Early Symptomatic Osteoarthritis Research Articles

Single versus Three Doses of Intraarticular Platelet-Rich Plasma Injection in Treatment of Early Osteoarthritis Knee Joint—A Prospective Comparative Study

Background Autologous platelet-rich plasma (PRP), which contains a pool of growth factors, appears to offer an easy solution for delivering multiple growth factors needed for tissue repair. The objective of the study is to compare between single versus three doses of intraarticular platelet-rich plasma injection in the treatment of early osteoarthritis knee joint. Materials and Methods A prospective comparative study was done on 100 patients with early osteoarthritis knee who were randomized into two groups in an alternating fashion—single-dose injection and triple-dose injection groups. PRP (5 mL) obtained by double-spin method was injected per knee and followed up at 1, 3, and 6 months and outcomes measured using WOMAC (Western Ontario and McMaster universities osteoarthritis index) and VAS (visual analog scale) scores. Results VAS scores showed a statistically significant difference in triple-dose group at all follow-ups. In WOMAC, such a difference was observed for stiffness subscore at all the follow-ups, but the pain subscore and total score showed an improvement only at the final follow-up with the functional assessment subscore showing no statistical difference at any follow-ups. Conclusion PRP injection appears to be effective in early symptomatic osteoarthritis with better clinical results using a triple-dose regimen.

The effectiveness of leucocyte-poor platelet-rich plasma injections on symptomatic early osteoarthritis of the knee: the PEAK randomized controlled trial.

Platelet-rich plasma (PRP) intra-articular injections may provide a simple and minimally invasive treatment for early-stage knee osteoarthritis (OA). This has led to an increase in its adoption as a treatment for knee OA, although there is uncertainty about its efficacy and benefit. We hypothesized that patients with early-stage symptomatic knee OA who receive multiple PRP injections will have better clinical outcomes than those receiving single PRP or placebo injections. A double-blinded, randomized placebo-controlled trial was performed with three groups receiving either placebo injections (Normal Saline), one PRP injection followed by two placebo injections, or three PRP injections. Each injection was given one week apart. Outcomes were prospectively collected prior to intervention and then at six weeks, three months, six months, and 12 months post-intervention. Primary outcome measures were Knee Injury and Osteoarthritis Outcome Score (KOOS) and EuroQol five-dimension five-level index (EQ-5D-5L). Secondary outcomes included visual analogue scale for pain and patient subjective assessment of the injections. A total of 102 patients were recruited. The follow-up period was 12 months, at intervals of six weeks, 12 weeks, six months, and 12 months. KOOS-Total significantly improved in all groups at these time intervals compared to pre-injection. There was an improvement in EQ-5D-5L index scores in saline and single injection groups, but not in the multiple injection group. Comparison of treatment groups showed no additional beneficial effect of single or multiple PRP injections above that displayed in the saline injection group. Subjective patient satisfaction and recommendation of treatment received demonstrated a similar pattern in all the groups. There was no indication of superiority of either single or multiple PRP injections compared to saline injections. There is no evidence that single or multiple PRP had any additional beneficial effect compared to saline injection up to 12 months, follow-up after treatment of early stage symptomatic OA of the knee. Cite this article: Bone Joint J2022;104-B(6):663-671.

Biochemical, clinical, demographic and imaging biomarkers for disease progression in knee osteoarthritis.

Aim: To identify prognostic biomarker(s) for knee osteoarthritis (OA) in the Osteoarthritis Initiative (OAI) cohort. Methods: Multilevel regression was used to determine the association between baseline biomarkers and change in biomarkers from baseline to 24 months with clinical and radiographic OA progression over 48months of follow-up. Results: Higher values of baseline urinary CTXII were consistently associated with an increased risk of OA disease progression outcomes: Kellgren & Lawrence grade (odds ratio [OR]: 1.15, 95% CI: 1.03-1.28); medial joint space narrowing (OR: 1.06, 95% CI: 1.02-1.10); lateral osteophytes (OR: 1.05, 95% CI: 1.01-1.10); joint space width (regression coefficient: -0.005, 95% CI: -0.008-0.001); and Western Ontario and McMaster Universities Arthritis Index pain scores (OR: 1.02, 95% CI: 1.01-1.04). Changes in serum PIIANP and serum COMP over 24months were associated with clinical disease progression. Conclusion: Urinary CTXII showed stronger associations with radiographic OA and appears to be a reliable prognostic marker, while changes in other biomarkers were found in early symptomatic OA, supporting the phasic nature of OA.

