Objective:Knee osteoarthritis (OA) and type 2 diabetes (T2D) commonly coexist, but their combined impact on health-related quality of life (HRQoL) remains understudied. We assessed the association between symptomatic knee OA and HRQoL in individuals with T2D and explored potential explanations. Design:We conducted a secondary analysis of a cross-sectional study of individuals with T2D. Symptomatic knee OA was defined using NICE criteria (age ≥45 years, activity-related knee pain, morning stiffness ≤30 min; no inflammatory arthritis). HRQoL (EQ-VAS, 0-100), sleep disturbance (PROMIS Sleep Disturbance 4a), depressed symptoms (PROMIS Depression 8b), fatigue (PROMIS Fatigue 4a), and walking limitation (Health Assessment Questionnaire) were assessed via questionnaire. Linear regression modeled associations between knee OA and HRQoL, adjusting for age, gender, BMI, education, and comorbidities. The explanatory effects of sleep, mood, and mobility were assessed via further sequential adjustment. Results:We included 341 participants: mean age 66.4 years, 51.9 % female, 29.0 % had knee OA. Participants with T2D and knee OA reported lower HRQoL, greater sleep disturbance, fatigue, depressive symptoms, and walking limitations than those without knee OA. Knee OA was associated with lower HRQoL (β = -11.96; 95 % CI: -16.59 to -7.32) in the unadjusted analysis. Adjustment for confounders partially attenuated this effect (β = -8.33; 95 % CI: -12.72 to -3.94). Further adjustment for sleep, mood, and walking limitations fully attenuated the association. Conclusion:Symptomatic knee OA is strongly associated with impaired HRQoL in T2D, explained by sleep disturbance, low mood, and mobility limitation. Integrated care addressing OA may improve quality of life in this population.

Objectives Sex disparities exist in the receipt of total knee arthroplasty (TKA) for osteoarthritis (OA), with females disproportionately less likely to undergo surgery. Understanding the reasons for this gap is critical for equitable health care delivery. Lower willingness to undergo TKA, a strong predictor of future surgery, may explain lower rates of TKA referral among females vs males. However, it is unknown whether surgeons’ recommendations for TKA differ by patient sex among those who express TKA willingness at orthopedic consultation. We examined the inter-relationships of patient sex and TKA willingness on surgeon’s TKA recommendations. Methods This cross-sectional study included individuals with knee OA referred for TKA to 2 centralized hip/knee centers in Alberta, Canada. A pre-consultation questionnaire assessed patients’ TKA need, readiness, willingness, importance of various TKA outcomes, health status and contextual factors. Using multivariable logistic regression, we examined the determinants of TKA “definite willingness” (yes/no) in females and males, separately, and in a combined model, the odds of a female vs a male being “definitely willing”, adjusting for these factors. Using multivariable log Poisson regression adjusting for clustering by surgeon and potential confounders, we examined the adjusted risk ratios (RRs) for receipt of a TKA recommendation associated with patient sex and willingness. Results Of 2,064 participants, 58.6% were female with mean age (SD) 65.7 (9.2) years. Compared with males, females had worse knee symptoms, were more likely to report their symptoms as unacceptable and to have received non-surgical therapies. In both sexes, definite TKA willingness was associated with greater knee pain, unacceptable symptoms, and expectations for TKA regarding pain relief and activities. Adjusting for these factors, females were less likely than males to be “definitely willing” (adjusted OR 0.61, 95% CI 0.46, 0.82). The risk ratio for receiving a TKA recommendation for those “definitely willing” was 1.26 (95% CI 1.14, 1.38) for females and 1.90 (95% CI 1.48, 2.43) for males. Conclusion Among individuals with knee OA referred for TKA consultation with an orthopedic surgeon, females had greater clinical need but were less likely than males to indicate willingness to undergo surgery if offered. Among patients who were “definitely willing” to consider TKA, surgeons were more likely to recommend surgery to males than females, indicating sex disparities in TKA recommendations at the point of surgeon consultation.

