Low back pain and other musculoskeletal pain comorbidities in individuals with symptomatic osteoarthritis of the knee: data from the osteoarthritis initiative

Identifying determinants for falls among Iranian older adults: insights from the Bushehr Elderly Health Program

BACKGROUND

Falls are a common cause of fractures in older adults. This study aimed to investigate the factors associated with spontaneous falls among people aged ≥ 60 years in southern Iran.

METHODS

The baseline data of 2,426 samples from the second stage of the first phase of a prospective cohort, the Bushehr Elderly Health (BEH) program, were included in the analysis. A history of spontaneous falls in the year before recruitment was measured by self-report using a standardized questionnaire. Demographic characteristics, as well as a history of osteoarthritis, rheumatoid arthritis, low back pain, Alzheimer's disease, epilepsy, depression, and cancer, were measured using standardized questionnaires. A tandem gait (heel-to-toe) exam, as well as laboratory tests, were performed under standard conditions. A multiple logistic regression model was used in the analysis and fitted backwardly using the Hosmer and Lemeshow approach.

RESULTS

The mean (standard deviation) age of the participants was 69.34 (6.4) years, and 51.9% of the participants were women. A total of 260 (10.7%, 95% CI (9.5-12.0)%) participants reported a spontaneous fall in the year before recruitment. Adjusted for potential confounders, epilepsy (OR = 4.31), cancer (OR = 2.73), depression (OR = 1.81), low back pain (OR = 1.79), and osteoarthritis (OR = 1.49) increased the risk of falls in older adults, while the ability to stand ≥ 10 s in the tandem gait exam (OR = 0.49), being male (OR = 0.60), engaging in physical activity (OR = 0.69), and having high serum triglyceride levels (OR = 0.72) reduced the risk of falls.

CONCLUSION

The presence of underlying diseases, combined with other risk factors, is significantly associated with an increased risk of falls among older adults. Given the relatively high prevalence of falls in this population, it is crucial to pay special attention to identifying and addressing these risk factors.

Predictive models of radiographic progression and pain progression in patients with knee osteoarthritis: data from the FNIH OA biomarkers consortium project

OBJECTIVES

The progression of knee osteoarthritis (OA) can be defined as either radiographic progression or pain progression. This study aimed to construct models to predict radiographic progression and pain progression in patients with knee OA.

METHODS

We retrieved data from the FNIH OA Biomarkers Consortium project, a nested case-control study. A total of 600 subjects with mild to moderate OA (Kellgren-Lawrence grade of 1, 2, or 3) in one target knee were enrolled. The patients were classified as radiographic progressors (n = 297), non-radiographic progressors (n = 303), pain progressors (n = 297), or non-pain progressors (n = 303) according to the change in the minimum joint space width of the medial compartment and the WOMAC pain score during the follow-up period of 24-48 months. Initially, 376 variables concerning demographics, clinical questionnaires, imaging measurements, and biochemical markers were included. We developed predictive models based on multivariate logistic regression analysis and visualized the models with nomograms. We also tested whether adding changes in predictors from baseline to 24 months would improve the predictive efficacy of the models.

RESULTS

The predictive models of radiographic progression and pain progression consisted of 8 and 10 variables, respectively, with area under curve (AUC) values of 0.77 and 0.76, respectively. Incorporating the change in the WOMAC pain score from baseline to 24 months into the pain progression predictive model significantly improved the predictive effectiveness (AUC = 0.86).

CONCLUSIONS

We identified risk factors for imaging progression and pain progression in patients with knee OA over a 2- to 4-year period, and provided effective predictive models, which could help identify patients at high risk of progression.

Reduction in Healthcare Resource Utilization Following Treatment With a Home-Based Footworn Device in Patients With Knee Osteoarthritis: A Retrospective Claims Analysis

Background: One in 7 US adults has knee osteoarthritis (OA) and almost two-thirds of them suffer from low back pain. OA is the third most rapidly rising condition associated with disability and leads to a significant burden on the healthcare system and society. Objective: This study looked at the healthcare resource utilization (HCRU) in patients with knee OA and low back pain before and after the utilization of a new, home-based, noninvasive, biomechanical intervention. Methods: This was a retrospective claims analysis of 585 patients treated with a personalized, noninvasive, home-based, biomechanical treatment that aims to alleviate knee pain and improve function (AposHealth®). The date of the first AposHealth claim was the index date. Data prior to the index date and post-index date were used to monitor changes in HCRU while in treatment. Descriptive statistics, including frequencies, means and standard deviations, were used to present patient characteristics. To standardize the results, an average monthly claims data rate was calculated and an expected annual rate was extrapolated. Annual HCRU rate per 1000 members was calculated. Results: HCRU decreased after utilizing the new intervention including a decrease of 79% in diagnostic claims, a 70% decrease in outpatient services, a 22% decrease in non-operative treatments, a 61% decrease in pain medications including an 85% drop in opioids use, and a 44% decrease in intra-articular injections. The pre-index estimated rate for total knee replacement (TKR), which is based on existing literature, was 15.1%, whereas the post-index rate of TKR was 0.9%. Conclusions: Patients with knee OA treated with a home-based, noninvasive, biomechanical intervention incurred fewer healthcare resources, leading to an overall reduction in the cost of care.

Considerations beyond spine pain: do different co-occurring lower body joint pains differentially influence physical function and quality of life ratings?

BACKGROUND

Patients seeking medical care for back pain often have coexisting painful joints and the effects of different combinations and number of coexisting pain sites (hip, knee, foot/ankle) to back pain on physical function domains and quality of life rating are not yet established. The purpose of this study was to determine the differences in functional outcomes and QOL among individuals with back pain who have concurrent additional pain sites or no pain sites.

METHODS

Data from the Osteoarthritis Initiative (OAI) cohort were used for this cross-sectional analysis. Men and women aged 45-79 years with back pain were binned into nine groups by presence or not of coexisting hip, knee, ankle/foot pain and combinations of these sites (N = 1,642). Healthy controls reported no joint pain. Main outcomes included Knee Injury and Osteoarthritis Outcome score (KOOS; quality of life and function-sports-and-recreation), Western Ontario McMaster Universities Osteoarthritis Index (WOMAC; Activities of Daily Living, Pain), Medical Outcomes Short Form-12 (SF-12) Physical Component score, and self-reported function in last 7-30 days (lifting 25-pound objects, housework). 20-m and 400-m walk times and gait speed and repeated chair rise test times were collected.

