| 1. |
- Badawy, Mona, et al.
(author)
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Hospital volume and the risk of revision in Oxford unicompartmental knee arthroplasty in the Nordic countries -an observational study of 14,496 cases
- 2017
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In: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 18:1
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Journal article (peer-reviewed)abstract
- Background: High procedure volume and dedication to unicompartmental knee arthroplasty (UKA) has been suggested to improve revision rates. This study aimed to quantify the annual hospital volume effect on revision risk in Oxfordu? nicompartmental knee arthroplasty in the Nordic countries. Methods: 14,496 cases of cemented medial Oxford III UKA were identified in 126 hospitals in the four countries included in the Nordic Arthroplasty Register Association (NARA) database from 2000 to 2012. Hospitals were divided by quartiles into 4 annual procedure volume groups (≤11, 12-23, 24-43 and ≥44). The outcome was revision risk after 2 and 10 years calculated using Kaplan Meier method. Multivariate Cox regression analysis was used to assess the Hazard Ratio (HR) of any revision due to specific reasons with 95% confidence intervals (CI). Results: The implant survival was 80% at 10 years in the volume group ≤11 procedures per year compared to 83% in other volume groups. The HR adjusted for age category, sex, year of surgery and nation was 0.87 (95% CI: 0.76-0.99, p = 0.036) for the group 12-23 procedures per year, 0.78 (95% CI: 0.68-0.91, p = 0.002) for the group 24-43 procedures per year and 0.82 (95% CI: 0.70-0.94, p = 0.006) for the group ≥44 procedures per year compared to the low volume group. Log-rank test was p = 0.003. The risk of revision for unexplained pain was 40-50% higher in the low compared with other volume groups. Conclusion: Low volume hospitals performing ≤11 Oxford III UKAs per year were associated with an increased risk of revision compared to higher volume hospitals, and unexplained pain as revision cause was more common in low volume hospitals.
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| 2. |
- Bergh, Camilla, et al.
(author)
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Increased risk of revision in patients with non-traumatic femoral head necrosis.
- 2014
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In: Acta orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 85:1, s. 11-17
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Journal article (peer-reviewed)abstract
- Background and purpose Previous studies of patients who have undergone total hip arthroplasty (THA) due to femoral head necrosis (FHN) have shown an increased risk of revision compared to cases with primary osteoarthritis (POA), but recent studies have suggested that this procedure is not associated with poor outcome. We compared the risk of revision after operation with THA due to FHN or POA in the Nordic Arthroplasty Register Association (NARA) database including Denmark, Finland, Norway, and Sweden. Patients and methods 427,806 THAs performed between 1995 and 2011 were included. The relative risk of revision for any reason, for aseptic loosening, dislocation, deep infection, and periprosthetic fracture was studied before and after adjustment for covariates using Cox regression models. Results 416,217 hips with POA (mean age 69 (SD 10), 59% females) and 11,589 with FHN (mean age 65 (SD 16), 58% females) were registered. The mean follow-up was 6.3 (SD 4.3) years. After 2 years of observation, 1.7% in the POA group and 3.0% in the FHN group had been revised. The corresponding proportions after 16 years of observation were 4.2% and 6.1%, respectively. The 16-year survival in the 2 groups was 86% (95% CI: 86-86) and 77% (CI: 74-80). After adjusting for covariates, the relative risk (RR) of revision for any reason was higher in patients with FHN for both periods studied (up to 2 years: RR = 1.44, 95% CI: 1.34-1.54; p < 0.001; and 2-16 years: RR = 1.25, 1.14-1.38; p < 0.001). Interpretation Patients with FHN had an overall increased risk of revision. This increased risk persisted over the entire period of observation and covered more or less all of the 4 most common reasons for revision.
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| 3. |
- Dale, Håvard, et al.
(author)
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Increasing risk of prosthetic joint infection after total hip arthroplasty.
