Intermittent And Constant Osteoarthritis Pain Research Articles

Less pain reported 5 years after cementless compared to cemented unicompartmental knee replacement: an analysis of pain, neuropathy, and co-morbidity scores

PurposeTo compare patient-reported pain scores and assess the influence of neuropathy and co-morbidity, on knee pain following cemented and cementless medial unicompartmental knee replacement (UKR) 5 years after surgery.MethodIn this longitudinal study, 262 cemented and 262 cementless Oxford UKR performed for the same indications and with the same techniques were recruited. Patients were reviewed at five years, evaluating patient-reported pain and association with clinical outcomes. Intermittent and Constant Osteoarthritis Pain (ICOAP), PainDETECT (PD), Charnley score, Oxford Knee Score (OKS) and American Knee Society Score (AKSS) were compared.ResultsIn both cohorts, intermittent pain was more common than constant pain (47% vs 21%). Cementless knees reported significantly less pain than cemented (ICOAP-Total 5/100 vs 11/100, p < 0.0001). A greater proportion of cementless knees experienced no pain at all (ICOAP = 0/100, 61% vs 43%, p < 0.0001) and 75% fewer experienced severe or extreme pain. Pain sub-scores in PD, OKS and AKSS follow this trend. Pain was unlikely to be neuropathic (PD positive: 5.26%), but patients reporting high levels of ‘strongest’ pain were three times more likely to be neuropathic. Patients with co-morbidities (Charnley C) experienced greater pain than those without (Charnley A+B) across all knee-specific scores, despite scores being knee specific.ConclusionBoth cemented and cementless UKR in this study had substantially less pain than that reported in literature following TKR. Cementless UKR had significantly less pain than cemented UKR in all scores. Two-thirds of patients with a cementless UKR had no pain at all at 5 years, and pain experienced was most likely to be mild and intermittent with no patients in severe or extreme pain. Patients with cementless UKR that had higher levels of pain were more likely to have co-morbidity or evidence or neuropathic pain. It is unclear why cementless UKR have less pain than cemented; further study is necessary.

The Natural History of Knee Osteoarthritis Pain Experience and Risk Profiles

The study aimed to characterize the natural history of the pain experience, concurrently considering intermittent and constant pain over 4 years, and determine baseline factors associated with unfavorable trajectories in individuals with chronic knee pain. The Osteoarthritis Initiative (OAI) is a prospective, observational study of people with or at higher risk for knee osteoarthritis. The Intermittent and Constant Osteoarthritis Pain (ICOAP) was assessed annually at 48-to-96-month OAI visits. Twenty-eight baseline sociodemographic, knee-specific, and health-related characteristics were assessed. Group-based dual-trajectory modeling identified pain experience patterns indicated by ICOAP intermittent and constant pain scores over 4 years. Multivariable multinomial logistic regression models determined baseline factors associated with membership in each dual-trajectory group. Four longitudinal pain experience patterns were identified (n = 3,584, mean age = 64.8 [standard deviation 9.0] years, BMI = 28.6 [5.0] kg/m2; 57.9% women). Group 1 (37.7%) had minimal intermittent and no constant pain; Group 2 (35.1%) had mild intermittent and no constant pain; Group 3 (18.5%) had mild intermittent and low-grade constant pain; and Group 4 (8.7%) had moderate intermittent and constant pain. Baseline widespread pain, knee stiffness, back pain, hip pain, ankle pain, obesity, depressive symptoms, more advanced radiographic disease, and analgesic use were each associated with an increased risk of membership in less favorable Groups 2, 3, and 4. These distinct courses of pain experience may be driven by different underlying pain mechanisms. The benchmarked ICOAP scores could be used to stratify patients and tailor management. Addressing and preventing the development of modifiable risks (eg, widespread pain and knee joint stiffness) may reduce the chance of belonging to unfavorable dual-trajectory groups. PerspectiveConcurrently tracking intermittent versus constant pain experience, group-based dual-trajectory modeling identified 4 distinct pain experience patterns over 4 years. The benchmarked ICOAP scores in these dual trajectories could aid in stratifying patients for tailored management strategies and intensity of care.

