Associations between physical examination and self-reported physical function in older community-dwelling adults with knee pain

What is the Relationship Between Patients’ And Clinicians’ Reports of the Outcomes of Elective Surgery?

Objectives

To identify studies in which patients’ and clinicians’ reports of health status and complications of one of four elective operations - hip and knee replacement, varicose vein surgery and groin hernia repair - are reported, and to describe the associations that have been reported between clinicians’ and patients’ reports.

Methods

Systematic search of several bibliographic databases and review of citations of articles meeting inclusion criteria. A narrative summary of the findings was conducted.

Results

Most of the 62 studies of health status identified were for hip (23) or knee (33) disease. The literature on complications was even more limited with 12 studies of surgical site infection, one for urinary tract infection and none for lower respiratory tract infections. Procedure-specific complications were restricted to one for arthroplasties and three for hernia repair. Despite considerable variation in the findings of studies, some clear patterns emerge, albeit they are largely based on arthroplasty. Patients’ and clinicians’ views of health status generally correlate moderately (0.5-0.6) when both are reporting on the same dimension of health status. Inevitably this is confined to disability, though patients’ and clinicians’ reports of symptoms are also moderately correlated. In contrast, comparisons of different dimensions, such as patients’ reports of disability and clinicians’ reports of impairment, result in poor correlation (0.3). There is huge variation in the way postoperative complications are measured which limits the extent to which an overview can be undertaken. Despite that, moderate to strong correlations have been reported between patients’ and clinicians’ views of complications.

Conclusions

Patients’ views of their level of disability reflect clinicians’ views and can be relied upon to assess this dimension of health status. In addition, patients are the ‘gold standard’ judges of symptoms and quality of life. Given these findings, clinicians, provider managers, commissioners and politicians can be confident that patients’ reports provide an accurate indication of the outcome of elective surgery.

Predictive mechanisms linking brain opioids to chronic pain vulnerability and resilience

Chronic pain is a major global healthcare problem that is currently inadequately treated. In addition, the current use of opioids for treatment has reached far beyond the paucity of evidence for long-term benefits relative to risks. Benefit-risk models for opioid and non-opioid treatments would benefit from a rational, mechanism-based understanding of neuroplastic and neurochemical contributions to chronic pain. Here, we evaluate the findings and limitations of representative research investigating brain neuroplasticity and neurochemistry in chronic pain. In sum, the mechanisms of pain-related neuroplasticity in the brain remain poorly understood because neuroimaging studies have been largely descriptive. We argue that definition is needed of optimal (pain-resilient) and suboptimal (pain-vulnerable) functioning of the endogenous opioid system in order to identify neurochemical contributions to aberrant neuroplasticity in chronic pain. We outline the potential benefits of computational approaches that utilize evolutionary and statistical optimality principles, illustrating this approach with mechanistic hypotheses on opioid function. In particular, we discuss the role of predictive mechanisms in perceptual and associative plasticity and evidence for their modulation by endogenous opioids. Future research should attempt to utilize formal computational models to provide evidence for the clinical validity of this approach, thereby providing a rational basis for future treatment and, ideally, prevention.

LINKED ARTICLES

This article is part of a themed section on Emerging Areas of Opioid Pharmacology. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.14/issuetoc.

Physical examination findings and their relationship with performance-based function in adults with knee osteoarthritis

BACKGROUND

Many physical examination (PE) maneuvers exist to assess knee function, none of which are specific to knee osteoarthritis (KOA). The Osteoarthritis Research Society International also recommends the use of six functional performance measures to assess function in adults with KOA. While earlier studies have examined the relationship between PE findings and self-reported function or PE findings and select performance tests in adults with knee pain and KOA, few have examined the all three types of measures. This cross-sectional study specifically examines the relationships between results of PE findings, functional performance tests and self-reported function in adults with symptomatic KOA.

METHODS

We used baseline PE data from a prospective randomized controlled trial in 87 participants aged ≥40 years with symptomatic and radiographic KOA. The PE performed by three experienced physical therapists included: muscle assessment, function and special tests. Participants also completed functional performance tests and the Western Ontario and McMaster Osteoarthritis Index (WOMAC). Multivariate linear regression identified contributions of PE findings towards functional performance and WOMAC scores, adjusting for age and gender.

