Depressive symptoms and multi-joint pain partially mediate the relationship between obesity and opioid use in people with knee osteoarthritis.

OBJECTIVES: To assess the relation of obesity to opioid use in people with or at risk of knee osteoarthritis (OA), and the extent to which this association is mediated by number of painful joints or depressive symptoms. METHODS: We used data from the Multicenter Osteoarthritis Study, a longitudinal cohort of older adults with or at risk of knee OA. Opioid use was identified by prescription medications and self-report. Obesity was defined as BMI ≥ 30 kg/m2. Multi-joint pain was assessed using a standardized body homunculus, and depressive symptoms using the Center for Epidemiological Studies Depression scale. We quantified the direct and indirect effect of obesity on opioid use through the number of painful joints or depressive symptoms using causal mediation analysis by natural-effects models. RESULTS: We studied 2,335 participants (mean age: 68; mean BMI 31 kg/m2; 60% women). Persons with obesity had ∼50% higher odds of opioid use than those without. Estimates of indirect (mediated) effect by the number of painful joints and depressive symptoms suggested an increased odds of opioid use by 34% (odds ratio [OR] = 1.34, 95% CI: 1.04, 1.70) and 35% (OR 1.35, 95% CI: 1.05, 1.71), respectively, in obese vs non-obese individuals. The total effect of obesity on opioid use was higher in women than in men. CONCLUSIONS: Multi-joint pain and depressive symptoms partially explained greater opioid use among obese persons with knee OA, demonstrating that the negative impact of obesity on knee OA extends beyond its influence on knee pain and structural progression.

Does weight-bearing versus non-weight-bearing pain reflect different pain mechanisms in knee osteoarthritis?: the Multicenter Osteoarthritis Study (MOST).

OBJECTIVE: Knee osteoarthritis (OA) is predominantly characterized by pain with weight-bearing activities. Pain at rest also occurs but the mechanisms for this are not clear. We evaluated the relations of nociceptive signal alterations to weight-bearing and non-weight-bearing pain in knee OA. DESIGN: We used data from a NIH-funded longitudinal cohort of older adults with or at risk of knee OA. We evaluated quantitative sensory testing (QST) measures (pressure pain threshold (PPT) at patellae and the wrist; mechanical temporal summation (TS); conditioned pain modulation (CPM)). Each WOMAC pain question was dichotomized as having at least moderate pain, and we further categorized them as weight-bearing pain and non-weight-bearing pain. We evaluated the relation of QST measures to each pain outcome using logistic regression, adjusting for potential confounders. RESULTS: 2,749 participants (5,479 knees) were included (mean age 64 ± 11, 57% female). Each SD unit decrease in patellar PPT was associated with greater odds of both weight-bearing pain (OR 1.51 (95% CI 1.27, 1.79)) and non-weight-bearing pain (OR 1.46 (1.20-1.77)), while wrist PPT was associated with greater odds of weight-bearing pain (OR 1.27 (1.15, 1.39)) but only with pain during sitting/lying (OR 1.20 (1.01, 1.43)). TS was significantly associated with greater odds of pain with walking and stairs (OR 1.11 (1.01, 1.23), 1.11 (1.03, 1.20), respectively). CPM was not associated with any pain outcomes. CONCLUSIONS: Our findings challenge the hypothesis that non-weight-bearing pain may reflect greater pain sensitization and/or inefficient CPM than weight-bearing pain in knee OA, suggesting other mechanisms are likely responsible.

A consensus-based framework for conducting and reporting osteoarthritis phenotype research.

