Predicting the course of functional limitation among older adults with knee pain: do local signs, symptoms and radiographs add anything to general indicators?

Modifiable physical and behavioural factors associated with widespread pain in older adults with radiographic evidence of knee osteoarthritis

OBJECTIVE

To identify modifiable physical and behavioural factors associated with widespread pain (WSP) in older adults with radiographic evidence of knee osteoarthritis (OA).

METHODS

Cross-sectional initial visit data of participants with radiographic knee OA (Kellgren-Lawrence grade of ≥2) from the Osteoarthritis Initiative Study were analysed. WSP was defined as pain on both sides of the body, above and below the waist, and in the axial skeleton. Time (hrs/d) spent participating in sitting and moderate-strenuous physical activities were calculated from the Physical Activity Scale for the Elderly questionnaire. Physical function was quantified using gait speed and the chair stand test. Restless sleep was assessed using an item on the CES-D Scale. Logistic regression models were constructed to examine the strength of the associations between primary exposures and WSP in unadjusted and adjusted analyses.

RESULTS

Among the 2637 participants (mean age 62.6 years, 58.6% female), 16.8% met the criteria for WSP. All primary measures of interest were related to WSP in unadjusted analyses. In adjusted multivariable analysis, slow gait speed (adjusted odds ratio [aOR] 1.43; 95% CI 1.01, 2.02), lower chair stand rate (aOR 0.98; 95% CI 0.97-0.99), and restless sleep (aOR 1.61; 95% CI 1.25-2.08) maintained significant associations with WSP.

CONCLUSION

Poor sleep behaviours and low physical function capacity are associated with WSP in adults with radiographic knee OA. These findings highlight the importance of assessing sleep, physical function, and pain distribution in this population. Interventions to improve physical function and sleep behaviours should be investigated as potential strategies to mitigate WSP.

Prognostic factors associated with changes in knee pain outcomes, identified from initial primary care consultation data. A systematic literature review

BACKGROUND

Data collected during initial primary care consultations could be a source of baseline prognostic factors associated with changes in outcome measures for patients with knee pain.

OBJECTIVES

To identify, appraise and synthesize studies investigating prognostic factors associated with changes in outcome for people presenting with knee pain in primary care.

METHODS

EMBASE, CINAHL, AMED, MEDLINE and MedRxiv electronic databases were searched from inception to March 2021 and repeated in August 2022. Prospective cohort studies of adult participants with musculoskeletal knee pain assessing the association between putative prognostic factors and outcomes in primary care were included. The Quality in Prognostic Studies (QUIPS) tool and The Modified Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework, specific to prognostic reviews were used to appraise and synthesize the evidence respectively.

RESULTS

Eight studies were included. Eight knee pain outcomes were identified. Methodological and statistical heterogeneity resulted in qualitative analysis. All evidence was judged to be of low to very low quality. Bilateral knee pain (multivariable odds ratio (OR) range 2.60-2.74; 95%CI range 0.90-8.10, p value = 0.09) and a lower educational level (multivariable (OR) range 1.74-5.6; 95%CI range 1.16-16.20, p value = <0.001) were synonymously associated with persisting knee pain at 12-month follow up. A total of 37 univariable and 63 multivariable prognostic factors were statistically associated with outcomes (p ≤ 0.05) in single studies.

CONCLUSIONS

There was consensus from two independent studies that bilateral knee pain and lower educational level were associated with persistent knee pain. Many baseline factors were associated with outcome in individual studies but not consistently between studies. The current understanding, accuracy and reliability of the prognostic value of initial primary care consultation data for knee pain outcomes are limited. This review will provide an essential guide for candidate variable selection in future primary care prognostic confirmatory studies.Key messagesBilateral knee pain and lower educational level were associated with persistent knee pain.Many baseline factors were associated with outcome in individual studies but not consistently between studies.The current understanding, accuracy and reliability of the prognostic value of initial primary care consultation data for knee pain outcomes are limited.

Evaluation of two electronic-rehabilitation programmes for persistent knee pain: protocol for a randomised feasibility trial

INTRODUCTION

Persistent, knee pain is a common cause of disability. Education and exercise treatment are advocated in all clinical guidelines; however, the increasing prevalence of persistent knee pain presents challenges for health services regarding appropriate and scalable delivery of these treatments. Digital technologies may help address this, and this trial will evaluate the feasibility and acceptability of two electronic-rehabilitation interventions: 'My Knee UK' and 'Group E-Rehab'.

METHODS AND ANALYSIS

This protocol describes a non-blinded, randomised feasibility trial with three parallel groups. The trial aims to recruit 90 participants (45 years or older) with a history of persistent knee pain consistent with a clinical diagnosis of knee osteoarthritis. Participants will be randomly assigned in a 1:1:1 allocation ratio. The 'My Knee UK' intervention arm will receive a self-directed unsupervised internet-based home exercise programme plus short message service support (targeting exercise behaviour change) for 12 weeks; the 'Group E-Rehab' intervention arm will receive group-based physiotherapist-prescribed home exercises delivered via videoconferencing accompanied by internet-interactive educational sessions for 12 weeks; the control arm will receive usual physiotherapy care or continue with their usual self-management (depending on their recruitment path). Feasibility variables, patient-reported outcomes and clinical findings measured at baseline, 3 and 9 months will be assessed and integrated with qualitative interview data from a subset of Group E-Rehab and My Knee UK participants. If considered feasible and acceptable, a definitive randomised controlled trial can be conducted to investigate the clinical effectiveness and cost-effectiveness of one or both interventions with a view to implementation in routine care.

ETHICS AND DISSEMINATION

The trial was approved by the West of Scotland Research Ethics Committee 5 (Reference: 20/WS/0006). The results of the study will be disseminated to study participants, the study grant funder and will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ISRCTN15564385.

Musculoskeletal pain in Parkinson's disease: a narrative review

The prevalence of musculoskeletal (MSK) pain in people with Parkinson's disease (PD) is higher than that of age-matched controls. In this review, we outline what is known about MSK pain in PD, focusing on the neck, shoulder, knee, hip and low back. We also compare what is known about MSK pain in PD to what is known in older adults without PD. Finally, we outline areas of for future research related to MSK pain in people with PD.

Associations of Coexisting Pain and Fatigue Severity with Physical Performance and Quality of Life among Middle-Aged and Older Individuals with Chronic Knee Pain: A randomized controlled trial

OBJECTIVE

To examine associations of combined pain and fatigue severity with physical performance and quality of life in people with chronic knee pain.

DESIGN

Cross-sectional.

SETTING

General community.

PARTICIPANTS

Adults (N = 193) aged ≥ 50 years with chronic knee pain.

METHODS

Physical performance measures included Six-Minute Walk test, Timed Up and Go test, and 20-feet timed walk test. Quality of life (QOL) was measured by the Medical Outcomes Study Short Form-12 Health Survey. Brief Pain Inventory (BPI) and Brief Fatigue Inventory (BFI) were used to evaluate pain and fatigue. Multiple linear regression analyses were conducted to examine associations of coexisting pain and fatigue severity with physical performance and quality of life.

RESULTS

Based on BPI and BFI scores, participants were categorized into four severity groups: mild pain/fatigue; moderate pain/mild fatigue; mild pain/moderate fatigue; and moderate pain/fatigue (which included severe pain/fatigue). The moderate pain/fatigue group had significantly worse physical performance on Six Minute Walk (standardized beta (β) = - 0.22, 95% confidence interval (CI) [-.38, -.06], P < 0.05), poorer physical (β = - 0.41, 95% CI [-.61, -.20], P < 0.001) and mental QOL (β = - 0.26, 95% CI [-.46, -.07], P < 0.05) compared to the mild pain/fatigue group. Moreover, the mild pain/moderate fatigue group had significantly lower levels of mental QOL (β = - 0.27, 95% CI [-.44, -.10], P < 0.05) when compared to the mild pain/fatigue group. The moderate pain/mild fatigue group did not differ statistically compared to the mild pain/fatigue group.