10-Year natural course of early hip osteoarthritis in middle-aged persons with hip pain: a CHECK study

ObjectiveTo explore the natural course of hip osteoarthritis (OA) in a population of first-time presenters with hip complaints.MethodsData were collected at baseline and after 2, 5, 8 and 10 years...

Establishing outcome measures in early knee osteoarthritis.

The classification and monitoring of individuals with early knee osteoarthritis (OA) are important considerations for the design and evaluation of therapeutic interventions and require the identification of appropriate outcome measures. Potential outcome domains to assess for early OA include patient-reported outcomes (such as pain, function and quality of life), features of clinical examination (such as joint line tenderness and crepitus), objective measures of physical function, levels of physical activity, features of imaging modalities (such as of magnetic resonance imaging) and biochemical markers in body fluid. Patient characteristics such as adiposity and biomechanics of the knee could also have relevance to the assessment of early OA. Importantly, research is needed to enable the selection of outcome measures that are feasible, reliable and validated in individuals at risk of knee OA or with early knee OA. In this Perspectives article, potential outcome measures for early symptomatic knee OA are discussed, including those measures that could be of use in clinical practice and/or the research setting.

Prevalence and development of hip and knee osteoarthritis according to American College of Rheumatology criteria in the CHECK cohort

BackgroundWe aimed to evaluate the prevalence of hip and knee osteoarthritis (HOA and KOA) according to American College of Rheumatology (ACR) criteria among participants with suspected early symptomatic osteoarthritis (OA) in the CHECK cohort. We also assessed whether participants not fulfilling ACR criteria at baseline develop ACR-defined OA at 2-year and/or 5-year follow up, and which baseline factors are associated with this development.MethodsThe CHECK cohort included 1002 subjects with first presentation of knee and/or hip complaints. The primary outcome was onset of HOA and/or KOA according to the ACR criteria, including the clinical classification criteria and the combined clinical and radiographic classification criteria at 2-year and/or 5-year follow up.ResultsOf the participants with hip complaints, 63% (n = 370) were classified as having HOA at baseline according to the ACR criteria. Of those not classified with HOA at baseline, 40% developed HOA according to the clinical or combined clinical/radiographic ACR criteria after 2 and/or 5 years. Up to 92% of participants (n = 829) with knee complaints were classified as having KOA at baseline; of those not classified with KOA at baseline, 55% developed KOA according to the clinical ACR criteria or the clinical/radiographic ACR criteria after 2 and/or 5 years. The following factors were associated with development of HOA: morning stiffness (OR 2.39; 95% CI 1.14–4.98), painful internal rotation (OR 2.53; 95% CI 1.23–5.19), hip flexion < 115° (OR 2.33; 95% CI 1.17–4.64) and erythrocyte sedimentation rate (ESR) < 20 mm/h (OR 2.94; 95% CI 1.13–7.61). No variables were associated with development of KOA at 2-year and/or 5-year follow up.ConclusionsA large proportion of persons with hip complaints not fulfilling the ACR criteria at baseline develop HOA after 2 and/or 5 years of follow up. Almost all persons with knee complaints already fulfill the clinical and/or radiographic ACR criteria for OA, and half of the persons not fulfilling criteria at baseline will do so after 5 years of follow up. Several individual ACR criteria for HOA at baseline were associated with the development of HOA at follow up. This association was not proven for KOA, probably because of the small number of subjects developing KOA in this study.