RESULTS

Compared to back pain alone, pain at all five sites was associated with 39%-86% worse KOOS, WOMAC, and SF-12 scores (p < .0001). Back-Hip and Back-Knee did not produce worse scores than Back pain alone, but Back-Hip-Knee and Back-Knee-Ankle/Foot did. The 20-m, 400-m walk, and repeated chair times were worse among individuals with pain at all five sites. Additional hip and knee sites to back pain, but not ankle/foot, worsened performance-based walk times and chair rise scores.

CONCLUSIONS

The number and type of coexistent lower body musculoskeletal pain among patients with back pain may be associated with perceived and performance-based assessments. Management plans that efficiently simultaneously address back and additional coexistent pain sites may maximize treatment functional benefits, address patient functional goals in life and mitigate disability.

Machine Learning Models for Low Back Pain Detection and Factor Identification: Insights From a 6-Year Nationwide Survey

This study aimed to enhance performance, identify additional predictors, and improve the interpretability of biopsychosocial machine learning models for low back pain (LBP). Using survey data from a 6-year nationwide study involving 17,609 adults aged ≥50 years (Korea National Health and Nutrition Examination Survey), we explored 119 factors to detect LBP in individuals who reported experiencing LBP for at least 30 days within the previous 3 months. Our primary model, model 1, employed eXtreme Gradient Boosting (XGBoost) and selected primary factors (PFs) based on their feature importance scores. To extend this, we introduced additional factors, such as lumbar X-ray findings, physical activity, sitting time, and nutrient intake levels, which were available only during specific survey periods, into models 2 to 4. Model performance was evaluated using the area under the curve, with predicted probabilities explained by SHapley Additive exPlanations. Eleven PFs were identified, and model 1 exhibited an enhanced area under the curve .8 (.77-.84, 95% confidence interval). The factors had varying impacts across individuals, underscoring the need for personalized assessment. Hip and knee joint pain were the most significant PFs. High levels of physical activity were found to have a negative association with LBP, whereas a high intake of omega-6 was found to have a positive association. Notably, we identified factor clusters, including hip joint pain and female sex, potentially linked to osteoarthritis. In summary, this study successfully developed effective XGBoost models for LBP detection, thereby providing valuable insight into LBP-related factors. Comprehensive LBP management, particularly in women with osteoarthritis, is crucial given the presence of multiple factors. PERSPECTIVE: This article introduces XGBoost models designed to detect LBP and explores the multifactorial aspects of LBP through the application of SHapley Additive exPlanations and network analysis on the 4 developed models. The utilization of this analytical system has the potential to aid in devising personalized management strategies to address LBP.

Estimating the cost and epidemiology of mild to severe chronic pain associated with osteoarthritis in England: a retrospective analysis of linked primary and secondary care data

OBJECTIVE

Osteoarthritis (OA) affects 10% of adults in the UK. Despite over one-third of people with OA experiencing chronic pain, few studies have examined the population-level impact of chronic pain associated with OA. We compared resource-use and epidemiological outcomes in patients with mild, moderate and severe chronic OA-associated pain and matched controls without known OA.

DESIGN

Retrospective, longitudinal, observational cohort study (July 2008 to June 2019).

SETTING

Electronic records extracted from Clinical Practice Research Datalink GOLD primary care linked to Hospital Episode Statistics (HES).

PARTICIPANTS

Patients (cases; n=23 016) aged ≥18 years with chronic OA-associated pain. Controls (n=23 016) without OA or chronic pain matched on age, sex, comorbidity burden, general practitioner practice and available HES data.

INTERVENTIONS

None.

PRIMARY AND SECONDARY OUTCOME MEASURES

Total healthcare resource use (HCRU), direct healthcare costs in 0-12, 12-24 and 24-36 months postindex. Secondary outcomes included incidence and prevalence of chronic OA-associated pain and pharmacological management.

RESULTS

HCRU was consistently greater in cases versus controls for all resource categories during preindex and postindex periods. Across follow-up periods, resource use was greatest in patients with severe pain. In the first 12 months postindexing, mean total costs incurred by cases were four times higher versus matched controls (£256 vs £62); costs were approximately twice as high in cases vs controls for months 12-24 (£166 vs £86) and 24-36 (£150 vs £81; all p<0.0001). The incidence of new cases of chronic pain associated with OA was 2.64 per 1000 person-years; the prevalence was 1.4%.

CONCLUSIONS

This study highlights the real-world cost of chronic pain associated with OA in cases versus matched controls. We included patients with mild, moderate and severe pain associated with OA, and showed HCRU in discrete 1-year time frames. The true economic burden of pain associated with OA is likely to be considerably higher when indirect costs are considered.

Chronic Low Back Pain with and without Concomitant Osteoarthritis: A Retrospective, Longitudinal Cohort Study of Patients in England

Objective

Despite the high prevalence of chronic low back pain (CLBP) and osteoarthritis (OA), few estimates of the economic cost of these conditions in England have been published. The aim of the present analysis was to characterise the economic burden of moderate-to-severe pain associated with CLBP + OA and CLBP alone compared with general population-matched controls without CLBP or OA. The primary objective was to describe the total healthcare resource use (HCRU) and direct healthcare costs associated with the target patient populations. Secondary objectives were to describe treatment patterns and surgical procedures.

Methods

This was a retrospective, observational cohort study of patients receiving healthcare indicative of moderate-to-severe chronic pain associated with CLBP, with or without OA. We used linked longitudinal data from the Clinical Practice Research Datalink GOLD and Hospital Episode Statistics (HES). Patients (cases) were matched 1 : 1 with controls on age, sex, comorbidity burden, GP practice, and HES data availability.

Results

The CLBP-alone cohort comprised 13 554 cases with CLBP and 13 554 matched controls; the CLBP + OA cohort comprised 7803 cases with both OA and CLBP and 7803 matched controls. Across all follow-up periods, patients with CLBP alone and those with CLBP + OA had significantly more GP consultations, outpatient attendances, emergency department visits, and inpatient stays than controls (all p < 0.0001). By 36 months after indexing, the mean (SD) per-patient total direct healthcare cost in the CLBP-alone cohort was £5081 (£5905) for cases and £1809 (£4451) for controls (p < 0.0001); in the CLBP + OA cohort, the mean (SD) per-patient total direct healthcare cost was £8819 (£7143) for cases and £2428 (£4280) for controls (p < 0.0001).

