Better functional and similar pain outcomes in osteoarthritis compared to rheumatoid arthritis after primary total knee arthroplasty: a cohort study

An interdisciplinary perspective on peripheral drivers of pain in rheumatoid arthritis

Pain is one of the most debilitating symptoms of rheumatoid arthritis (RA), and yet remains poorly understood, especially when pain occurs in the absence of synovitis. Without active inflammation, experts most often attribute joint pain to central nervous system dysfunction. However, advances in the past 5 years in both immunology and neuroscience research suggest that chronic pain in RA is also driven by a variety of abnormal interactions between peripheral neurons and mediators produced by resident cells in the local joint environment. In this Review, we discuss these novel insights from an interdisciplinary neuro-immune perspective. We outline a potential working model for the peripheral drivers of pain in RA, which includes autoantibodies, resident immune and mesenchymal cells and their interactions with different subtypes of peripheral sensory neurons. We also offer suggestions for how future collaborative research could be designed to accelerate analgesic drug development.

Total Joint Arthroplasty in the Patient with Inflammatory Arthritis: A Review

Inflammatory arthritis is a family of conditions including rheumatoid arthritis, juvenile inflammatory arthritis, and spondyloarthropathies affecting both the large and small joints. Total joint arthroplasty is commonly used for surgical management of end-stage disease. Preoperative and postoperative considerations as well as perioperative medical management and intraoperative treatment of patients with inflammatory arthritis undergoing total joint arthroplasty are reviewed. Although individualized, multidisciplinary approaches to treatment are necessary due to the complex nature of the disease and the varying levels of severity, patients generally have favorable outcomes with respect to pain scores and functional outcomes.

Postoperative function of patients with rheumatoid arthritis after total knee arthroplasty in the last decade was comparable in the unadjusted cohort but inferior in the propensity score matched cohort with that of patients with osteoarthritis

BACKGROUND

The perioperative pain and function of total knee arthroplasty (TKA) in patients with rheumatoid arthritis (RA) approach those in patients with osteoarthritis (OA). This study aimed to evaluate whether the clinical outcomes, especially functions, of patients with RA reached those of OA, utilizing a background-matched cohort.

METHODS

Patients who underwent TKA between 2013 and 2021 were enrolled. Preoperative and minimum 2-year postoperative scores, specifically the Original Knee Society Score (OKSS) and New Knee Society Score (2011KSS), between RA and OA were compared. Clinical assessments were performed on unadjusted and propensity-score matched cohorts, ensuring age, sex, body mass index, and valgus deformity rate parity.

RESULTS

In an unadjusted cohort involving 98 patients with RA and 560 patients with OA, patients with RA demonstrated inferior preoperative OKSS-Function Score (FS) but similar postoperative functional scores to OA patients. In the matched cohort of 83, patients with RA displayed lower preoperative OKSS- FS (median difference: 20, P < 0.001) and 2011KSS functional activities (difference: 9, P = 0.01) beyond minimum clinically important differences than patients with OA. Patients with RA improved more in OKSS-FS, yielding no postoperative difference compared with patients with OA. However, postoperative 2011KSS functional activities remained lower in patients with RA (difference: 9.5, P = 0.03), especially in advanced functions, than in those with OA.

CONCLUSION

Postoperative function showed no difference between patients with RA and OA in the unadjusted cohort; within the background-matched cohort, postoperative function, especially advanced function, was inferior in patients with RA to those with OA.

Global mapping of institutional and hospital-based (Level II-IV) arthroplasty registries: a scoping review

PURPOSE

Four joint arthroplasty registries (JARs) levels exist based on the recorded data type. Level I JARs are national registries that record primary data. Hospital or institutional JARs (Level II-IV) document further data (patient-reported outcomes, demographic, radiographic). A worldwide list of Level II-IV JARs must be created to effectively assess and categorize these data.

METHODS

Our study is a systematic scoping review that followed the PRISMA guidelines and included 648 studies. Based on their publications, the study aimed to map the existing Level II-IV JARs worldwide. The secondary aim was to record their lifetime, publications' number and frequency and recognise differences with national JARs.