RESULTS

Participants' mean age was 60.4 years (SD = 10.5), mean disease duration was 8.4 years (SD = 10.1) and 27 participants had varus knee alignment. Mean WOMAC pain and function scores were 211 (SD = 113) and 709 (SD = 394), respectively. Weakness was present in major hip and knee muscles. Seventy-nine participants had a positive Ely's, 65 a positive Waldron and 49 a positive Grind. Mean 6-min walk was 404 m (SD = 83) and mean Berg Balance was 53 (SD = 4). Regression analysis identified positive findings on 5 special tests (P < 0.05) as indicative of poorer 6 min walk. Positive Apley's was associated (P < 0.05) with slower 20 m walk and a positive Ober with poorer balance scores (P < 0.05).

CONCLUSIONS

Diminished hip muscle strength and flexibility, and patella dysfunction were prevalent in these adults with symptomatic KOA. Results of functional performance tests suggest balance and walking ability are impaired and are associated with PE findings of muscle length imbalance, hip muscle weakness and patella dysfunction. None of the PE measures were associated with self-reported function. Therefore, performance-based test results may be more useful in informing rehabilitation interventions.

The relationship between the presence of depressive symptoms and the severity of self-reported knee pain in the middle aged and elderly

PURPOSE

Knee pain is a very common symptom of knee osteoarthritis (OA), and identification of the major contributors to knee pain is important to establish management plans for patients with knee OA. Among the potential contributors, we hypothesized that coexisting depressive symptoms might increase the severity of knee pain because the increased cytokine levels and neurotransmitter changes related to depression are known to influence the threshold of physical pain perception. Therefore, a possible relationship between self-reported depressive symptoms and self-reported knee pain has been explored. Additionally, we sought to determine factors influencing the severity of knee pain in a middle-aged and elderly Korean population using data from the fifth Korean National Health and Nutrition Examination Survey.

METHODS

In total, 6599 persons aged ≥50 years were evaluated in terms of the radiographic severity of OA and pain severity using 10-point numerical rating scales. Depressive mood was assessed using a polar question: "Had the subject felt despair or depression every day for more than 2 weeks during the past year?"

RESULTS

The Kellgren-Lawrence knee OA grade, depression, gender, educational level, household income, smoking status, marital status, living place, comorbidity status, BMI, and age were identified by multiple linear regression as variables affecting knee pain severity. The presence of depressive symptoms was associated with an increased risk of severe knee pain (odds ratio 2.55 [95 % confidence interval 1.77-3.66]). After stratifying the group in terms of the radiographic severity of knee OA, the relationship with depression persisted in the minimal (2.89 [1.90-4.32]) and moderate OA subgroups (2.29 [1.33-3.94]), but not in the severe OA subgroup.

CONCLUSIONS

Severe knee pain was independently associated with the presence of depressive symptoms in middle-aged and elderly Korean subjects. This suggests that screening for and treatment of depression may help improve knee pain in elderly individuals.

LEVEL OF EVIDENCE

II.

Impairment-targeted exercises for older adults with knee pain: a proof-of-principle study (TargET-Knee-Pain)

BACKGROUND

Therapeutic exercise is an effective intervention for knee pain and osteoarthritis (OA) and should be individualised. In a preliminary, proof-of-principle study we sought to develop a home exercise programme targeted at specific physical impairments of weak quadriceps, reduced knee flexion range of motion (ROM) and poor balance, and evaluate whether receipt of this was associated with improvements in those impairments and in patient-reported outcomes among older adults with knee pain.

METHODS

This community-based study used a single group, before-after study design with 12-week follow-up. Participants were 58 adults aged over 56 years with knee pain and evidence of quadriceps weakness, loss of flexion ROM, or poor balance, recruited from an existing population-based, observational cohort. Participants received a 12-week home exercise programme, tailored to their physical impairments. The programme was led, monitored and progressed by a physiotherapist over six home visits, alternating with six telephone calls. Primary outcome measures were maximal isometric quadriceps strength, knee flexion ROM and timed single-leg standing balance, measured at baseline, 6 and 12 weeks by a research nurse blinded to the nature and content of participants' exercise programmes. Secondary outcome measures included the WOMAC.