The course of pain and function in osteoarthritis and timing of arthroplasty: the CHECK cohort

Background and purpose — It is unknown whether different trajectories of pain or function are associated with timing of total hip or knee arthroplasty (THA/TKA) in osteoarthritis (OA) patients. We investigated this association in early symptomatic OA patients.Patients and methods — Data from the prospective Dutch CHECK cohort (patients with early hip/knee OA complaints) covering 9 years of follow-up were used. Pain and function were measured annually using the WOMAC questionnaires. Changes in pain/function over time were estimated using a linear mixed model adjusted for baseline age, sex, BMI, maximal Kellgren and Lawrence score, number of painful joints, and comorbidities. The same covariates were included in a Cox regression model, with time to first arthroplasty as event. Both were combined in a joint model to assess the association between changes in pain/function and time to arthroplasty.Results — Of the 868 eligible patients, 84 received a TKA/THA during follow-up. Patients receiving arthroplasty were somewhat older, had a higher Kellgren and Lawrence score and worse WOMAC scores at baseline. Irrespective of receiving arthroplasty, about two-thirds of the patients showed at least 1 period of deterioration of pain/function (≥ 10 points WOMAC subscale). In approximately two fifths this deterioration was followed by another deterioration in the following year. Worse pain and function levels increased the hazard of receiving THA/TKA (1.08 [95% CI 1.06–1.10] for pain and 1.07 [CI 1.05–1.08] for function). Changes in pain or function over time were not associated with timing of THA/TKAInterpretation — Worse pain and function levels rather than long-term changes are associated with timing of THA/TKA.

Trajectories of Physical Work Capacity in Early Symptomatic Osteoarthritis of Hip and Knee: Results from the Cohort Hip and Cohort Knee (CHECK) Study.

Purpose To evaluate the 5-year course of physical work capacity of participants with early symptomatic osteoarthritis (OA) of the hip and/or the knee; to identify trajectories and explore the relationship between trajectories and covariates. Methods In a prospective cohort study, physical work capacity was measured at baseline, using a test protocol (functional capacity evaluation) consisting of work-related physical activities. Participants were invited to participate in 1, 2 and 5year follow-up measurements. Multilevel analysis and latent classes analysis were performed, in models with test performances as dependent variables and age, sex, work status, self-reported function (Western Ontario McMasters Arthritis Scale-WOMAC), body mass index (BMI) and time as independent variables. Multiple imputation was used to control for the influence of missing data. Results At baseline and after 1, 2 and 5years there were 96, 64, 61 and 35 participants. Mean (SD) age at baseline was 56 (4.9) years, 84% were females. There was no statistically significant change in test performances (lifting low and high, carrying, static overhead work, repetitive bending, repetitive rotations) between the 4 measurements. Male sex, younger age and better self-reported function were statistically significant (p < 0.05) determinants of higher performance on most of the tests; having a paid job, BMI and progression of time were not. Three trajectories were identified: 'weak giving way', 'stable and able', and'strong with decline'. Discussion In subgroups of participants with early symptomatic OA, determined by age, sex and self-reported function, physical work capacity seems to be a stable characteristic over 5years.

Brief Report: Induction of Matrix Metalloproteinase Expression by Synovial Wnt Signaling and Association With Disease Progression in Early Symptomatic Osteoarthritis.

Increased Wnt signaling in chondrocytes is associated with development of osteoarthritis (OA). However, OA is considered a disease of the entire joint, where the synovium has been attributed an important role in disease pathogenesis and progression. This study was undertaken to determine whether Wnt signaling in synovial tissue could contribute to pathologic development of OA through the production of matrix metalloproteinases (MMPs), and to assess the relationship of synovial expression of Frizzled (FZD) receptors and the Wnt inhibitor FRZB to MMP expression and disease progression in patients with early OA in the Dutch Cohort Hip and Cohort Knee (CHECK) study cohort. In mouse knee joints, human WNT8A and mouse Wnt16 were overexpressed using adenoviral vectors, and expression of messenger RNA (mRNA) for MMPs in the synovium was determined by reverse transcription-polymerase chain reaction or Luminex assay. In human synovial tissue from a subgroup of patients with early OA with knee pain enrolled in the CHECK cohort, levels of Wnt family members were assessed for linkage to MMP expression and disease progression. In addition, MMP production in human synovium from patients with end-stage OA was determined after stimulation of Wnt signaling with WNT3A or inhibition with FRZB or DKK1 in the synovium. Overexpression of WNT8A and Wnt16 in mouse knee joints induced MMP expression in vivo. Expression of MMPs relevant to human OA in the synovium from CHECK study participants significantly correlated with expression of FZD1, FZD10, and FRZB mRNA. Moreover, increased FZD1 mRNA expression and decreased FRZB mRNA expression were observed in CHECK study patients who experienced disease progression compared to those who were nonprogressors. Stimulation of human OA synovium with WNT3A induced the production of various MMPs, whereas inhibition of Wnt signaling with FRZB or DKK1 reduced the production of MMPs. Wnt signaling in the synovium may potently induce progression of OA via increased production of MMPs.

