Eight-year trajectories of changes in health-related quality of life in knee osteoarthritis: Data from the Osteoarthritis Initiative (OAI)

The Causal Association between Alcohol, Smoking, Coffee Consumption, and the Risk of Arthritis: A Meta-Analysis of Mendelian Randomization Studies

Objective: To evaluate the genetic causality between alcohol intake, smoking, coffee consumption, and arthritis. Methods: Mendelian randomization (MR) studies with alcohol, smoking, and coffee consumption behaviors as exposures, and osteoarthritis (OA) and rheumatoid arthritis (RA) as outcomes were retrieved from up to July 2023. Two researchers with relevant professional backgrounds independently assessed the quality and extracted data from the included studies. Meanwhile, we applied MR analyses of four lifestyle exposures and five arthritis outcomes (two for OA and three for RA) with gene-wide association study (GWAS) data that were different from the included studies, and the results were also included in the meta-analysis. Statistical analyses were performed using Stata 16.0 and R software version 4.3.1. Results: A total of 84 studies were assessed. Of these, 11 were selected for meta-analysis. As a whole, the included studies were considered to be at a low risk of bias and were of high quality. Results of the meta-analysis showed no significant genetic causality between alcohol intake and arthritis (odds ratio (OR): 1.02 (0.94-1.11)). Smoking and arthritis had a positive genetic causal association (OR: 1.44 (1.27-1.64)) with both OA (1.44 (1.22-1.71)) and RA (1.37 (1.26-1.50)). Coffee consumption and arthritis also had a positive genetic causal association (OR: 1.02 (1.01-1.03)). Results from the subgroup analysis showed a positive genetic causality between coffee consumption and both OA (OR: 1.02 (1.00-1.03)) and RA (OR: 1.56 (1.19-2.05)). Conclusion: There is positive genetic causality between smoking and coffee consumption and arthritis (OA and RA), while there is insufficient evidence for genetic causality between alcohol intake and arthritis.

Net cost savings arising from patient completion of an active self-management program

OBJECTIVE

The objective of this study is to investigate changes in willingness for total knee replacement (TKR) surgery following a randomised control trial (RCT) of an osteoarthritis management program, and to extrapolate orthopaedic cost consequences for private health insurers (PHI).

METHODS

Willingness for surgery data from the RCT is analysed using a multinomial logistic regression model. A decision analytic model is used to conduct a break-even cost benefit analysis of the intervention from a PHI payer perspective. The analysis estimates the minimum probability of progression to surgery required for the intervention to be cost-neutral when considering savings limited to reduced orthopaedic costs. Cost data and orthopaedic pathway probabilities are sourced from payer data.

RESULTS

At baseline, 39% of participants in the treatment and control group were willing for surgery. At 12 months, 16% of participants in the treatment group remained willing for surgery, versus 36% in the control group. Participants in the treatment group are 2.96 (95% CI: 1.01-8.66) times more likely than those in the control group to move from initially willing for surgery, to unsure or unwilling at 12 months. The analysis indicates that the intervention is likely to be cost saving when at least 60% of initially willing participants progress to surgery over a 5-year time horizon.

CONCLUSION

Our study estimates that an education, exercise and weight loss intervention can deliver both improved participant outcomes and a return on investment to Australian PHIs through a reduction in TKR surgery incidence.

Regular walking exercise prior to knee osteoarthritis reduces joint pain in an animal model

We investigated the effect of regular walking exercise prior to knee osteoarthritis (OA) on pain and synovitis in a rat monoiodoacetic acid (MIA)-induced knee OA model. Seventy-one male Wistar rats were divided into three groups: (i) Sedentary + OA, (ii) Exercise + OA, and (iii) Sedentary + Sham groups. The Exercise + OA group underwent a regular treadmill walking exercise at 10 m/min (60 min/day, 5 days/week) for 6 weeks, followed by a 2-mg MIA injection in the right knee. The right knee joint was removed from rats in this group at the end of the 6-week exercise period and at 1 and 6 weeks after the MIA injection. After the 6 weeks of treadmill exercise but before MIA injection, there were no significant differences among the three groups in the pressure pain threshold, whereas at 1 week post-injection, the Exercise + OA group's pressure pain threshold was significantly higher than that in the Sedentary + OA group, and this difference persisted until the end of the experimental period. The histological changes in articular cartilage and subchondral bone revealed by toluidine blue staining showed no difference between the Sedentary + OA and EX + OA groups. The expression levels of interleukin (IL)-4 and IL-10 mRNA in the infrapatellar fat pad and synovium were significantly increased by the treadmill exercise. Significant reductions in the number of CD68-, CD11c-positive cells and IL-1β mRNA expression and an increase in the number of CD206-positive cells were observed at 1 week after the MIA injection in the Exercise + OA group compared to the Sedentary + OA group. These results suggest that regular walking exercise prior to the development of OA could alleviate joint pain through increases in the expressions of anti-inflammatory cytokines in the rat infrapatellar fat pad and synovium.