CONCLUSIONS

Coexisting moderate pain and moderate fatigue were related to worse physical performance and QOL. Fatigue contributed to lower levels of mental QOL. Clinical assessment of fatigue in addition to pain should be included as a standard examination for chronic knee pain.

The Arthroplasty Candidacy Help Engine tool to select candidates for hip and knee replacement surgery: development and economic modelling

BACKGROUND

There is no good evidence to support the use of patient-reported outcome measures (PROMs) in setting preoperative thresholds for referral for hip and knee replacement surgery. Despite this, the practice is widespread in the NHS.

OBJECTIVES/RESEARCH QUESTIONS

Can clinical outcome tools be used to set thresholds for hip or knee replacement? What is the relationship between the choice of threshold and the cost-effectiveness of surgery?

METHODS

A systematic review identified PROMs used to assess patients undergoing hip/knee replacement. Their measurement properties were compared and supplemented by analysis of existing data sets. For each candidate score, we calculated the absolute threshold (a preoperative level above which there is no potential for improvement) and relative thresholds (preoperative levels above which individuals are less likely to improve than others). Owing to their measurement properties and the availability of data from their current widespread use in the NHS, the Oxford Knee Score (OKS) and Oxford Hip Score (OHS) were selected as the most appropriate scores to use in developing the Arthroplasty Candidacy Help Engine (ACHE) tool. The change in score and the probability of an improvement were then calculated and modelled using preoperative and postoperative OKS/OHSs and PROM scores, thereby creating the ACHE tool. Markov models were used to assess the cost-effectiveness of total hip/knee arthroplasty in the NHS for different preoperative values of OKS/OHSs over a 10-year period. The threshold values were used to model how the ACHE tool may change the number of referrals in a single UK musculoskeletal hub. A user group was established that included patients, members of the public and health-care representatives, to provide stakeholder feedback throughout the research process.

RESULTS

From a shortlist of four scores, the OHS and OKS were selected for the ACHE tool based on their measurement properties, calculated preoperative thresholds and cost-effectiveness data. The absolute threshold was 40 for the OHS and 41 for the OKS using the preferred improvement criterion. A range of relative thresholds were calculated based on the relationship between a patient's preoperative score and their probability of improving after surgery. For example, a preoperative OHS of 35 or an OKS of 30 translates to a 75% probability of achieving a good outcome from surgical intervention. The economic evaluation demonstrated that hip and knee arthroplasty cost of < £20,000 per quality-adjusted life-year for patients with any preoperative score below the absolute thresholds (40 for the OHS and 41 for the OKS). Arthroplasty was most cost-effective for patients with lower preoperative scores.

LIMITATIONS

The ACHE tool supports but does not replace the shared decision-making process required before an individual decides whether or not to undergo surgery.

CONCLUSION

The OHS and OKS can be used in the ACHE tool to assess an individual patient's suitability for hip/knee replacement surgery. The system enables evidence-based and informed threshold setting in accordance with local resources and policies. At a population level, both hip and knee arthroplasty are highly cost-effective right up to the absolute threshold for intervention. Our stakeholder user group felt that the ACHE tool was a useful evidence-based clinical tool to aid referrals and that it should be trialled in NHS clinical practice to establish its feasibility.

FUTURE WORK

Future work could include (1) a real-world study of the ACHE tool to determine its acceptability to patients and general practitioners and (2) a study of the role of the ACHE tool in supporting referral decisions.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Association between radiographic anterior cruciate ligament tear and joint symptoms: Data from the osteoarthritis initiative

INTRODUCTION

Symptomatic osteoarthritis (OA) in the knee is defined as the presence of OA radiographic features in combination with knee symptoms. Pain has not been shown to correlate meaningfully to radiographic severity. We aimed to determine the relationship between a tear of the anterior cruciate ligament (ACL) with knee symptoms and radiographic OA.

METHODS

A within-person, between-knee cross-sectional study of 37 participants from the Osteoarthritis Initiative (OAI) with a complete or partial ACL tear detected on magnetic resonance imaging in 1 knee (index knee) were included. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS) and radiographs of both knees, 1 with an ACL tear and one without (control knee) were scored for OA severity (Kellgren-Lawrence Grading) and symptoms. A generalized estimating equation with linear regression was used to compare symptom scores within individuals as well as to radiographic severity.

RESULTS

Thirty-seven individuals (40% female, average age = 60.7years, body mass index = 31.0 kg/m² ) reported no difference in knee symptoms (WOMAC pain odds ratio [OR] =1.92, 95%CI 0.699-5.248, P = .21; KOOS symptoms OR = 2.12, 95%CI 0.740-6.065, P = .09), stiffness (OR = 1.67, 95%CI 0.653-5.583, P = .35) or functional disability (OR = 1 0.97, 95%CI 0.515-7.508, P = .32) in the knee that exhibited an ACL tear compared to the control knee. Only knee function and disability (WOMAC Disability OR = 1.12, 95%CI 1.003-1.249, P = .04) were associated with radiographic severity between index and control knees.

CONCLUSION

Individuals did not report an increase in knee pain, stiffness or disability in their ACL-deficient knee. Only disability was associated with worsening severity of radiographic OA in ACL-deficient knees.

Improving Patient Reported Outcomes and Preventing Depression and Anxiety in Older Adults With Knee Osteoarthritis: Results of a Sequenced Multiple Assignment Randomized Trial (SMART) Study

OBJECTIVE

Older adults with knee osteoarthritis (OA) and comorbid subsyndromal depressive symptoms are at elevated risk for incidental major depression or anxiety disorders. Using an indicated prevention paradigm, the authors conducted a sequenced multiple assignment randomized trial (SMART) to: 1) evaluate the effect of cognitive behavioral therapy (CBT) and physical therapy (PT), together with the temporal ordering of these interventions, on patient-reported global impression of change (P-GIC), mood, anxiety, and pain; and 2) compare the strategies' impact on incidence of common psychiatric disorders over 12-months.

METHODS

This intervention development trial compared four adaptive strategies delivered in two stages (each up to 8 weeks), contrasted with enhanced usual care (EUC). The strategies were CBT followed by an increased dose of CBT (CBT-CBT), CBT followed by PT (CBT-PT), PT followed by an increased dose of PT (PT-PT), and PT followed by CBT (PT-CBT). Participants (n = 99) were aged 60 years and older and met clinical criteria for knee OA and subthreshold depression. Response was defined as at least "much better" on the P-GIC. Participants were assessed quarterly for 12 months for incidence of psychiatric disorders.

RESULTS

Stage 1 response was higher for PT (47.5%) compared to CBT (20.5%). Non-responders receiving an additional dose of the same intervention experienced a response rate of 73%, higher than for switching to a different intervention. All strategies were superior to EUC (5%). Although not powered to detect effects on disorders, neither intervention strategy nor response status affected 12-month incidence of depression and anxiety disorders.

CONCLUSION

As response rates were similar for PT-PT and CBT-CBT, it may be dose and not type of these interventions that are necessary for clinical benefit. For non-responders, this finding may guide providers to stay the clinical course for up to 12 weeks before switching. These results support future trials of SMART designs in late-life depression prevention.

Exploratory Study of 6-Month Pain Trajectories in Individuals With Predominant Patellofemoral Osteoarthritis: A Cohort Study

BACKGROUND

Knowledge of patellofemoral osteoarthritis (OA) pain trajectories is vital to helping clinicians and patients make shared disease-specific decisions regarding treatment options and coping strategies.

OBJECTIVES

To describe the pain trajectories of people living with patellofemoral OA who present to a chronic care management program, and to explore baseline characteristics associated with different trajectories.

METHODS

In this prospective longitudinal cohort study, 88 participants who presented to a chronic care management program reported their worst pain over the previous week at baseline and at 6, 12, 18, and 26 weeks using a 10-cm visual analog scale. Trajectories (classes) were identified using latent class growth analysis. Demographics, pain, physical performance, strength, quality of life, mental health, and lower limb/foot structural measures obtained at baseline were assessed for association with trajectory class membership.