Short-term clinical results of intra-articular PRP injections for early osteoarthritis of the knee

PurposeTo assess the short-term results of repeated intra-articular platelet rich plasma (PRP) injections into the knee in patients with early osteoarthritis (OA) and to determine a better treatment protocol. MethodsThis is a retrospective study in 191 knees (127 patients) with minimum of 12 months follow-up. We compared the clinical results of three types of injection method, once a month, twice monthly, and three injections at monthly interval. The outcomes were assessed using Visual Rating Scale (VRS), functional score, knee score, range of motion (ROM), WOMAC Stiffness/Pain/Function score, IKDC score, before the first injection and at 12 months post treatment. ResultsThere were significant improvements in all scores after treatment as compared to the pre-treatment values (p < 0.05), except Knee score after 1st and 2nd injection and ROM in three groups. The parameters of Visual Rating Scale (VRS), functional score, and WOMAC Stiffness/Pain/Function score showed significant differences among the three groups in favour of the three injections group (p < 0.05). At 12 months, the effects began to decline in one injection and two injections groups, and the data in one injection group showed significant difference compared to two injection group (p < 0.001). Three injections group had higher scores and more improvement at 12 months after treatment when compared to the other two groups. ConclusionPRP injection appears to be effective in early symptomatic OA knees. The results after treatment are encouraging with significant reduction in pain and improvement in knee function at 12 months after treatment when compared to the pre-treatment status. Three injections per month yielded significantly better results in short-term follow-up.

Predicting early symptomatic osteoarthritis in the human knee using machine learning classification of magnetic resonance images from the osteoarthritis initiative

Machine learning algorithms applied to T2 maps have the potential to provide important prognostic information for the development of OA. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2243-2250, 2017.

Reduction in Cylindrical Grasp Strength Is Associated With Early Thumb Carpometacarpal Osteoarthritis.

Advanced thumb carpometacarpal (CMC) osteoarthritis (OA) can cause substantial impairment in hand function, from grasping heavy objects to fine manipulation of implements and tools. In the clinical setting, we commonly measure the grip strength of gross grasp with a hand dynamometer in patients with CMC OA. Cylindrical grasp, which requires more thumb contribution than gross grasp, is an alternative method of measuring grip strength and one that may provide insight into thumb-related conditions. Because gross grasp and cylindrical grasp use the thumb in different planes, measurement of gross grasp alone might underestimate impairment. Therefore, it is important to evaluate cylindrical grasp as well. To our knowledge this tool has yet to be examined in a population with early thumb CMC OA. (1) Is cylindrical grasp and gross grasp strength reduced in subjects with early thumb CMC OA compared with asymptomatic control subjects? (2) What is the association of cylindrical and gross grasp to thumb CMC OA after adjusting for age, sex, and hand dominance? We recruited 90 subjects with early symptomatic and radiographic thumb CMC OA and 38 asymptomatic healthy control subjects for this multisite controlled study. Demographic information, hand examination, comprehensive histories, plain film radiographs, and cylindrical and gross grasp strength data were collected on all 128 subjects. Mean grasp strength was calculated for cylindrical and gross grasp in the population with early CMC OA and the control population. A t-test was performed on cylindrical and gross grasp to evaluate the difference between the mean in the control and early CMC OA populations. We used separate linear regression models for the two types of grasp to further quantify the association of grasp with a diagnosis of early thumb CMC OA controlling for age, sex, and whether the subject used their dominant or nondominant hand in the study. Cylindrical grasp was weaker in the population with thumb CMC OA compared with healthy control subjects (6.3 ± 2.7 kg versus 8.4 ± 2.5 kg; mean difference, 2.1; 95% CI, 1.1-3.1; p < 0.001), but there was no difference in gross grasp force (29.6 ± 11.6 kg versus 31.4 ± 10.1 kg; mean difference, 1.7; 95% CI, -2.5 to 6.0; p = 0.425). When adjusting for age, sex, and handedness, cylindrical grasp reduction was related to CMC OA (β = -2.3; standard error [SE], 0.46; p < 0.001) (Y-intercept = 8.2; SE, 1.8; R2 = 0.29), whereas gross grasp was not reduced in early thumb CMC OA (β = -2.8; SE, 1.6; p = 0.072) (Y-intercept = 34.3; SE, 6.3; R2 = 0.48). A reduction in cylindrical grasp is associated with early symptomatic and radiographic CMC OA, whereas gross grasp is not associated with early thumb CMC OA, suggesting that cylindrical grasp may be a better tool to detect changes in thumb and hand function seen during early disease stages. Cylindrical grasp may serve as a more-sensitive measure for detecting early changes in early CMC OA. The associated decline in hand function also might provide an opportunity for measuring the effectiveness of treatment and intervention.