Trajectories of physical function and quality of life in people with osteoarthritis: results from a 10-year population-based cohort

OBJECTIVE

To identify long-term trajectories of physical function and health-related quality of life (HRQoL) among people with hip and/or knee osteoarthritis (HKOA) and the sociodemographic, lifestyle, and clinical factors associated with different trajectories.

METHODS

Participants with HKOA from the EpiDoC study, a 10-year follow-up (2011-2021) population-based cohort, were considered. Sociodemographic, lifestyle, and clinical variables were collected at baseline in a structured interview and clinical appointment. Physical function and HRQoL were evaluated with the Health Assessment Questionnaire (HAQ) and EuroQoL, respectively, at baseline and the three follow-ups. Group-based trajectory modeling identified physical function and HRQoL trajectories. Multinomial logistic regression analyzed the associations between the covariates of interest and trajectory assignment (p < 0.05).

RESULTS

We included 983 participants with HKOA. We identified three trajectories for each outcome: "consistently low disability" (32.0%), "slightly worsening moderate disability" (47.0%), and "consistently high disability" (21.0%) for physical function; "consistently high HRQoL" (18.3%), "consistently moderate HRQoL" (48.4%) and "consistently low HRQoL" (33.4%) for HRQoL. Age ≥ 75 years, female sex, multimorbidity, and high baseline clinical severity were associated with higher risk of assignment to poorer physical function and HRQoL trajectories. Participants with high education level and with regular physical activity had a lower risk of assignment to a poor trajectory. Unmanageable pain levels increased the risk of assignment to the "consistently moderate HRQoL" trajectory.

CONCLUSION

Although the trajectories of physical function and HRQoL remained stable over 10 years, approximately 70% of people with HKOA maintained moderate or low physical function and HRQoL over this period. Modifiable risk factors like physical activity, multimorbidity and clinical severity were associated with poorer physical function and HRQoL trajectories. These risk factors may be considered in tailored healthcare interventions.

Development of a nomogram prediction model for gait speed trajectories in persons with knee osteoarthritis

To examine heterogeneous trajectories of 8-year gait speed among patients with symptomatic knee osteoarthritis (KOA) and to develop a nomogram prediction model. We analyzed data from the Osteoarthritis Initiative (OAI) assessed at baseline and follow-up over 8 years (n = 1289). Gait speed was measured by the 20-m walk test. The gait speed trajectories among patients with KOA were explored by latent class growth analysis. A nomogram prediction model was created based on multivariable logistic regression. Three gait speed trajectories were identified: the fast gait speed group (30.4%), moderate gait speed group (50.5%) and slow gait speed group (19.1%). Age ≥ 60 years, female, non-white, nonmarried, annual income < $50,000, obesity, depressive symptoms, comorbidity and WOMAC pain score ≥ 5 were risk factors for the slow gait trajectory. The area under the ROC curve of the prediction model was 0.775 (95% CI 0.742-0.808). In the external validation cohort, the AUC was 0.773 (95% CI 0.697-0.848). Heterogeneous trajectories existed in the gait speed of patients with KOA and could be predicted by multiple factors. Risk factors should be earlier identified, and targeted intervention should be carried out to improve physical function of KOA patients.

Characterizing 16-Week Responder Profiles Using Group-Based Trajectory Modeling in Over 4300 Clinical Trial Participants Receiving Pharmaceutical Treatment for Moderate to Severe Osteoarthritis

INTRODUCTION

We sought to identify and characterize distinct responder profiles among osteoarthritis (OA) subjects treated with tanezumab, nonsteroidal anti-inflammatory drugs (NSAIDs), or placebo.