Conclusion

Moderate-to-severe chronic pain associated with CLBP-with or without OA-has a substantial impact on patients and healthcare providers, leading to higher HCRU and costs versus controls among people with CLBP alone or together with OA.

Weight-cycling over 6 years is associated with pain, physical function and depression in the Osteoarthritis Initiative cohort

Body weight significantly impacts health and quality of life, and is a leading risk factor for the development of knee osteoarthritis (OA). Weight cycling may have more negative health consequences compared to steady high or low weight. Using the Osteoarthritis Initiative dataset, we investigated the effects of weight cycling on physical function, quality of life, and depression over 72-months compared to stable or unidirectional body weight trajectories. Participants (n = 731) had knee OA and were classified as: (1) stable-low (BMI < 25), (2) stable-overweight (BMI = 25-29.9), and (3) stable-obese (BMI ≥ 30); (4) steady-weight-loss; (5) steady-weight-gain (weight loss/gain ≥ 2.2 kg every 2-years); (6) gain-loss-gain weight cycling, and (7) loss-gain-loss weight cycling (weight loss/gain with return to baseline), based on bi-annual assessments. We compared Knee Injury and Osteoarthritis Outcome Knee-Related Quality of Life, Function in Sports and Recreation, Physical Activity in the Elderly, Short Form SF-12, repeated chair rise, 20-m gait speed, and Center for Epidemiological Studies Depression using repeated-measures ANOVA. The steady weight loss group demonstrated the worst pain, physical function, and depressive symptoms over time (p's < 0.05). More research is needed to confirm these findings, and elucidate the mechanisms by which steady weight loss is associated with functional decline in knee OA.

Comorbidities in people with hand OA and their associations with pain severity and sensitization: Data from the longitudinal Nor-Hand study

Objective

To determine whether the comorbidity burden and co-existing comorbidities are cross-sectionally and/or longitudinally associated with pain and pain sensitization in a cohort study of people with hand OA.

Design

We examined whether comorbidity burden and individual comorbidities based on the self-administered Comorbidity Index (range: 0-42) at baseline were associated with pain outcomes at baseline and 3 years follow-up. Pain outcomes included hand and overall bodily pain (range: 0-10) as well as pressure pain thresholds at the tibialis anterior muscle (kg/cm²) and temporal summation (distal radioulnar joint) as measures of central pain sensitization. We performed linear regression analyses adjusted for age, sex, body mass index, physical exercise and education.

Results

We included 300 and 196 participants in cross-sectional and longitudinal analyses, respectively. Using baseline data, the burden of comorbidities was associated with greater pain in hands (beta ​= ​0.61, 95% CI 0.37, 0.85) and overall body (beta ​= ​0.60, 95% CI 0.37, 0.87). Similar strength of associations was found between comorbidity burden (baseline) and follow-up pain. Among the individual comorbidities, back pain and depression were associated with nearly one unit higher pain score in hands and overall body at both baseline and follow-up. Only back pain was related to lower pressure pain thresholds at follow up (beta ​= ​-0.24, 95% CI -0.50, -0.001).

Conclusion

People with hand OA and greater comorbidity burden, co-existing back pain or depression reported greater pain severity than their counterparts, also 3 years later. These results acknowledge the relevance of accounting for comorbidities in the pain experience in people with hand OA.

Biomarkers and longitudinal changes in lumbar spine degeneration and low back pain: the Johnston County Osteoarthritis Project

OBJECTIVE

To determine if baseline biomarkers are associated with longitudinal changes in the worsening of disc space narrowing (DSN), vertebral osteophytes (OST), and low back pain (LBP).

DESIGN

Paired baseline (2003-2004) and follow-up (2006-2010) lumbar spine radiographs from the Johnston County Osteoarthritis Project were graded for severity of DSN and OST. LBP severity was self-reported. Concentrations of analytes (cytokines, proteoglycans, and neuropeptides) were quantified by immunoassay. Pressure-pain threshold (PPT), a marker of sensitivity to pressure pain, was measured with a standard dolorimeter. Binary logistic regression models were used to estimate odd ratios (OR) and 95% confidence intervals (CI) of biomarker levels with DSN, OST, or LBP. Interactions were tested between biomarker levels and the number of affected lumbar spine levels or LBP.

RESULTS

We included participants (n = 723) with biospecimens, PPT, and paired lumbar spine radiographic data. Baseline Lumican, a proteoglycan reflective of extracellular matrix changes, was associated with longitudinal changes in DSN worsening (OR = 3.19 [95% CI 1.22, 8.01]). Baseline brain-derived neuropathic factor, a neuropeptide, (OR = 1.80 [95% CI 1.03, 3.16]) was associated with longitudinal changes in OST worsening, which may reflect osteoclast genesis. Baseline hyaluronic acid (OR = 1.31 [95% CI 1.01, 1.71]), indicative of systemic inflammation, and PPT (OR = 1.56 [95% CI 1.02, 2.31]) were associated with longitudinal increases in LBP severity.

CONCLUSION

These findings suggest that baseline biomarkers are associated with longitudinal changes occurring in structures of the lumbar spine (DSN vs OST). Markers of inflammation and perceived pressure pain sensitivity were associated with longitudinal worsening of LBP.

How Back Pain Affects Patient Satisfaction After Primary Total Knee Arthroplasty

BACKGROUND

Although back pain (BP) has been shown to be a predictor of dissatisfaction after total knee arthroplasty (TKA) in some reports, these studies did not use a scale to quantify the degree of pain. The purpose of this study was to quantify the effect of BP intensity on patient satisfaction reported at 1 year after TKA.

