The decline in joint replacement surgery in rheumatoid arthritis is associated with a concomitant increase in the intensity of anti-rheumatic therapy: a nationwide register-based study from 1995 through 2010.

BACKGROUND AND PURPOSE: Drug-based treatment of rheumatoid arthritis (RA) has evolved markedly over the past 2 decades. Using nationwide register data, we studied how this has affected the rates of hip, knee, shoulder, and elbow replacement from 1995 to 2010. METHODS: The number of primary joint replacements was obtained from the Finnish Arthroplasty Register. To test the hypothesis that improvements in medical treatment of RA reduce the need for joint replacements, we also collected data about purchases of different disease-modifying anti-rheumatic agents (DMARDs) and biological drugs from the nationwide drug registers. RESULTS: The annual incidence of primary joint replacements for RA declined from 19 per 10(5) in 1995 to 11 per 10(5) in 2010. The decline was greater for upper-limb operations than for lower-limb operations. At the same time, the numbers of individuals using methotrexate, hydroxychloroquine, and sulfasalazine (the most commonly used DMARDs) increased 2- to 4-fold. INTERPRETATION: Our results are in accordance with observations from other countries, and indicate that the use of joint replacements in RA has decreased dramatically. Our data suggest that effective medical therapy is the most likely explanation for this favorable development.

Incidence of rheumatoid arthritis-related ankle replacement and ankle arthrodesis: a Finnish nationwide register-based study from 1997­2010.

BACKGROUND AND PURPOSE: For 20 years, medical treatment of rheumatoid arthritis (RA) has been improving and the incidence of joint surgery has decreased. We investigated the rates of primary ankle joint arthrodesis and total ankle arthroplasty in patients with RA in Finland between 1997 and 2010 to establish whether trends have changed during that period. METHODS: The annual figures for primary ankle joint arthrodeses and total ankle replacements performed in patients with RA were obtained from nationwide population-based registries. Incidences were calculated per population of 10(5) and they are reported in 2-year periods. RESULTS: During the study period, 593 primary ankle joint arthrodeses and 318 total ankle arthroplasties were performed in patients with RA. The incidence of ankle joint arthrodesis reached its highest value (2.4/10(5)) in 1997-1998 and it was lowest in 2001-2002 (1.1/10(5)). After 2002, the incidence increased slightly but did not reach the level in 1997-1998, even though total ankle replacements almost ended in Finland during the period 2009-2010. From 1997, total ankle replacements increased until 2003-2004 (incidence 1.5/10(5)) and then gradually decreased. In 2009-2010, the incidence of total ankle replacements was only 0.4/10(5). INTERPRETATION: During the observation period 1997-2010, while total ankle replacements generally became more common in patients with RA, the incidence of primary ankle joint arthrodesis decreased and did not increase in the period 2009-2010, even though total ankle replacement surgery almost ended in Finland. No change in the incidence of these operations, when pooled together, was observed from 1997 to 2010.

Wear particles promote endotoxin tolerance in macrophages by inducing interleukin-1 receptor-associated kinase-M expression.

Toll-like receptors (TLRs) recognizing pathogen-associated molecular patterns (PAMP) play a role in local immunity and participate in implant-associated loosening. TLRs-mediated signaling is regulated by interleukin-1 receptor-associated kinase-M (IRAK-M). Our previous studies have proved that IRAK-M is induced by wear particles in macrophages from periprosthetic tissues. In this study, the IRAK-M-related mechanisms were further explored by lipopolysaccharide (LPS) and/or titanium (Ti) particles stimulations and small interfering RNAs (siRNAs). The protein level of IRAK-M was studied using western blotting and tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß) levels were measured using ELISA. Results showed that in RAW264.7 cells stimulated by LPS after Ti particle pre-exposure, IRAK-M was slightly changed, compared with LPS stimulation. And levels of TNF-α and IL-1ß in cultures stimulated by LPS first after Ti particle pre-exposure were lower than in the other two groups which were stimulated by LPS with or without Ti particles (p < 0.001), whereas there were no statistic differences between the later two (p > 0.05). The cytokines were lowest in Ti particles alone stimulation. After siRNAs silenced, IRAK-M-deficient cells exhibited increased expression of the cytokines in LPS stimulation after Ti particle pre-exposure and when stimulated with Ti particles alone. Our findings suggest that debris-induced IRAK-M decreases foreign body reactions, but at the same time, the over-expression of IRAK-M may also be detrimental on local intrusion of PAMPs or bacteria, negatively regulates the LPS-induced and TLRs-mediated inflammation and results in immunosuppression in periprosthetic tissue, which may predispose to implant-associated infections.