Arabic version of the intermittent and constant osteoarthritis pain questionnaire (ICOAP-Ar): translation, cross-cultural adaptation, and measurement properties

BackgroundPain is the most incapacitating symptom of knee osteoarthritis (OA), with intermittent and/or continuous nature as described by the patients. Accuracy of pain assessment tools across different cultures is important. This study aimed to translate and culturally adapt the Intermittent and Constant OsteoArthritis Pain (ICOAP) measure into Arabic (ICOAP-Ar) and evaluate its psychometric properties in patients with knee OA.MethodsThe ICOAP was cross-culturally adapted following the recommended guidelines from English. Knee OA patients from outpatient clinics were recruited to assess the structural (confirmatory factor analysis) and construct validity (Spearman’s correlation coefficient - rho) to assess the relationship between the ICOAP-Ar and the pain and symptoms subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS), in addition to internal consistency (Cronbach’s alpha and the corrected item-total correlation). A week later, test-retest reliability (intraclass correlation coefficient (ICC)) was evaluated. Following four weeks of physical therapy treatment, the ICOAP-Ar responsiveness was evaluated using the receiver operating characteristic curve.ResultsNinety-seven participants were recruited (age = 52.97 ± 9.9). A model with single pain construct showed acceptable fit (Comparative fit index = 0.92). The ICOAP-Ar total and subscales had a strong to moderate negative correlation with the KOOS pain and symptoms domains, respectively. The ICOAP-Ar total and subscales demonstrated satisfactory internal consistency (α = 0.86–0.93). The ICCs were excellent (ICCs = 0.89–0.92) with acceptable corrected item total correlations (rho = 0.53–0.87) for the ICOAP-Ar items. The ICOAP-Ar responsiveness was good with moderate effect size (ES = 0.51–0.65) and large standardized response mean (SRM = 0.86–0.99). A cut-off point of 51.1/100 was determined with moderate accuracy (Area under the curve = 0.81, sensitivity = 85%, specificity = 71%). No floor or ceiling effects were found.ConclusionsThe ICOAP-Ar exhibited good validity, reliability, and responsiveness after physical therapy treatment for knee OA, which renders it reliable for evaluating knee OA pain in clinical and research settings.

Inflammatory ultrasound features as prognostic factors of pain and functional outcomes following intra-articular platelet-rich plasma in knee osteoarthritis.

To explore inflammatory ultrasound predictors of improvements in pain and function over 2, 6, and 12 months following administration of intra-articular platelet-rich plasma (PRP) in knee osteoarthritis (OA). Patients with painful mild-moderate radiographic knee OA from a subset of the RESTORE RCT underwent ultrasound assessment according to the standardized OMERACT scanning protocol to detect inflammatory features such as synovitis, synovial hypertrophy, and effusion with power Doppler. The study knee was treated with 3 once-weekly PRP injections obtained after centrifugation at 1500 g for 5 min. Numerical Rating Score (NRS), Intermittent and Constant Osteoarthritis Pain (ICOAP) questionnaire, and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) function sub-score were used to measure pain and functional severity. Separate linear regression models were performed to determine whether baseline ultrasound-detected features of inflammation predicted the improvement in pain and function following PRP injection in both unadjusted and adjusted models for confounders. Forty-four participants were included, with 25 (56.8%) being female. In an unadjusted model, higher OMERACT scores for inflammatory features such as global synovitis and/or effusion were significantly associated with greater improvement in all outcomes measured at 2 months but not at 6 and 12 months for pain measures. Only global synovitis showed significant association with functional improvement at 2 and 12 months. Similar findings were observed in the adjusted model. Ultrasound indices of knee inflammation predicted short-term improvements in pain severity and both short- and longer-term improvements in function following intra-articular PRP injection.

A Systematic Review of Psychometric Properties of Knee-Related Outcome Measures Translated, Cross-Culturally Adapted, and Validated in Arabic Language.

