRs of revision of CoC and CoXLP were statistically non-significantly higher. CONCLUSION: In young patients, MoXLP for primary cementless THA had higher revision-free survival and lower HR for revision than MoM bearings. Longer follow-up is needed to compare MoXLP, CoC, and CoXLP.

Excess mortality during the first year after arterial trauma.

INTRODUCTION: Extant studies on arterial trauma originate from outside Denmark and their findings may therefore not apply to a Danish setting. The aim of the present study was to investigate the long-term mortality and clinical characteristics of patients with arterial trauma treated in Odense University Hospital (OUH). METHODS: This study was based on a historical cohort comprising all arterial traumas treated at OUH between 1990 and 2012. The Personal Identification Numbers were drawn and cross-referenced between The Danish Vascular Registry and the Accident Analysis Group. Mortality was compared with the expected mortality from the entire Danish population, matched to age, sex and date of trauma. RESULTS: A total of 231 patients were analysed. The median follow-up period was 6.9 years (range: 0-22.47). Traffic was the most common cause of arterial trauma, violence the least common. Patients were mainly men (69%) with a median age of 32 years. Women had a median age of 46 years. The mortality rate ratios were as follows: overall in the first year 15.34 (95% confidence interval (CI): 10.34-21.93). Overall mortality rate ratios for year 1-5 was 1.66 (95% CI: 0.82-2.98); but when stratified, the effect was only significant in the reconstructed subgroup (2.22 (95% CI: 1.01-4.24). CONCLUSION: Excess mortality was observed in patients with arterial traumas in the first year. However, patients receiving reconstructive arterial surgery after traumas had an excess mortality, even after adjustment for the effect of the first year. Whether the observed mortality is due to surgery itself, patients' risk behaviour or other factors remains unclear. Further national investigation is needed. FUNDING: not relevant. TRIAL REGISTRATION: not relevant. The study was approved by the Danish Data Protection Agency on 14 June 2013.