Tone Wikene Nystad

Reduction in orthopaedic surgery in patients with rheumatoid arthritis: a Norwegian register-based study

Objectives: The disease course of patients with rheumatoid arthritis (RA) has become milder in recent years. In this study we investigated the incidence of orthopaedic surgery in patients with RA. Method: From the Norwegian Arthroplasty Register we selected joint replacement procedures conducted during the years 1994–2012 (n = 11 337), and from the Norwegian Patient Register we obtained data on synovectomies (n = 4782) and arthrodeses (n = 6022) during 1997–2012. Using Poisson regression we analysed the time trends in the incidence of procedures performed. Results: There was a significant decrease in the incidence of arthroplasty surgery (coefficient of −0.050 per year) and synovectomies (coefficient of −0.10) and a declining trend of arthrodeses in patients with RA in the study periods. The greatest reduction was found in procedures involving the wrist and hand. Conclusions: We found a decrease in orthopaedic surgery in patients with RA that continued into the biologic era and throughout the study period. The general increasing trend in the use of synthetic and biological disease-modifying anti-rheumatic drugs (DMARDs) thus coincides with less joint destruction and an improved long-term prognosis of patients with RA.

Improved survival for anatomic total shoulder prostheses: Results of 4,173 shoulder arthroplasties reported to the Norwegian Arthroplasty Register from 1994 through 2012

Background and purpose — Previously, implant survival of total shoulder prostheses was reported to be inferior to that of hemiprostheses. However, the use of total prostheses has increased in Norway due to reported good functional results. On this background, we wanted to study implant survival of 4 major shoulder prosthesis types in Norway between 1994 and 2012. Patients and methods — The study population comprised 4,173 patients with shoulder replacements reported to the Norwegian Arthroplasty Register, including 2,447 hemiprostheses (HPs), 444 anatomic total prostheses (ATPs), 454 resurfacing prostheses (RPs), and 828 reversed total prostheses (RTPs). Three time periods were compared: 1994–1999, 2000–2005, and 2006–2012. Kaplan-Meier failure curves were used to compare implant failure rates for subgroups of patients, and adjusted risks of revision were calculated using Cox regression analysis. Results — For prostheses inserted from 2006 through 2012, the 5-year survival rates were 95% for HPs (as opposed to 94% in 1994–1999), 95% for ATPs (75% in 1994–1999), 87% for RPs (96% in 1994–1999), and 93% for RTPs (91% in 1994–1999). During the study period, the implant survival improved significantly for ATPs (p < 0.001). A tendency of better results with acute fracture and worse results in sequelae after previous fractures was seen in all time periods. Interpretation — The 5-year implant survival rates were good with all prosthesis types, and markedly improved for anatomic total prostheses in the last 2 study periods. The better functional results with total shoulder prostheses than with hemiprostheses support the trend towards increased use of total shoulder prostheses.

Antibiotic susceptibility of blood culture isolates of anaerobic bacteria at a Norwegian university hospital

In the present study the susceptibility of 200 blood culture isolates of anaerobic bacteria to benzylpenicillin, clindamycin, metronidazole, imipenem and piperacillin‐tazobactam was examined. Metronidazole, imipenem, and piperacillin‐tazobactam showed the highest activity, with 98.5% of the isolates being fully susceptible to either agent. A high rate of reduced susceptibility to clindamycin among both Bacteroides spp. (37%) and Clostridium spp. (28%) was found. Almost all Bacteroides isolates were resistant to penicillin, and only 60% of Prevotella spp. were susceptible to this agent. The antibiotic susceptibility of anaerobic bacteria in Norway should be surveyed regularly.

Linezolid and Human Polymorphonuclear Leukocyte Function

Background: To examine whether linezolid, a new oxazolidinone antibiotic, has an effect on human polymorphonuclear leukocyte (PMN) function. Methods: Flow-cytometric techniques for the demonstration of PMN chemotaxis towards zymosan-activated serum, and phagocytosis and respiratory burst after incubation in linezolid. Results: Linezolid at concentrations of 10– 160 mg/l did not significantly influence PMN function as measured by chemotaxis, phagocytosis and respiratory burst. Conclusions: Linezolid at therapeutic or supratherapeutic concentrations does not influence human PMN function. This applies to the chemically pure substance as well as to the commercial preparation containing additives for intravenous infusion.