RESULTS

At 12 weeks, participants receiving strengthening exercises demonstrated a statistically significant change in quadriceps isometric strength compared to participants not receiving strengthening exercises: 3.9 KgF (95 % CI 0.1, 7.8). Changes in knee flexion ROM (2.1° (-2.3, 6.5)) and single-leg balance time (-2.4 s (-4.5, 6.7)) after stretching and balance retraining exercises respectively, were not found to be statistically significant. There were significant improvements in mean WOMAC Pain and Physical Function scores: -2.2 (-3.1, -1.2) and -5.1 (-7.8, -2.5).

CONCLUSIONS

A 12-week impairment-targeted, home-based exercise programme for symptomatic knee OA appeared to be associated with modest improvements in self-reported pain and function but no strong evidence of greater improvement in the specific impairments targeted by each exercise package, with the possible exception of quadriceps strengthening.

TRIAL REGISTRATION

Clinical Trial Registration Number: ISRCTN 61638364 Date of registration: 24 June 2010.

Maximum Power During Vertical Jump and Isometric Knee Extension Torque Alter Mobility Performance: A Cross-Sectional Study of Healthy Individuals

OBJECTIVE

To provide reference values of muscle function (MF) and mobility performance (MP) and to clarify the effects of MF on MP.

DESIGN

A normative cross-sectional study.

SETTING

An urban area of Niigata, Japan.

PARTICIPANTS

A total of 401 individuals (210 men and 191 women) with a mean age of 41.8 years (range, 7-79 years) who lived in the community and did not have impairments in activities of daily living.

METHODS

Grip strength, isometric knee extension torque (IKET), and maximum ground reaction force (Fmax) and maximum power (Pmax) during a vertical jump were used as measurements of MF. The chair-rise test (CRT) and the timed "Up and Go" test (TUG) were used to assess MP.

MAIN OUTCOME MEASUREMENTS

Mean values of GS, IKET, CRT, TUG, Fmax, and Pmax were calculated according to age and gender. A stepwise multiple regression analysis was used to identify MF factors with an effect on CRT and TUG in participants ≥20 years of age.

RESULTS

Our results showed that all MF parameters were decreased in individuals ≥20 years of age compared to those <20 years old. Moreover, all of the MP parameters increasingly deteriorated with increasing age. CRT and TUG were affected by Pmax and IKET in men and by IKET in women according to logistic regression analysis.

CONCLUSION

The study findings suggest that muscle power affects MP more than the muscle strength in persons aged ≥20 years.

Differences in health-related quality of life among subjects with frequent bilateral or unilateral knee pain: data from the Osteoarthritis Initiative study

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

To examine associations between frequent bilateral knee pain (BKP) and unilateral knee pain (UKP) and health-related quality of life (QoL). We hypothesized that frequent BKP would be associated with poorer health-related QoL than would frequent UKP and no knee pain.

BACKGROUND

Knee pain is one of the most frequently reported types of joint pain among adults in the United States. It is the most frequent cause of limited physical function, disability, and reduced QoL.

METHODS

Data were collected from the Osteoarthritis Initiative public-use data sets. Health-related QoL was assessed in 2481 participants (aged 45-79 years at baseline). The Knee injury and Osteoarthritis Outcome Score QoL subscale (knee-specific measure) and the physical component summary and mental component summary (MCS) scores of the Medical Outcomes Study 12-Item Short-Form Health Survey (SF-12) (generic measure) were used to assess health-related QoL. Multiple regression analyses were used to examine the relationships between frequent knee pain and health-related QoL, adjusted for sociodemographic and health covariates.

RESULTS

Compared with subjects with no knee pain, subjects with frequent BKP and UKP had significantly lower scores on the Knee injury and Osteoarthritis Outcome Score QoL subscale (mean difference, -35.2; standard error [SE], 0.86; P<.001 and mean difference, -29.2; SE, 0.93; P<.001; respectively) and the SF-12 physical component summary score (mean difference, -6.25; SE, 0.41; P<.001 and mean difference, -4.10; SE, 0.43; P<.001; respectively), after controlling for sociodemographic and health covariates. The SF-12 MCS score was lower among those with BKP (-1.29; SE, 0.42; P<.001). Frequent UKP was not associated with the SF-12 MCS.

CONCLUSION

Subjects with frequent BKP had lower health-related QoL than those with frequent unilateral or no knee pain, as reflected in lower Knee injury and Osteoarthritis Outcome Score QoL subscale and SF-12 physical component summary and MCS scores.