Objectives Knee osteoarthritis (OA) is a leading cause of physical disability worldwide. Assessing physical function is important to guide treatment. The 6-minute walk test (6MWT), recommended by the Osteoarthritis Research Society International (OARSI) as a performance-based measure of physical function,[1] was originally developed to assess submaximal aerobic fitness in people with cardiovascular and respiratory disease. In knee OA, evidence regarding its association with other measures of OA-related function is inconsistent,[2,3] raising uncertainty about the degree to which 6WMT performance reflects knee OA severity vs other patient-related factors. In individuals with symptomatic knee OA scheduled for primary total knee arthroplasty (TKA), this study assessed the contributions of OA-related and non-OA-related patient factors to 6MWT distance. Methods In this cross-sectional study within the Alberta BEST-Knee cohort, participants with symptomatic knee OA scheduled for primary TKA completed a standardized questionnaire assessing sociodemographic factors (age, sex, level of education), patient-reported knee OA symptoms (WOMAC pain, KOOS-PS), comorbidities (number of symptomatic lower extremity joints, lower back pain, number of non-MSK comorbidities, BMI), and psychosocial factors (PHQ-8 depressive symptoms, arthritis coping). A subset of participants additionally completed the 6MWT prior to surgery. The characteristics of those who completed the 6MWT were compared by tertiles of 6MWT distance. Multivariable linear regression modeling was used to assess the contribution of OA-related and non-OA patient factors to 6MWT distance. Results Among 278 participants (mean age 67 years, 65% female), individuals in the lowest tertile of 6MWT distance were more likely to be older, female, not have post-secondary education, report more comorbidities, have higher BMI, more depressive symptoms, poorer arthritis coping, greater perceived difficulty walking, higher WOMAC pain, worse KOOS-PS, and were more likely to be using a gait aid than those in the middle and uppermost tertiles. In multivariable analysis, lower scores for knee pain and disability, younger age, male sex, lower BMI, fewer non-musculoskeletal comorbidities, post-secondary education, and greater perceived arthritis coping were associated with greater 6MWT distance (Table 1). Low back pain, number of other troublesome joints, or depressive symptoms were not independently associated with 6MWT distance. Table 1. Multivariable Linear Regression Analysis of the Association Between Knee Osteoarthritis Patient Factors and Six-Minute Walk Test Distance Conclusion While 6MWT distance declines with greater knee OA symptom severity, other biomedical and psychosocial factors also significantly influence 6MWT performance. These factors should be considered when using and interpreting the 6MWT in this population. References [1.] Dobson F. Osteoarthritis Cartilage 2013;46:981-9. [2.] Maly MR. J Arthroplasty 2011;26:728-37. [3.] Lee SH. BMC Musculoskelet Disord 2022;23:1040.

Objective:People with knee osteoarthritis (OA) describe intermittent, constant, predictable, and unpredictable pain, but how different pain patterns affect symptom experience is unknown. Design:This secondary cohort analysis included individuals aged ≥30 years with knee OA referred for TKA consultation in Alberta, Canada. Pre-consult questionnaires assessed socio-demographics, health status, and knee symptoms (Intermittent and Constant Osteoarthritis Pain [ICOAP] measure assesses intermittent and constant pain severity, and frequency of predictable and unpredictable intermittent pain; Patient Acceptable Symptom State [PASS] assesses if current knee symptoms are 'acceptable' or 'unacceptable'). Multivariable robust Poisson regression assessed associations of intermittent and constant pain severity and frequency of predictable and unpredictable intermittent pain with unacceptable knee symptoms. We tested for an interaction between intermittent pain severity and unpredictable pain frequency, adjusting for age, sex, education, comorbidity, and troublesome joints. Results:Of 2360 participants, 1798 with intermittent pain scores >0 and PASS responses were included. 1293 reported intermittent, constant, predictable and unpredictable knee pain; 1268 reported 'unacceptable' symptoms. In bivariate analyses, all pain patterns were associated with risk for unacceptable symptoms. In the fully adjusted model, older age and greater intermittent and constant pain were associated with higher risk of unacceptable symptoms. No significant interaction was observed between intermittent pain severity and unpredictable pain frequency. Conclusions:Among people with advanced symptomatic knee OA, more than two-thirds reported predictable and unpredictable intermittent and constant knee pain. Associations between pain predictability and symptom state acceptability were explained by greater intermittent and constant pain severity. Further research is warranted to confirm these findings across a broader spectrum of knee OA severity.