Comorbid diseases as predictors of survival of primary total hip and knee replacements: a nationwide register-based study of 96 754 operations on patients with primary osteoarthritis.

OBJECTIVES: To examine how comorbid diseases (cardiovascular diseases, hypertension, diabetes, cancer, pulmonary diseases, depression, psychotic disorders and neurodegenerative diseases) affect survival of hip and knee replacements. METHODS: Data for this register-based study were collected by combining data from five nationwide health registers. 43 747 primary total hip and 53 007 primary total knee replacements performed for osteoarthritis were included. The independent effects of comorbid diseases on prosthesis survival were analysed using multivariate Cox regression analysis. RESULTS: Occurrence of one or more of the diseases analysed was associated with poorer survival of hip (HR for revision 1.16, 95% CI 1.08 to 1.23) and knee replacements (1.23, 1.16 to 1.30). Cardiovascular diseases and psychotic disorders were associated with increased risk of revision after both hip (1.19, 1.06 to 1.34 and 1.41, 1.04 to 1.91, respectively) and knee replacement (1.29, 1.14 to 1.45 and 1.41, 1.07 to 1.86, respectively). Hypertension and diabetes were associated with early revision (0-5 years after primary operation) after knee replacements (1.14, 1.01 to 1.29 and 1.27, 1.08 to 1.50, respectively). Cancer was associated with poorer survival of hip replacements (1.27, 1.05 to 1.54) and late revision (>5 years) of knee replacements (2.21, 1.31 to 3.74). Depression affected the risk of early revision after hip replacement (1.50, 1.02 to 2.21). Neurodegenerative and pulmonary diseases did not affect prosthesis survival. CONCLUSIONS: Comorbid diseases may play an important role in predicting survival of primary hip and knee replacements. The mechanisms underlying these findings and their effect on cost-effectiveness of joint replacements, merit further research.

IRAK-M in macrophages around septically and aseptically loosened hip implants.

The most common long-term complication of joint arthroplasty is loosening, which is mediated by chronic inflammatory cytokines produced by macrophages stimulated by implant-derived debris and eventually bacterial components adherent to such debris. In this study, antiinflammatory interleukin-1 receptor-associated kinase-M (IRAK-M) was studied in macrophages in interface membranes in vivo using immunohistochemical staining and in titanium particle-stimulated macrophages in vitro using reverse transcriptase-polymerase chain reaction. Results show that the interface membranes of septically and aseptically loosened prosthesis express more IRAK-M protein than control membranes from osteoarthritic patient and that IRAK-M mRNA-levels increase upon particle stimulation. These findings suggest that, the upregulation of IRAK-M in macrophages is involved in the local immunosuppression around implants, and may contribute to septic and aseptic implant loosening.

Is longer waiting time for total knee replacement associated with health outcomes and medication costs? Randomized clinical trial.