METHODS

A multicenter prospective cohort was taken in which 9,057 patients undergoing primary unilateral TKA were enrolled in FORCE-TJR and demographic and clinical data were collected. Back pain (BP) intensity was assessed using the Oswestry back disability index (ODI) pain intensity questionnaire. Patients were classified into 4 categories based on the severity of BP. Patient-reported outcomes (PROs) were collected preoperatively and postoperatively after 1 year including the Knee injury and Osteoarthritis Outcome Score (KOOS) (total score, pain, Activities of Daily Living (ADL), and Quality of Life (QOL), Short-Form health survey 36-item (SF-36) Physical Component Score (PCS), and Mental Component Score (MCS)). We used a validated 5-point Likert satisfaction scale. Univariate analyses of the difference between the satisfied and dissatisfied patients' groups was performed. Multivariate logistic regression models with 95% confidence interval (CI) were used to quantify the effect of BP intensity on patient dissatisfaction at 1 year. Receiver operating characteristic (ROC) analyses were performed with measurement of area under curve (AUC).

RESULTS

At 1 year, a total of 1,657 TKA patients (18.3%) were dissatisfied. A total of 4,765 patients (52.6%) reported back pain at the time of surgery, including mild BP in 2,264 patients (24.9%), moderate BP in 1,844 patients (20.3%), and severe BP in 657 patients (7.2%). Severe back pain was significantly associated with patient dissatisfaction at 1 year after TKA (P = .0006). The multivariate regressions showed that patients who had severe BP were 1.6 times more likely to be dissatisfied when compared to patients who had no BP [odds ratio (OR) 1.63; 95% confidence interval (CI) (1.23-2.16), P = .0006]. While patients who had mild BP [OR 0.98; 95% CI (0.82-1.17), P = .87] or moderate BP [OR 0.97; 95% CI (0.80-1.18), P = .78] were not associated with an increased likelihood of dissatisfaction. Other predictive variables for dissatisfaction, include age [OR for younger patients <65 years versus older patients ≥65 years, 0.74; 95% CI (0.59-0.92)], educational level [OR for post high school versus less, 0.83; 95% CI (0.71, 0.97)], smoking [OR for nonsmoker versus current smoker, 0.63; 95% CI (0.45, 0.87)], and Charlson comorbidity index [OR for CCI ≥2 versus 0, 1.25; 95% CI (1.05, 1.49)].

CONCLUSION

Increased BP intensity was associated with increased risk of dissatisfaction 1 year after TKA. Only patients who had severe BP were 1.6 times more likely to be dissatisfied. The data presented here can help to improve shared decision-making and patient counseling before surgery. Surgeons should consider a spine evaluation in patients who have severe BP prior to TKA.

Biomechanical and clinical relationships between lower back pain and knee osteoarthritis: a systematic review

BACKGROUND

Osteoarthritis (OA) and lower back pain (LBP) are most common health problems which lead to pain and disability. This study aimed to systematically review the evidence to find any relationship between knee osteoarthritis (KOA) and LBP or any potential causation.

METHODS

The databases of Scopus, MEDLINE, and Embase were searched from inception to 01 October 2022. Any study published in English assessing live humans over 18 years with KOA and LBP was eligible to be included. Studies were independently screened by two researchers. Data of the included studies were extracted based on the participants, outcomes related to knee and lumbar spine, reported association or causation between LBP and KOA, and study design. Data were narratively analyzed and presented as graphs and table. Methodology quality was assessed.

RESULTS

Of 9953 titles and abstracts, duplicates were removed, and 7552 were screened. Altogether, 88 full texts were screened, and 13 were eligible for the final inclusion. There were some biomechanical and clinical causations were observed for the concurrent presence of LBP and KOA. Biomechanically, high pelvic incidence is a risk factor for development of spondylolisthesis and KOA. Clinically, knee pain intensity was higher in KOA when presents with LBP. Less than 20% of studies have justified their sample size during the quality assessment.

DISCUSSION

Development and progression of KOA in patients with degenerative spondylolisthesis may be induced by significantly greater mismatches of lumbo-pelvic sagittal alignment. Elderly patients with degenerative lumbar spondylolisthesis and severe KOA reported a different pelvic morphology, increased sagittal malalignment with a lack of lumbar lordosis due to double-level listhesis, and greater knee flexion contracture than in patients with no to mild and moderate KOA. People with concurrent LBP and KOA have reported poor function with more disability. Both LBP and lumbar kyphosis indicate functional disability and knee symptoms in patients with KOA.

CONCLUSIONS

Different biomechanical and clinical causations were revealed for the concurrent existence of KOA and LBP. Therefore, careful assessment of both back and knee joints should be considered when treating KOA and vice versa.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022238571.

Impact of pain in other body regions on the foot-specific quality of life in patients with hallux valgus

OBJECTIVES

The purpose of this study was to clarify the prevalence of pain outside the foot, and to determine the associations of pain outside the foot with foot-specific quality of life (QOL) in patients with hallux valgus.

METHODS

Patients scheduled to undergo hallux valgus surgery were recruited. Patients answered whether they experienced disabling pain in 13 body regions other than the foot. Foot-specific QOLwas assessed using the Self-Administered Foot Evaluation questionnaire (SAFE-Q). Foot pain was quantified using the visual analogue scale (VAS). Patient characteristics, including age, sex, comorbidity, anxiety, and depression, were also surveyed. The association between pain elsewhere and the SAFE-Q and pain VAS scores were assessed using univariate and multivariate analyses.

RESULTS

Of 102 patients, 55 (54%) experienced pain other than the foot. All SAFE-Q subscale scores were lower, and pain VAS was higher in patients with pain elsewhere than in patients without. In the multivariate analysis, an increase in the number of pain regions was independently associated with a decrease in SAFE-Q scores and an increase in pain VAS.

CONCLUSION

More than half of the patients with hallux valgus experienced pain elsewhere. The presence of pain elsewhere was associated with poorer foot-specific QOL and severer foot pain.

Efficacy and Safety of Dietary Undenatured Type II Collagen on Joint and Motor Function in Healthy Volunteers: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study

Prevalence of osteoarthritis (OA) is increasing alarmingly worldwide. Slowing down the progression of OA and diverse locomotive organ disorders is gaining interest in improving the quality of life (QOL) and extending healthy life-span. In a pilot study, intake of a small amount of undenatured type II collagen exhibited suppression of damage to the articular cartilage via oral immune tolerance. It also demonstrated improvement of knee and joint flexibility and mobility with continued intake of undenatured type II collagen (NEXT-II®) derived from chicken sternum cartilage. This randomized, double-blind, placebo-controlled, parallel-group clinical investigation (RCT) evaluated the efficacy and safety of 12 weeks of regular intake of NEXT-II^® on joint and motor function in healthy Japanese male and female participants (aged 20 to <75 years).