BACKGROUND: The concept of osteoarthritis (OA) heterogeneity is evolving and gaining renewed interest. According to this concept, distinct subtypes of OA need to be defined that will likely require recognition in research design and different approaches to clinical management. Although seemingly plausible, a wide range of views exist on how best to operationalize this concept. The current project aimed to provide consensus-based definitions and recommendations that together create a framework for conducting and reporting OA phenotype research. METHODS: A panel of 25 members with expertise in OA phenotype research was composed. First, panel members participated in an online Delphi exercise to provide a number of basic definitions and statements relating to OA phenotypes and OA phenotype research. Second, panel members provided input on a set of recommendations for reporting on OA phenotype studies. RESULTS: Four Delphi rounds were required to achieve sufficient agreement on 11 definitions and statements. OA phenotypes were defined as subtypes of OA that share distinct underlying pathobiological and pain mechanisms and their structural and functional consequences. Reporting recommendations pertaining to the study characteristics, study population, data collection, statistical analysis, and appraisal of OA phenotype studies were provided. CONCLUSIONS: This study provides a number of consensus-based definitions and recommendations relating to OA phenotypes. The resulting framework is intended to facilitate research on OA phenotypes and increase combined efforts to develop effective OA phenotype classification. Success in this endeavor will hopefully translate into more effective, differentiated OA management that will benefit a multitude of OA patients.

Concordance between physiotherapists and physicians for care of patients with musculoskeletal disorders presenting to the emergency department.

BACKGROUND: Overcrowding in emergency departments (ED) is a major concern worldwide. To answer increasing health care demands, new models of care including advanced practice physiotherapists (APP) have been implemented in EDs. The purpose of this study was to assess diagnostic, treatment and discharge plan concordance between APPs and ED physicians for patients consulting to the ED for minor musculoskeletal disorders (MSKD). METHODS: Patients presenting to two EDs in Montréal (Canada) with a minor MSKD were recruited and independently assessed by an APP and ED physician. Both providers had to formulate diagnosis, treatment and discharge plans. Cohen's kappa (κ) and Prevalence and Bias Adjusted Kappas (PABAK) with associated 95%CI were calculated. Chi Square and t-tests were used to compare treatment, discharge plan modalities and patient satisfaction between providers. RESULTS: One hundred and thirteen participants were recruited, mean age was 50.3 ± 17.4 years old and 51.3% had an atraumatic MSKD. Diagnostic inter-rater agreement between providers was very good (κ = 0.81; 95% CI: 0.72-0.90). In terms of treatment plan, APPs referred significantly more participants to physiotherapy care than ED physicians (κ = 0.27; PABAK = 0.27; 95% CI: 0.07-0.45; p = 0.003). There was a moderate inter-rater agreement (κ = 0.46; PABAK = 0.64; 95% CI: 0.46-0.77) for discharge plans. High patient satisfaction was reported with no significant differences between providers (p = 0.57). CONCLUSION: There was significant agreement between APPs and ED physicians in terms of diagnosis and discharge plans, but more discrepancies regarding treatment plans. These results tend to support the integration of APPs in ED settings, but further prospective evaluation of the efficiency of these types of models is warranted.

Adverse effects as a consequence of being the subject of orthopaedic manual therapy training, a worldwide retrospective survey.

BACKGROUND: Physical therapists (PTs) use a range of manual therapy techniques developed to an advanced level through postgraduate orthopaedic manipulative physical therapy (OMPT) programmes. The aim of this study was to describe the adverse effects experienced by students after having techniques performed on them as part of their OMPT training. DESIGN: A descriptive online survey of current students and recent graduates (≤5 years)m of OMPT programmes across the 22 Member Organisations of the International Federation of Orthopaedic Manipulative Physical Therapists. RESULTS: The questionnaire was completed by 1640 respondents across 22 countries (1263 graduates, 377 students. Some 60% of respondents reported never having experienced adverse effects during their manual therapy training. Of the 40% who did, 66.4% reported neck pain, 50.9% headache and 32% low back pain. Most reports of neck pain started after a manipulation and/or mobilisation, of which 53.4% lasted ≤24 h, 38.1% > 24 h but <3 months and 13.7% still experienced neck pain to date. A small percentage of respondents (3.3%) reported knowing of a fellow student experiencing a major adverse effect. CONCLUSION: Mild to moderate adverse effects after practising manual therapy techniques are commonly reported, but usually resolve within 24 h. However, this survey has identified the reported occurrence of major adverse effects that warrant further investigation.

A prospective cohort study examining medical and social factors associated with engagement in life activities following total hip replacement.