RESULTS

One hundred five Level II-IV JARs were identified. Forty-eight hospital-based, 45 institutional, and 12 regional JARs. Fifty JARs were found in America, 39 in Europe, nine in Asia, six in Oceania and one in Africa. They have published 485 cohorts, 91 case-series, 49 case-control, nine cross-sectional studies, eight registry protocols and six randomized trials. Most cohort studies were retrospective. Twenty-three per cent of papers studied patient-reported outcomes, 21.45% surgical complications, 13.73% postoperative clinical and 5.25% radiographic outcomes, and 11.88% were survival analyses. Forty-four JARs have published only one paper. Level I JARs primarily publish implant revision risk annual reports, while Level IV JARs collect comprehensive data to conduct retrospective cohort studies.

CONCLUSIONS

This is the first study mapping all Level II-IV JARs worldwide. Most JARs are found in Europe and America, reporting on retrospective cohorts, but only a few report on studies systematically.

Meta-analysis of outcomes after total knee arthroplasty in patients with rheumatoid arthritis and osteoarthritis

The purpose of this study was to compare the difference in functional scores and the incidence of complications after TKA between RA and osteoarthritis. The PubMed, MedLine, The Cochrane Library, Embase and Web of Science databases were searched for all clinical studies up to 15 March 2023 comparing outcomes after total knee replacement in patients with RA and OA, with two review authors independently screening the literature. A total of 7,820,115 (knee-counted) cases were included in 34 studies. The results of meta-analysis showed that the scores of the RA group were lower than that of the osteoarthritis group in the postoperative knee joint score [MD=-2.72,95%CI(-5.06,-0.38),P=0.02] and the postoperative knee joint function score [MD=-11.47,95%CI(-16.55,-6.39),P<0.00001], and the difference was statistically significant. The incidence of deep venous thrombosis (OR=0.84,95%CI(0.79,0.90),P<0.00001) and pulmonary embolism (OR=0.84,95%CI(0.78,0.91),P<0.00001) were significantly lower in RA than in osteoarthritis (P<0.00001). Compared with patients with osteoarthritis, patients with rheumatoid arthritis have lower knee society scores and functional scores after total knee arthroplasty, and a higher risk of prosthetic infection, loosening, and revision, but TKA can still effectively reduce pain in RA patients, Improve function and quality of life without increasing the risk of lower extremity venous thrombosis and pulmonary embolism. Therefore, total knee replacement can be used as a treatment option for patients with rheumatoid arthritis who have not responded to conservative treatment. Patients should fully understand the benefits and possible risks of total knee replacement and develop an individualized treatment plan.

Inferior outcomes of primary total knee arthroplasty in patients with rheumatoid arthritis compared to patients with osteoarthritis

PURPOSE

The purpose of this study was to compare the functional outcomes, activity levels, mortalities, implant survival rates, and complications of total knee arthroplasty (TKA) in patients with rheumatoid arthritis (RA) with those in patients with osteoarthritis (OA) over a minimum 10-year follow-up period.

METHODS

Between January 2007 and December 2009, 90 TKAs performed in 57 patients with RA (RA group) were retrospectively reviewed and matched with a control group of 180 TKAs performed in 114 patients with OA. The functional outcomes (Knee Society Score), activity levels (Koval grade), mortalities, implant survival rates, and complications were compared between the two groups with a minimum 10-year follow-up period. The mean follow-up periods were 12.3 years in the RA group and 12.6 years in the OA group.

RESULTS

The mean Knee Society knee scores in the RA and OA groups improved from 37.7 ± 5.4 to 38.2 ± 5.3 preoperatively to 72.9 ± 22.8 to 83.1 ± 11.0 points, respectively, at the final follow-up (p < 0.05). At the final follow-up, 38 of 48 (79.2%) in the RA group and 105 of 109 (96.3%) in the OA group (p < 0.05) were outdoor ambulatory patients. The cumulative mortality rates in the RA and OA groups were 15.8% (9/57) and 4.4% (5/114) (p < 0.05) at the final follow-up, respectively. Kaplan-Meier survivorship analysis with revision of either component as an endpoint in the RA and OA groups estimated 94.4% and 98.3% chance of survival for 10 years, respectively.