OBJECTIVE:Knee osteoarthritis (OA) commonly affects individuals with type 2 diabetes (T2DM) and is associated with increased risk of diabetes-related complications. To better understand potential mechanisms, we examined the association between symptomatic knee OA and glycemic control in individuals with T2DM. METHODS:In this cross-sectional study, we recruited individuals with T2DM aged ≥45 years from three academic centers in Canada. Online questionnaires assessed demographics, medical history, and joint symptoms. We abstracted glycosylated hemoglobin (HbA1c) from clinic records. Knee OA was defined as fulfilling the National Institute of Clinical Excellence criteria. Target glycemic control was defined as an HbA1c level ≤7.0%. Multivariable logistic regression assessed the association between knee OA and target glycemic control, adjusting for age, gender, education level, and body mass index. Secondary analyses assessed associations between knee OA with pain ≥20/100 (and knee OA with walking difficulty) and target glycemic control. RESULTS:Among 351 participants (mean age 66.2 years, 50.7% women), 28.5% met the criteria for knee OA and 43.9% were at glycemic target. In unadjusted analyses, those with knee OA had lower odds of being at target glycemic control (odds ratio [OR] 0.60, 95% confidence interval [CI] 0.37-0.97), but the association was not statistically significant after adjusting for confounders (OR 0.65, 95% CI 0.39-1.08). In those with knee OA with pain ≥20/100, a negative association with target glycemic control was statistically significant in adjusted analysis (OR 0.58, 95% CI 0.34-0.99). CONCLUSION:Individuals with T2DM and painful knee OA are less likely to be at glycemic target, increasing their risk of diabetes complications.

OBJECTIVES:Within the first phase of developing classification criteria for Early-stage Symptomatic Knee Osteoarthritis, among individuals with knee osteoarthritis (OA) we explored: 1) symptoms within the first year of noticing their knee(s); 2) features that indicated OA was the cause; and 3) timing and reasons that initially prompted seeking healthcare. DESIGN:We conducted a cross-sectional online survey of individuals with knee OA recruited from Australia, Canada, the Netherlands, and the USA. Only individuals who indicated they recalled their first symptoms were eligible. Using free-text, participants described changes in how their knee looked, felt, moved, their overall state within the first year of noticing their knee(s), features perceived to indicate knee OA was the cause, and reasons for initially seeking healthcare. We assessed the timing of seeking care by an ordinal scale. Data were analyzed using descriptive statistics and summative content analysis. RESULTS:We included 92 participants (median age 67 years [interquartile range (IQR) 59,75], 69% women, median body mass index (BMI) 26 kg/m2 [IQR 24,30]). Within the first year from onset, frequently reported symptoms were knee pain (70%), swelling (58%), crepitus (42%), stiffness (29%), and instability (24%). While few could provide specific clinical features, approximately half (53%) perceived medical imaging as important to indicate OA. Only 35% sought healthcare within the first year of experiencing symptoms. CONCLUSIONS:Individuals with knee OA recalled varied knee symptoms within the first year and few sought healthcare. We were unable to ascertain, from the perspective of patients, specific clinical features that indicated they had OA and not another condition.