- 2012
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In: Acta orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 83:5, s. 449-58
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Journal article (peer-reviewed)abstract
- Background and purpose The risk of revision due to infection after primary total hip arthroplasty (THA) has been reported to be increasing in Norway. We investigated whether this increase is a common feature in the Nordic countries (Denmark, Finland, Norway, and Sweden). Materials and methods The study was based on the Nordic Arthroplasty Register Association (NARA) dataset. 432,168 primary THAs from 1995 to 2009 were included (Denmark: 83,853, Finland 78,106, Norway 88,455, and Sweden 181,754). Adjusted survival analyses were performed using Cox regression models with revision due to infection as the endpoint. The effect of risk factors such as the year of surgery, age, sex, diagnosis, type of prosthesis, and fixation were assessed. Results 2,778 (0.6%) of the primary THAs were revised due to infection. Compared to the period 1995-1999, the relative risk (with 95% CI) of revision due to infection was 1.1 (1.0-1.2) in 2000-2004 and 1.6 (1.4-1.7) in 2005-2009. Adjusted cumulative 5-year revision rates due to infection were 0.46% (0.42-0.50) in 1995-1999, 0.54% (0.50-0.58) in 2000-2004, and 0.71% (0.66-0.76) in 2005-2009. The entire increase in risk of revision due to infection was within 1 year of primary surgery, and most notably in the first 3 months. The risk of revision due to infection increased in all 4 countries. Risk factors for revision due to infection were male sex, hybrid fixation, cement without antibiotics, and THA performed due to inflammatory disease, hip fracture, or femoral head necrosis. None of these risk factors increased in incidence during the study period. Interpretation We found increased relative risk of revision and increased cumulative 5-year revision rates due to infection after primary THA during the period 1995-2009. No change in risk factors in the NARA dataset could explain this increase. We believe that there has been an actual increase in the incidence of prosthetic joint infections after THA.
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| 4. |
- Engesæter, Lars B, et al.
(author)
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Low revision rate after total hip arthroplasty in patients with pediatric hip diseases.
- 2012
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In: Acta orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 83:5, s. 436-41
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Journal article (peer-reviewed)abstract
- Background The results of primary total hip arthroplasties (THAs) after pediatric hip diseases such as developmental dysplasia of the hip (DDH), slipped capital femoral epiphysis (SCFE), or Perthes' disease have been reported to be inferior to the results after primary osteoarthritis of the hip (OA). Materials and methods We compared the survival of primary THAs performed during the period 1995-2009 due to previous DDH, SCFE, Perthes' disease, or primary OA, using merged individual-based data from the Danish, Norwegian, and Swedish arthroplasty registers, called the Nordic Arthroplasty Register Association (NARA). Cox multiple regression, with adjustment for age, sex, and type of fixation of the prosthesis was used to calculate the survival of the prostheses and the relative revision risks. Results 370,630 primary THAs were reported to these national registers for 1995-2009. Of these, 14,403 THAs (3.9%) were operated due to pediatric hip diseases (3.1% for Denmark, 8.8% for Norway, and 1.9% for Sweden) and 288,435 THAs (77.8%) were operated due to OA. Unadjusted 10-year Kaplan-Meier survival of THAs after pediatric hip diseases (94.7% survival) was inferior to that after OA (96.6% survival). Consequently, an increased risk of revision for hips with a previous pediatric hip disease was seen (risk ratio (RR) 1.4, 95% CI: 1.3-1.5). However, after adjustment for differences in sex and age of the patients, and in fixation of the prostheses, no difference in survival was found (93.6% after pediatric hip diseases and 93.8% after OA) (RR 1.0, CI: 1.0-1.1). Nevertheless, during the first 6 postoperative months more revisions were reported for THAs secondary to pediatric hip diseases (RR 1.2, CI: 1.0-1.5), mainly due to there being more revisions for dislocations (RR 1.8, CI: 1.4-2.3). Comparison between the different diagnosis groups showed that the overall risk of revision after DDH was higher than after OA (RR 1.1, CI: 1.0-1.2), whereas the combined group Perthes' disease/SCFE did not have a significantly different risk of revision to that of OA (RR 0.9, CI: 0.7-1.0), but had a lower risk than after DDH (RR 0.8, CI: 0.7-1.0). Interpretation After adjustment for differences in age, sex, and type of fixation of the prosthesis, no difference in risk of revision was found for primary THAs performed due to pediatric hip diseases and those performed due to primary OA.
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| 5. |
- Hailer, Nils P, et al.