Sixty-four participants were randomized to receive either NEXT-II^® (undenatured type II collagen 3.2 mg/d) or placebo over a period of 12 consecutive weeks. Efficacy on joint and motor functions were evaluated measuring knee passive range of motion as the primary outcome; the Japan Knee Osteoarthritis Measure (JKOM), Visual Analog Scale (VAS) for knee discomfort, and motor functions (10-meter walking and stair-climbing test) as the secondary outcomes; and Japan Low back pain Evaluation Questionnaire (JLEQ) and VAS for lower back discomfort as the exploratory outcomes.

Fifty-eight participants (placebo = 28; NEXT-II^® group = 30) completed the study. In the assessment of knee passive range of motion, significant improvements in "flexion" and "flexible angle (range)" were observed in the NEXT-II^® group at 4, 8, and 12 weeks of treatment. NEXT-II^® induced significant improvements in JKOM, VAS for knee and lower back discomfort, 10-meter walking test, stair-climbing test, and JLEQ.

Results demonstrate that undenatured type II collagen is safe and efficacious in improving knee flexibility and mobility, reducing knee and lower back pain, and enhancing motor function.

Association between the number of chronic pain sites and neuropathic-like symptoms in community-dwelling older adults with chronic pain: a cross-sectional study

OBJECTIVES

We investigated the relationship between the number of chronic pain sites and the prevalence and severity of neuropathic-like symptoms in community-dwelling older Japanese adults with chronic pain.

DESIGN

Cross-sectional study.

SETTING

The data analysed are from a study conducted in the city of Itoshima, Japan in 2017.

PARTICIPANTS

The study population was 988 participants (age 65-75 years) not in need of long-term care who completed questionnaires assessing sociodemographic factors, psychological factors and chronic pain.

PRIMARY OUTCOME MEASURES

The primary outcome was the participants' neuropathic-like symptoms evaluated by the PainDETECT Questionnaire (PD-Q). We classified the participants into mild and moderate-to-severe pain groups according to the pain intensity on the PD-Q. The number of chronic pain sites was categorised into groups with 1, 2-3 and ≥4 sites.

RESULTS

The age-adjusted and sex-adjusted prevalence of neuropathic-like symptoms was significantly higher among the participants with 2-3 or ≥4 sites compared with the single-site group. In the binomial logistic regression analyses, the multivariable-adjusted ORs and 95% CIs for neuropathic-like symptoms among the participants with 2-3 and ≥4 sites were 1.94 (1.13 to 3.33) and 3.90 (2.22 to 6.85), respectively compared with the participants with single-site pain. The ORs for moderate-to-severe neuropathic-like symptoms increased significantly with the increase in the number of chronic pain sites.

CONCLUSIONS

The number of chronic pain sites was positively associated with the presence and severity of neuropathic-like symptoms in community-dwelling older Japanese adults with chronic pain.

A bidirectional study of the association between insomnia, high-sensitivity C-reactive protein, and comorbid low back pain and lower limb pain

OBJECTIVES

To examine the possible bidirectional association between insomnia and comorbid chronic low back pain (LBP) and lower limb pain and to explore whether high-sensitivity C-reactive protein (hsCRP) amplifies these associations.

METHODS

We calculated adjusted risk ratios (RR) with 95% confidence intervals (CI) for the development of insomnia and mild-to-severe chronic LBP and lower limb pain at 11 years follow-up in participants aged ≥32 years and with hsCRP ≤10 mg/L at baseline in 2007-2008: 3,714 without chronic LBP or lower limb pain (sample 1) and 7,892 without insomnia (sample 2).

RESULTS

Compared to participants without chronic pain, participants with comorbid chronic LBP and lower limb pain had a RR of insomnia of 1.37 (95% CI 1.12-1.66). Compared with participants without insomnia, participants with insomnia did not have an increased risk of comorbid chronic LBP and lower limb pain (RR: 1.06, 95% CI 0.76-1.46); however, participants with insomnia had a RR of chronic LBP of 1.20 (95% CI 1.02-1.42). There was no strong amplifying effect of elevated hsCRP (3.00-10.0 mg/L) on these associations.

CONCLUSIONS

These findings suggest that elevated hsCRP does not amplify the associations between insomnia and mild-to-severe chronic LBP and lower limb pain. Further research using data on the temporal relation between insomnia, chronic pain, and inflammatory responses are required to fully understand the causal pathways.

The facilitation of trunk muscles by abdominal bracing during walking in chronic low back pain patients

Walking is known to be beneficial for chronic low back pain (LBP) patients and fast walking recruits more trunk muscles. Abdominal bracing has also been shown to improve LBP and facilitate several trunk muscles. We aimed to investigate the effects of walking velocity and abdominal bracing on the activation of trunk muscles in chronic LBP patients during walking. Forty-six volunteers with chronic LBP underwent walking exercise on the treadmill without ("non-braced walking") and with abdominal bracing ("braced walking") at speeds of 4, 5, and 6 km/h, with the surface electrodes placed on their trunk muscles to measure muscle activity. The root mean square values of the surface electromyography amplitude data were obtained at the multifidus of lower (ML) and upper lumbar (MU), erector spinae of lower lumbar (EL) and thoracic (ET), rectus abdominis (RA), and external oblique (EO). All muscles activated significantly more at faster walking. The "braced walking" facilitated the ET and RA significantly more than the "non-braced walking". The interaction between the walking speed and abdominal bracing was significant at ML, MU, and RA. The increase in muscle activation observed at lower speed diminished as speed increased. Since "braced walking" seems to additionally facilitate the trunk muscles especially at slower gait speeds, patients who cannot walk fast may still be able to train their muscles by "braced walking."

Prevalence of low back pain and related disability in patients with femoroacetabular impingement syndrome

BACKGROUND

Low back pain (LBP) has been associated with worse hip function for persons with femoroacetabular impingement syndrome (FAIS). Reports are limited to surgical populations and based on the presence or absence of LBP, regardless of pain severity.

OBJECTIVES

To report the prevalence of clinically significant LBP for persons with FAIS; compare demographics, pain, and function between those with and without clinically significant LBP; and evaluate relationships between hip function and both LBP-related disability and LBP severity. We hypothesized that participants with LBP would be older, have higher body mass index (BMI), and report worse groin pain, longer symptom duration, and worse hip function. We hypothesized that worse LBP-related disability and LBP severity would be related to worse hip function.