The effect of stationary walking on the quality of life of the elderly women: a randomized controlled trial

INTRODUCTION

Aging has a profound effect on all the body organs and quality of life. One of the appropriate interventions is exercises such as walking. Nevertheless, the risk of falling and its complications are lower in stationary walking than walking on ground. Due to the higher life expectancy in women than men, the increasing number of elderly, and the low quality of life of women compared to men, this study aimed to assess the impact of stationary walking on the quality of life of the elderly women.

METHODS

In this clinical trial, 66 household elderly women covered by health centers of Maragheh were randomly selected and divided into experimental and control groups. Six weeks exercise intervention was conducted. The participants completed the quality of life questionnaire of the elderly, before and after the intervention. SPSS software was used to analyze the data.

RESULTS

Mean scores of quality of life, in various aspects of the experimental group, before and after intervention, showed significant difference; there was no statistically significant difference in the control group. In addition, there was a significant difference in the mean and standard deviation of different aspects of quality of life in pre- and post-test of experiment and control groups.

CONCLUSION

Using regular and constant exercise program such as stationary walking can increase the quality of life of the elderly women. It can improve healthy aging and having a healthy life at this age, too. Therefore, it is recommended to have stationary walking program in daily lives of the elderly.

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.

Associations for change in physical and psychological factors and treatment response following exercise in knee osteoarthritis: an exploratory study

OBJECTIVE

Understanding how changes in physical and psychological factors following therapeutic exercise are associated with treatment outcome could have important implications for refining rehabilitation programs for knee osteoarthritis (OA). The objective of this study was to examine the association of changes in these factors with changes in pain and function after an exercise program for people with knee OA.

METHODS

In total, 152 people with knee OA completed an exercise program consisting of lower extremity strengthening, stretching, range of motion, balance and agility, and aerobic exercises. The change from baseline to the 2-month followup was calculated for physical and psychological factors, including self-reported knee instability, quadriceps strength, knee and ankle range of motion, lower extremity muscle flexibility, fear of physical activity, anxiety, and depressive symptoms. Treatment response was defined as a minimum of a 20% improvement from baseline in both a numerical knee pain rating scale and the Western Ontario and McMaster Universities Osteoarthritis Index physical function scale. The association of each factor with treatment response was examined with logistic regression mutually adjusted for age, sex, body mass index, radiographic severity, and exercise group.

RESULTS

Change in self-reported knee instability (odds ratio [OR] 1.67 [95% confidence interval (95% CI) 1.13-2.47]) and fear of physical activity (OR 0.93 [95% CI 0.88-1.00]) were the only 2 factors that were significantly associated with treatment response after adjustment for covariates.

CONCLUSION

Improvement in knee instability and fear of physical activity were associated with increased odds of a positive treatment response following therapeutic exercise in subjects with knee OA.

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.

Effects of comprehensive geriatric assessment and targeted intervention on mobility in persons aged 75 years and over: a randomized controlled trial

OBJECTIVE

To assess the effect of a comprehensive geriatric assessment and individually tailored intervention on mobility in older people. In addition, the effectiveness of the geriatric intervention was evaluated among a subgroup of persons with musculoskeletal pain.

DESIGN

Three-year geriatric development project with randomized assignment to intervention and control group.

SETTING

Research centre, community and assisted living facilities.

PARTICIPANTS

Seven hundred and eighty-one Finnish persons aged 75-98 years were assigned to an intervention (n = 404) or control (n = 377) group.

INTERVENTION

A comprehensive geriatric assessment with a multifactorial intervention lasting two years. The intervention included individualized referrals, recommendations, physical activity counselling and supervised resistance training.

MEASUREMENTS

Perceived limitation in walking 400m was gathered annually during the intervention and at the one-year post-intervention follow-up.

RESULTS

The proportion of persons with mobility limitation at the beginning, at the two-year intervention and at the one-year post-intervention follow-up was 16%, 15%, 12% and 14%, respectively, in the intervention group. In the control group, the corresponding proportions were 19%, 18%, 23% and 26%. The treatment effect was significant at the end of the two-year intervention (odds ratio 0.82, 95% confidence interval 0.70-0.96, P = 0.013), and at the one-year post-intervention follow-up (0.84, 0.75-0.94, P = 0.002). The parallel positive effect of the intervention on mobility was even greater among persons with musculoskeletal pain.

CONCLUSION

The comprehensive geriatric assessment and individually tailored multifactorial intervention had a positive effect on mobility, underlining their importance in health promotion and disability prevention in older people.