(author)
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Hydroxyapatite coating does not improve uncemented stem survival after total hip arthroplasty!
- 2015
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In: Acta orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 86:1, s. 18-25
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Journal article (peer-reviewed)abstract
- Background and purpose - It is still being debated whether HA coating of uncemented stems used in total hip arthroplasty (THA) improves implant survival. We therefore investigated different uncemented stem brands, with and without HA coating, regarding early and long-term survival. Patients and methods - We identified 152,410 THA procedures using uncemented stems that were performed between 1995 and 2011 and registered in the Nordic Arthroplasty Register Association (NARA) database. We excluded 19,446 procedures that used stem brands less than 500 times in each country, procedures performed due to diagnoses other than osteoarthritis or pediatric hip disease, and procedures with missing information on the type of coating. 22 stem brands remained (which were used in 116,069 procedures) for analysis of revision of any component. 79,192 procedures from Denmark, Norway, and Sweden were analyzed for the endpoint stem revision. Unadjusted survival rates were calculated according to Kaplan-Meier, and Cox proportional hazards models were fitted in order to calculate hazard ratios (HRs) for the risk of revision with 95% confidence intervals (CIs). Results - Unadjusted 10-year survival with the endpoint revision of any component for any reason was 92.1% (CI: 91.8-92.4). Unadjusted 10-year survival with the endpoint stem revision due to aseptic loosening varied between the stem brands investigated and ranged from 96.7% (CI: 94.4-99.0) to 99.9% (CI: 99.6-100). Of the stem brands with the best survival, stems with and without HA coating were found. The presence of HA coating was not associated with statistically significant effects on the adjusted risk of stem revision due to aseptic loosening, with an HR of 0.8 (CI: 0.5-1.3; p = 0.4). The adjusted risk of revision due to infection was similar in the groups of THAs using HA-coated and non-HA-coated stems, with an HR of 0.9 (CI: 0.8-1.1; p = 0.6) for the presence of HA coating. The commonly used Bimetric stem (n = 25,329) was available both with and without HA coating, and the adjusted risk of stem revision due to aseptic loosening was similar for the 2 variants, with an HR of 0.9 (CI: 0.5-1.4; p = 0.5) for the HA-coated Bimetric stem. Interpretation - Uncemented HA-coated stems had similar results to those of uncemented stems with porous coating or rough sand-blasted stems. The use of HA coating on stems available both with and without this surface treatment had no clinically relevant effect on their outcome, and we thus question whether HA coating adds any value to well-functioning stem designs.
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| 6. |
- Hailer, Nils P, et al.
(author)
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Hydroxyapatite coating does not improve uncemented stem survival after total hip arthroplasty! : An analysis of 116,069 THAs in the Nordic Arthroplasty Register Association (NARA) database
- 2015
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In: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 86:1, s. 18-25
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Journal article (peer-reviewed)abstract
- Background and purposeIt is still being debated whether HA coating of uncemented stems used in total hip arthroplasty (THA) improves implant survival. We therefore investigated different uncemented stem brands, with and without HA coating, regarding early and long-term survival.Patients and methods We identified 152,410 THA procedures using uncemented stems that were performed between 1995 and 2011 and registered in the Nordic Arthroplasty Register Association (NARA) database. We excluded 19,446 procedures that used stem brands less than 500 times in each country, procedures performed due to diagnoses other than osteoarthritis or pediatric hip disease, and procedures with missing information on the type of coating. 22 stem brands remained (which were used in 116,069 procedures) for analysis of revision of any component. 79,192 procedures from Denmark, Norway, and Sweden were analyzed for the endpoint stem revision. Unadjusted survival rates were calculated according to Kaplan-Meier, and Cox proportional hazards models were fitted in order to calculate hazard ratios (HRs) for the risk of revision with 95% confidence intervals (CIs).ResultsUnadjusted 10-year survival with the endpoint revision of any component for any reason was 92.1% (CI: 91.8-92.4). Unadjusted 10-year survival with the endpoint stem revision due to aseptic loosening varied between the stem brands investigated and ranged from 96.7% (CI: 94.4-99.0) to 99.9% (CI: 99.6-100). Of the stem brands with the best survival, stems with and without HA coating were found. The presence of HA coating was not associated with statistically significant effects on the adjusted risk of stem revision due to aseptic loosening, with an HR of 0.8 (CI: 0.5-1.3; p = 0.4). The adjusted risk of revision due to infection was similar in the groups of THAs using HA-coated and non-HA-coated stems, with an HR of 0.9 (CI: 0.8-1.1; p = 0.6) for the presence of HA coating. The commonly used Bimetric stem (n = 25,329) was available both with and without HA coating, and the adjusted risk of stem revision due to aseptic loosening was similar for the 2 variants, with an HR of 0.9 (CI: 0.5-1.4; p = 0.5) for the HA-coated Bimetric stem.Interpretation Uncemented HA-coated stems had similar results to those of uncemented stems with porous coating or rough sand-blasted stems. The use of HA coating on stems available both with and without this surface treatment had no clinically relevant effect on their outcome, and we thus question whether HA coating adds any value to well-functioning stem designs.