DESIGN

Observational cross-sectional study.

SETTING

Hip preservation clinic.

PARTICIPANTS

158 persons with FAIS.

INTERVENTIONS

n/a MAIN OUTCOME MEASURE(S): Visual analog pain scales (VAS 0-100) were used to categorize participants with (≥30) and without (<30) clinically significant LBP. Age, sex, BMI, pain severity and duration, and hip function (33-item Hip Outcome Tool [iHOT33]) were compared between those with and without clinically significant LBP. Correlations were evaluated between the modified Oswestry Disability Index (ODI) and iHOT33, ODI and groin pain severity, LBP severity and iHOT33, and LBP and groin pain severity.

RESULTS

Sixty percent of participants reported clinically significant LBP (n = 95). These participants reported worse iHOT33 scores (mean difference: 10.1 points) than those without clinically significant LBP (p = .001). Worse ODI scores were associated with worse iHOT33 scores (P < .001; ρ = -0.74). Significant relationships were also observed between (1) ODI and groin pain, (2) LBP and iHOT33, and (3) LBP and groin pain, but the magnitudes of these correlations were weak (ρ ≤ 0.36).

CONCLUSIONS

Clinically significant LBP is highly prevalent in persons with FAIS and is associated with worse hip function. Worse LBP-related disability, but not LBP severity, was strongly associated with worse hip function.

Prevalence and Risk Factors Associated with Low Back Pain in the Saudi Adult Community: A Cross-Sectional Study

Worldwide, low back pain is common and linked with many risk factors. There is a lack of studies in the Saudi Arabian community on low back pain prevalence and risk factors. Therefore, the present research will investigate the prevalence of low back pain in the middle-aged and elderly community population and examine the risk factors contributing to low back pain in Saudi Arabia. The present paper is a cross-sectional study of the community living in Riyadh and the surrounding areas in Saudi Arabia. Data were collected between October 2019 and April 2020 via trained research assistants. A total of 276 participants were included in the analysis. The prevalence of low back pain was 27.9% (n = 77) among the participants included in this study. All participants reported low back pain severity with a mean of 4.35 ± 2.19 on the pain rating scale. Older age, arthritis, hypertension, anemia, osteoporosis, and a history of fractures were all associated with having LBP. Low back pain is highly prevalent in the Saudi community adult population living in Riyadh and its surrounding areas. More than a fourth of the sample reported experiencing back pain. The study outlines several modifiable risk factors (BMI, education, employment status, marital status, and smoking status) and unmodifiable risk factors (arthritis, hypertension, anemia, osteoporosis, and a history of fractures) associated with low back pain in the study sample.

Association between clusters of back and joint pain with opioid use in middle-aged community-based women: a prospective cohort study

Background

To determine the relationship between clusters of back pain and joint pain and prescription opioid dispensing.

Methods

Of 11,221 middle-aged participants from the Australian Longitudinal Study of Women’s Health, clusters of back pain and joint pain from 2001 to 2013 were identified using group-based trajectory modelling. Prescription opioid dispensing from 2003 to 2015 was identified by linking the cohort to Pharmaceutical Benefit Scheme dispensing data. Multinomial logistic regression was used to examine the association between back pain and joint pain clusters and dispensing of prescription opioids. The proportion of opioids dispensed in the population attributable to back and join pain was calculated.

Results

Over 12 years, 68.5 and 72.0% women reported frequent or persistent back pain and joint pain, respectively. There were three clusters (‘none or infrequent’, ‘frequent’ and ‘persistent’) for both back pain and joint pain. Those in the persistent back pain cluster had a 6.33 (95%CI 4.38-9.16) times increased risk of having > 50 opioid prescriptions and those in persistent joint pain cluster had a 6.19 (95%CI 4.18-9.16) times increased risk of having > 50 opioid prescriptions. Frequent and persistent back and joint pain clusters together explained 41.7% (95%CI 34.9-47.8%) of prescription opioid dispensing. Women in the frequent and persistent back pain and joint pain clusters were less educated and reported more depression and physical inactivity.

Conclusion

Back pain and joint pain are major contributors to opioid prescription dispensing in community-based middle-aged women. Additional approaches to reduce opioid use, targeted at those with frequent and persistent back pain and joint pain, will be important in order to reduce the use of opioids and their consequent harm in this population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04741-4.

Exploring the relationship between pain intensity and knee moments in participants with medial knee osteoarthritis: a cross-sectional study

Background

High biomechanical loading is believed to be a risk factor to pain in people with knee osteoarthritis (OA), but controversial findings have been reported on the relationship between external knee adduction moment (KAM) and pain. A more comprehensive analysis considering other factor such as external knee flexion moment (KFM) could help better reveal this relationship. This study explored the relationship between external knee adduction moment and pain intensity in participants with knee osteoarthritis (OA) using an integrated path analysis model.

Methods

This was a cross-sectional study based on laboratory setting. Forty-seven participants with clinical and radiographic medial knee OA were analyzed for their external knee adduction moment (KAM) and knee flexion moment (KFM) during walking using a motion analysis system. Pain intensity was measured by visual analogue scale (VAS) and the pain subscale of the Knee Injury and Osteoarthritis Outcome Score. Varus/valgus alignment was captured and quantified using a bi-planar X-ray system. Using a path analysis model, the relationships between pain intensity, KAM, KFM, OA radiographic severity, knee varus angle and walking speed were examined.

Results

The proposed path model met the goodness-of-fit criteria. Based on this model, KAM had a negative effect on VAS pain indirectly through the mediation of KFM. The model indicated KAM and KFM were negatively related to one another; and KFM was positively related to VAS. The KAM index, defined as (KAM/ (KAM + KFM)), was negatively related to VAS.

Conclusions

Path analysis enabled the construction of a more integrated pathokinematic framework for people with knee OA. The KAM index which reflected the load sharing on the frontal and sagittal planes also revealed its relationship with pain. Re-distribution of mechanical loading from frontal to sagittal plane might be a strategy for pain avoidance associated with mechanical irritation.