CONCLUSION

TKA in patients with RA had worse functional outcomes and higher mortality over a minimum 10-year follow-up period, compared with TKA in patients with OA.

LEVEL OF EVIDENCE

IV.

Outcomes of Total Knee Arthroplasty in Patients With Rheumatoid Arthritis

The purpose of this study was to examine current literature regarding the efficacy of total knee arthroplasty for patients with rheumatoid arthritis. Studies that assessed total knee arthroplasty outcomes in patients with rheumatoid arthritis were identified on MEDLINE from January 2009 to November 2018. All 4 studies that assessed knee pain and 9 of 11 studies that assessed knee function noted significant improvement in average knee score. However, between 10% and 47% of patients had significant knee pain at final follow-up. Total knee arthroplasty provides significant improvement in knee pain and function for patients with rheumatoid arthritis. However, the rates of postoperative pain vary widely. [Orthopedics. 2021;44(5):e626-e632.].

Quality of life and life-space mobility after total knee arthroplasty in patients with rheumatoid arthritis: a pilot case-controlled study

[Purpose] The purpose of this study was to identify factors inhibiting improvement in the quality of life after total knee arthroplasty in patients with rheumatoid arthritis. [Participants and Methods] This was a pilot case-control study. The sample comprised of five participants with rheumatoid arthritis and 11 participants with osteoarthritis, who underwent total knee arthroplasty. We compared the groups in terms of physical function, walking ability, Japanese Knee Osteoarthritis Measure, and Life-Space Assessment. Measurements were taken before surgery and at four weeks and five months post-surgery. All patients underwent rehabilitation for five months postoperatively, first as inpatients, and then as outpatients after discharge. [Results] In the period from 4 weeks to 5 months post-surgery, physical function improved similarly in both groups in terms of muscle strength and walking ability. Despite the patients with rheumatoid arthritis being younger, their self-health assessment score by the Japanese Knee Osteoarthritis Measure and measures of life-space mobility by Life-Space Assessment were lower. [Conclusion] It is important to consider exercise therapy, and gait instruction to alleviate anxiety about health status and improve the quality of life and life-space mobility in patients with rheumatoid arthritis who undergo total knee arthroplasty.

Better clinical outcome of total knee arthroplasty for rheumatoid arthritis with perioperative glucocorticoids and disease-modifying anti-rheumatic drugs after an average of 11.4-year follow-up

Background

Previous evidence suggested that perioperative anti-rheumatic therapy for patients receiving total knee arthroplasty (TKA) helped improve postoperative rehabilitation for rheumatoid arthritis (RA), yet long-term effects and outcomes of perioperative drug therapy in TKA presently remain unclear. This study investigated whether perioperative treatment with glucocorticoids (GC) and disease-modifying anti-rheumatic drugs (DMARDs) can improve clinical outcomes for patients with RA undergoing TKA.

Methods

Patients between January 2000 and December 2011 were allocated into three groups based on perioperative drug therapy: A, control group (no GC or DMARDs), B, DMARD group (DMARDs given without GC), and C, co-therapy group (DMARDs plus GC). The patients were followed up for average 11.4 years. Baseline characteristics, pre- and post-operative Hospital for Special Surgery score (HSS), laboratory parameters, and complications were recorded by follow-up.

Results

Fifty-six RA patients undergoing 91 TKAs were included in this study. Patients who received perioperative GC with DMARDs (group C) achieved larger/increased range of motion (ROM) (C:122.17 vs A:108.31 vs B:108.07, p = 0.001, partial eta squared (η² p) = 0.18) at 1 year, better HSS score (C, 83.01 vs A, 79.23 vs B, 77.35, p = 0.049, η² p = 0.067), pain relief (C, 1.09 vs A, 1.17 vs B, 1.75, p = 0.02, η² p = 0.094), and ROM (C, 130.81 vs A, 112.82 vs B, 113.58, p = 0.001, η²p = 0.142) at latest follow-up comparing with the other treatment groups. No differences were noted in laboratory tests, blood loss, volume of transfusion, or complications among groups.