RESULTS

Individuals in class 1 (28%) exhibited high, persistent pain from baseline (7.8 ± 1.7 cm), which continued over time (P = .52). Class 2 (57%) displayed moderate baseline pain (4.8 ± 1.8 cm), which also remained persistent (P = .97). Individuals in class 3 (15%) showed low, improving pain (baseline pain, 2.6 ± 1.2 cm) over time (P = .017). At baseline, poor Knee injury and Osteoarthritis Outcome Score (KOOS) scores, local and proximal sensitivity to pressure, and lower knee extensor strength were associated with increased odds of following the high-pain trajectory (range [95% confidence interval], 1.03 [1.00, 1.07] to 16.24 [2.53, 104.34]).

CONCLUSION

Distinct pain trajectories appear to exist in people with patellofemoral OA presenting to a chronic care management program. Baseline variables may be useful for identifying individuals at risk of poorer prognosis. Larger studies are needed to confirm the efficacy of this finding.

LEVEL OF EVIDENCE

Prognosis, level 2b. J Orthop Sports Phys Ther 2019;49(1):5-16. Epub 12 Sep 2018. doi:10.2519/jospt.2019.8354.

Optimal primary care management of clinical osteoarthritis and joint pain in older people: a mixed-methods programme of systematic reviews, observational and qualitative studies, and randomised controlled trials

Background

Osteoarthritis (OA) is the most common long-term condition managed in UK general practice. However, care is suboptimal despite evidence that primary care and community-based interventions can reduce OA pain and disability.

Objectives

The overall aim was to improve primary care management of OA and the health of patients with OA. Four parallel linked workstreams aimed to (1) develop a health economic decision model for estimating the potential for cost-effective delivery of primary care OA interventions to improve population health, (2) develop and evaluate new health-care models for delivery of core treatments and support for self-management among primary care consulters with OA, and to investigate prioritisation and implementation of OA care among the public, patients, doctors, health-care professionals and NHS trusts, (3) determine the effectiveness of strategies to optimise specific components of core OA treatment using the example of exercise and (4) investigate the effect of interventions to tackle barriers to core OA treatment, using the example of comorbid anxiety and depression in persons with OA.

Data sources

The North Staffordshire Osteoarthritis Project database, held by Keele University, was the source of data for secondary analyses in workstream 1.

Methods

Workstream 1 used meta-analysis and synthesis of published evidence about effectiveness of primary care treatments, combined with secondary analysis of existing longitudinal population-based cohort data, to identify predictors of poor long-term outcome (prognostic factors) and design a health economic decision model to estimate cost-effectiveness of different hypothetical strategies for implementing optimal primary care for patients with OA. Workstream 2 used mixed methods to (1) develop and test a ‘model OA consultation’ for primary care health-care professionals (qualitative interviews, consensus, training and evaluation) and (2) evaluate the combined effect of a computerised ‘pop-up’ guideline for general practitioners (GPs) in the consultation and implementing the model OA consultation on practice and patient outcomes (parallel group intervention study). Workstream 3 developed and investigated in a randomised controlled trial (RCT) how to optimise the effect of exercise in persons with knee OA by tailoring it to the individual and improving adherence. Workstream 4 developed and investigated in a cluster RCT the extent to which screening patients for comorbid anxiety and depression can improve OA outcomes. Public and patient involvement included proposal development, project steering and analysis. An OA forum involved public, patient, health professional, social care and researcher representatives to debate the results and formulate proposals for wider implementation and dissemination.

Results

This programme provides evidence (1) that economic modelling can be used in OA to extrapolate findings of cost-effectiveness beyond the short-term outcomes of clinical trials, (2) about ways of implementing support for self-management and models of optimal primary care informed by National Institute for Health and Care Excellence recommendations, including the beneficial effects of training in a model OA consultation on GP behaviour and of pop-up screens in GP consultations on the quality of prescribing, (3) against adding enhanced interventions to current effective physiotherapy-led exercise for knee OA and (4) against screening for anxiety and depression in patients with musculoskeletal pain as an addition to current best practice for OA.

Conclusions

Implementation of evidence-based care for patients with OA is feasible in general practice and has an immediate impact on improving the quality of care delivered to patients. However, improved levels of quality of care, changes to current best practice physiotherapy and successful introduction of psychological screening, as achieved by this programme, did not substantially reduce patients’ pain and disability. This poses important challenges for clinical practice and OA research.

Limitations

The key limitation in this work is the lack of improvement in patient-reported pain and disability despite clear evidence of enhanced delivery of evidence-based care.

Future work recommendations

(1) New thinking and research is needed into the achievable and desirable long-term goals of care for people with OA, (2) continuing investigation into the resources needed to properly implement clinical guidelines for management of OA as a long-term condition, such as regular monitoring to maintain exercise and physical activity and (3) new research to identify subgroups of patients with OA as a basis for stratified primary care including (i) those with good prognosis who can self-manage with minimal investigation or specialist treatment, (ii) those who will respond to, and benefit from, specific interventions in primary care, such as physiotherapy-led exercise, and (iii) develop research into effective identification and treatment of clinically important anxiety and depression in patients with OA and into the effects of pain management on psychological outcomes in patients with OA.

Trial registration

Current Controlled Trials ISRCTN06984617, ISRCTN93634563 and ISRCTN40721988.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research Programme and will be published in full inProgramme Grants for Applied Research Programme; Vol. 6, No. 4. See the NIHR Journals Library website for further project information.

Emerging Treatment Models in Rheumatology: Challenges for Osteoarthritis Trials

At a time when advancing understanding of osteoarthritis (OA) has created opportunities for new treatments, development of treatments has remained considerably behind advances in other rheumatic diseases. We describe elements of trial design and measurements that have inhibited success and offer suggestions that may help break the log jam. Among the problems with trials that include pain as an outcome measure are reliance on a single, non-optimal pain outcome, overestimation of likely effects of treatments on pain, and failure to identify patient subgroups most likely to respond to specific treatments. With regard to the use of structure modification as an outcome measure, demonstrating structure modification is often highly challenging, even with the use of magnetic resonance imaging. Many OA patients have advanced disease that is unlikely to respond to treatments that prevent cartilage loss. Further, prevention of cartilage loss and reduction of pain correlate weakly at best, and in at least some patients, reduction in pain may actually increase joint damage, making it impossible to demonstrate dual treatment effects on structure and pain in such scenarios. For structure outcomes, treatment effects on pain-sensitive structures such as bone and synovium may be more achievable than preventing cartilage loss. We suggest that changes in trial design related to some of these issues may increase the chances that new exciting and effective OA treatments will become available.

Effects of laying on of hands with and without a spiritual context on pain and functionality of older women with knee osteoarthritis: study protocol for a randomized controlled trial

BACKGROUND

Laying on of hands (LooH) is a culturally-accepted therapy in several traditions. In Brazil, "Spiritism" (third-largest religious tradition in number of followers) uses LooH with the name of "Spiritist Passe" (SP). However, there are few studies assessing SP's role in medical outcomes. The present study aims to investigate the effects of LooH, with and without a spiritual context, on pain, joint stiffness, and functional capacity of older women (≥60 years old) with knee osteoarthritis (KOA).

METHODS/DESIGN

In this triple-blind, prospective randomized controlled trial, older women with KOA are assigned to three groups: LooH with a spiritual context group, LooH group without a spiritual context, and a control group receiving no intervention. Patients are assessed by a blinded researcher at baseline, 8 weeks, and 16 weeks. Pain, joint stiffness, and functional capacity are assessed using Western Ontario and McMaster Universities Osteoarthritis Index. Other measures such as anxiety, depression, gait speed, and quality of life will also be assessed. To detect differences between groups, a post-intervention comparison between the three groups and a mean change (post-pre) comparison among the three groups will be done using analysis of variance. All statistical analyses will be performed using an intention-to-treat approach and a per-protocol analysis.

DISCUSSION

A pragmatic design using SP, LooH without spiritual context, and no LooH may provide further scientific evidence on SP's feasibility and efficacy for KOA patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT02917356.