Impact of pain reported during isometric quadriceps muscle strength testing in people with knee pain: data from the osteoarthritis initiative

BACKGROUND

Muscle force testing is one of the more common categories of diagnostic tests used in clinical practice. Clinicians have little evidence to guide interpretations of muscle force tests when pain is elicited during testing.

OBJECTIVE

The purpose of this study was to examine the construct validity of isometric quadriceps muscle strength tests by determining whether the relationship between maximal isometric quadriceps muscle strength and functional status was influenced by pain during isometric testing.

DESIGN

A cross-sectional design was used.

METHODS

Data from the Osteoarthritis Initiative were used to identify 1,344 people with unilateral knee pain and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale scores of 1 or higher on the involved side. Measurements of maximal isometric quadriceps strength and ratings of pain during isometric testing were collected. Outcome variables were WOMAC physical function subscale, 20-m walk test, 400-m walk test, and a repeated chair stand test. Multiple regression models were used to determine whether pain during testing modified or confounded the relationship between strength and functional status.

RESULTS

Pearson r correlations among the isometric quadriceps strength measures and the 4 outcome measures ranged from -.36 (95% confidence interval=-.41, -.31) for repeated chair stands to .36 (95% confidence interval=.31, .41) for the 20-m walk test. In the final analyses, neither effect modification nor confounding was found for the repeated chair stand test, the 20-m walk test, the 400-m walk test, or the WOMAC physical function subscale. Moderate or severe pain during testing was weakly associated with reduced strength, but mild pain was not.

LIMITATIONS

The disease spectrum was skewed toward mild or moderate symptoms, and the pain measurement scale used during muscle force testing was not ideal.

CONCLUSIONS

Given that the spectrum of the sample was skewed toward mild or moderate symptoms and disease, the data suggest that isometric quadriceps muscle strength tests maintain their relationship with self-report or performance-based disability measures even when pain is elicited during testing.

Psychological health impact on 2-year changes in pain and function in persons with knee pain: data from the Osteoarthritis Initiative

OBJECTIVE

We determined whether baseline depressive symptoms, knee-related confidence and general psychological distress influenced changes in pain and function during 2 years of follow-up.

DESIGN

We included persons in the Osteoarthritis Initiative (OAI) dataset with baseline pain of 1 or greater on a 0-10 scale in at least one knee and no knee or hip surgery during the 2-year follow-up (n=3407). The four outcome variables were repeated chair standing, 20 m walk and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain and Disability. Linear mixed effects models assessed the association of each mental health variable with the yearly change in each baseline adjusted outcome measure after controlling for covariates.

RESULTS

Depressive symptoms were significantly predictive of worsening in most outcomes. The magnitude of worsening predicted for each year was small. For example, the dichotomized WOMAC Pain model indicated that depressed persons experience more rapid worsening than non-depressed persons at an average rate of 0.59 WOMAC points per year (95% CI 0.176, 1.013, P=0.005). Similar significant but very small effects of depressive symptoms on other outcomes were observed. Knee confidence was not predictive of change. General psychological distress was predictive of change in 20-m walk and WOMAC Pain.

CONCLUSIONS

The most consistent psychological predictor of yearly worsening was baseline depressive symptoms. Although a statistically robust predictor of outcome, given that change was very small and highly dependent on baseline status, our results indicate that a considerable degree of persistent depressive symptoms would be required to have a meaningful effect on future self-reported outcome.

Factors associated with rapid progression to knee arthroplasty: complete analysis of three-year data from the osteoarthritis initiative

OBJECTIVES

Only a few studies have identified prognostic factors indicating risk of future knee arthroplasty in patients with osteoarthritis (OA) of the knee. The Osteoarthritis Initiative (OAI) is a National Institutes of Health and privately funded cohort study of 4796 persons with or at high risk of knee OA. The OAI is ideally suited to a more extensive study of knee arthroplasty prognostic factors than has been undertaken. The purpose of our study was to identify patient factors which predict rapid progression to knee arthroplasty, defined as arthroplasty within three years of baseline data collection.

METHODS

We used alternating logistic regression models to analyze complete three year follow-up data from the OAI on 4670 persons with, or at risk for knee OA, aged 45 to 79 years during the years 2004 to 2008.