METHODS

Subject-level data were derived from three randomized, double-blind, placebo- or NSAID-controlled trials of tanezumab in subjects with moderate-to-severe OA. Subjects received subcutaneous tanezumab (2.5 mg, n = 1527; 5 mg, n = 1279) every 8 weeks, oral NSAIDs (n = 994) daily, or placebo (n = 513). Group-based trajectory modeling (GBTM, an application of finite mixture statistical modeling that uses response trajectory to identify and summarize complex patterns in longitudinal data) was used to identify subgroups of subjects following similar patterns of response in each treatment arm, based on daily pain intensity scores from baseline through Week 16. We then examined whether subject-related variables were associated with any of the subgroups using multinomial logistic regression.

RESULTS

A three-subgroup/four-inflection point trajectory model was selected based on clinical and statistical considerations. The subgroups were high responders (substantial pain improvement and a large majority of members achieved ≥ 30% improvement before Week 16), medium responders (gradual pain improvement and a majority of members achieved ≥ 30% improvement by Week 16), and non-responders (little to no pain improvement over 16 weeks). Across all treatments, fluctuation in pain intensity in the week prior to treatment was consistently associated with treatment response. Other variables were positively (age, body mass index, days of rescue medication use) or negatively (severity of disease based on Kellgren-Lawrence grading) associated with response but effects were small and/or varied across treatments.

CONCLUSIONS

Across all treatments, GBTM identified three subgroups of subjects that were characterized by extent of treatment response (high, medium, and non-responders). Similar analyses (e.g., grouping of subjects based on response trajectory and identification of subgroup-related variables) in other studies of OA could inform clinical trial design and/or treatment approaches. (NCT02697773; NCT02709486; NCT02528188).

Use of machine learning in osteoarthritis research: a systematic literature review

Objective

The aim of this systematic literature review was to provide a comprehensive and exhaustive overview of the use of machine learning (ML) in the clinical care of osteoarthritis (OA).

Methods

A systematic literature review was performed in July 2021 using MEDLINE PubMed with key words and MeSH terms. For each selected article, the number of patients, ML algorithms used, type of data analysed, validation methods and data availability were collected.

Results

From 1148 screened articles, 46 were selected and analysed; most were published after 2017. Twelve articles were related to diagnosis, 7 to prediction, 4 to phenotyping, 12 to severity and 11 to progression. The number of patients included ranged from 18 to 5749. Overall, 35% of the articles described the use of deep learning And 74% imaging analyses. A total of 85% of the articles involved knee OA and 15% hip OA. No study investigated hand OA. Most of the studies involved the same cohort, with data from the OA initiative described in 46% of the articles and the MOST and Cohort Hip and Cohort Knee cohorts in 11% and 7%. Data and source codes were described as publicly available respectively in 54% and 22% of the articles. External validation was provided in only 7% of the articles.

Conclusion

This review proposes an up-to-date overview of ML approaches used in clinical OA research and will help to enhance its application in this field.

Impact of pain sensitisation on the quality of life of patients with knee osteoarthritis

Objectives

We aim to evaluate the effect on different ways of classifying pain sensitisation on impact and quality of life (QoL) in knee osteoarthritis (KOA).

Methods

We used baseline data from a cohort of consecutive patients with KOA listed for arthroplasty. We collected demographics and number of painful body sites. We measured pressure pain thresholds at the right forearm (PPT_arm). Pain sensitisation was classified using: (1) widespread pain, (2) lowest 10th percentile of PPT_arm and (3) PainDETECT questionnaire ≥13/38. Impact and QoL were assessed using Western Ontario and McMaster Universities Osteoarthritis Index and Short Form-36. Impact and QoL scores in patients with or without pain sensitisation were compared. We evaluated the association of pain sensitisation measures with QoL scores using multivariable regression.

Results

233 patients (80% female, mean age 66 years) included in the analysis; 7.3%, 11.6% and 4.7% were classified as having pain sensitisation by widespread pain, low PPT_arm and PainDETECT criteria, respectively. There was minimal overlap of patients as classified as pain sensitisation phenotype by different measures. Patients with pain sensitisation had poorer QoL compared with those without. Low PPT_arm identified patients with poorer general health, while widespread pain and PainDETECT identified poorer QoL in more psychological domains. There was weak correlation between number of painful body sites and PainDETECT (rho=0.23, p<0.01), but no significant correlation with PPT_arm.