Knee Extensor Strength and Risk of Structural, Symptomatic, and Functional Decline in Knee Osteoarthritis: A Systematic Review and Meta-Analysis

OBJECTIVE

To perform a systematic review and meta-analysis on the association between knee extensor strength and the risk of structural, symptomatic, or functional deterioration in individuals with or at risk of knee osteoarthritis (KOA).

METHODS

We systematically identified and methodologically appraised all longitudinal studies (≥1-year followup) reporting an association between knee extensor strength and structural (tibiofemoral, patellofemoral), symptomatic (self-reported, knee replacement), or functional (subjective, objective) decline in individuals with or at risk of radiographic or symptomatic KOA. Results were pooled for each of the above associations using meta-analysis, or if necessary, summarized according to a best-evidence synthesis.

RESULTS

Fifteen studies were included, evaluating >8,000 participants (51% female), with a followup time between 1.5 and 8 years. Meta-analysis revealed that lower knee extensor strength was associated with an increased risk of symptomatic (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] pain: odds ratio [OR] 1.35, 95% confidence interval [95% CI] 1.10-1.67) and functional decline (WOMAC function: OR 1.38, 95% CI 1.00-1.89, and chair-stand task: OR 1.03, 95% CI 1.03-1.04), but not increased risk of radiographic tibiofemoral joint space narrowing (JSN) (OR 1.15, 95% CI 0.84-1.56). No trend in risk was observed for KOA status (present versus absent). Best-evidence synthesis showed inconclusive evidence for lower knee extensor strength being associated with increased risk of patellofemoral deterioration.

CONCLUSION

Meta-analysis showed that lower knee extensor strength is associated with an increased risk of symptomatic and functional deterioration, but not tibiofemoral JSN. The risk of patellofemoral deterioration in the presence of knee extensor strength deficits is inconclusive.

Clinical Prediction Models for Patients With Nontraumatic Knee Pain in Primary Care: A Systematic Review and Internal Validation Study

Study Design Systematic review and validation study. Background Many prognostic models of knee pain outcomes have been developed for use in primary care. Variability among published studies with regard to patient population, outcome measures, and relevant prognostic factors hampers the generalizability and implementation of these models. Objectives To summarize existing prognostic models in patients with knee pain in a primary care setting and to develop and internally validate new summary prognostic models. Methods After a sensitive search strategy, 2 reviewers independently selected prognostic models for patients with nontraumatic knee pain and assessed the methodological quality of the included studies. All predictors of the included studies were evaluated, summarized, and classified. The predictors assessed in multiple studies of sufficient quality are presented in this review. Using data from the Musculoskeletal System Study (BAS) cohort of patients with a new episode of knee pain, recruited consecutively by Dutch general medical practitioners (n = 372), we used predictors with a strong level of evidence to develop new prognostic models for each outcome measure and internally validated these models. Results Sixteen studies were eligible for inclusion. We considered 11 studies to be of sufficient quality. None of these studies validated their models. Five predictors with strong evidence were related to function and 6 to recovery, and were used to compose 2 prognostic models for patients with knee pain at 1 year. Running these new models in another data set showed explained variances (R²) of 0.36 (function) and 0.33 (recovery). The area under the curve of the recovery model was 0.79. After internal validation, the adjusted R² values of the models were 0.30 (function) and 0.20 (recovery), and the area under the curve was 0.73. Conclusion We developed 2 valid prognostic models for function and recovery for patients with nontraumatic knee pain, based on predictors with strong evidence. A longer duration of complaints predicted poorer function but did not adequately predict chance of recovery. Level of Evidence Prognosis, levels 1a and 1b. J Orthop Sports Phys Ther 2017;47(8):518-529. Epub 16 Jun 2017. doi:10.2519/jospt.2017.7142.

Structural predictors of response to intra-articular steroid injection in symptomatic knee osteoarthritis

Background

The aim was to examine if structural factors could affect response to intra-articular steroid injections (IASI) in knee osteoarthritis (OA).

Method

Persons with painful knee OA participated in an open-label trial of IASI where radiographic joint space narrowing (JSN) and Kellgren-Lawrence (KL) grade, whole-organ magnetic resonance imaging (MRI) scores (WORMS) and quantitative assessment of synovial tissue volume (STV) were assessed on baseline images. Participants completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) and a question about knee pain with a visual analogue scale for pain during nominated activity (VAS_NA), and Outcome Measures in Rheumatology (OMERACT)-Osteoarthritis Research Society International (OARSI) criteria were used to assess responder status within 2 weeks (short term) and 6 months (longer term). Regression models were used to examine predictors of short and longer term response to IASI.

Results

Subjects (n = 207) attended and had IASI. Information on responder status was available on 199 participants. Of these, 188 subjects, mean age 63.2 years (standard deviation (SD) 10.3), 97 (51.6%) female, had x-rays and 120 had MRI scans available. Based on the OMERACT-OARSI criteria, 146 (73.4%) participants responded to therapy and 40 (20.1%) were longer term responders. A few factors were associated with a reduced KOOS-pain and VAS_NA response though none were associated with OMERACT-OARSI responder status in the short term. Higher MRI meniscal damage (odds ratio (OR) = 0.74; 95% CI 0.55 to 0.98), increasing KL maximal grade (OR = 0.43; 95% CI 0.23 to 0.82) and joint space narrowing (JSN) maximal score (OR = 0.60; 95% CI 0.36 to 0.99) were each associated with a lower odds of longer term responder status. Baseline synovitis was not associated with treatment response. The predicted probability of longer term response decreased from 38% to 12% as baseline maximal JSN increased from grade 0 to 3.

Conclusion

Compared with those who have mild structural damage, persons with more severe knee damage on either MRI or x-ray are less likely to respond to knee IASI.

Trial registration

ISRCTN.com, ISRCTN07329370. Registered 21 May 2010. Retrospectively registered

The Influence of Knee Pain Location on Symptoms, Functional Status, and Knee-related Quality of Life in Older Adults With Chronic Knee Pain: Data From the Osteoarthritis Initiative

OBJECTIVE

To evaluate whether knee pain location can influence symptoms, functional status, and knee-related quality of life in older adults with chronic knee pain.

MATERIALS AND METHODS

A total of 2959 painful knees from the Osteoarthritis Initiative database were analyzed. Trained interviewers recorded patient-reported location of knee pain. Painful knees were divided into 3 groups of patellofemoral only pain, tibiofemoral only pain, and combined pain. Self-reported knee-specific symptoms, functional status, and knee-related quality of life were assessed using the Knee Injury and Osteoarthritis Outcome Score.

RESULTS

The most common knee pain pattern was tibiofemoral only pain (62%), followed by patellofemoral only pain (23%), and combined pain (15%). The combined pain pattern was associated with greater odds of reporting pain, symptoms, sports, or recreational activity limitations and lower knee-related quality of life compared with either isolated knee pain patterns, after adjusting for demographics and radiographic disease severity. Individual item analysis further revealed that patients with combined pain had greater odds of reporting difficulty with daily weight-bearing activities that required knee bending compared with tibiofemoral or patellofemoral only pain patterns. Furthermore, symptoms, functional status, and knee-related quality of life were comparable between patients with patellofemoral and tibiofemoral only pain patterns, after adjusting for demographics and radiographic disease severity.

DISCUSSION

Combined patellofemoral and tibiofemoral pain is associated with poorer clinical presentation compared with isolated knee pain from either location. In addition, patellofemoral pain in isolation may be as important as tibiofemoral pain in causing symptoms and functional limitation in older adults with chronic knee pain.

Physical Activity Minimum Threshold Predicting Improved Function in Adults With Lower-Extremity Symptoms

OBJECTIVE

To identify an evidence-based minimum physical activity threshold to predict improved or sustained high function for adults with lower-extremity joint symptoms.