Hip replacement surgery in patients with ankylosing spondylitis

Objectives Although TNF-α inhibitors’ striking effect on clinical symptoms have revolutionised the treatment of ankylosing spondylitis (AS), no certain influence on the development of spinal ankylosis and joint destruction has been documented. We wished to investigate whether improved treatment has affected the use of hip arthroplasty surgery. Methods Using the Norwegian Arthroplasty Register, we selected hip prosthesis procedures performed in patients with AS in 1988–2010 (n=534), and compared the trend in the number of procedures being performed annually in 1988–2002 versus 2003–2010. Patients with osteoarthritis (OA) (n=95094) were used as a control group. Results The frequency of hip prosthesis surgery increased significantly in both groups up until 2002. In 2003–2010, although not statistically significant (p=0.087), there was a trend towards a reduced frequency in the AS group when compared with the expected continued increase as was seen among patients with OA. Mean age at surgery increased significantly (p<0.001) from 49.9 years to 56.4 years when comparing patients with AS up until and after 2002. Conclusions TNF-α inhibitors were introduced to patients with AS in Norway in 2000–2003, and our findings suggest that they may have altered the prognosis by inhibiting or slowing large joint arthritis and thus reducing the need for hip replacement surgery.

Incidence and Predictive Factors for Orthopedic Surgery in Patients with Psoriatic Arthritis

Objective. To investigate the incidence of orthopedic procedures in patients with psoriatic arthritis (PsA), and how patient characteristics, time of diagnosis, and treatment affect the need for surgery. Methods. We reviewed the medical history of 1432 patients with possible PsA at Haukeland University Hospital in Bergen, Norway. There were 590 patients (mean age 49 yrs, 52% women) who had sufficient journal information and a confirmed diagnosis of PsA, and who were included in the present study. Relevant orthopedic procedures were obtained from the hospital’s administrative patient records. Survival analyses were completed to evaluate the effect of different factors such as year of diagnosis, age, sex, radiographic changes, disease activity, and treatment, on the risk of surgery. Results. There were 171 procedures (25% synovectomies, 15% arthrodesis, and 53% prostheses) performed on 117 patients. These factors all increased the risk of surgery: female sex [relative risk (RR) 1.9, p = 0.001], age ≥ 70 years at diagnosis (RR 2.4, p = 0.001), arthritis in initial radiographs (RR 2.2, p = 0.006), and maximum erythrocyte sedimentation rate 30–59 mm/h (RR 1.6, p = 0.026). Time period of diagnosis had no effect on the outcome. In a subanalysis of surgery exclusive of hip and knee arthroplasty, diagnosis in earlier years (1954–1985 vs 1999–2011) was a risk factor (RR 2.1, p = 0.042). Antirheumatic treatment changed significantly over time. Conclusion. There were 20% of patients with PsA who needed surgery. We found that the prognosis of patients with PsA did not change regarding the risk of orthopedic surgery, despite the change in treatment. A possible explanation is the increase in large joint replacements in the general population.

Predictors for orthopaedic surgery in patients with rheumatoid arthritis: results from a retrospective cohort study of 1010 patients diagnosed from 1972 to 2009 and followed up until 2015

Objectives: To investigate how patient characteristics, time of diagnosis, and treatment affect the need for orthopaedic surgery in patients with rheumatoid arthritis (RA). Method: We reviewed the medical history of 1544 patients diagnosed with RA at Haukeland University Hospital in Bergen, Norway, from 1972 to 2009, of whom 1010 (mean age 57 years, 69% women) were included in the present study. Relevant orthopaedic procedures were obtained from the Norwegian Arthoplasty Register and the hospital’s administrative patient records. In total, 693 procedures (joint synovectomies 22%, arthrodeses 21%, prostheses 41%, and forefoot procedures 12%) were performed in 315 patients. Survival analyses were completed to evaluate the impact of different factors such as age, gender, radiographic changes, and year of diagnosis, on the risk of undergoing surgery. Results: Patients diagnosed in 1972–1985 and 1986–1998 had a relative risk of undergoing surgery of 2.4 and 2.2 (p < 0.001), respectively, compared to patients diagnosed in 1999–2009. Radiographic changes at diagnosis and female gender were also significant risk factors. Anti-rheumatic medication was significantly different in the three time periods. Conclusion: Patients with a diagnosis in the early years had a greatly increased risk of having orthopaedic surgery performed. This is probably due to the year of diagnosis being a proxy for the type and intensity of medical treatment.

SAT0043 Factors affecting the need for orthopaedic surgery in patients with rheumatoid arthritis. results from 1010 patients diagnosed with ra from 1972-2009