BACKGROUND: The aim of this prospective randomized study was to evaluate the effect of waiting time (WT) on health-related quality of life (HRQoL), knee pain and physical function, and the use and costs of medication of patients awaiting total knee replacement. METHODS: When placed on the waiting list, 438 patients were randomized into a short waiting time (SWT ≤ 3 months) or a nonfixed waiting time (NFWT > 3 months) group. HRQoL was measured by the 15D, and pain and physical function by modified Knee Society Clinical Rating System at baseline, admission, and 3 and 12 months postoperatively. The costs of medication due to osteoarthritis were calculated at the same measurement points. All analyses were performed using the intention-to-treat principle. RESULTS: The mean WT was 94 and 239 days in the SWT and NFWT groups, respectively. Apart from higher weekly cost of medication in the SWT group at admission and better HRQoL in the NFWT group 1 year postoperatively, there were no statistically significant differences between the groups in other outcomes during the follow-up. CONCLUSION: Those in the SWT group had higher weekly costs of medication at admission, and reached better HRQoL 3 months earlier than those in the NFWT group, but the latter had better HRQoL after operation. Otherwise, the length of WT was not associated with different health and HRQoL outcomes in the groups.

Incidence of prosthetic joint infections after primary knee arthroplasty.

We report the 1-year incidence of postoperative infections in an unselected series of 2647 consecutive primary knee arthroplasties (3137 knees) performed in a modern specialized hospital dedicated solely to joint arthroplasty surgery in 2002 to 2006. The rates of superficial and prosthetic joint infections were 2.9% and 0.80%, respectively. Prospective surveillance by hospital infection register failed to detect 6 of the 24 prosthetic joint infections. Increased rate of prosthetic joint infections was associated with complex surgery and with several patient-related factors, for example, comorbidity, obesity, and poor preoperative clinical state. The rate of prosthetic joint infections in contemporary knee arthroplasty is low and mainly related to patient-related factors, of which patient comorbidity has the most profound effect on the infection rate.

The effect of waiting time on health-related quality of life, pain, and physical function in patients awaiting primary total hip replacement: a randomized controlled trial.

OBJECTIVE: This prospective randomized study assessed the effect of waiting time (WT) on health outcomes in Finnish patients admitted to hospital for primary total hip replacement (THR). METHODS: A total of 395 consecutive patients with a need for a primary THR because of osteoarthritis and who were placed on the waiting list between August 2002 and November 2003. After placement on the waiting list, the patients were randomly assigned to a short WT (

Total hip replacement in patients eighty years of age and older.

BACKGROUND: The number of people eighty years of age and older in developed countries is increasing, with a concomitant increased demand for total hip replacement. We analyzed the outcomes of total hip arthroplasty for patients in this age group using data from the Finnish National Arthroplasty Registry. METHODS: Data from the Finnish Arthroplasty Registry on 6540 patients (6989 hips) who were eighty years of age or older at the time of a total hip arthroplasty, performed between 1980 and 2004, were evaluated with use of survival analyses. Factors affecting survivorship rates were sought, and the reasons for revision were identified. RESULTS: The mean age of the patients undergoing a primary total hip arthroplasty was 82.7 years. The mean longevity of 3065 patients who died following total hip arthroplasty was 5.1 years. With revision total hip arthroplasty for any reason as the end point, Kaplan Meier survivorship was 97% (95% confidence interval, 96% to 97%) at five years (2617 hips) and 94% (95% confidence interval, 93% to 95%) at ten years (532 hips). Of the 195 hip replacements that required revision, 183 had information on the reason for revision. Eighty-four (46%) were revised for aseptic loosening; thirty-six (20%), for recurrent dislocation; twenty-four (13%), for a periprosthetic fracture; and twenty-three (13%), for infection. Seven hundred and twenty-nine patients had undergone hybrid fixation (a cemented stem and a cementless cup). The survivorship of these replacements was significantly better than that for replacements with cementless fixation in 399 patients (p < 0.05). CONCLUSIONS: In patients who had a total hip arthroplasty when they were more than eighty years old, the prevalence of aseptic loosening was less than that encountered in younger patients, but recurrent dislocation, periprosthetic fracture, and infection were more common in this age group. Cementation of the femoral stem demonstrated better long-term results than cementless fixation, indicating that it may provide better initial fixation and, therefore, longer life-in-service.

Is longer waiting time associated with health and social services utilization before treatment? A randomized study.

OBJECTIVE: To determine whether longer waiting time for major joint replacement is associated with health and social services utilization before treatment. METHODS: When placed on the waiting list, patients were randomized to short (

Evaluating waiting time effect on health outcomes at admission: a prospective randomized study on patients with osteoarthritis of the knee joint.