During the previous two decades, patient-reported outcome measures (PROMs) have been well tested, and the tools were validated in different languages across the globe. This systematic review aimed to identify the knee disease-specific outcome tools in Arabic and evaluate their methodological quality of psychometric properties of the most promising tools based on the COSMIN checklist and PRISMA guidelines. Articles published in English, from the inception of databases until the date of search (10 August 2022), were included. Articles without at least one psychometric property (reliability, validity, and responsiveness) evaluation, and articles other than in the English language, were excluded from the study. The key terms [“Arabic” AND “Knee” AND (“Questionnaire” OR “Scale”)] were used in three databases, i.e., PubMed, Scopus, and Web of Science (WoS) in the advanced search strategy. Key terms were either in the title or abstract for PubMed. Key words were in the topic (TS) for WoS. COSMIN (COnsensus-based Standards for the selection of health Measurement Instruments) risk of bias checklist was used to evaluate the methodological quality of psychometric properties of the Arabic knee-related outcome measures. A total of 99 articles were identified in PubMed, SCOPUS, and WoS. After passing inclusion and exclusion criteria, 20 articles describing 22 scales from five countries were included in this review. The instruments validated in the Arabic language are Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), knee injury and osteoarthritis outcome score (KOOS), knee outcome survey- activities of daily living scale (KOS-ADLS), Oxford knee score (OKS), anterior knee pain scale, osteoarthritis of knee and hip health-related quality of life (OAKHQoL) scale, Lysholm knee score (LKS), international documentation committee subjective knee form (IKDC), intermittent and constant osteoarthritis pain (ICOAP) questionnaire, Kujala patellofemoral pain scoring system (PFPSS), anterior knee pain scale (AKPS) and osteoarthritis quality of life questionnaire (OAQoL),. All were found to have good test-retest reliability (Intra Correlation Coefficient), internal consistency (Cronbach’s alpha), and construct validity (Visual Analog Scale, Short Form-12, RAND-36, etc.). Of 20 instruments available to assess self-reported knee symptoms and function, 12 were validated in the Saudi Arabian population. Among them, KOS-ADLS is the best PROM to be used in various knee conditions, followed by KOOS and WOMAC. The assessed methodological quality of evidence says that the knee Arabic PROMs are reliable instruments to evaluate knee symptoms/function.

Identifying multiple knee pain trajectories and the prediction of opioid and NSAID medication used: A latent class growth approach.

Knee pain is a major source of distress and disability, with pain progression highly variable between individuals. Previous studies defining pain trajectories have all used a single measure of pain, and these differ across studies. Different measures reflect diverse pain mechanisms. To ascertain the clinical utility of pain trajectories, we explored associations between opioid and non-steroidal anti-inflammatory drug (NSAID) use. We model pain trajectories using two measures-Intermittent and Constant Osteoarthritis Pain (ICOAP) and the painDETECT, in 2141 participants, across 3 waves (the baseline, 1- and 3-year assessments) of the Knee Pain In the Community (KPIC) cohort. Latent class growth analysis identified six trajectories using ICOAP subscales (High-Stable, Low-Stable, Moderate Worsening, Moderate Recovering, Worsening, and Recovering) and four trajectories using painDETECT (High-stable, Low-stable, Moderate Worsening, and Moderate Recovering). There was a high degree of correspondence between people assigned to pain trajectories between ICOAP intermittent and constant subscales, but less so using painDETECT. Opioid use was associated with ICOAP trajectories only (e.g., High-Stable and Worsening intermittent ICOAP trajectories) and in women. Different measures of pain produce different patterns of pain progression and these are differentially related to medication use. Opioid use is linked to trajectories of pain based on the impact of pain on behavior and not pain symptoms. Thus, managing pain's behavioral impact is more central to understanding opioid use than managing pain symptoms. These findings support more in-depth questioning about the type of pain and its progression in clinical practice.

Synovitis Is Associated With Constant Pain in Knee Osteoarthritis: A Cross-sectional Study of OMERACT Knee Ultrasound Scores.

To examine the association between ultrasound (US)-detected knee inflammation and intermittent and constant pain experiences in patients with knee osteoarthritis (OA). Participants with radiographically early-stage (Kellgren-Lawrence arthritis grading scale [KL] ≤ 2) and late-stage (KL ≥ 3) disease and frequent symptoms underwent musculoskeletal US measures of inflammation using the Outcome Measures in Rheumatology (OMERACT) knee US scoring system. Pain experiences were captured using the Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP) tool. We assessed the association between US-synovitis and ICOAP pain experiences using a series of linear, logistic, or multinomial logistic regression models (as appropriate for each variable), while adjusting for age, sex, BMI, and radiographic stage. Secondary analyses were performed similarly by radiographic stage. Pain and synovitis measures from 248 patients (453 knees) were included. Worse synovitis was associated with higher ICOAP constant pain scores (β 8.05, 95% CI 0.67-15.43), but not intermittent pain scores. Moderate-to-severe synovitis was associated with a 4.73-fold increased relative risk (95% CI 1.06-17.00) of a constant pain pattern. In secondary analyses, moderate-to-severe synovitis in early radiographic OA was associated with 2.70-higher odds (95% CI 1.04-7.02) of any constant pain, 3.28-higher odds (95% CI 1.43-7.52) of any intermittent pain, and with higher intermittent (β 10.47, 95% CI 1.03-19.91) and constant (β 12.62, 95% CI 3.02-22.23) pain scores. No associations were identified for synovitis in those with late radiographic OA. In patients with knee OA, moderate-to-severe synovitis is most strongly associated with constant pain. Inflammation may play context-specific roles across pain experiences, especially in earlier radiographic stages of knee OA.