Conclusion

Patients with KOA with pain sensitisation have poorer QoL compared with those without, regardless of classification method. Different criteria defined patients with different pattern of QoL impact.

Patient Characteristics Independently Associated With Knee Osteoarthritis Symptom Severity at Initial Orthopedic Consultation

BACKGROUND/OBJECTIVE

The objective of this study was to identify patient and disease characteristics associated with the symptomatic severity of knee osteoarthritis (OA) at the time of initial knee OA diagnosis by an orthopedist.

METHODS

This medical records review included patients initially diagnosed with knee OA during 2016 to 2017 by a single orthopedic surgeon in a university-based tertiary care setting. All variables were assessed at first OA diagnosis. Main outcomes were subscales of the Knee Injury and Osteoarthritis Outcome Score-Pain, other Symptoms, knee-related quality of life, and function in daily living. Multivariable regression analyses examined the following predictors of main outcomes: sex, race, age, insurance type, body mass index, Charlson comorbidity index, and radiographic OA severity (Kellgren-Lawrence grade).

RESULTS

Of the 559 patients included in the study, most were African American (52.1%), female (71.7%), and had severe radiographic OA (Kellgren-Lawrence grade, 4; 68.7%). Female sex, African American racial/ethnic group, Medicaid insurance, younger age, and severe radiographic OA were independently statistically significantly associated with worse symptoms, pain, and function (p < 0.05 for all). Body mass index and Charlson comorbidity index were not statistically significant predictors of any outcome.

CONCLUSIONS

This study identified disparities in the perception of knee OA problems at initial orthopedist diagnosis based on sex, age, race, insurance, and radiographic OA severity. Because most of these variables are also associated with more rapid progression of OA, identifying their biopsychosocial underpinnings may help determine which interventions are most likely to redress these disparities and delay progression to end-stage knee OA.

Differences in synovial fibrosis relative to range of motion in knee osteoarthritis patients

This study tests if differences exist in the severity of synovial fibrosis between patients undergoing total knee arthroplasty (TKA) for osteoarthritis (OA) to help explain disparate deficits in pre- and postoperative range of motion (ROM) between patient groups. 117 knee OA patients were grouped by women (n = 74) and men (n = 43) or those who self-reported as Black (n = 48) or White (n = 69). ROM was measured pre- and post-TKA. Condyles and synovium collected during TKA were scored histologically for OA severity and synovitis. Fibrosis was measured from picrosirius-stained sections of the synovium. Data were analyzed using Mann-Whitney, parametric, and Spearman's rho tests with alpha at 0.05. We found no significant differences between patient age, BMI, radiographic scores, or deformity type when grouped by sex or race, or between metrics or OA severity when grouped by sex. Notably, higher synovitis was measured in women (p = .039) than men. White patients had greater ROM before (p = 0.46) and after surgery (p = .021) relative to Black patients. Fibrosis, but not OA severity and synovitis scores, for the total patient sample negatively correlated with preoperative (r _s  = -0.330; p = .0003) but not postoperative (r_s  = -0.032; p = .7627) ROM. Black patients manifested more fibrosis than White patients (p = <.0001), without significant differences between sexes. Statement of Clinical Significance: Coupled with histological scoring, measuring perioperative differences in synovial fibrosis against ROM may refine OA classification and justify the in-depth preoperative assessment of the knee as a whole. Such individualized analyses could guide personalized strategies to relieve symptomatic OA when TKA is not readily accessible and promote equitable TKA outcomes.

Influence of Anxiety/Depression, Age, Gender and ASA on 1-Year Follow-Up Outcomes Following Total Hip and Knee Arthroplasty in 5447 Patients