METHODS

Prospective multisite data from 1,629 adults, age ≥49 years with symptomatic lower-extremity joint pain/aching/stiffness, participating in the Osteoarthritis Initiative accelerometer monitoring substudy were clinically assessed 2 years apart. Improved/high function in 2-year gait speed and patient-reported outcomes (PROs) were based on improving or remaining in the best (i.e., maintaining high) function quintile compared to baseline status. Optimal thresholds predicting improved/high function were investigated using classification trees for the legacy federal guideline metric requiring 150 minutes/week of moderate-vigorous (MV) activity in bouts lasting 10 minutes or more (MV-bout) and other metrics (total MV, sedentary, light intensity activity, nonsedentary minutes/week).

RESULTS

Optimal thresholds based on total MV minutes/week predicted improved/high function outcomes more strongly than the legacy or other investigated metrics. Meeting the 45 total MV minutes/week threshold had increased relative risk (RR) for improved/high function (gait speed RR 1.8, 95% confidence interval [95% CI] 1.6, 2.1 and PRO physical function RR 1.4, 95% CI 1.3, 1.6) compared to less active adults. Thresholds were consistent across sex, body mass index, knee osteoarthritis status, and age.

CONCLUSION

These results supported a physical activity minimum threshold of 45 total MV minutes/week to promote improved or sustained high function for adults with lower-extremity joint symptoms. This evidence-based threshold is less rigorous than federal guidelines (≥150 MV-bout minutes/week) and provides an intermediate goal towards the federal guideline for adults with lower-extremity symptoms.

Prognosis of Pain and Physical Functioning in Patients With Knee Osteoarthritis: A Systematic Review and Meta-Analysis

OBJECTIVE

To systematically summarize the literature on the course of pain in patients with knee osteoarthritis (OA), prognostic factors that predict deterioration of pain, the course of physical functioning, and prognostic factors that predict deterioration of physical functioning in persons with knee OA.

METHODS

A search was conducted in PubMed, CINAHL, Embase, Psych-INFO, and SPORTDiscus up to January 2014. A meta-analysis and a qualitative data synthesis were performed.

RESULTS

Of the 58 studies included, 39 were of high quality. High heterogeneity across studies (I(2)  >90%) and within study populations (reflected by large SDs of change scores) was found. Therefore, the course of pain and physical functioning was interpreted to be indistinct. We found strong evidence for a number of prognostic factors predicting deterioration in pain (e.g., higher knee pain at baseline, bilateral knee symptoms, and depressive symptoms). We also found strong evidence for a number of prognostic factors predicting deterioration in physical functioning (e.g., worsening in radiographic OA, worsening of knee pain, lower knee extension muscle strength, lower walking speed, and higher comorbidity count).

CONCLUSION

Because of high heterogeneity across studies and within study populations, no conclusions can be drawn with regard to the course of pain and physical functioning. These findings support current research efforts to define subgroups or phenotypes within knee OA populations. Strong evidence was found for knee characteristics, clinical factors, and psychosocial factors as prognostics of deterioration of pain and physical functioning.

Six-year course and prognosis of traumatic knee symptoms in general practice: Cohort study

BACKGROUND

Traumatic knee symptoms are frequently seen, however, evidence about the course and prognostic factors are scarce.

OBJECTIVES

To describe the one and six-year course of traumatic knee symptoms presenting in general practice, and to identify prognostic factors for persistent knee symptoms.

METHODS

Adolescents (≥12 years) and adults with traumatic knee symptoms (n = 328) from general practice were followed for six years with self-report questionnaires and physical examination.

RESULTS

Persistent knee symptoms were reported by 27% of the patients at one year and by 33% at six years. There was a strong relationship (OR: 11.0, 95% CI: 5.0-24.2) between having persistent knee symptoms at one year and at six-year follow-up. Prognostic factors associated with persistent knee symptoms at one year were age, poor general health, history of non-traumatic knee symptoms, absence floating patella and laxity on the anterior drawer test (AUC: 0.72). At six-year follow-up, age, body mass index > 27, non-skeletal co-morbidity, self-reported crepitus of the knee, history of non-traumatic knee symptoms, and laxity on the anterior drawer test were associated with persistent knee symptoms (AUC: 0.82).

CONCLUSION

Traumatic knee symptoms in general practice seem to become a chronic disorder in one out of three patients. Several prognostic factors assessed at baseline were associated with persistent knee symptoms at one and six-year follow-up.

Differentiation between osteoarthritis and psoriatic arthritis: implications for pathogenesis and treatment in the biologic therapy era

Rheumatologists have long considered OA and PsA as two completely distinct arthropathies. This review highlights how some forms of generalized OA and PsA may afflict the same entheseal-associated anatomical territories. While degeneration or inflammation may be clearly discernible at the two extremes, there may be a group of patients where differentiation is impossible. Misdiagnosis of a primary degeneration-related pathology as being part of the PsA spectrum could lead to apparent failure of disease-modifying agents, including apparent anti-TNF and apparent IL23/17 axis therapy failure. This is not a reflection of poor clinical acumen, but rather a failure to appreciate that the pathological process overlaps in the two diseases. Whether the category of OA-PsA overlap disease exists or whether it represents the co-occurrence of two common arthropathies that afflict the same anatomical territories has implications for the optimal diagnosis and management of both OA and PsA.

Decrease of muscle strength is associated with increase of activity limitations in early knee osteoarthritis: 3-year results from the cohort hip and cohort knee study

OBJECTIVE

To determine whether a decrease in muscle strength over 3 years is associated with an increase in activity limitations in persons with early symptomatic knee osteoarthritis (OA), and to examine whether the longitudinal association between muscle strength and activity limitations is moderated by knee joint proprioception and laxity.

DESIGN

A longitudinal cohort study with 3-year follow-up. Measurements were performed at the second (t0) and fifth (t1) year of the Cohort Hip and Cohort Knee (CHECK) study. Statistical analyses included paired t tests, chi-square tests, and regression analyses. In regression analyses, the association between muscle strength and activity limitations was adjusted for confounders.

SETTING

A rehabilitation and rheumatology center.

PARTICIPANTS

Subjects (N=146) with early symptomatic knee OA from the CHECK study.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Muscle strength, proprioception, and laxity were assessed using specifically designed measurement devices. Self-reported and performance-based activity limitations were measured with the Western Ontario and McMaster Universities Osteoarthritis Index, the Get Up and Go test, the walk test, and the stair-climb test.

RESULTS

A total of 116 women (79.5%) and 30 men (20.5%), with a mean age ± SD of 58.4±4.9 years and a mean body mass index ± SD of 25.5±3.6, were included in the study. Overall, small 3-year changes in muscle strength and activity limitations were observed. At the group level, the average muscle strength increased by 10% (1.0±0.3 to 1.1±0.3Nm/kg) over the 3 years. The 3-year decrease in muscle strength was independently associated with an increase in performance-based activity limitations on all 3 measures (B=-1.12, B=-5.83, and B=-1.25, respectively). Proprioception and laxity did not moderate this association.

CONCLUSIONS

In patients with early knee OA, decreased muscle strength is associated with an increase in activity limitations. Our results are a step toward understanding the role of muscle weakness in the development of activity limitations in knee OA. Further well-designed experimental studies are indicated to establish the causal role of muscle weakness in activity limitations.

The avoidance model in knee and hip osteoarthritis: a systematic review of the evidence

The avoidance model in patients with knee and hip osteoarthritis (OA) hypothesizes that pain and psychological distress lead to avoidance of activities, and thereby to muscle weakness and activity limitations. This paper systematically reviews the scientific evidence for the validity of this avoidance model. A qualitative data synthesis was used to identify levels of evidence. Sixty studies were included. In knee OA, strong evidence was found that avoidance of activities is associated with activity limitations via muscle weakness (mediation by muscle weakness), strong evidence was found for an association between muscle weakness and activity limitations, and weak evidence was found that pain and psychological distress are associated with muscle weakness via avoidance of activities (mediation by avoidance). In hip OA, weak evidence was found for mediation by muscle weakness; and strong evidence was found for an association between muscle weakness and activity limitations. More research is needed on the consecutive associations between pain or psychological distress, avoidance of activities and muscle weakness, and to confirm causal relationships.