What Does the Future Hold? Health-Related Quality of Life 3-12 Years Following a Youth Sport-Related Knee Injury.

Knee trauma can lead to poor health-related quality of life (HRQoL) and osteoarthritis. We aimed to assess HRQoL 3–12 years following youth sport-related knee injury considering HRQoL and osteoarthritis determinants. Generic (EQ-5D-5L index, EQ-VAS) and condition-specific (Knee injury and Osteoarthritis Outcome Score quality of life subscale, KOOS QOL) HRQoL were assessed in 124 individuals 3–12 years following youth sport-related knee injury and 129 uninjured controls of similar age, sex, and sport. Linear regression examined differences in HRQoL outcomes by injury group. Multivariable linear regression explored the influence of sex, time-since-injury, injury type, body mass index, knee muscle strength, Intermittent and Constant Osteoarthritis Pain (ICOAP) score, and Godin Leisure-Time Exercise Questionnaire (GLTEQ) moderate-to-strenuous physical activity. Participant median (range) age was 23 years (14–29) and 55% were female. Injury history was associated with poorer KOOS QOL (−8.41; 95%CI −10.76, −6.06) but not EQ-5D-5L (−0.0074; −0.0238, 0.0089) or EQ-VAS (−3.82; −8.77, 1.14). Injury history (−5.14; −6.90, −3.38), worse ICOAP score (−0.40; −0.45, −0.36), and anterior cruciate ligament tear (−1.41; −2.77, −0.06) contributed to poorer KOOS QOL. Worse ICOAP score contributed to poorer EQ-5D-5L (−0.0024; −0.0034, −0.0015) and higher GLTEQ moderate-to-strenuous physical activity to better EQ-VAS (0.10; 0.03, 0.17). Knee trauma is associated with poorer condition-specific but not generic HRQoL 3–12 years post-injury.

Association of Intermittent and Constant Knee Pain Patterns With Knee Pain Severity and With Radiographic Knee Osteoarthritis Duration and Severity.

To examine the relation of knee pain patterns to pain severity and to radiographic osteoarthritis (OA) severity and duration. The Multicenter Osteoarthritis Study is a longitudinal cohort of older adults with or at risk of knee OA. Participants' Intermittent and Constant Osteoarthritis Pain (ICOAP) scores were characterized as 1) no intermittent or constant pain, 2) intermittent pain only, 3) constant pain only, and 4) a combination of constant and intermittent pain. Knee pain severity was assessed using the Western Ontario andMcMaster Universities Osteoarthritis Index(WOMAC) pain subscale and a visual analog scale (VAS). Radiographic knee OA (ROA) severity was defined as Kellgren/Lawrence grade ≥2, and ROA duration was defined according to the clinic visit at which ROA was first noted. We assessed the relation of ICOAP pain patterns to knee pain severity, ROA severity, and ROA duration using regression models with generalized estimating equations. There were 2,322 participants (mean age 68.8 years, body mass index 31.0 kg/m2 , 60% female). Higher ICOAP pain patterns, i.e., a mix of constant and intermittent pain, were associated with greater WOMAC pain severity compared with those patients without either pain pattern (odds ratio [OR] 43.2 [95% confidence interval (95% CI) 26.4-61.3]). Results were similar for the VAS (OR 71.2 [95% CI 45.7-110.9]). Those patients with more severe and longer duration of ROA were more likely to have a mix of constant and intermittent pain compared with those without either pain (OR 3.7 [95% CI 3.1-4.6] and OR 2.9 [95% CI 2.5-3.5], respectively). Knee pain patterns are associated with radiographic disease stage and duration, as well as pain severity, highlighting the fact that pain patterns are important for understanding symptomatic disease progression.