Objective The Intermittent and Constant Osteoarthritis Pain (ICOAP) questionnaire was developed to assess the osteoarthritis (OA) pain experience, but does not currently incorporate pain predictability, which people with OA considered important. We assessed the construct validity and responsiveness of two supplemental questions assessing the frequency of predictable and unpredictable intermittent knee pain. Design This was a secondary analysis of a prospective cohort of individuals aged 30 years or older undergoing total knee arthroplasty, TKA, for knee OA. Standardized questionnaires assessed socio-demographics, health status, ICOAP intermittent and constant pain subscales, the frequency of predictable and unpredictable intermittent knee pain (5-point Likert scale from never to very often), KOOS-QOL, and two ICOAP comparator measures (Pain Catastrophizing, and Perceived Arthritis Coping Efficacy), pre- and 12-months post-TKA. Construct validity was assessed by examining the Spearman correlations between pre-TKA predictability scores, ICOAP, KOOS QOL and comparator measures. Responsiveness was assessed with standardized response means (SRMs) for pre-post TKA change in predictability scores. Results Of 1366 participants (mean age 67.2 years; 60.8 ​% female), 1302 had intermittent knee pain. Predictable and unpredictable pain were reported ‘very often’ by 35.3 ​% and 18.1 ​%, respectively. Spearman correlations for frequency of predictable intermittent knee pain with KOOS QOL, PCS and Coping Efficacy were 0.39, 0.32 and −0.15, respectively; for unpredictable pain, correlations were 0.46, 0.46 and −0.27, respectively (p ​< ​0.0001 for all). SRMs were 1.23 for predictable and 1.31 for unpredictable pain. Conclusion Our findings support the construct validity and responsiveness of the two predictability items.

OBJECTIVE:Classification criteria for early-stage symptomatic knee osteoarthritis (EsSKOA) should discriminate individuals with EsSKOA from those with other causes of knee symptoms. We sought to identify conditions in the differential diagnosis of EsSKOA in adults with knee symptoms. DESIGN:We conducted an online survey of clinicians. Those consulting monthly on at least five people with undiagnosed knee symptoms were eligible. From qualitative work and clinical experience, we developed three case scenarios representing possible EsSKOA: 1. 40-year-old with 1 month of knee stiffness and swelling; 2. 50-year-old with 8 months of knee discomfort while walking; and 3. 60-year-old with intense knee discomfort getting out of a car 1 week ago. For each scenario, participants indicated conditions on a pre-defined list that they would consider in the differential diagnosis, and the top three diagnoses based on clinical experience. The proportions that considered each condition and among the top three diagnoses for each scenario were summarized overall and by clinical discipline. RESULTS:127 clinicians responded (43% female, 48% in practice ≤15 years, 50% university-affiliated practice, 7 clinical disciplines). Knee OA and meniscal injuries were among the top three conditions in the differential diagnosis for all three scenarios, followed by immune-mediated and crystal-induced inflammatory arthritis (scenario 1), patellofemoral pain syndrome (scenario 2), and collateral ligament injuries (scenario 3). CONCLUSION:The differential diagnosis for EsSKOA in adults presenting with undiagnosed knee symptoms includes symptomatic established radiographic knee OA, patellofemoral pain syndrome, meniscal and collateral ligament injuries, and immune-mediated and crystal-induced inflammatory arthritis.