Conclusions

Compared with the other perioperative anti-rheumatic treatments, the combination of GC and DMARDs results in improved HSS score, better function, larger range of motion, and reduced postoperative pain for TKA patients with RA in the long term. Further investigation is warranted to look for a better understanding of more specific medication effects and strike a good balance between the benefits and complications for long-term pharmacotherapy.

Rheumatoid Arthritis Flares After Total Hip and Total Knee Arthroplasty: Outcomes at One Year

OBJECTIVE

Most patients with rheumatoid arthritis (RA) undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) have active RA and report postoperative flares; whether RA disease activity or flares increase the risk of worse pain and function scores 1 year later is unknown.

METHODS

Patients with RA were enrolled before THA/TKA. Patient-reported outcomes, including the Hip disability and Osteoarthritis Outcome Score (HOOS)/Knee Injury and Osteoarthritis Outcome Score (KOOS) and physician assessments of disease characteristics and activity (Disease Activity Score in 28 joints [DAS28] and Clinical Disease Activity Index), were collected before surgery. Patient-reported outcomes were repeated at 1 year. Postoperative flares were identified using the RA Flare Questionnaire weekly for 6 weeks and were defined by concordance between patient report plus physician assessment. We compared baseline characteristics and HOOS/KOOS scores using 2-sample t-test/Wilcoxon's rank sum test as well as chi-square/Fisher's exact tests. We used multivariate linear and logistic regression to determine the association of baseline characteristics, disease activity, and flares with 1-year outcomes.

RESULTS

One-year HOOS/KOOS scores were available for 122 patients (56 with THA and 66 with TKA). Although HOOS/KOOS pain was worse for patients who experienced a flare within 6 weeks of surgery, absolute improvement was not different. In multivariable models, baseline DAS28 predicted 1-year HOOS/KOOS pain and function; each 1-unit increase in DAS28 worsened 1-year pain by 2.41 (SE 1.05; P = 0.02) and 1-year function by 4.96 (SE 1.17; P = 0.0001). Postoperative flares were not independent risk factors for pain or function scores.

CONCLUSION

Higher disease activity increased the risk of worse pain and function 1 year after arthroplasty, but postoperative flares did not.

Polymyositis has minimal effect on primary total knee or hip arthroplasty outcomes

To assess whether polymyositis is associated with more complications and higher healthcare utilization after total knee or hip arthroplasty (TKA/THA). Using the 1998-2014 U.S. National Inpatient Sample data, we performed multivariable-adjusted logistic regression analyses to assess the association of polymyositis with in-hospital complications (implant infection, revision, transfusion, mortality) and healthcare utilization (hospital charges, length of hospital stay, discharge to non-home setting), controlling for important covariates and confounders. Sensitivity analyses additionally adjusted the main models for hospital location/teaching status, bed size, and region. Of the 4,116,485 THAs and 8,127,282 TKAs, 853 people with polymyositis had THAs (0.02%) and 1038 had TKAs (0.01%). In multivariable-adjusted analyses, compared to people without polymyositis, people with polymyositis had similar odds of hospital charges above the median, hospital stay > 3 days, and discharge to non-home setting post-TKA and post-THA. Polymyositis was associated with significantly lower odds ratio (OR; 95% confidence interval [CI]) of revision and mortality post-THA, 0.44 (0.36, 0.55) and 0.63 (0.48, 0.84), but not post-TKA, 2.98 (0.47, 18.95) and 4.40 (0.61, 31.64), respectively. Findings from the main analyses were confirmed in the sensitivity analyses. People with polymyositis had no increase in healthcare utilization post-TKA/THA. A lower revision rate and mortality post-THA in people with polymyositis need further confirmation. Study findings should reassure the key stakeholders about the benefits of TKA/THA, including people with polymyositis.

Association of Early Postoperative Pain Trajectories With Longer-term Pain Outcome After Primary Total Knee Arthroplasty

IMPORTANCE

Studies to date have not comprehensively examined pain experience after total knee arthroplasty (TKA). Discrete patterns of pain in this period might be associated with pain outcomes at 6 to 12 months after TKA.