Indian hedgehog in synovial fluid is a novel marker for early cartilage lesions in human knee joint

To determine whether there is a correlation between the concentration of Indian hedgehog (Ihh) in synovial fluid (SF) and the severity of cartilage damage in the human knee joints, the knee cartilages from patients were classified using the Outer-bridge scoring system and graded using the Modified Mankin score. Expression of Ihh in cartilage and SF samples were analyzed with immunohistochemistry (IHC), western blot, and enzyme-linked immunosorbent assay (ELISA). Furthermore, we detected and compared Ihh protein levels in rat and mice cartilages between normal control and surgery-induced osteoarthritis (OA) group by IHC and fluorescence molecular tomography in vivo respectively. Ihh expression was increased 5.2-fold in OA cartilage, 3.1-fold in relative normal OA cartilage, and 1.71-fold in OA SF compared to normal control samples. The concentrations of Ihh in cartilage and SF samples was significantly increased in early-stage OA samples when compared to normal samples (r = 0.556; p < 0.001); however, there were no significant differences between normal samples and late-stage OA samples. Up-regulation of Ihh protein was also an early event in the surgery-induced OA models. Increased Ihh is associated with the severity of OA cartilage damage. Elevated Ihh content in human knee joint synovial fluid correlates with early cartilage lesions.

The epidemiology and impact of pain in osteoarthritis

Osteoarthritis (OA) is the most common form of arthritis and a leading cause of disability worldwide, largely due to pain, the primary symptom of the disease. The pain experience in knee OA in particular is well-recognized as typically transitioning from intermittent weight-bearing pain to a more persistent, chronic pain. Methods to validly assess pain in OA studies have been developed to address the complex nature of the pain experience. The etiology of pain in OA is recognized to be multifactorial, with both intra-articular and extra-articular risk factors. Nonetheless, greater insights are needed into pain mechanisms in OA to enable rational mechanism-based management of pain. Consequences of pain related to OA contribute to a substantial socioeconomic burden.

Effects of balance training on functional outcome after total knee replacement in patients with knee osteoarthritis: a randomized controlled trial

Objective:

To evaluate the effectiveness of additional balance training on mobility and function outcome in patients with knee osteoarthritis after total knee replacement.

Design:

A prospective intervention study and randomized controlled trial.

Setting:

A university-based teaching hospital.

Participants:

Patients who received total knee replacement surgery were recruited sequentially from the orthopedic department. They were randomly assigned to either the experimental group or control group.

Interventions:

The control group received conventional function training for eight weeks. The experimental group not only received the same conventional training as the control group, but also received additional balance exercises in each admission.

Main outcome measures:

Before and after training we took the following measurements: distance of functional forward reach; duration of single leg stance; timed sit-to-stand test; timed up-and-down stair test; timed 10-m walk; timed up-and-go test; and the Western Ontario and McMaster Universities Osteoarthritis Index score.

Results:

58 patients in the experimental group with a mean (SD) age of 71.4 (6.6) years and 55 in the control group with mean (SD) age of 72.9 (7.3) years, completed the study. After eight-weeks intervention with additional balance exercises, the experimental group demonstrated significant changes in 10-m walk ( P < 0.001, 95% confidence interval (CI): 3.6 to 4.4 seconds) and in timed up-and-go ( P < 0.001, 95% confidence interval: 2.6 to 3.4 seconds) tests. Significant changes of all other measures and Western Ontario and McMaster Universities Osteoarthritis Index score were also observed in the experimental group (all P < 0.001).

Conclusion:

Additional balance training exerted a significant beneficial effect on the function recovery and mobility outcome in patients with knee osteoarthritis after total knee replacement.

Epidemiology of osteoarthritis and associated comorbidities

Osteoarthritis (OA) is the most common cause of walking-related disability among older adults in the United States, and the prevalence and incidence of OA are increasing rapidly. Systemic and local risk factors for knee OA have been identified, and obesity and joint injury appear to be the strongest risk factors that are both modifiable and have the potential for substantial impact on a population level. The risk factors for functional decline and disability in persons with symptomatic OA have been examined in relatively few studies. The course of functional decline in persons with symptomatic OA on a population level is generally one of stable to slowly deteriorating function, but on an individual level, many patients maintain function or improve during the first 3 years of follow-up. Obesity stands out as one of few modifiable risk factors of OA that also is a potentially modifiable predictor of functional decline. Physical activity also appears to have a substantial protective impact on future OA-related disability. Further epidemiologic studies and randomized controlled trials are needed to prioritize prevention through targeting these modifiable risk factors for OA and related disability.

A randomized controlled trial comparing patellar retention versus patellar resurfacing in primary total knee arthroplasty: 5-10 year follow-up

Background

The primary purpose of this randomized controlled trial (RCT) was to compare knee-specific outcomes (stiffness, pain, function) between patellar retention and resurfacing up to 10 years after primary total knee arthroplasty (TKA). Secondarily, we compared re-operation rates.

Methods

38 subjects with non-inflammatory arthritis were randomized at primary TKA surgery to receive patellar resurfacing (n = 21; Resurfaced group) or to retain their native patella (n = 17; Non-resurfaced group). Evaluations were performed preoperatively, one, five and 10 years postoperatively by an evaluator who was blinded to group allocation. Self-reported knee-specific stiffness, pain and function, the primary outcomes, were measured by the Western Ontario McMaster Osteoarthritis Index (WOMAC). Revision rate was determined at each evaluation and through hospital record review.

Results

30 (88%) and 23 (72%) of available subjects completed the five and 10-year review respectively. Knee-specific scores continued to improve for both groups over the 10-years, despite diminishing overall health with no significant group differences seen. All revisions occurred within five years of surgery (three Non-resurfaced subjects; one Resurfaced subject) (p = 0.31). Two revisions in the Non-resurfaced group were due to persistent anterior knee pain.

Conclusions

We found no differences in knee-specific results between groups at 5–10 years postoperatively. The Non-resurfaced group had two revisions due to anterior knee pain similar to rates reported in other studies. Knee-specific results provide useful postoperative information and should be used in future studies comparing patellar management strategies.

ClinicalTrials.gov identifier

NCT01500252

Evaluation of separate quantitative radiographic features adds to the prediction of incident radiographic osteoarthritis in individuals with recent onset of knee pain: 5-year follow-up in the CHECK cohort

OBJECTIVE

Detailed radiographic evaluation might enable the identification of osteoarthritis (OA) earlier in the disease. This study evaluated whether and which separate quantitative features on knee radiographs of individuals with recent onset knee pain are associated with incidence of radiographic OA and persistence and/or progression of clinical OA during 5-year follow-up.

METHOD

From the Cohort Hip & Cohort Knee study participants with knee pain at baseline were evaluated. Radiographic OA development was defined as Kellgren & Lawrence (K&L) grade ≥ II at 5-year follow-up. Clinical OA was defined as persistent knee pain and as progression of Westen Ontario & McMaster Universities Osteoarthritis index (WOMAC) pain and function score during follow-up. At baseline radiographic damage was determined by quantitative measurement of separate features using Knee Images Digital Analysis, and by K&L-grading.

RESULTS

Measuring osteophyte area [odds ratio (OR) =7.0] and minimum joint space width (OR=0.7), in addition to demographic and clinical characteristics, improved the prediction of radiographic OA 5 years later [area under curve receiver operating characteristic=0.74 vs 0.64 without radiographic features]. When the predictive score (based on multivariate regression coefficients) was larger than the cut-off for optimal specificity, the chance of incident radiographic OA was 54% instead of the prior probability of 19%. Evaluating separate quantitative features performed slightly better than K&L-grading (AUC=0.70). Radiographic characteristics hardly added to prediction of clinical OA.

CONCLUSION

In individuals with onset knee pain, radiographic characteristics added to the prediction of radiographic OA development 5 years later. Quantitative radiographic evaluation in individuals with suspected OA is worthwhile when determining treatment strategies and designing clinical trials.