Exploring Fatigue Trajectories in Early Symptomatic Knee and Hip Osteoarthritis: 6-year Results from the CHECK Study.

To examine whether different groups of fatigue trajectories can be identified among patients with early symptomatic osteoarthritis (OA) of the knee or hip, to describe the level of fatigue severity within each of these fatigue groups, and to investigate the involvement of age, sex, use of medication, comorbidity, and OA severity in relation to group membership. Six years of followup data on fatigue (Medical Outcomes Study Short Form-36 Vitality scale) came from the Cohort Hip and Cohort Knee (CHECK) cohort. Growth mixture modeling was applied to identify distinct fatigue trajectories as well as to take into account the effects of the patient characteristics. Three fatigue trajectories were identified: low fatigue, low-to-high fatigue, and high fatigue. Latter trajectories showed considerable overlap from years 2 to 6, but differed in some patient characteristics in comparison with each other and in comparison with the low fatigue group. Comorbidity, medication use, and sex were significantly associated with the identified trajectories. Women, individuals with a comorbid disease, and those who used medication were more likely to follow a high fatigue trajectory. These findings suggest heterogeneous development of fatigue in the early OA population associated with varying patient characteristics. Further, this study shows that a considerable number of patients with OA already experience elevated levels of fatigue at an early stage of OA. While these findings need to be replicated, the identification of these trajectories with differing patient characteristics may warrant tailored psychosocial interventions for patients with elevated levels of fatigue.

Defining hip pain trajectories in early symptomatic hip osteoarthritis – 5 year results from a nationwide prospective cohort study (CHECK)

To define distinct hip pain trajectories in individuals with early symptomatic hip osteoarthritis (OA) and to determine risk factors for these pain trajectories. Data were obtained from the nationwide prospective Cohort Hip and Cohort Knee (CHECK) study. Participants with hip pain or stiffness and a completed 5-year follow-up were included. Baseline demographic, anamnestic, physical examination characteristics were assessed. Outcome was annually assessed by the Numeric Rating Scale (NRS) for pain. Pain trajectories were retrieved by latent class growth analysis (LCGA). Multinomial logistic regression was used to calculate risk ratios. 545 participants were included. Four distinct pain trajectories were uncovered by LCGA. We found significant differences in baseline characteristics, including body mass index (BMI); symptom severity; pain coping strategies and in criteria for clinical hip OA (American College of Rheumatology (ACR)). Lower education, higher activity limitation scores, frequent use of pain transformation as coping strategy and painful internal hip rotation were more often associated with trajectories characterized by more severe pain. No association was found for baseline radiographic features. We defined four distinct pain trajectories over 5 years follow-up in individuals with early symptomatic hip OA, suggesting there are differences in symptomatic progression of hip OA. Baseline radiographic severity was not associated with the pain trajectories. Future research should be aimed at measuring symptomatic progression of hip OA with even more frequent symptom assessment.