OBJECTIVES

To examine patterns of individual post-TKA pain trajectories and to assess their independent associations with longer-term pain outcome after TKA.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study combined data from a national US TKA cohort with ancillary pain severity data at 2 weeks and 8 weeks after the index TKA using a numeric rating scale. All participants received primary, unilateral TKA within the Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement (FORCE-TJR) national network of community sites in 22 states or at the lead site (University of Massachusetts Medical School). Participants had a date of surgery between May 1, 2013, and December 1, 2014. The data analysis was performed between January 13, 2015, and July 5, 2016.

EXPOSURES

Pain trajectories in the postoperative period (8 weeks).

MAIN OUTCOMES AND MEASURES

Index knee pain at 6 months after TKA using the Knee Injury and Osteoarthritis Outcome Score (KOOS) pain scale. Group-based trajectory methods examined the presence of pain trajectories in the postoperative period (8 weeks) and assessed whether trajectories were independently associated with longer-term pain (6 months).

RESULTS

The cohort included 659 patients who underwent primary TKA with complete data at 4 points (preoperative, 2 weeks, 8 weeks, and 26 weeks). Their mean (SD) age was 67.1 (8.0) years, 64.5% (425 of 659) were female, the mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 30.77 (5.66), 94.5% (613 of 649) were white, and the mean (SD) preoperative 36-Item Short Form Health Survey physical component summary and mental component summary scores were 34.1 (8.2) and 53.8 (11.4), respectively. Two pain trajectory subgroups were identified at 8 weeks after TKA: patients who experienced fast pain relief in the first 8 weeks after TKA (fast pain responders, composing 72.4% [477 of 659] of the sample) and patients who did not (slow pain responders, composing 27.6% [182 of 659] of the sample). After adjusting for patient factors, the pain trajectory at 8 weeks after TKA was independently associated with the mean KOOS pain score at 6 months, with a between-trajectory difference of -11.3 (95% CI, -13.9 to -8.7).

CONCLUSIONS AND RELEVANCE

The trajectory among slow pain responders at 8 weeks after surgery was independently associated with improved but greater persistent index knee pain at 6 months after TKA compared with that among fast pain responders. Early identification of patients with a trajectory of slow pain response at 8 weeks after TKA may offer an opportunity for interventions in the perioperative period to potentially improve the long-term pain outcomes after TKA.

Rheumatoid Arthritis Patients Achieve Better Satisfaction but Lower Functional Activities as Compared to Osteoarthritis Patients After Total Knee Arthroplasty

BACKGROUND

Recently, poor patient satisfaction after total knee arthroplasty (TKA) has gained attention mainly in osteoarthritis (OA) patients; however, satisfaction after TKA remains to be understood in rheumatoid arthritis (RA) patients. This study aimed to examine satisfaction and function after RA TKA using patient-reported outcome measures and to compare the results with those of OA-TKA.

METHODS

This study enrolled 534 TKAs of 501 patients consisting of 75 TKAs of 70 RA patients and 459 TKAs of 431 OA patients. Data of patient-reported outcome measures such as new Knee Society Score 2011, Pain Catastrophizing Scale, and Pain DETECT Score were collected at 2 years. Multiple regression analysis was performed with Knee Society Score satisfaction score set as a dependent variable in order to clarify factors affecting patient satisfaction. Principle component analysis was performed, and satisfaction and function components were compared between RA and OA.

RESULTS

All activity scores were significantly lower in RA TKA than in OA TKA, whereas the range of motion and patient satisfaction scores were significantly better in RA TKA than in OA TKA. Scores for symptom, expectation, basic activity, and discretional activity positively affected patient satisfaction (P < .001), while Pain Catastrophizing Scale negatively did (P = .021). Importantly, diagnosis of RA itself pushed up the patient satisfaction score by 1.5 points. Principle component analysis revealed that RA TKA achieved significantly higher satisfaction component (P = .001), but lower function component (P < .0001) compared to OA TKA.

CONCLUSION

Patient satisfaction was better but functional activity was lower in RA than in OA. As poor functional activity was evident preoperatively in RA patients, to improve functional outcome should be future challenge for RA TKA.