RESULTS

A total of 128 knees (116 persons) underwent knee arthroplasty during the study period. After adjusting for known prognostic factors, several previously unidentified predictors of future knee arthroplasty were found including past history of knee surgery (RR=2.04, 95% CI=1.33, 3.13), knee flexion contracture in degrees (RR=1.06, 95% CI=1.02, 1.11) and pain, on a 0 to 10 scale, with active knee flexion (RR=1.58, 95% CI=1.04, 2.39).

DISCUSSION/CONCLUSIONS

This study identifies new and easily measured clinical variables that are associated with more rapid progression to arthroplasty. The data may help to inform both physicians and patients of medical history and clinical examination findings most highly associated with short-term arthroplasty.

Difficulties in the daily life of patients with osteoarthritis of the knee: scale development and descriptive study

AIM

The aim of this study was to develop an instrument to assess difficulties in daily life experienced by patients with osteoarthritis of the knee and to investigate factors influencing difficulties in daily life.

BACKGROUND

Osteoarthritis of the knee is commonly associated with clinical symptoms and disabilities. No scale has been available to assess the comprehensive and subjective difficulties felt in daily life by patients affected in social and cultural lifestyle. Therefore, little is known about difficulties in osteoarthritis of the knee patients and supportive care necessary for them.

DESIGN

A scale development and descriptive study.

METHODS

The participants consisted of 362 patients with osteoarthritis of the knee. The scale development involved several phases including item development, reliability testing, criterion-related validity testing and construct validity testing.

RESULTS

The exploratory factor analysis included three domains: 'suffering in social life', 'hardship in activities in daily life' and 'apprehension about the future life'. A confirmatory factor analysis confirmed validity of the construct, with a demonstrated good fit between the factor structure of the new scale and the observed data. Difficulties in daily life scores were significantly influenced by pain, loss of balance, muscle weakness, stiffness and swelling.

CONCLUSION

We developed a reliable and valid scale for the measurement of difficulties in daily life experienced by patients with osteoarthritis of the knee. It is important for healthcare professionals to understand these difficulties in daily life experienced by patients with osteoarthritis of the knee and to educate patients with practical information and self-management strategies.

RELEVANCE TO CLINICAL PRACTICE

This new scale could provide useful information to guide clinical practice in assessing and managing difficulties in daily life experienced by patients with osteoarthritis of the knee.

Impairment-targeted exercises for older adults with knee pain: protocol for a proof-of-principle study

BACKGROUND

Exercise therapy for knee pain and osteoarthritis remains a key element of conservative treatment, recommended in clinical guidelines. Yet systematic reviews point to only modest benefits from exercise interventions.One reason for this might be that clinical trials tend to use a one-size-fits-all approach to exercise, effectively disregarding the details of their participants' clinical presentations. This uncontrolled before-after study (TargET-Knee-Pain) aims to test the principle that exercises targeted at the specific physical impairments of older adults with knee pain may be able to significantly improve those impairments. It is a first step towards testing the effectiveness of this more individually-tailored approach.

METHODS/DESIGN

We aim to recruit 60 participants from an existing observational cohort of community-dwelling older adults with knee pain. Participants will all have at least one of the three physical impairments of weak quadriceps, a reduced range of knee flexion and poor standing balance. Each participant will be asked to undertake a programme of exercises, targeted at their particular combination and degree of impairment(s), over the course of twelve weeks. The exercises will be taught and progressed by an experienced physiotherapist, with reference to a "menu" of agreed exercises for each of the impairments, over the course of six fortnightly home visits, alternating with six fortnightly telephone calls. Primary outcome measures will be isometric quadriceps strength, knee flexion range of motion, timed single-leg standing balance and the "Four Balance Test Scale" at 12 weeks. Key secondary outcome measures will be self-reported levels of pain, stiffness and difficulties with day-to-day functional tasks (WOMAC). Outcome measures will be taken at three time-points (baseline, six weeks and twelve weeks) by a study nurse blinded to the exercise status of the participants.

DISCUSSION

This study (TargET-Knee-Pain) is the first step towards exploring whether an impairment-targeted approach to exercise prescription for older adults with knee pain may have sufficient efficacy to warrant further testing. If warranted, future randomised clinical trials may compare this approach with more traditional one-size-fits-all exercise approaches.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN61638364.