Objective:The 6-minute walk test (6MWT), an Osteoarthritis Research Society International (OARSI)-recommended measure of physical function in knee osteoarthritis (OA), was originally developed to assess submaximal aerobic fitness in people with cardiovascular disease. The degree to which 6MWT performance reflects knee OA severity versus other patient factors remains unclear. Our objective was to assess the contributions of OA-related and non-OA-related patient characteristics to 6MWT performance in individuals with symptomatic knee OA. Design:In this cross-sectional study, participants scheduled for total knee arthroplasty completed the 6MWT and standardized questionnaires. Participant characteristics were compared by tertiles of 6MWT distance. Multivariable linear regression modelling was used to assess associations between patient factors and 6MWT distance. Results:Among 278 participants (mean age 67.1 years, 65.5% female, mean WOMAC pain 57.0, and mean 6MWT distance 323.1m), older age (adjusted beta coefficient -4.0 per year, 95% confidence interval [CI] -5.4, -2.5), female sex (adjusted beta [95% CI] -43.0 [-67.3, -18.7]), presence of obesity (adjusted beta [95% CI] -44.4 [-68.2, -20.5]), greater knee pain (adjusted beta [95% CI] per unit increase in WOMAC pain -1.12 [-2.1, -0.2]), worse knee-OA related function (adjusted beta [95% CI] per unit increase in KOOS-PS -1.1 [-2.0, -0.1]) were associated with shorter 6MWT distance. Greater arthritis coping efficacy (adjusted beta [95% CI] 5.2 [1.4, 9.0]) was associated with longer 6MWT distance. Conclusions:While 6MWT distance declines with greater knee OA symptom severity, other demographic, biomedical and psychosocial factors also significantly influence 6MWT performance. These should be considered when interpreting the 6MWT in this population.

OBJECTIVES:Type 2 diabetes (T2D) and knee osteoarthritis (OA) frequently co-occur, and concomitant knee OA increases risk for diabetes complications. Despite this, OA is frequently undertreated. Diabetes health-care professionals' (HPs') perceptions of the impact of knee OA in people with T2D may impact how it is addressed in clinical practice. We aimed to understand how diabetes HPs perceive the impact of knee OA on diabetes management and outcomes. METHODS:In this qualitative study we performed a secondary analysis of semistructured interviews with 18 diabetes HPs (primary care providers, endocrinologists, and diabetes educators) in Ontario, Canada. Transcripts were inductively coded and thematically analyzed. RESULTS:We developed 3 themes: 1) Patients commonly raise OA-related concerns during diabetes appointments; 2) Impact of OA on diabetes management; and 3) Conscious disconnect between perceived patient and HP priorities. Diabetes HPs recognized that knee OA commonly co-occurred in their patients. Most HPs perceived that OA has deleterious effects on diabetes management through physical inactivity, as well as other mechanisms. Despite observing OA's impact on their patients, most participants did not address OA due to the focussed structure of diabetes appointments, "single-problem" appointments, and culture of siloed care. CONCLUSIONS:Diabetes HPs recognized the high prevalence of knee OA in their patients and its deleterious effects on diabetes management, although OA management was usually not prioritized. This highlights a missed opportunity in optimizing care for people with T2D. Implementing strategies to promote OA care during diabetes visits may improve disease outcomes for both conditions.

There is a high prevalence of knee osteoarthritis (OA) in people with type 2 diabetes (T2D), and knee OA increases risk for diabetes complications. Our objective was to assess the association between symptomatic knee OA and attainment of target blood glucose levels in individuals with T2D. In this cross-sectional study, we recruited individuals with T2D aged ≥45 years from diabetes clinics at 3 academic hospitals in Toronto. Participants completed standardized online questionnaires that assessed demographics, comorbidities, height and weight, and joint symptoms. From clinic records we abstracted participants’ most recent HbA1c (within 3 months). Knee OA was defined as fulfilling NICE criteria. We considered blood glucose control at target if HbA1c was ≤7.0%. We used multivariable logistic regression to assess the association between knee OA and being at blood glucose target, adjusting for age and gender. We then examined the effect of further adjusting for body mass index (BMI). In secondary analyses, we repeated modeling with exposure of interest knee OA with knee pain ≥20/100 on pain numeric rating scale (NRS) (yes/no). We included 351 participants. Mean age was 66.9 (SD 9.8) years, 50.7% women, mean BMI 29.1 (SD 6.8) kg/m 2 , and 28.5% fulfilled NICE criteria for knee OA. Mean HbA1c was 7.4 (SD 1.2); 44% had HbA1c at target (≤7.0%). In univariable analysis, those with knee OA had lower odds of being at target (OR 0.60, 95% CI 0.37 to 0.97). Results were similar after adjusting for age and gender (OR 0.59, 95% CI 0.36 to 0.95). When further adjusting for BMI the effect of knee OA was attenuated and was not statistically significant (OR 0.65, 95% CI 0.39 to 1.06). When exposure of interest was knee OA with self-reported pain ≥20/100, we found a stronger negative association; this met statistical significance even after adjusting for BMI (OR 0.59, 95% CI 0.35 to 0.997) (Figure 1). Figure 1. Effect of (A) knee osteoarthritis overall and (B) knee osteoarthritis with pain ≥20/100 on meeting glyeemic target (HbAlc ≤7.0%). Individuals with T2D with knee OA are less likely to be at the recommended target for glycemic control. This association was stronger for those who currently reported pain and remained significant even after adjusting for BMI. This suggests that symptomatic knee OA may increase the risk of diabetes complications through worse glycemic control, and symptom severity is likely important. Further studies are needed to better understand this relationship, as well as the role of additional mechanisms by which knee OA could lead to diabetes complications such as cardiorespiratory fitness and/or systemic inflammation. Best Abstract on Research by Early Career Faculty Award