Flares in Patients with Rheumatoid Arthritis after Total Hip and Total Knee Arthroplasty: Rates, Characteristics, and Risk Factors

OBJECTIVE

Rates of total knee arthroplasty (TKA) and total hip arthroplasty (THA) remain high for patients with rheumatoid arthritis (RA), who are at risk of flaring after surgery. We aimed to describe rates, characteristics, and risk factors of RA flare within 6 weeks of THA and TKA.

METHODS

Patients with RA were recruited prior to elective THA and TKA surgery and prospectively followed. Clinicians evaluated RA clinical characteristics 0-2 weeks before and 6 weeks after surgery. Patients answered questions regarding disease activity including self-reported joint counts and flare status weekly for 6 weeks. Per standard of care, biologics were stopped before surgery, while glucocorticoids and methotrexate (MTX) were typically continued. Multivariable logistic regression was used to identify baseline characteristics associated with postsurgical RA flares.

RESULTS

Of 120 patients, the mean age was 62 years and the median RA duration 14.8 years. Ninety-eight (82%) met 2010/1987 American College of Rheumatology/European League Against Rheumatism criteria, 53 (44%) underwent THA (and the rest TKA), and 61 (51%) were taking biologics. By 6 weeks, 75 (63%) had flared. At baseline, flarers had significantly higher disease activity (as measured by the 28-joint Disease Activity Score), erythrocyte sedimentation rate, C-reactive protein, and pain. Numerically more flarers used biologics, but stopping biologics did not predict flares, and continuing MTX was not protective. A higher baseline disease activity predicted flaring by 6 weeks (OR 2.12, p = 0.02).

CONCLUSION

Flares are frequent in patients with RA undergoing arthroplasty. Higher baseline disease activity significantly increases the risk. Although more patients stopping biologics flared, this did not independently predict flaring. The effect of early postsurgery flares requires further study.

Predictors of Patient-Reported Outcomes of Total Joint Arthroplasty in a Developing Country

BACKGROUND

In response to the growing burden of joint disease, developing countries are starting to create their own total joint arthroplasty (TJA) programs. To date, there has been limited research on predictors of TJA outcomes in a developing country. This investigation uses patient-reported outcome measures collected by a medical mission to assess predictors of TJA outcomes in the Dominican Republic.

METHODS

Baseline and postoperative information from 156 of the mission's recipients of hip and knee TJA was used. Demographics were abstracted from clinical notes, and self-reported pain and functional status were assessed using Western Ontario and McMaster University Osteoarthritis Index and Short-Form 36 measures. Bivariate analysis identified variables to include in multivariable regression models of factors associated with function and pain outcomes and improvement in these domains 1 or 2 years postoperatively.

RESULTS

The cohort had a mean age of 61.3 years, 82% were female, 79% had total knee arthroplasty, and 42% of the procedures were bilateral. In multivariate analyses, at P < .05, male sex, better preoperative function, and use of bilateral procedure were associated with better functional outcome. Male sex and worse preoperative pain were associated with better pain outcome. Worse preoperative pain and function, as well as bilateral surgery were associated with greater improvement in function. Additionally, a greater number of bothersome joints was associated with greater pain reduction.

CONCLUSION

Our findings of better follow-up pain scores among patients with worse pain preoperatively and better functional improvement among those undergoing bilateral replacements contrast with study results from developed countries. The explanations for these observations merit further study.

Patient Endorsement of the Outcome Measures in Rheumatology (OMERACT) Total Joint Replacement (TJR) clinical trial draft core domain set

BACKGROUND

A patient- and surgeon-Delphi-derived Outcome Measures in Rheumatology (OMERACT) draft core domain set for total joint arthroplasty (TJR) trials was recently developed. Our objective was to obtain further patient stakeholder endorsement of draft core domain set for TJR clinical trials.

METHODS

We surveyed two patient groups: (1) OMERACT patient partners; and (2) patients who had undergone hip or knee TJR. Patients received an introductory email with explanations about the core domain set and instructions to rate the core domains, i.e., important aspects, of OMERACT TJR clinical trial draft core domain set. Rating was on a nominal scale, where 1-3 indicated a domain of limited importance, 4-6 an important, but not critical domain, and 7-9 a critical domain. We used Mann-Whitney test (a non-parametric test) to compare the distribution of ratings between the two groups.