Effects of Vitamin D Supplementation on Disabling Foot Pain in Patients With Symptomatic Knee Osteoarthritis

OBJECTIVE

The present study was undertaken to determine whether vitamin D supplementation or maintaining sufficient vitamin D level reduces foot pain over 2 years in patients with symptomatic knee osteoarthritis (OA).

METHODS

A post hoc study was conducted from a randomized, double-blind, placebo-controlled trial named the Vitamin D Effect on Osteoarthritis (VIDEO) study. Symptomatic knee OA patients with serum 25-hydroxyvitamin D levels between 12.5 nmoles/liter and 60 nmoles/liter were included and randomly allocated to either monthly vitamin D₃ or placebo treatment (1:1) for 2 years. Manchester Foot Pain and Disability Index (MFPDI) was used to evaluate foot pain and disabling foot pain was defined as at least 1 of the 10 functional limitation items (items 1-9 and 11) being documented as on "most/every day(s)" in the last month. A repeated-measures, mixed-effects model was used to analyze the change of MFPDI scores between groups adjusting for potential confounders.

RESULTS

A total of 413 patients with a mean age of 63.2 years (49.7% males) were enrolled and 340 completed the study. The mean MFPDI score was 22.8 ± 7.3, with 23.7% of participants having disabling foot pain at baseline. There were significant differences in MFPDI scores change between groups over 2 years, with more improvements in the vitamin D group than in the placebo group (-0.03 versus 1.30; P = 0.013) and more improvement in those maintaining sufficient vitamin D levels (n = 226) than those who did not (n = 114) (-0.09 versus 2.19; P = 0.001).

CONCLUSION

Vitamin D supplementation and maintenance of sufficient vitamin D levels may improve foot pain in those with knee OA.

A new integrated behavioural intervention for knee osteoarthritis: development and pilot study

Background

Exercise-based approaches have been a cornerstone of physiotherapy management of knee osteoarthritis for many years. However, clinical effects are considered small to modest and the need for continued adherence identified as a barrier to clinical efficacy. While exercise-based approaches focus on muscle strengthening, biomechanical research has identified that people with knee osteoarthritis over activate their muscles during functional tasks. Therefore, we aimed to create a new behavioural intervention, which integrated psychologically informed practice with biofeedback training to reduce muscle overactivity, and which was suitable for delivery by a physiotherapist.

Methods

Through literature review, we created a framework linking theory from pain science with emerging biomechanical concepts related to overactivity of the knee muscles. Using recognised behaviour change theory, we then mapped a set of intervention components which were iteratively developed through ongoing testing and consultation with patients and physiotherapists.

Results

The underlying framework incorporated ideas related to central sensitisation, motor responses to pain and also focused on the idea that increased knee muscle overactivity could result from postural compensation. Building on these ideas, we created an intervention with five components: making sense of pain, general relaxation, postural deconstruction, responding differently to pain and functional muscle retraining. The intervention incorporated a range of animated instructional videos to communicate concepts related to pain and biomechanical theory and also used EMG biofeedback to facilitate visualization of muscle patterns. User feedback was positive with patients describing the intervention as enabling them to “create a new normal” and to be “in control of their own treatment.” Furthermore, large reductions in pain were observed from 11 patients who received a prototype version of the intervention.

Conclusion

We have created a new intervention for knee osteoarthritis, designed to empower individuals with capability and motivation to change muscle activation patterns and beliefs associated with pain. We refer to this intervention as Cognitive Muscular Therapy. Preliminary feedback and clinical indications are positive, motivating future large-scale trials to understand potential efficacy. It is possible that this new approach could bring about improvements in the pain associated with knee osteoarthritis without the need for continued adherence to muscle strengthening programmes.

Trial registration

ISRCTN51913166 (Registered 24-02-2020, Retrospectively registered).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04389-0.

Presence of back pain prior total knee arthroplasty and its effects on short-term patient-reported outcome measures

PURPOSE

Back pain may both decrease patient satisfaction after TKA and confound outcome assessment in satisfied patients. Our primary objective was to determine whether preoperative back pain is associated with differences in postoperative patient-reported outcome measures (PROMs).

METHODS

We retrospectively reviewed 234 primary TKA patients who completed PROMs preoperatively and 12 weeks postoperatively, which included a back pain questionnaire, the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) and the Forgotten Joint Score-12 (FJS-12). Cohorts were defined based on the severity of preoperative back pain (none, mild, moderate and severe) and compared. Demographics were compared using ANOVA and Chi-square analysis. Univariate ANCOVA analysis was utilized to compare PROMs while accounting for significant demographic differences.

RESULTS

Both preoperative KOOS JR scores (none: 47.90, mild: 47.61, moderate: 44.61 and severe: 38.70; p = 0.013) and 12-week postoperative KOOS JR scores (none: 61.24, mild: 64.94, moderate: 57.48 and severe: 57.01; p = 0.012) had a statistically significant inverse relationship with regard to the intensity of preoperative back pain. Although FJS-12 scores at the 12-week postoperative period trended lower with increasing levels of preoperative back pain (p = 0.362), it did not reach statistical significance. Patients who reported severe back pain preoperatively achieved the largest delta improvement from baseline compared to those with lesser pain intensity (p = 0.003). Patients who had a 2-grade improvement in their back pain achieved significantly higher KOOS JR scores 12 weeks postoperatively compared to patients with either 1-grade or no improvement (63.53 vs. 55.98; p = 0.042). Both preoperative (47.99 vs. 41.11; p = 0.003) and 12-week postoperative (64.06 vs. 55.73; p < 0.001) KOOS JR scores were statistically higher for those who reported mild or no back pain pre-and postoperatively than those who reported moderate or severe back pain pre-and postoperatively.

CONCLUSION

Knee pain and back pain both exert negative effects on outcome instruments designed to measure pain and function. Although mean improvement from pre- to postoperative KOOS JR scores for patients with severe pre-existing back pain was higher than their counterparts, this statistical difference is likely not clinically significant. This implies that all patients may experience similar benefits from TKA despite the presence or absence of back pain. Attempts to measure TKA outcomes using PROMs should seek to control for lumbago and other sources of body pain. Level of Evidence IIIRetrospective Cohort Study.

Low Back Pain as a Risk Factor for Recurrent Falls in People With Knee Osteoarthritis

OBJECTIVE

Knee osteoarthritis (OA) has been suggested to increase the risk of falls. Low back pain (LBP) is a potential risk factor for falls in people with knee OA, but this issue has not been addressed adequately in previous studies. The objective of this study was to investigate the relationship between LBP and falls in people with knee OA in a 12-month period.