AIMS: To evaluate the effect of waiting on health-related quality of life (HRQoL), pain and physical function in patients awaiting primary total knee replacement (TKR) due to osteoarthritis. METHODS: Some 438 patients awaiting TKR were randomized to a short waiting time (WT) group (< or =3 months) or a non-fixed WT group. In the final assessment, 310 patients (213 women) with a mean age of 68 years were included. HRQoL was measured on being placed on the waiting list and again at hospital admission using the generic 15D. Patients' self-report pain and physical function were evaluated using a scale modified from the Knee Society Clinical Rating System. RESULTS: The median WTs for patients with short and non-fixed WT were 73 days (range 8-600 days) and 266 days (range 28-818 days), respectively. At admission, as assessed by the intention-to-treat analysis, there were no statistically significant differences between the groups in the 15D total score and disease-specific pain and function. CONCLUSIONS: Our study showed that longer WT did not result in worse pre-operative HRQoL.

The effect of co-morbidities on health-related quality of life in patients placed on the waiting list for total joint replacement.

BACKGROUND: Co-morbidity is a powerful predictor of health care outcomes and costs, as well as an important cofounder in epidemiologic studies. The effect of co-morbidities is generally related to mortality or complications. This study evaluated the association between co-morbidity and health-related quality of life (HRQoL) in patients awaiting total joint replacement. METHODS: A total of 893 patients were recruited to the study between August 2002 and November 2003 in four Finnish hospitals. The effect of co-morbidity on HRQoL was measured by the generic 15D instrument and by a Visual Analog Scale (VAS). Comparative variance analysis of socio-demographic and clinical characteristics was described by using either an independent samples t-test or the Chi-square test. The differences in each of the 15D dimensions and the overall 15D single index score for patients were calculated. Two-sided p-values were calculated with the Levene Test for Equality of Variances. RESULTS: Patients with co-morbidity totaled 649; the incidence of co-morbidity was 73%. The mean number of co-morbidities among the patients was two. At baseline the 15D score in patients with and without co-morbidity was 0.778 vs 0.816, respectively. The difference of the score (0.038) was clinically and statistically significant (P < 0.001). The patients' scores with and without co-morbidity on the different 15D dimensions related to osteoarthritis-moving, sleeping, usual activities, discomfort and symptoms, vitality and sexual activity-were low in both groups. Patients with co-morbidity scored lower on the dimensions of moving, vitality and sexual activity compared to the patients without co-morbidity. Co-morbidity was significantly associated with a reduced HRQoL. Patients without co-morbidity had poorer VAS, arthritis had strong effect to their quality of life compared to the patients with co-morbidity. CONCLUSION: Assessing co-morbidity in patients placed on the waiting list for joint replacement may be useful method to prioritization in medical decision-making for healthcare delivery. The assessment of co-morbidities during waiting time is important as well as evaluating how the co-morbidity may affect the final outcomes of the total joint replacement.

Revision total knee arthroplasty with the total condylar III system: a comparative analysis of 71 consecutive cases of osteoarthritis or inflammatory arthritis.

BACKGROUND: As revision total knee arthroplasty surgery is becoming more common, it is necessary to evaluate how individual revision prosthesis systems perform in degenerative and inflammatory arthritides. In this study, results of the use of the Total Condylar III (TC III) system in osteoarthritis (55 knees) were compared to results of its use in inflammatory arthritis (16). METHODS: Patients were followed radiographically for 5.9 (3.0-10.2) years and clinically for 3.0 (0.2-6.8) years, using re-revision as the endpoint. RESULTS: At 1 year after revision and at final follow-up, the total Knee Society knee score, function score and range of motion had improved (p < 0.001) with no differences between osteoarthritis and inflammatory arthritis. No knee had definite component loosening, although 23 knees had asymptomatic radiolucent lines. Complications comprised 4 infections, 1 patellar pain syndrome and 1 rupture of the patellar tendon. Using any re-revision of the prosthesis as the endpoint, 5-year survival was 95% and 8-year survival was 94%. INTERPRETATION: Concentration of demanding revision knee arthroplasties to a few hands led to good or excellent knee joint knee score results in four-fifths of the patients, and showed good outcome with the TCIII system. In spite of ligamentous laxity, propensity to develop infections, bone destruction and poor general health, patients with inflammatory arthritis had results similar to those with osteoarthritis.