PREDICTING FACTORS OF JOINT PAIN

Joint pain could have impact on the wellbeing of elders with knee osteoarthritis (OA). Several factors could influence joint pain. Therefore, it is beneficial to explore contributing factors regarding with joint pain among Indonesian elders with knee osteoarthritis. The aim of this study was to explore predicting factors affecting joint pain of people with knee osteoarthritis. A descriptive cross sectional design was used and involved 100 participants. All participants were asked to answer the demographic questionnaire, Lifestyle Modification Behaviors Questionnaire (LMBQ), and Intermittent and Constant Osteoarthritis Pain (ICOAP). These instruments were validated by three experts. The internal consistency reliability of the LMBQ and ICOAP yielded a Cronbach Alpha coefficient of .84 and .95, respectively. The results indicated significant correlation between joint pain and age, body mass index, education, duration being diagnosed with OA , level of severity, and lifestyles modification behaviors. However, there was no significant difference between occupation, genders and joint pain. A multiple regression was conducted. Age, BMI, diseases duration, level severity of knee OA, and lifestyles behaviors were examined as predictors. These variables statistically significant predict join pain F (5.94) = 5.467, p&lt; 0.001), R2=0.225. Age, gender, BMI, diseases duration, severity of knee OA, and lifestyle behaviors were related to joint pain. Therefore, nursing and other health professional should concern and consider these factors in allocating care to reduce joint pain in this group.

Psychometric properties of the 12-item Knee injury and Osteoarthritis Outcome Score (KOOS-12) Spanish version for people with knee osteoarthritis.

To evaluate the validity, reliability, and responsiveness to change of the 12-item Knee injury and Osteoarthritis Outcome Score (KOOS) Spanish version questionnaire. This study was based on a questionnaire validation design. A cross-sectional survey of 199 patients with knee osteoarthritis (KOA) and ten healthy controls was studied to evaluate the validity and reliability of KOOS-12. One hundred and sixteen patients were assessed for test-retest reliability, and 38 patients were included for a responsiveness assessment. Structural validity was assessed by the confirmatory factor analysis (CFA). Item response theory-based methods were used to determine the performance of the items. Internal consistency reliability was appropriate for all scales (Cronbach's alpha = 0.85-0.94). The intra-class correlation coefficient of KOOS-12 scales ranged from 0.60 to 0.71. The CFA and generalized partial credit model showed that KOOS-12 scales presented a good overall model fit. No differential item functioning was found. Convergent validity was demonstrated by strong correlations (Spearman's rho ≥ 0.70) with KOOS, International Knee Documentation Committee subjective knee evaluation form (IKDC), and Knee Intermittent and Constant Osteoarthritis Pain (ICOAP). Known-groups validity showed that KOOS-12 well discriminated subgroups of patients (radiographic severity and nutritional status). Standardized response means for KOOS-12 scales were ≥ 0.75. Changes in KOOS-12 scales had a moderate to strong correlation (Pearson's r ≥ 0.40) with the changes in the KOOS, ICOAP, and IKDC scales. The KOOS-12 Spanish version is a valid, reliable, and responsiveness to change questionnaire to measure patients' opinions about their knee and associated problems in Mexican subjects with KOA. Key Points • KOOS-12 is a short self-reported measure that assesses patient's opinions about the difficulties they experience due to problems with their knee and also covers aspects of pain, functional limitations, and knee-related quality of life. • The Spanish version of KOOS-12 questionnaire is a valid instrument for measuring the patients' opinions about their knee and associated problems, and is both reliable and responsiveness to change.

Translation and cultural adaptation of the intermittent and constant osteoarthritis pain (ICOAP) knee questionnaire into Danish

Translation and cultural adaptation of the intermittent and constant osteoarthritis pain (ICOAP) knee questionnaire into Danish

Effectiveness of Platelet-ich Plasma Based on Gene Expression in Knee Osteoarthritis.

Intra-articular injection of Platelet-rich plasma (PRP) is an effective method for the treatment of patients with knee osteoarthritis (OA). This study aimed to assess the effects of PRP injection on OA, based on gene expression analysis. A sample of 30 subjects with knee OA was asked to complete the Persian versions of the Intermittent and Constant Osteoarthritis Pain (ICOAP) and Knee and Osteoarthritis Outcome Score (KOOS). Thereafter, the expression of IGF-1, HIF-1, cartilage oligometric matrix protein (COMP), and bone morphogenetic proteins (BMP2) were compared in the patient before and 1 month after PRP injection using real-time polymerase chain reaction (PCR). According to the results of the study, the expression of IGF-1, HIF-1, COMP and BMP2 were reported to be higher in subjects with PRP injection; however, only the up-regulation of IGF-1 was statistically significant (P<007). Moreover, the significant change in the KOOS and ICOAP scores was attributed to PRP injection (P<0.01). Intra-articular injections of PRP were reported to ease the pain, decrease the stiffness, and improve quality of life in patients with knee OA through the promotion of IGF-1 expression.