ARTICULAR SOUND AND CLINICAL STAGES IN KNEE ARTHROPATHY

Objective: To clarify the pathophysiology of knee arthropathy, articular sound in the knee joint was recorded using an accelerometer, vibroarthrography (VAG), during standing-up and sitting-down movements in patients with osteoarthropathy (OA) of the knees. Methods: VAG signals and angular changes of the knee joint during standing-up and sitting-down movements were recorded in patients with OA, including 17 knees with OA at Kellgren–Lawrence stage I and II, 16 knees with OA at III and IV stages, and 20 knees of age-matched control subjects. Results: The level of VAG signals was greater in knees with a higher stage of OA at 50–99 and 100–149 Hz among the groups (ANOVA with Tukey–Kramer multiple comparisons test, p < 0.01). The VAG signals did not correlate with WOMAC-pain or physical scores. Conclusions: We considered that the increase in VAG signals in these ranges of frequency corresponded with pathological changes of OA, but not self-reported clinical symptoms. This method of VAG can be used by clinicians during interventions to obtain pathological information regarding structural changes of the knee joint.

Type II collagen fragment HELIX-II is a marker for early cartilage lesions but does not predict the progression of cartilage destruction in human knee joint synovial fluid

To determine whether there is a direct correlation between the concentration of type II collagen fragment HELIX-II in synovial fluid and the severity of cartilage damage at the knee joint, 83 patients who had undergone knee arthroscopy or total knee replacement were enrolled in this study (49% women, mean ± SD age 49.5 ± 19). The content of HELIX-II in the synovial fluid samples was measured by enzyme-linked immunosorbent assay (ELISA). Cartilage damage at the knee joint was classified during arthroscopy or direct surgical observation, using the Outerbridge cartilage damage scoring system. The maximum damage score was defined as the highest score among the six areas of the knee joint, and the cumulative score was defined as the sum of the scores of the six areas of the knee joint. The intra-assay and inter-assay variations of the HELIX-II ELISA were lower than 13 and 15%, respectively. The level of HELIX-II in the severely damaged cartilage groups (cumulative scores = 11–24 or maximum score = 2–4) was much higher than in the slightly damaged cartilage groups (cumulative scores = 0–10 or maximum score = 0–1). The level of HELIX-II in cartilage from severely damaged cartilage groups was significantly higher than in the slightly damaged groups, but no significant difference was detected in the level of HELIX-II among the severely damaged cartilage sub-groups. There was a significant correlation between the HELIX-II concentration in the synovial fluid and the cumulative (r = 0.807) and maximum scores (r = 0.794). Thus, elevated HELIX-II level is correlated with early cartilage lesions, but does not have the sensitivity to predict the progression of severity of cartilage damage in the knee joint.

The association of obesity with walking independent of knee pain: the multicenter osteoarthritis study

Practice guidelines recommend addressing obesity for people with knee OA, however, the association of obesity with walking independent of pain is not known. We investigated this association within the Multicenter Osteoarthritis Study, a cohort of older adults who have or are at high risk of knee OA. Subjects wore a StepWatch to record steps taken over 7 days. We measured knee pain from a visual analogue scale and obesity by BMI. We examined the association of obesity with walking using linear regression adjusting for pain and covariates. Of 1788 subjects, the mean steps/day taken was 8872.9 ± 3543.4. Subjects with a BMI ≥35 took 3355 fewer steps per day independent of knee pain compared with those with a BMI ≤25 (95% CI -3899, -2811). BMI accounted for 9.7% of the variability of walking while knee pain accounted for 2.9%. BMI was associated with walking independent of knee pain.

Reasons for functional decline despite reductions in knee pain: the Multicenter Osteoarthritis Study

BACKGROUND

The majority of interventions for knee osteoarthritis aim to reduce knee pain with the assumption that improvements in function will automatically follow. However, this assumption is not universally true, and a paradoxical decline in function is not uncommon following reduction in knee pain.

OBJECTIVE

The purpose of this study was to examine what factors beyond knee pain are important for functional decline among people with reductions in knee pain.

DESIGN

This was an observational cohort study.

METHODS

The Multicenter Osteoarthritis Study (MOST) is a National Institutes of Health-funded longitudinal study of people who have or are at high risk for knee osteoarthritis. This study included individuals who had a meaningful reduction in pain in either knee over 30 months, defined as a 41% decrease in visual analog scale pain score with an absolute decrease of ≥20/100. Meaningful decline in walking speed was defined as a decrease of 0.1 m/s during a 20-m walk. To examine the association of risk factors with meaningful decline in walking speed, risk ratios were calculated and adjusted for potential confounders.

RESULTS

Of the 465 people with a meaningful reduction in knee pain (mean [SD] age=63.3 [7.8] years, 67% female, 82% Caucasian, mean [SD] body mass index=31.3 [6.3] kg/m(2)), 20% had a meaningful decline in walking speed. Adjusting for confounders, participants with new comorbidity and those with widespread pain had 1.8 and 1.7 times the risk of decline compared with their counterparts with no comorbidity or widespread pain (adjusted risk ratio=1.8 [95% confidence interval=1.1-3.0] and 1.7 [95% confidence interval=1.1-2.8], respectively).

LIMITATIONS

Generalizability is limited to people with a reduction in knee pain.

CONCLUSIONS

Reductions in knee pain are not always accompanied by improvements in walking speed. Health providers should consider that the onset of new comorbidity and presence of widespread pain may increase the risk of functional decline despite a reduction in knee pain.

Relationship between radiological severity and clinical and psychological factors in knee osteoarthritis

This study was designed to investigate the relationship between radiological severity and clinical and psychological factors in patients with knee osteoarthritis (OA). Patients with knee OA (n = 100) were included in the study. Radiographic staging was done using Kellgren-Lawrence (KL) radiological rating scale. Stage 1-2 changes according to KL were grouped as 'early' and stage 3-4 as 'late' radiological OA. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was used for self-reported disability. Performance-based functional assessments were measured as time needed to walk 15 m and time needed to climb ten steps. Health-related quality of life was assessed by Nottingham Health Profile (NHP). Beck Depression Inventory (BDI) was used to assess the presence and severity of depression. Social isolation was assessed by a related NHP subscale. Significantly higher scores were found in the late stage group for NHP pain, physical mobility and social isolation subscales and all WOMAC subscales. Mean BDI score was significantly higher (p = 0.001) and performance-based functional score was significantly worse (p < 0.001) in the late stage group compared to the early stage. In logistic regression analysis, NHP social isolation subscore was found to be associated with WOMAC pain subscore (p = 0.013, odds ratio [OR] = 1.163; 95% confidence interval [CI], 1.032-1.309) and radiological severity (p = 0.018, OR = 2.924; 95% CI, 1.198-7.136). Radiological severity is an important indicative factor for pain, disability, depression and social isolation. We believe that assessment of psychological involvement in addition to pain and disability might provide benefit in the management of patients with advanced radiological knee OA.

Do worsening knee radiographs mean greater chances of severe functional limitation?

OBJECTIVE

Development of functional limitation is thought to be unrelated to changes in severity of radiographic osteoarthritis (OA) of the knee. We evaluated the relationship of change in radiographic OA to the incidence of severe functional limitation.

METHODS

Participants of the Multicenter Osteoarthritis Study, a cohort study of persons with or at high risk of knee OA, were evaluated at 0 and 30 months. Subjects were classified as having no, incident, stable, or worsening radiographic OA. Incidence of severe functional limitation was defined by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function scores (≥36.1/68) and walking speed (≤1.0 meter/second) at 30 months. The relationship of the change in radiographic OA to the incidence of severe functional limitation was evaluated by calculating risk ratios adjusted for potential confounders.

RESULTS

Of the 2,210 subjects included (mean age 62 years, mean body mass index 30 kg/m², 60% women), 53% had no, 6% had incident, 14% had stable, and 27% had worsening radiographic OA. Persons with incident radiographic OA had 1.9 and 1.8 times the risk by WOMAC physical function score and walking speed, respectively, to have incident severe functional limitation compared with those with no radiographic OA over 30 months. Compared with those with stable radiographic OA, persons with worsening radiographic OA had 2.2 and 2.3 times the risk of incident severe functional limitation, respectively.