Introduction: There are many factors influencing the outcome after total joint arthroplasty (TJA). In particular, patient-related factors such as age, gender, ASA (American Society of Anesthesiologists), or preoperative anxiety/depression have become increasingly important. The aim of this study was to examine the association of these parameters with 1-year postoperative outcomes after total knee and total hip arthroplasty (TKA, THA). Methods: A retrospective cohort of 5447 TJA patients was evaluated by pre- and postoperative analysis of EQ-5D, EQ-VAS and WOMAC Score. Furthermore, major focus was put on the association between age, gender, ASA, preoperative anxiety/depression and outcome parameters. Results: 53.3% (2903/5447) of all patients were identified with anxiety/depression at time of surgery. In the analysis, patients without anxiety/depression showed statistically significantly (p < 0.05) better EQ-5D, EQ-VAS and WOMAC scores. In addition, patients with ASA 2 or 3 and age over 70 years showed statistically significantly (p < 0.01) worse EQ-5D and WOMAC scores. Gender did not influence the postoperative EQ-5D and WOMAC results, but men had significantly better EQ-VAS scores than women in this study. Conclusion: Preoperative anxiety/depression symptoms show worse clinical outcomes 1 year postoperatively after TJA. Other outcome-influencing factors are higher age and ASA 2 or 3. In the future, such patients should be identified, and as far as applicable, a treatment of anxiety/depression or comorbidities should be implemented preoperatively of the surgical procedure to improve clinical outcomes.

Improving Patient Outcomes Following Total Knee Arthroplasty: Identifying Rehabilitation Pathways Based on Modifiable Psychological Risk and Resilience Factors

Total knee arthroplasty (TKA) is a commonly implemented elective surgical treatment for end-stage osteoarthritis of the knee, demonstrating high success rates when assessed by objective medical outcomes. However, a considerable proportion of TKA patients report significant dissatisfaction postoperatively, related to enduring pain, functional limitations, and diminished quality of life. In this conceptual analysis, we highlight the importance of assessing patient-centered outcomes routinely in clinical practice, as these measures provide important information regarding whether surgery and postoperative rehabilitation interventions have effectively remediated patients’ real-world “quality of life” experiences. We propose a novel precision medicine approach to improving patient-centered TKA outcomes through the development of a multivariate machine-learning model. The primary aim of this model is to predict individual postoperative recovery trajectories. Uniquely, this model will be developed using an interdisciplinary methodology involving non-linear analysis of the unique contributions of a range of preoperative risk and resilience factors to patient-centered TKA outcomes. Of particular importance to the model’s predictive power is the inclusion of a comprehensive assessment of modifiable psychological risk and resilience factors that have demonstrated relationships with TKA and other conditions in some studies. Despite the potential for patient psychological factors to limit recovery, they are typically not routinely assessed preoperatively in this patient group, and thus can be overlooked in rehabilitative referral and intervention decision-making. This represents a research-to-practice gap that may contribute to adverse patient-centered outcomes. Incorporating psychological risk and resilience factors into a multivariate prediction model could improve the detection of patients at risk of sub-optimal outcomes following TKA. This could provide surgeons and rehabilitation providers with a simplified tool to inform postoperative referral and intervention decision-making related to a range of interdisciplinary domains outside their usual purview. The proposed approach could facilitate the development and provision of more targeted rehabilitative interventions on the basis of identified individual needs. The roles of several modifiable psychological risk and resilience factors in recovery are summarized, and intervention options are briefly presented. While focusing on rehabilitation following TKA, we advocate for the broader utilization of multivariate prediction models to inform individually tailored interventions targeting a range of health conditions.

Ethnic differences in the prevalence, socioeconomic and health related risk factors of knee pain and osteoarthritis symptoms in older Malaysians

Knee pain is often underreported, underestimated and undertreated. This study was conducted to estimate the prevalence, burden and further identify socioeconomic factors influencing ethnic differences in knee pain and symptoms of OA among older adults aged 55 years and over in Greater Kuala Lumpur (the capital city of Malaysia). The sample for the Malaysian Elders Longitudinal Research (MELoR) was selected using stratified random sampling, by age and ethnicity from the electoral rolls of three parliamentary constituencies. Information on knee pain was available in 1226 participants, mean age (SD) 68.96 (1.57) years (409 Malay, 416 Chinese, 401 Indian). The crude and weighted prevalence of knee pain and self-reported knee OA symptoms were 33.3% and 30.8% respectively. There were significant ethnic differences in knee pain (crude prevalence: Malays 44.6%, Chinese 23.5% and Indians 31.9%, p<0.001). The presence of two or more non-communicable diseases (NCD) attenuated the increased risk of knee pain among the ethnic Indians compared to the ethnic Chinese. The prevalence of knee pain remained significantly higher among the ethnic Malays after adjustment for confounders. While the prevalence of knee pain in our older population appears similar to that reported in other published studies in Asia, the higher prevalence among the ethnic Malays has not previously been reported. Further research to determine potential genetic susceptibility to knee pain among the ethnic Malays is recommended.