Comparing the Effect of continuous and Intermittent Physiotherapy on the Pain and Function in Moderate Knee Osteoarthritis; A Pilot Randomized Clinical Trial Study

Introduction: Osteoarthritis is one of the common types of joint disorder. This study compared the effects of continuous and intermittent physiotherapy on the pain and function of the individuals with moderate knee osteoarthritis. Materials and Methods: This randomized clinical trial study included 20 patients with moderate knee osteoarthritis randomly assigned into continuous and intermittent physiotherapy groups. The intervention was exactly the same for both groups including 10 sessions of conventional physical therapy. The treatment frequency was 6 and 3 sessions per week for continuous and intermittent groups, respectively. Using Knee injury and Osteoarthritis Outcome Score (KOOS) and Intermittent and Constant Osteoarthritis Pain (ICOAP) questioners, 6-minute-walking test, timed get up and go test, pain based on visual analogue scale (VAS), and function were assessed before, after 10 sessions, and after one month of follow up. The outcome was analyzed using independent t-test and, repeated measures ANOVA. Results: Prior to the study, there was no significant difference between groups (P > 0.05). At the end of the 10 th treatment session (P = 0.048), and after 1 month of follow up (P = 0.030), only the daily activity subscale of the KOOS questionnaire was significantly less in the continuous group. The records of 6-minute-walk test (P = 0.046), timed get up and go test (P = 0.040), continuous pain (P = 0.006), symptoms (P = 0.020), pain (P = 0.003), and quality of life (P = 0.010) subclasses of KOOS improved significantly in continuous group. After one month of follow up, daily activity subclass and pain based on VAS score were significantly better than baseline records (P = 0.002). In intermittent group, pain based on VAS score (P = 0.002) and continuous pain (P = 0.030) improved significantly after 10 th session and follow up period). Conclusion: It seems that the frequency of the treatment sessions has no significant effect on the treatment results in short term. Thus, the physiotherapist may take the subject's preference and their time limitations for scheduling the sessions. Continuous intervention may probably be the better choice to reach better results while intermittent protocol may result in more lasting effects.

Validation of the Intermittent and Constant Osteoarthritis Pain Questionnaire in Patients with Hand Osteoarthritis: Results from the Nor-Hand Study.

To examine the validity of a modified Intermittent and Constant Osteoarthritis Pain (ICOAP) questionnaire for assessment of pain in hand osteoarthritis (OA). The modified ICOAP-hand questionnaire was administered to 300 patients [89% female, median (interquartile range) age: 61 (57-66) yrs] in the Nor-Hand observational cohort study. The questionnaire was completed twice by 31 patients and test-retest reliability was assessed by intraclass correlation coefficients (ICC) for sum scores and weighted κ scores for individual items. Internal consistency was assessed by Cronbach's alpha coefficient and item-total correlations. Correlations between the ICOAP-hand questionnaire, the Australian/Canadian Hand OA Index (AUSCAN) hand pain subscale, and pain on a numerical rating scale (NRS) were analyzed using Spearman correlation analyses. We found a substantial overlap between constant and intermittent pain (46% reporting constant + intermittent pain and 33% reporting no pain). Test-retest reliability analysis of ICOAP-hand showed an ICC of 0.89 for the total scale and weighted κ values between 0.39-0.70 for the individual items. Principal component analysis revealed one component with an eigenvalue of 7.9, explaining 72% of the total variance. Cronbach's alpha coefficient values > 0.93 and strong item-total correlations proved high internal consistency. ICOAP-hand was strongly correlated with NRS hand pain and the AUSCAN pain subscale. ICOAP-hand is a reliable pain index that correlates with other available pain questionnaires. However, our results indicate that constant and intermittent pain do not represent separate constructs in hand OA, questioning the usefulness of the 2 subscales. [ClinicalTrials.gov: NCT03083548].

Translation, cross-cultural adaptation and validation of the traditional Chinese intermittent and constant osteoarthritis pain (ICOAP) questionnaire for knee osteoarthritis

ObjectivesTo translate and culturally adapt the Intermittent and Constant Osteoarthritis and Pain (ICOAP) measure to a traditional Chinese version, and to study its psychometric properties in patients with knee osteoarthritis...

Duloxetine Reduces Pain and Improves Quality of Recovery Following Total Knee Arthroplasty in Centrally Sensitized Patients: A Prospective, Randomized Controlled Study.