The inter-rater reliability and diagnostic accuracy of patellar mobility tests in patients with anterior knee pain

BACKGROUND

Patients with patellofemoral pain syndrome (PFPS) often have nonspecific findings on clinical examination. A tight knee and diminished patellar mobility in particular, may contribute to anterior knee pain.

METHODS

Qualifying patients with anterior knee pain of > 4 weeks were sequentially examined by 2 physicians who used the patellar mobility tests. The tests evaluated for diminished patellar translation superior-inferiorly and medial-laterally, diminished patellar tendon mobility, and absent inferior pole tilt. Each of the 4 tests was scored as 1 (diminished/absent) or 0 (nondiminished/normal), with the sum of the scores determining the patellar mobility scale. Inter-rater reliability and diagnostic accuracy were determined and analyzed. Receiver operating characteristic analysis was used to determine the capacity of the patellar mobility scale to predict PFPS.

RESULTS

98 patients participated in the study. The inter-rater reliability for the 4 individual patellar mobility tests was moderately strong, with diminished medial-lateral patellar mobility demonstrating the strongest reliability (Kappa value [K], 0.59; 95% confidence interval [CI], 0.42-0.72), followed by diminished superior-inferior mobility (K), 0.55; 95% CI, -0.37 to 0.69), inferior pole tilt (K, 0.48; 95% CI, -0.28 to 0.61), and patellar tendon mobility (K, 0.45; 95% CI, -0.27 to 0.56). The diagnostic accuracy of the individual patellar mobility tests in diagnosing PFPS was fair to moderate, with the individual diminished patella tendon mobility test having the highest level of diagnostic accuracy (sensitivity, 49%; specificity, 83%; likelihood ratio [LR] ± 2.8; 95% CI, 1.3-7.3) and also having the highest positive predictive value (0.88). Diminished medial-lateral mobility was second in diagnostic accuracy (sensitivity, 54%; specificity, 69%; LR ± 1.8; 95% CI, 0.9-3.6). Receiver operating characteristic analysis showed only moderate levels of diagnostic capacity (area under the curve, 0.65) because combining all 4 patellar mobility tests to form the patellar mobility scale did not improve the diagnostic accuracy.

CONCLUSION

The clinical importance of diminished patellar and/or patellar tendon mobility findings in the evaluation of patients with anterior knee pain remains unclear. We determined that individual patellar mobility tests had moderate levels of inter-rater reliability, the best agreement found with medial-lateral mobility. The accuracy of the patellar mobility scale for diagnosing PFPS was marginal. As a tool, this cluster of examination techniques may be used by physicians to better understand their patients' conditions and descriptively communicate their findings. However, the patellar mobility scale cannot be used alone for determining the diagnosis of PFPS, as defined in our study. Future studies aim to determine whether post-treatment symptomatic improvements correlate with an improvement on the patellar mobility scale.

Relationships of fear, anxiety, and depression with physical function in patients with knee osteoarthritis

OBJECTIVES

To explore whether the psychologic variables anxiety, depression, and fear-avoidance beliefs, and interactions between these variables, are associated with physical function in patients with knee osteoarthritis (OA). We hypothesized lower levels of function would be related to higher anxiety, higher depression, and higher fear-avoidance beliefs, and that high levels of 2 of these factors simultaneously might interact to have a greater adverse effect on physical function.

DESIGN

Cross-sectional, correlational design.

SETTING

Institutional practice.

PARTICIPANTS

Subjects included patients with knee OA (N=182; age, mean +/- SD, 63.9+/-8.8y; 122 women).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Self-report measures of function included the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, the Lower Extremity Function Scale (LEFS), and the Knee Outcome Survey-Activity of Daily Living Scale. The Get Up and Go test was used as a physical performance measure of function. Self-report measures for psychologic variables included the Beck Anxiety Inventory, the Center for Epidemiological Studies Depression Scale, and the Fear Avoidance Belief Questionnaire-Physical Activity Scale modified for the knee.

RESULTS

Higher anxiety was related to poorer function on the WOMAC physical function. Both high anxiety and fear-avoidance beliefs were related to poorer function on the LEFS and Knee Outcome Survey-Activity of Daily Living Scale. There was no association between the psychologic variables and the Get Up and Go test. The anxiety x depression interaction was associated with the LEFS.

CONCLUSIONS

Anxiety and fear-avoidance beliefs are associated with self-report measures of function in patients with knee OA. Depression may influence scores on the LEFS under conditions of low anxiety.