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| 7. |
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| 8. |
- Johanson, Per-Erik, et al.
(author)
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Outcome in design-specific comparisons between highly crosslinked and conventional polyethylene in total hip arthroplasty.
- 2017
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In: Acta orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 88:4, s. 363-369
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Journal article (peer-reviewed)abstract
- Background and purpose - Most registry studies regarding highly crosslinked polyethylene (XLPE) have focused on the overall revision risk. We compared the risk of cup and/or liner revision for specific cup and liner designs made of either XLPE or conventional polyethylene (CPE), regarding revision for any reason and revision due to aseptic loosening and/or osteolysis. Patients and methods - Using the Nordic Arthroplasty Register Association (NARA) database, we identified cup and liner designs where either XLPE or CPE had been used in more than 500 THAs performed for primary hip osteoarthritis. We assessed risk of revision for any reason and for aseptic loosening using Cox regression adjusted for age, sex, femoral head material and size, surgical approach, stem fixation, and presence of hydroxyapatite coating (uncemented cups). Results - The CPE version of the ZCA cup had a risk of revision for any reason similar to that of the XLPE version (p = 0.09), but showed a 6-fold higher risk of revision for aseptic loosening (p < 0.001). The CPE version of the Reflection All Poly cup had an 8-fold elevated risk of revision for any reason (p < 0.001) and a 5-fold increased risk of revision for aseptic loosening (p < 0.001). The Charnley Elite Ogee/Marathon cup and the Trilogy cup did not show such differences. Interpretation - Whether XLPE has any advantage over CPE regarding revision risk may depend on the properties of the polyethylene materials being compared, as well as the respective cup designs, fixation type, and follow-up times. Further research is needed to elucidate how cup design factors interact with polyethylene type to affect the risk of revision.
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| 9. |
- Kreipke, Rasmus, et al.
(author)
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Dual Mobility Cups : Effect on Risk of Revision of Primary Total Hip Arthroplasty Due to Osteoarthritis: A Matched Population-Based Study Using the Nordic Arthroplasty Register Association Database
- 2019
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In: The Journal of bone and joint surgery. American volume. - 1535-1386. ; 101:2, s. 169-176
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Journal article (peer-reviewed)abstract
- BACKGROUND: The dual mobility acetabular cup (DMC) was designed to reduce prosthetic instability and has gained popularity for both primary and revision total hip arthroplasty (THA). We compared the risk of revision of primary THA for primary osteoarthritis between patients treated with a DMC and those who received a metal-on-polyethylene (MoP) or ceramic-on-polyethylene (CoP) bearing. METHODS: A search of the Nordic Arthroplasty Register Association (NARA) database identified THAs performed with a DMC during 1995 to 2013. With use of propensity score matching, 2,277 of these patients were matched (1:1), with regard to sex, age, component fixation, and year of surgery, with patients with an MoP or CoP bearing. We estimated the cumulative incidence of revision taking death as a competing risk into consideration and performed competing risk regression with revision or death as end points. RESULTS: There was no difference in the overall risk of revision between the DMC group and the propensity-score-matched MoP/CoP group (adjusted hazard ratio [HR] = 1.18; 95% confidence interval [95% CI] = 0.87 to 1.62). Patients with a DMC bearing had a lower risk of revision due to dislocation (adjusted HR = 0.09; 95% CI = 0.03 to 0.29) but a higher risk of revision caused by infection (adjusted HR = 3.20; 95% CI = 1.49 to 6.85). CONCLUSIONS: There was no difference in overall risk of revision between the DMC and MoP/CoP groups. The DMCs protected against revision due to dislocation but THAs performed with this bearing were more commonly revised because of infection. There may have been a selection bias toward placing DMC implants in patients with greater frailty as the mortality rates were higher in the DMC group than in the age and sex-matched MoP/CoP group. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
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| 10. |
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| 11. |
- Robertsson, Otto, et al.