Unexplained postoperative pain is one of the most feared complications of total knee arthroplasty (TKA). A persistent noxious peripheral stimulus, such as the pain of chronic knee osteoarthritis, can cause central sensitization in which the central nervous system becomes hyperexcitable, resulting in hypersensitivity to both noxious and non-noxious stimuli. Patients with central sensitization may be more susceptible to unexplained pain after TKA. Duloxetine, a selective serotonin norepinephrine reuptake inhibitor (SNRI), can ameliorate the pain associated with central sensitization, and we aimed to determine whether it could reduce postoperative pain and improve quality of recovery after TKA in patients with central sensitization. Patients undergoing TKA were screened for central sensitization preoperatively with use of the Central Sensitization Inventory (CSI). Among 464 patients with primary osteoarthritis who were scheduled for primary unilateral TKA, 80 were identified as being centrally sensitized and were included in the study. Forty patients were randomly assigned to the duloxetine group (30 mg 1 day before surgery and for 6 weeks after surgery), and 40 were randomized to the control group (no duloxetine). Pain and quality of recovery were assessed with use of the Brief Pain Inventory (BPI), the Short Form-36 (SF-36), the Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP), and the Hamilton Depression Scale. The prevalence of adverse medication effects was also noted. The patients in the duloxetine group had better performance across pain metrics during the initial 2 to 12-week postoperative period (p < 0.05). The duloxetine group also had a superior quality of recovery 2 weeks after TKA, as indicated by emotional and physical functioning (all p < 0.05). There was no difference between groups in the prevalence of adverse events. A substantial number of patients are centrally sensitized before TKA. Surgeons should consider selective incorporation of duloxetine into the multimodal postoperative analgesic protocol, according to the severity of central sensitization, to minimize the possibility of persistent pain following TKA. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Strawberries improve pain symptoms in obese participants with radiographic evidence of knee osteoarthritis

Osteoarthritis (OA), a common form of arthritis is mainly characterized by inflammation, joint pain and cartilage degeneration but without any effective pharmacological cure. Obese are at risk of OA. We have previously reported the effects of dietary berries in improving cardio‐metabolic outcomes in obese adults. To our knowledge no previous reports have examined the effects of berries on OA. Thus, in the present study we examined the hypothesis that strawberries will improve metabolic profiles and symptoms of pain in obese participants with radiographic evidence of knee OA. In a randomized placebo‐controlled crossover trial obese participants [n=17 (Females 13, Males: 4); age: 56±7y; BMI: 39±6 (mean±SD)] were randomized to one of the two groups: strawberry (50g freeze‐dried) or placebo, each for 12 weeks. Blood draws, anthropometric measurements and surveys for pain scores [visual analog scale of pain (VAS) and Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP)] and quality of life indices [Health assessment questionnaire disability index (HAQ‐DI)] were administered at screen, 12, 14 (washout) and 26 weeks of the study. We found significant decreases in pain scores (VAS) in the strawberry vs. placebo group at 12 weeks (0.71±0.31 and 0.90±0.47, respectively, p&lt;0.05). While no differences were noted in biochemical profiles, especially, glucose, HbA1c, total‐ and LDL cholesterol and C‐reactive protein, HDL‐cholesterol was significantly lower in the strawberry vs. placebo group at 12 weeks (50±16 and 55±6.5mg/dL, respectively, p&lt;0.05). Thus, strawberry bioactive compounds may help alleviate pain symptoms in knee OA. These findings deserve further investigation in larger trials.Support or Funding InformationCalifornia Strawberry Commission, NIH grant U54GM104938 (OSCTR)

Relation of pain sensitization to development of constant, persistent pain in knee osteoarthritis: The multicenter osteoarthritis study