Revision total knee arthroplasty: 1990 through 2002. A review of the Finnish arthroplasty registry.

BACKGROUND: National and regional arthroplasty registries have been used to study the results of primary total knee arthroplasties. The purpose of this paper was to present the results of revision total knee replacements and describe predictors of survival of those replacements, with repeat revision as the end point. METHODS: The nationwide Finnish Arthroplasty Registry included 2637 revision total knee arthroplasties from 1990 through 2002. Survivorship of the revision total knee arthroplasties was analyzed, with repeat revision as the end point. The survivorship analyses comprised evaluations of the proportional hazards assumption followed by calculations of univariate and multivariate statistics and model diagnostics as appropriate. RESULTS: The survival rate following the revision total knee arthroplasties was 95% (95% confidence interval, 94% to 96%) at two years (1874 knees), 89% (95% confidence interval, 88% to 90%) at five years (944 knees), and 79% (95% confidence interval, 78% to 81%) at ten years (141 knees). Multivariate regression analysis showed the most significant predictors of prosthetic survival to be the age of the patient and the life in service of the primary total knee replacement (that is, the time between the primary total knee replacement and the revision). Survivorship was also significantly predicted by the year of the first revision total knee arthroplasty and the reason for the revision. CONCLUSIONS: An age greater than seventy years, revision five years or more after the primary arthroplasty, and absence of patellar subluxation are positive indicators of survival of a revision total knee replacement. We believe that normal aging as well as the deconditioning effect of disease (osteoarthritis and rheumatoid arthritis) and its treatment (primary total knee replacement) may lead to a reduced activity level, which, together with a presumed reluctance to operate on elderly patients, protects against repeat revisions. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.

Health-related quality of life in patients waiting for major joint replacement. A comparison between patients and population controls.

BACKGROUND: Several quality-of-life studies in patients awaiting major joint replacement have focused on the outcomes of surgery. Interest in examining patients on the elective waiting list has increased since the beginning of 2000. We assessed health-related quality of life (HRQoL) in patients waiting for total hip (THR) or knee (TKR) replacement in three Finnish hospitals, and compared patients' HRQoL with that of population controls. METHODS: A total of 133 patients awaiting major joint replacement due to osteoarthritis (OA) of the hip or knee joint were prospectively followed from the time the patient was placed on the waiting list to hospital admission. A sample of controls matched by age, gender, housing and home municipality was drawn from the computerised population register. HRQoL was measured by the generic 15D instrument. Differences between patients and the population controls were tested by the independent samples t-test and between the measurement points by the paired samples t-test. A linear regression model was used to explain the variance in the 15D score at admission. RESULTS: At baseline, 15D scores were significantly different between patients and the population controls. Compared with the population controls, patients were worse off on the dimensions of moving (P < 0.001), sleeping (P < 0.001), sexual activity (P < 0.001), vitality (P < 0.001), usual activities (P < 0.001) and discomfort and symptoms (P < 0.001). Further, psychological factors--depression (P < 0.001) and distress (P = 0.004)--were worse among patients than population controls. The patients showed statistically significantly improved average scores at admission on the dimensions of moving (P = 0.026), sleeping (P = 0.004) and discomfort and symptoms (P = 0.041), but not in the overall 15D score compared with the baseline. In patients, 15D score at baseline (P < 0.001) and body mass index (BMI) (P = 0.020) had an independent effect on patients' 15D score at hospital admission. CONCLUSION: Although patients' HRQoL did not deteriorate while waiting, a consistently worse HRQoL was observed in patients waiting for major joint replacement compared with population controls.