Defining knee pain trajectories in early symptomatic knee osteoarthritis in primary care: 5-year results from a nationwide prospective cohort study (CHECK).

GPs have high consultation rates for symptoms related to knee osteoarthritis (OA). Many risk factors for symptomatic knee OA progression remain unknown. To define distinct knee pain trajectories in individuals with early symptomatic knee OA and determine the risk factors for these pain trajectories. Data were obtained from the multicentre prospective Cohort Hip and Cohort Knee study in the Netherlands. Participants with knee OA, according to the clinical criteria of the American College of Rheumatology, and a completed 5-year follow-up were included. Baseline demographic, anamnestic, and physical examination characteristics were assessed. Outcome was annually assessed by the Numeric Rating Scale for pain. Pain trajectories were retrieved by latent class growth analysis. Multinomial logistic regression was used to calculate relative risk ratios. In total, 705 participants were included. Six distinct pain trajectories were identified with favourable and unfavourable courses. Statistically significant differences were found in baseline characteristics, including body mass index (BMI), symptom severity, and pain coping strategies between the different trajectories. Higher BMI, lower level of education, greater comorbidity, higher activity limitation scores, and joint space tenderness were more often associated with trajectories characterised by more pain at first presentation and pain progression--compared with the reference group with a mild pain trajectory. No association was found for baseline radiographic features. These results can help differentiate those patients who require more specific monitoring in the management of early symptomatic knee OA from those for whom a 'wait-and-see' policy seems justifiable. Radiography provided no additional benefit over clinical diagnosis of early symptomatic knee OA in general practice.

Identifying Trajectories of Pain Severity in Early Symptomatic Knee Osteoarthritis: A 5-year Followup of the Cohort Hip and Cohort Knee (CHECK) Study

To identify subgroups of pain trajectories in patients with symptomatic knee osteoarthritis (OA), and to explain these different trajectories by patient characteristics, lifestyle, and coping factors, as well as radiographic features. Longitudinal data of pain severity (0-10) from 5 years of followup of the CHECK (Cohort Hip and Cohort Knee) study was used. Latent class growth analysis identified homogeneous subgroups with distinct trajectories of pain. Multinomial regression analysis was used to examine different lifestyle and coping characteristics between the trajectories. In longitudinal pain data of 5 years of followup in 705 participants, 3 pain trajectories were identified: marginal, mild, and moderate pain trajectories. Compared with the marginal pain trajectory, the mild and moderate pain trajectories can be characterized by the following baseline variables: body mass index (BMI) > 25, additional hip pain, low education level, using the coping strategy "worrying," and having ≥ 3 comorbidities. Moderate pain trajectory can be supplemented with the Kellgren-Lawrence grading scale grade ≥ 2 radiological change. Three trajectories of pain were identified. Participants with a BMI > 25, secondary school as highest education level, having at least 3 comorbidities, additional hip pain, and/or whose coping style is worrying are more likely to develop a moderate or mild pain trajectory compared with those without these characteristics. In the management of knee pain in people with early symptomatic OA, attention should also be given to additional factors such as hip pain, other comorbidities, passive coping strategy, and obesity.

Predictors and outcome of pain-related avoidance of activities in persons with early symptomatic knee osteoarthritis: a five-year followup study.