(author)
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Knee arthroplasty in Denmark, Norway and Sweden. A pilot study from the Nordic Arthroplasty Register Association
- 2010
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In: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 81:1, s. 82-89
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Journal article (peer-reviewed)abstract
- Background and purpose The number of national arthroplasty registries is increasing. However, the methods of registration, classification, and analysis often differ. Methods We combined data from 3 Nordic knee arthroplasty registers, comparing demographics, methods, and overall results. Primary arthroplasties during the period 1997-2007 were included. Each register produced a dataset of predefined variables, after which the data were combined and descriptive and survival statistics produced. Results The incidence of knee arthroplasty increased in all 3 countries, but most in Denmark. Norway had the lowest number of procedures per hospital-less than half that of Sweden and Denmark. The preference for implant brands varied and only 3 total brands and 1 unicompartmental brand were common in all 3 countries. Use of patellar button for total knee arthroplasty was popular in Denmark (76%) but not in Norway (11%) or Sweden (14%). Uncemented or hybrid fixation of components was also more frequent in Denmark (22%) than in Norway (14%) and Sweden (2%). After total knee arthroplasty for osteoarthritis, the cumulative revision rate (CRR) was lowest in Sweden, with Denmark and Norway having a relative risk (RR) of 1.4 (95% CI: 1.3-1.6) and 1.6 (CI: 1.4-1.7) times higher. The result was similar when only including brands used in more than 200 cases in all 3 countries (AGC, Duracon, and NexGen). After unicompartmental arthroplasty for osteoarthritis, the CRR for all models was also lowest in Sweden, with Denmark and Norway having RRs of 1.7 (CI: 1.4-2.0) and 1.5 (CI: 1.3-1.8), respectively. When only the Oxford implant was analyzed, however, the CRRs were similar and the RRs were 1.2 (CI: 0.9-1.7) and 1.3 (CI: 1.0-1.7). Interpretation We found considerable differences between the 3 countries, with Sweden having a lower revision rate than Denmark and Norway. Further classification and standardization work is needed to permit more elaborate studies.
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| 12. |
- Schrama, Johannes, et al.
(author)
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Increased risk of revision for infection in rheumatoid arthritis patients with total hip replacements
- 2015
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In: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 86:4, s. 469-476
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Journal article (peer-reviewed)abstract
- Background and purpose — Medical treatment of rheumatoid arthritis (RA) has changed dramatically over the last 15 years, including immune modulation. We investigated the risk of revision for infection after primary total hip replacement (THR) in patients with rheumatoid arthritis over a 16-year period, and compared it with that in THR patients with osteoarthritis (OA). Patients and methods — We identified 13,384 THRs in RA patients and 377,287 THRs in OA patients from 1995 through 2010 in a dataset from the Nordic Arthroplasty Register Association (NARA). Kaplan-Meier survival curves, with revision for infection as the endpoint, were constructed. Cox regression analyses were performed to calculate the relative risk (RR) of revision for infection adjusted for age, sex, fixation technique, and year of primary surgery. Results — RA patients had a 1.3 times (95% CI 1.0–1.6) higher risk of revision for infection. After 2001, this risk increased more for RA patients than for OA patients. During the first 3 months and from 8 years postoperatively, the risk of revision for infection was higher in RA patients with THRs fixated with antibiotic-loaded cement than in corresponding OA patients. Interpretation — We found a slightly higher overall risk of revision for infection in RA patients than in OA patients, but this difference was only present after 2001. In THRs with antibiotic-loaded cement, the risk of very early and late infections leading to revision was higher in RA patients than in OA patients
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| 13. |
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