Background Surgery still comprises a necessary part of treating RA patients, when medication fail to prevent joint destruction. Orthopaedic corrective procedures are considered a reliable and objective proxy for a destructed joint, and is an important outcome measure in RA. Objectives To investigate how patient characteristics, time of diagnosis and treatment affect the need for orthopaedic surgery in patients with rheumatoid arthritis (RA). Methods We reviewed the medical history of 1544 patients diagnosed with RA at Haukeland University Hospital in Bergen, Norway from 1972 to 2009, of which 1010 (mean age 57, 69% women) were included in the study. Relevant orthopaedic procedures were obtained from the Norwegian Arthroplasty Register and the hospitals administrative patient records. 693 procedures (joint synovectomies 22%, arthrodeses 21%, prostheses 41% and forefoot procedures 12%) were performed in 315 patients. Survival analyses were completed to evaluate the impact of age, sex, radiographic changes and year of diagnosis, on the risk of undergoing surgery. Results Patients diagnosed in 1972–1985 and 1986–1998 had a relative risk (RR) of 2.4 and 2.2 (p<0.001) respectively, of surgery compared to patients diagnosed in 1999–2009. Radiographic changes at diagnosis and female sex were also significant risk factors. Disease activity at baseline did not affect the outcome. Anti-rheumatic medication was significantly different in the three time periods. Variable category 5 yearsa 10 yearsa RR 95% CI p-value Gender, male 13 22 1 female 19 30 1.35 1.02–1.77 0.035 Age (years)  <69 15 27 1  ≥70 22 31 1.04 0.77–1.42 0.78 Radiolographic changes at diagnosis  No arthritis 12 21 1  Possible arthritis, or MR findings only 19 26 1.01 0.66–1.57 0.92  Arthritis 23 34 1.46 1.10–1.94 0.008  Osteoarthritis 35 55 2.81 1.94–4.05 <0.001 Time period  1999–2009 12 18 1  1986–1998 25 38 2.16 1.62–2.87 <0.001  1972–1985 15 37 2.38 1.71–3.31 <0.001 a5- and 10-year survival, in percent. Conclusions Patients with early years of diagnosis had greatly increased risk of having an RA related procedure performed. This is probably due to the year of diagnosis being a proxy for the type and intensity of medical treatment. References Goodman SM. Rheumatoid Arthritis Therapy and Joint-replacement Surgery: Are We Making a Difference? J Rheumatol. 2016;43:833–5. Disclosure of Interest None declared

SAT0061 Reduction in Joint Replacement Surgery in Patients with Reumatoid Arthritis

Background The disease course of patients with rheumatoid arthritis has become milder in recent years,(1, 2) and the change in treatment mainly represented by methotrexate from the late 1970ties is believed to be a major contributor to this,(3) although it has been argued that the improved outcome is partly a secular trend.(4) Joint replacement surgery can be considered an objective proxy for a destructed joint, and studying its change in incidence over time gives valuable information regarding the prognosis of patients with rheumatoid arthritis. Objectives We wished to investigate the incidence of joint replacement surgery in patients with rheumatoid arthritis and relate the change over time to the change in use of disease modifying anti rheumatic drugs (DMARDs). Methods From the Norwegian Arthroplasty Register we selected arthroplasties of the hip, knee, ankle, toe, shoulder, elbow, wrist, carpus and fingers in patients with rheumatoid arthritis in the years 1994-2012 (n=11337, 82% women), and using Poisson regression we analysed the time trend in the incidence of procedures being performed. Analyses were performed for each joint, joints grouped together and for different age categories. For the communal analysis operations in patients with osteoarthritis were included for comparison. We also collected data from the Norwegian Prescription Database established in 2004 to analyse changes in the number of individuals using methotrexate, leflunomide, sulfasalazine or hydroxychloroquine, and any change in mean weekly per oral methotrexate dose. Results We found a significant decrease in the incidence of arthroplasty surgery in patients with rheumatoid arthritis (coefficient of -0.050 per year, p<0.001) as opposed to a significant increase in patients with osteoarthritis (coefficient of 0.047 per year, p<0.001). The decrease was most prominent in the age groups 50-59 years, 60-69 years and 70-79 years, and finger joint prostheses had the greatest reduction with an incidence of 0.5 per 100 000 in 2012 compared with 7.49 per 100 000 in 1994. From 2004 to 2012 the use of methotrexate increased steadily from 0.030 to 0.056 users per 100 000 inhabitants, and mean dose increased from 10.8 to 12.1 mg per week. Only small changes were seen for the other DMARDs Conclusions The reduction in rheumatic surgery reported by other authors (5, 6) was confirmed in this large material from the Norwegian Arthroplasty Register, and the trend seen in earlier time periods continued into the biologic era and throughout the study period 1994-2012. In addition to the introduction of TNF-α inhibitors in 1998, the use of methotrexate increased in all available years from 2004-2012, thus coinciding with the reduction in prosthesis surgery and the improved prognosis of patients with rheumatoid arthritis. References Bergstrom U et al. PubMed PMID: 10380838. Pincus T et al. PubMed PMID: 16339290. Finckh A et al. PubMed PMID: 16540549. Verstappen SM et al. PubMed PMID: 22137919. Fevang BT et al. PubMed PMID: 17394183. Jamsen E et al. PubMed PMID: 23992137. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.1446