Purpose: Patients with knee osteoarthritis (OA) often start with acute intermittent, activity-related pain, which evolves to additionally experiencing chronic, persistent pain. Why this transition happens is not known. It is possible that peripheral and central sensitization, which are associated with knee pain severity in knee OA, contributes to the transition from solely acute intermittent to chronic, persistent pain. We assessed whether a marker of sensitization, pressure pain threshold (PPT), was associated with developing chronic, persistent pain over time in a large cohort of older adults with or at risk of knee OA. Methods: The Multicenter Osteoarthritis (MOST) Study is a NIH-funded longitudinal cohort of persons with or at high risk of knee OA. Subjects had a standardized somatosensory evaluation of mechanical pressure pain thresholds (PPT) at the wrist and patella and completed pain questionnaires at baseline and two years later. PPT was assessed with an algometer (1 cm2 tip, 0.5 Kg/sec) as the point at which the subject felt the pressure first changed to slight pain. We averaged of 3 PPT trials at each anatomic site. Lower PPT indicates more sensitization/pain sensitivity; at a site of disease (e.g., knee), it indicates peripheral sensitization, and at a site without disease (e.g., wrist), it indicates central sensitization. The Intermittent and Constant OA Pain (ICOAP) instrument assesses presence and severity of intermittent and constant pain, and for intermittent pain, its frequency. Using the knee-specific ICOAP, pain patterns were defined as: 1) no intermittent or constant pain; 2) intermittent pain only (of at least mild severity occurring at least sometimes); and 3) constant pain (of at least mild severity) with or without intermittent pain. Among subjects with either no pain or intermittent pain only at baseline, we evaluated the relation of baseline PPT to incidence of constant pain using logistic regression. We evaluated baseline PPT as a continuous measure, and also evaluated PPT as tertiles to evaluate for a dose-response and threshold effect. All analyses were adjusted for age, sex, BMI, depressive symptoms, catastrophizing, widespread pain, and clinic site. Results: There were 1951 subjects included (mean age 68, 60% female, mean BMI 31), of whom ∼8% developed constant pain over two years. A higher level of sensitization, as reflected by lower PPT, was associated with higher risk of developing incident constant pain [knee PPT: OR 1.14 (95% CI 1.01–1.27, p = 0.03); wrist PPT: OR 1.12 (95% CI 0.97–1.33, p = 0.1)]. Figure 1 illustrates the adjusted ORs for risk of incident constant pain by PPT tertiles for the knee (p = 0.05) and the wrist (p = 0.02). Because there appeared to be a threshold effect for the wrist PPT, we evaluated the lowest PPT tertile with the higher two tertiles. The lowest knee PPT tertile, reflecting greater peripheral sensitization, was associated with a higher risk of developing incident constant pain compared with the two higher PPT tertiles (less sensitization) [OR: 1.57 (95% CI 1.00–2.48, p = 0.05)]. Similarly, a higher level of central sensitization as measured by the lowest wrist PPT tertile was also associated with a higher risk of incident constant pain [OR: 2.01 (95% CI 1.15–3.51, p = 0.01)]. Conclusions: Higher levels of peripheral and central sensitization were associated with greater risk of evolution or progression of the pain pattern from no or intermittent pain to constant pain over time. These findings support the hypothesis that sensitization plays an important role in changing a patient’s pattern and severity of OA-related pain. These findings have implications for understanding the transition from acute to chronic pain.

Transcultural adaptation and validation of the Chinese version of the intermittent and constant osteoarthritis pain (ICOAP) measure in patients with knee osteoarthritis.

This study aimed to translate and adapt the intermittent and constant osteoarthritis pain (ICOAP) measure into the Chinese language (ICOAP-C), and to study its psychometric properties in patients with knee osteoarthritis (OA). The ICOAP was translated and cognitively pretested following internationally recommended guidelines. The reliability, including the internal consistency and the test-retest reliability, was then evaluated in 108 outpatients with knee OA. The validity was assessed by comparing the ICOAP-C with the Western Ontario and McMaster Universities Osteoarthritis Index Pain Subscale (WOMAC-PS), the Knee Injury and Osteoarthritis Outcome Score Pain Short-Form (KOOS-PS), and pain on a visual analogue scale (VAS). Seventy-four patients undergoing total knee arthroplasty (TKA) participated in the evaluation of the responsiveness of the ICOAP-C over a 6-month period. All participants completed the questionnaires, and no floor or ceiling effects were found. All ICOAP-C scales exhibited satisfactory internal consistency. The intraclass correlation coefficients (ICCs) were excellent, i.e., 0.932 for "total pain", 0.908 for "intermittent pain" and 0.892 for "constant pain". Regarding the convergent validity, the ICOAP-C scores exhibited strong correlations with the WOMAC-PS and moderate correlations with the KOOS-PS and the VAS. The responsiveness of the ICOAP-C at 6 months after TKA was good [standardized response mean (SRM) range: 0.94-1.20; effect size (ES) range: 1.41-1.71]. The ICOAP-C exhibited good reliability, validity, and responsiveness. This scale is a reliable instrument for evaluating the pain experiences of patients with knee OA and is useful for outcome measurement in clinical research.