OBJECTIVES: Studies show limited improvement in the frequency of engaging in life activities after joint replacement. However, there is a paucity of research that has examined factors, including other life events, which influence engagement following total hip replacement (THR). This research sought to identify factors associated with engaging in life activities following THR. METHODS: A prospective cohort study was conducted with 376 people who had a THR for osteoarthritis (OA). Data were collected pre-surgery and 1 year post-surgery. The primary outcome was change in frequency in engagement in life activities (Late Life Disability Index (LLDI): higher scores indicate higher frequency of engagement (range 0-80)). Analyses included multivariable regression. Factors considered included: positive/negative life events, a new comorbidity, another joint replacement and complications post-surgery. RESULTS: Participants' mean age was 64 years; 46% were male. 68% of participants had at least one comorbidity pre-surgery; 36% reported at least one new comorbidity after surgery. The mean change in LLDI frequency was an increase of 6.29 (±8.10). 36% reported one or more positive impact life events in the year following surgery; 63% reported one or more negative life events. The number of positive life events (beta = 1.24; 95% CI: 0.49, 1.99) was significantly associated with change in LLDI frequency after adjusting for age, sex, education, body mass index (BMI), comorbidities pre-surgery, number of symptomatic joints and pre-surgery pain and function, LLDI limitations and depression. CONCLUSIONS: These findings highlight the significant influence of social factors and life circumstances on engagement in life activities following THR.

Exploring the relationship between disease-related pain and cortisol levels in women with osteoarthritis.

OBJECTIVES: To determine if (1) Osteoarthritis (OA)-related pain is associated with the diurnal cortisol pattern and cortisol levels; (2) the diurnal pattern of cortisol varies with severity of OA pain and (3) the association between OA pain and cortisol is mediated by daily experience variables (DEV). DESIGN: In a community-based study of changes in regional and widespread pain among women with OA, participants (n = 31) completed daily diaries and collected three saliva samples daily for 7 days. Severity of OA-related pain was assessed by the validated Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale. Multilevel regression analyses estimated associations between OA pain and diurnal cortisol levels and slopes, controlling for body mass index (BMI), medication use, time and day. Mediation analyses examined DEV as potential mediators of the association between OA pain and cortisol. RESULTS: The mean age was 57 years and average BMI 31 kg/m2. Mean WOMAC pain subscale score was 8.8. Women with higher WOMAC pain scores had higher cortisol throughout the day. The estimated association of WOMAC with cortisol [ß 0.083(0.02, 0.15) P = 0.009] represents a ∼9% increase in cortisol for every unit increase in WOMAC pain score. Women with WOMAC pain scores ≥9 had higher cortisol levels than those with scores <9. Examination of DEV revealed no significant mediated associations between these relationships at the daily level. CONCLUSION: In women with OA, disease-related pain is positively associated with cortisol production, particularly with greater pain severity. Future studies should explore biologic mediating variables between OA pain and cortisol.

International framework for examination of the cervical region for potential of Cervical Arterial Dysfunction prior to Orthopaedic Manual Therapy intervention.

A consensus clinical reasoning framework for best practice for the examination of the cervical spine region has been developed through an iterative consultative process with experts and manual physical therapy organisations. The framework was approved by the 22 member countries of the International Federation of Orthopaedic Manipulative Physical Therapists (October 2012). The purpose of the framework is to provide guidance to clinicians for the assessment of the cervical region for potential of Cervical Arterial Dysfunction in advance of planned management (inclusive of manual therapy and exercise interventions). The best, most recent scientific evidence is combined with international expert opinion, and is presented with the intention to be informative, but not prescriptive; and therefore as an aid to the clinician's clinical reasoning. Important underlying principles of the framework are that 1] although presentations and adverse events of Cervical Arterial Dysfunction are rare, it is a potentially serious condition and needs to be considered in musculoskeletal assessment; 2] manual therapists cannot rely on the results of one clinical test to draw conclusions as to the presence or risk of Cervical Arterial Dysfunction; and 3] a clinically reasoned understanding of the patient's presentation, including a risk:benefit analysis, following an informed, planned and individualised assessment, is essential for recognition of this condition and for safe manual therapy practice in the cervical region. Clinicians should also be cognisant of jurisdictionally specific requirements and obligations, particularly related to patient informed consent, when intending to use manual therapy in the cervical region.