CONCLUSION

Changes in structural disease are associated with the development of severe functional limitations in persons with or even at high risk of knee OA.

The independent effect of pain in one versus two knees on the presence of low physical function in a multicenter knee osteoarthritis study

OBJECTIVE

Although knee pain severity is thought to greatly impact function, the additional contribution of pain in 1 versus 2 knees is not known. We examined the relationship between unilateral versus bilateral pain with low physical functioning at baseline and 30 months while accounting for knee pain severity.

METHODS

The Multicenter Osteoarthritis Study is a cohort study of people who have or are at high risk for knee osteoarthritis. We defined low physical function as Western Ontario and McMaster Universities Osteoarthritis Index physical functioning scores > or = 28 of 68, consistent with poor functional outcome. Incidence and improvement from low physical function were defined as scores that declined below and improved above this threshold at 30 months. We examined the association between pain in 1 or 2 knees with low physical function with risk ratios (RRs) adjusting for known confounders.

RESULTS

Of the 2,069 subjects (mean +/- SD age 63 +/- 8 years, mean +/- SD body mass index 31 +/- 6 kg/m(2), 63% women), the prevalence of low physical functioning was 50% lower among persons with unilateral pain compared with those with bilateral pain (adjusted prevalence ratio 0.5 [95% confidence interval (95% CI) 0.3-0.7]). Of those without low physical functioning at baseline, the risk of incidence at 30 months was 30% less for unilateral compared with bilateral pain (adjusted RR 0.7 [95% CI 0.5-1.0]). Of those with low physical functioning at baseline, improvement was 1.7 times more likely for those with unilateral compared with bilateral pain (adjusted RR 1.7 [95% CI 1.3-2.2]).

CONCLUSION

The presence of pain in 1 versus 2 knees provides important information regarding present and future physical functioning.

Moving to maintain function in knee osteoarthritis: evidence from the osteoarthritis initiative

OBJECTIVES

To investigate the association between baseline physical activity and 1-year functional performance in adults with knee osteoarthritis (OA).

DESIGN

Prospective cohort study of knee OA development and progression with 1-year follow-up.

SETTING

Community.

PARTICIPANTS

Osteoarthritis Initiative public data on adults with knee OA (n=2274; age, 45-79y) who participated in functional performance assessments (timed 20-m walk and chair stand test) at baseline and 1-year follow-up.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

A good 1-year performance outcome (separately defined for walk time and chair stand measures) was improvement from baseline quintile or maintenance in the best quintile.

RESULTS

Almost 2 in 5 persons with radiographic knee OA improved or maintained high performance at 1 year. Physical activity measured by the Physical Activity Scale for the Elderly (PASE) was significantly associated with good walk rate and chair stand outcomes (odds ratio per 40 units PASE [95% confidence interval]=1.13 [1.13, 1.17] and 1.10 [1.05, 1.15], respectively), as were participation in sports/recreational activities (1.45 [1.23, 1.71] and 1.29 [1.09, 1.51], respectively) and lifestyle activities (1.11 [1.06, 1.16] and 1.09 [1.04, 1.14], respectively). An independent protective relationship for these physical activity measures approached significance after adjusting for sociodemographic and health factors. Older adults reported the least baseline physical activity and least frequent good 1-year outcomes.

CONCLUSIONS

These findings support public health recommendations to be physically active in order to preserve function for persons with knee OA. Physical activity messages should specifically target older adults whose low activity levels may jeopardize their ability to maintain functional performance.

Clinically important improvement in function is common in people with or at high risk of knee OA: the MOST study

OBJECTIVE

To calculate the frequency of clinically important improvement in function over 30 months and identify risk factors in people who have or are at risk of knee osteoarthritis (OA).

METHODS

Subjects were from the Multicenter Osteoarthritis (MOST), a longitudinal study of persons with or at high risk of knee OA. We defined minimal clinically important improvement (MCII) with the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) physical function using 3 different methods. Baseline risk factors tested for improvement included age, sex, educational attainment, presence of radiographic knee OA (ROA), the number of comorbidities, body mass index (BMI), knee pain, walking speed, isokinetic knee extensor strength, depressive symptoms, physical activity, and medication usage. We used logistic regression to evaluate the association of baseline risk factors with MCII.

RESULTS

Of the 1801 subjects (mean age 63 yrs, BMI = 31, 63% women), most had mild limitations in baseline function (WOMAC = 19 +/- 11). Regardless of how defined, a substantial percentage of subjects (24%-39%) reached MCII at 30 months. Compared to their counterparts, people with MCII were less likely to have ROA and to use medications, and were more likely to have a lower BMI, less knee pain, a faster walking speed, more knee strength, and fewer depressive symptoms. After adjustment, MCII was 40% to 50% less likely in those with ROA, and 1.9 to 2.0 times more likely in those walking 1.0 meters/second faster than counterparts.

CONCLUSION

Clinically important improvement is frequent in people with or at high risk of knee OA. The absence of ROA and a faster walking speed appear to be associated with clinically important improvements.

Pre-radiographic MRI findings are associated with onset of knee symptoms: the most study

OBJECTIVE

Magnetic resonance imaging (MRI) has greater sensitivity to detect osteoarthritis (OA) damage than radiographs but it is uncertain which MRI findings in early OA are clinically important. We examined MRI abnormalities detected in knees without radiographic OA and their association with incident knee symptoms.

METHOD

Participants from the Multicenter Osteoarthritis Study (MOST) without frequent knee symptoms (FKS) at baseline were eligible if they also lacked radiographic features of OA at baseline. At 15 months, knees that developed FKS were defined as cases while control knees were drawn from those that remained without FKS. Baseline MRIs were scored at each subregion for cartilage lesions (CARTs); osteophytes (OST); bone marrow lesions (BML) and cysts. We compared cases and controls using marginal logistic regression models, adjusting for age, gender, race, body mass index (BMI), previous injury and clinic site.

RESULTS

36 case knees and 128 control knees were analyzed. MRI damage was common in both cases and controls. The presence of a severe CART (P=0.03), BML (P=0.02) or OST (P=0.02) in the whole knee joint was more common in cases while subchondral cysts did not differ significantly between cases and controls (P>0.1). Case status at 15 months was predicted by baseline damage at only two locations; a BML in the lateral patella (P=0.047) and at the tibial subspinous subregions (P=0.01).

CONCLUSION

In knees without significant symptoms or radiographic features of OA, MRI lesions of OA in only a few specific locations preceded onset of clinical symptoms and suggest that changes in bone play a role in the early development of knee pain. Confirmation of these findings in other prospective studies of knee OA is warranted.

Risk factors for functional decline in osteoarthritis of the hip or knee

PURPOSE OF REVIEW

To summarize recent studies on risk factors for functional decline (i.e. worsening of pain and activity limitations) in osteoarthritis of the hip or knee; after a long period of neglect, information on risk factors for functional decline has markedly improved in recent years.

RECENT FINDINGS

Studies show slow worsening of pain and activity limitations over time. There is a considerable between-individual variation in the course of pain and activity limitations; identification of risk factors for functional decline is therefore highly relevant. Risk factors for functional decline include characteristic physical impairments in osteoarthritis (pain, stiffness, reduced muscle strength, laxity of the knee joint, proprioceptive inaccuracy, poor standing balance and impaired range of joint motion), cognitive and visual impairments, comorbidity and overweight, psychological and social factors (anxiety, depression, fatigue, poor self-efficacy and social support), health behaviors and sociodemographic factors.

SUMMARY

The information on risk factors can be used pragmatically to construct prediction rules on functional decline in osteoarthritis patients. Both clinicians and patients value the ability to prognosticate future pain and activity limitations. Furthermore, the information on risk factors can be used to construct causative models to explain pain and activity limitations: examples include 'instability of joints' and 'avoidance of activity' as causal mechanism of pain and activity limitations. Improved understanding of pain and activity limitations is the basis for improved treatment and rehabilitation of osteoarthritis patients.