RESULTS

Thirty one survey participants from the OMERACT patient partner group and 118 knee/hip TJR patients responded with response rates of 66 and 80%, respectively. Majority of the survey respondents were female, 87 vs. 53%, and were 55 years or older, 57 vs. 94%. Median (interquartile range [IQR]) scores for six core domains by OMERACT and knee/hip TJR patient groups were, respectively: pain, 8 [8, 9] and 9 [8, 9]; function, 9 [8, 9] and 9 [8, 9]; patient satisfaction, 8 [8, 9] and 8 [7, 9]; revision surgery, 7 [7, 8] and 7 [5, 9]; adverse events, 8 [7, 9] and 8 [6, 9]; and death, 9 [6, 9] and 9 [4, 9]. No statistically significant differences in rating were noted for any of the six core domains between the two groups (p ≥ 0.31). Among the additional domains, ratings for patient participation did not differ by group (p = 0.98), but ratings for cost were significantly different (p = 0.005). Patients provided qualitative feedback regarding core domains, and did not propose any modifications to the draft core domain set.

CONCLUSIONS

Two separate patient stakeholder groups endorsed the OMERACT TJR draft core domain set for TJR trials.

Patients with Rheumatoid Arthritis have Similar Excellent Outcomes after Total Knee Replacement Compared with Patients with Osteoarthritis

OBJECTIVE

Although new treatments for rheumatoid arthritis (RA) are extremely effective in preventing disease progression, rates of total knee replacement (TKR) continue to rise. The ongoing need for TKR is problematic, especially as functional outcomes in patients with RA have been reported to be worse than in patients with osteoarthritis (OA). The purpose of this study is to assess pain, function, and quality of life 2 years after TKR in contemporary patients with RA compared with patients with OA.

METHODS

Primary TKR cases enrolled between May 1, 2007 and July 1, 2010 in a single institution TKR registry were eligible for this study. Validated RA cases were compared with OA at baseline and at 2 years.

RESULTS

We identified 4456 eligible TKR, including 136 RA. Compared with OA, RA TKR had significantly worse preoperative Western Ontario and McMaster Universities Osteoarthritis Index pain (55.9 vs 46.6, p < 0.0001) and function (58.7 vs 47.3, p < 0.0001); however, there were no differences at 2 years. Within RA, there was no difference for patients who were treated with biologic disease-modifying antirheumatic drugs versus those who did not in pain (p = 0.41) or function (p = 0.39) at 2 years. In a multivariate regression, controlling for multiple potential confounders, there was no independent association of RA with 2-year pain (p = 0.18) or function (p = 0.71). Satisfaction was high for both RA and OA.

CONCLUSION

Patients with RA undergoing primary TKR have excellent 2-year outcomes, comparable with OA, in spite of worse preoperative pain and function. In this contemporary cohort, RA is not an independent risk factor for poor outcomes.

[Recovery of knee function after total knee arthroplasty: different outcomes in patients with osteoarthritis and rheumatoid arthritis]

INTRODUCTION

Following total knee arthroplasty (TKA), no investigations have been published to assess possible differences between rheumatoid arthritic (RA) and osteoarthritic (OA) patients with respect to patient-reported outcome measures of knee function.

PATIENTS AND METHODS

A cohort of 128 consecutively operated patients (OA: n = 92, RA: n = 36) treated with bicondylar TKA was included in this prospective, clinical study. Knee function was assessed preoperatively and at 6 and 12 months after TKA, using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Oxford Knee Score (OKS).

RESULTS

Both OKS and KOOS revealed a statistically significant improvement for OA and RA patients at 6 and 12 months after surgery, as compared to the preoperative status. The results of the OKS at 6 and 12 months did not show a further improvement for either group. The KOOS, however, revealed an additional improvement between 6 and 12 months for the osteoarthritis group, regarding the total score and all subscores, but not for the RA subgroup.

CONCLUSION

Functional recovery after TKA improves in the second 6 months after surgery in OA patients, but not in RA patients, when knee function is exclusively assessed with patient-reported outcome measures.