Purpose (the aim of the study): The National Institute of Health and Care Excellence (NICE) guideline on osteoarthritis (OA) recommends that adults aged ≥45 should be diagnosed with OA clinically, without investigations, if they have activity-related joint pain and either no morning joint-related stiffness or morning stiffness that lasts no longer than 30 minutes. While the NICE criteria are frequently used and referenced as diagnostic criteria for OA, they have not been validated. The objective of this study was to prospectively validate the NICE criteria for knee OA.

OBJECTIVE:The National Institute of Health and Care Excellence (NICE) criteria for osteoarthritis (OA) obviate the need for physical examination or imaging, and their use may improve timely diagnosis of OA. However, they have not been validated. METHODS:Within a larger study of individuals with type 2 diabetes, participants with and without self-reported knee pain underwent assessment of the NICE criteria for knee OA by questionnaire (index test) and clinical evaluation for established or possible knee OA by a rheumatologist (reference standard). We calculated the sensitivity, specificity, likelihood ratio positive (LR+), and likelihood ratio negative (LR-) of the NICE criteria and modified NICE criteria without the stiffness criterion. RESULTS:Our study included 96 participants: the mean ± SD age was 65.4 ± 8.3 years and 52% were women. Individuals who fulfilled the NICE criteria for knee OA (55.2%) included a spectrum of pain severity on an 11-point pain numeric rating scale with a median score of 5 (range 1-9). Rheumatologist assessment identified 56 participants (58.3%) with symptomatic knee OA. The sensitivity, specificity, LR+, and LR- of the NICE criteria for symptomatic knee OA were 0.84 (95% confidence interval [CI] 0.74-0.94), 0.85 (95% CI 0.74-0.96), 5.6, and 0.19, respectively. For the modified NICE criteria, these were 0.89 (95% CI 0.82-0.97), 0.85 (95% CI 0.74-0.96), 5.93, and 0.13. CONCLUSION:The NICE criteria have high sensitivity and specificity for detecting symptomatic knee OA in a population with type 2 diabetes. We found that a modified version, omitting the stiffness criterion, performed similarly. These criteria should be validated in other settings and populations.

Purpose (the aim of the study): The Osteoarthritis Research Society International (OARSI) has launched an initiative to develop classification criteria for early-stage symptomatic knee osteoarthritis (EsSKOA). The goal is to establish a standardized way to identify and enrol individuals with symptomatic knee OA but without established or later-stage knee OA into clinical studies, i.e., at an earlier stage of symptomatic disease. The classification criteria must accurately discriminate individuals with EsSKOA both from individuals with other causes for their knee symptoms and individuals with established or later-stage knee OA.