It has been hypothesized that pain and low vitality lead to an increase in avoidance of activities in persons with early symptomatic knee osteoarthritis (OA), and that avoidance of activities leads to an increase in activity limitations. The present study aimed to evaluate these hypotheses. Baseline, 2-year, and 5-year followup data of 828 participants from the Cohort Hip and Cohort Knee Study with early symptomatic knee OA were used. Autoregressive generalized estimating equations and linear regression models were used to analyze the longitudinal and cross-sectional associations between self-reported knee pain, vitality, pain-related avoidance of activities, and activity limitations. The models were adjusted for the covariates age, sex, education level, body mass index, comorbidity, radiographic severity, and hip pain. In longitudinal analyses, knee pain and vitality predicted a subsequent increase in avoidance of activities. Pain-related avoidance of activities predicted a subsequent increase in activity limitations; however, this relationship lost statistical significance (P = 0.089) after adjustment for covariates. Cross-sectional analyses showed strong relationships between knee pain, low vitality, pain-related avoidance of activities, and activity limitations at all time points. In persons with early symptomatic knee OA, knee pain and low vitality lead to a subsequent increase in avoidance of activities. Pain-related avoidance of activities is related to activity limitations at inception of symptoms, but also years later. Therefore, it can be recommended to monitor and target avoidance of activities at various stages of the disease.

Intermittent and constant pain and physical function or performance in men and women with knee osteoarthritis: data from the osteoarthritis initiative.

Severe constant and intermittent knee pain are associated with "unacceptable" symptoms in older adults with osteoarthritis (OA) [22]. We hypothesized that constant and intermittent pain would be independently related to physical function, with intermittent knee pain being a better predictor of future declines in physical function in early symptomatic knee OA. This study included men (n = 189) and women (n = 133) with radiographic, unilateral knee OA, observed using data from the Osteoarthritis Initiative (OAI). Pain types were measured using the Intermittent and Constant Osteoarthritis Pain (ICOAP) scale. Physical function was measured using the Western Ontario and McMaster Universities Arthritis Index (WOMAC-PF) and Knee Injury and Osteoarthritis Outcome Score (KOOS-FSR) and physical performance tests. High baseline intermittent (B = 0.277; p = 0.001) and constant (B = 0.252; p = 0.001) knee pain were related to poor WOMAC-PF. Increased constant (B = 0.484; p = 0.001) and intermittent (B = 0.104; p = 0.040) pain were related to 2-year decreased WOMAC-PF. High baseline intermittent knee pain predicted poor KOOS-FSR at year 2 (B = -0.357; p = 0.016). Increased constant pain was related to decreased chair stand test performance over 2 years in women (B = 0.077; p = 0.001). High baseline intermittent pain was related to poor performance on repeated chair stands (B = 0.035; p = 0.021), while baseline constant pain was related to poor 400-m walk performance in women (B = 0.636; p = 0.047). Intermittent and constant knee pain were independent factors in self-perceived physical function and were important predictors of future limitations in physical function. Identifying intermittent and constant pain in early symptomatic OA may allow patients to adopt strategies to prevent worsening pain and future declines in physical function.

Alarmins S100A8/S100A9 aggravate osteophyte formation in experimental osteoarthritis and predict osteophyte progression in early human symptomatic osteoarthritis

ObjectiveAlarmins S100A8 and S100A9 are major products of activated macrophages regulating cartilage damage and synovial activation during murine and human osteoarthritis (OA). In the current study, we investigated whether S100A8...

Cohort Profile: Cohort Hip and Cohort Knee (CHECK) study.

The Cohort Hip and Cohort Knee (CHECK) study included participants with early symptomatic osteoarthritis (OA) of the hip or knee and evaluated clinical, radiographic and biochemical variables in order to establish the course, prognosis and underlying mechanisms of early symptomatic osteoarthritis. A total of 1002 participants aged 45-65 years, with symptomatic OA characterized by pain of knee and/ or hip, entered the cohort in the period October 2002 to September 2005. They were included at or within 6 months of their first visit to the general practitioner for these symptoms. An overview of measures that are included in the study can be found on the website [www.check-research.com]. On the basis of their presenting symptoms, participants were divided into two groups. Participants with mild symptoms visited the research centre at years 0, 2, 5, 8 and 10 (variable visiting group) and participants with more serious symptoms visited the research centre each year (annual visiting group). After 7 years, only 105 participants (10%) had dropped out; their baseline characteristics did not differ significantly from those of other participants. CHECK is a valuable source of information on early symptomatic OA, that allows the examination of high-quality data on clinical, radiographic and biochemical variables. The CHECK steering group welcomes collaboration with national and international colleagues. Requests for collaboration or access to data can be sent to [checkreu@umcutrecht.nl].