METHODS

Participants with knee OA (Kellgren/Lawrence [K/L] grade ≥1) completed questionnaires for LBP and falls that occurred in the preceding 12 months. Binary and ordinal logistic regression analyses were performed to assess the relationship between LBP or moderate-to-severe LBP (numeric rating scale ≥4 points) and any fall (≥1 fall) or recurrent falls (≥2 falls) after adjustment for age, sex, K/L grade, knee pain severity, and quadriceps strength. Sensitivity analyses were performed excluding people with sciatica, nonchronic LBP, K/L grade 1, and those receiving pain medications.

RESULTS

We included 189 participants (ages 61-90 years, 78.3% women) in this study. Of these participants, 41 (21.6%) reported falls in the preceding 12 months. People with any LBP (n = 101) and those with moderate-to-severe LBP (n = 45) had 2.7- and 3.7-times higher odds of recurrent falls, respectively. Sensitivity analyses revealed a strong correlation between moderate-to-severe LBP and recurrent falls.

CONCLUSION

Thorough investigation of LBP as a risk factor for recurrent falls in people with knee OA may provide a novel insight into the pathomechanics of recurrent falls in this population.

Coexistence of low back pain and lumbar kyphosis is associated with increased functional disability in knee osteoarthritis: the Nagahama Study

OBJECTIVE

To examine the association of low back pain (LBP) and lumbar kyphosis with functional disabilities and knee symptoms in patients with knee osteoarthritis (OA).

METHODS

We analyzed 586 participants (80.1% female; age, 68.8 ± 5.2 years) from the Nagahama Study who were aged ≥60 years and had radiographically confirmed knee OA. The Knee Scoring System (KSS) was used to assess functional disabilities and knee symptoms. LBP was defined as the presence of any persistent back pain for more than 3 months. Lumbar kyphosis was determined by skin-surface methods using a computer-aided electronic device called the Spinal Mouse. Multiple linear regression analysis was used for assessing the association of LBP and lumbar kyphosis with the KSS scores. Subgroup analyses based on sex were also performed.

RESULTS

LBP and lumbar kyphosis were independently associated with a lower KSS function score after adjustment for covariates (mean difference [95%CI, confidence interval] = -4.96 [-7.56 to -2.36] points for LBP alone, -4.47 [-8.51 to -0.43] points for lumbar kyphosis alone, and -13.86 [-18.86 to -8.86] points for the coexistence of LBP and lumbar kyphosis, respectively). The coexistence of LBP and lumbar kyphosis in women was associated with a lower KSS symptom score (mean difference [95%CI] = -4.49 [-6.42 to -2.55] points).

CONCLUSION

These findings suggest that both LBP and lumbar kyphosis are useful clinical signals indicating functional disability and knee symptoms in patients with knee OA.

Association of musculoskeletal pain in other body parts with new-onset shoulder pain: a longitudinal study among survivors of the Great East Japan Earthquake

OBJECTIVE

Shoulder pain is a common health problem coexisting with other musculoskeletal pain. However, the effects of pre-existing musculoskeletal pain on the development of shoulder pain are not clear. The present study aimed to elucidate the association between coexisting musculoskeletal pain at other body sites and new-onset shoulder pain among survivors of the Great East Japan Earthquake (GEJE).

DESIGN

This is a longitudinal study.

SETTING

The study was conducted at the severely damaged coastal areas in Ishinomaki and Sendai cities.

PARTICIPANTS

The survivors who did not have shoulder pain at 3 years after the GEJE were followed up 1 year later (n=2131).

INTERVENTIONS

Musculoskeletal pain (low back, hand and/or foot, knee, shoulder and neck pain) was assessed using self-reported questionnaires.

MAIN OUTCOME MEASURES

The outcome of interest was new-onset shoulder pain, which was defined as shoulder pain absent at 3 years but present at 4 years after the disaster. The main predictive factor for new-onset shoulder pain was musculoskeletal pain in other body parts at 3 years after the GEJE; this was categorised according to the number of pain sites (0, 1, ≥2). Multiple regression analyses were conducted to calculate the odds ratio (OR) and 95% confidence interval (CI) for new-onset shoulder pain due to musculoskeletal pain in other body parts.

RESULTS

The incidence of new-onset shoulder pain was 6.7% (143/2131). Musculoskeletal pain in other body parts was significantly associated with new-onset shoulder pain. Using the survivors without other musculoskeletal pain as reference, the adjusted OR and 95% CI for new-onset shoulder pain were 1.86 (1.18 to 2.94) for those with one body part and 3.22 (2.08 to 4.98) for those with ≥2 body parts presenting with musculoskeletal pain (p<0.001).

CONCLUSIONS

Pre-existing musculoskeletal pain in other body parts was significantly associated with new-onset shoulder pain among survivors; this provides useful information for clinical and public health policies.

Total knee arthroplasty for patients with medial knee osteoarthritis improves trunk movement during gait

BACKGROUND

Previous studies have indicated that the kinematics of the knee joint affect the trunk and pelvis during gait. However, the factors that influence trunk movement in knee osteoarthritis patients during gait after surgery remain unclear.

OBJECTIVE

To examine the effect of total knee arthroplasty (TKA) on trunk movement during gait by comparing knee osteoarthritis patients with healthy controls.

METHODS

Fourteen medial knee osteoarthritis patients who underwent initial unilateral TKA and 11 controls participated in this study. Knee and hip joint flexion and trunk and pelvic tilts during gait were acquired using a three-dimensional motion analysis system. Knee joint range of motion, pain, and kinematic data were collected preoperatively and 1 year postoperatively for knee osteoarthritis patients.

RESULTS

Knee extension limitation and pain significantly improved postoperatively compared with preoperative stages. Preoperatively, the peak anterior trunk tilt during the stance phase was significantly larger in osteoarthritis patients than in controls. The peak anterior trunk tilt during the stance phase was significantly smaller postoperatively than at preoperative stages.

CONCLUSIONS

These results suggest that after TKA, the trunk movements of knee osteoarthritis patients were approximately equal to those of controls, with improvement in clinical outcomes such as knee extension limitation and pain.

The contribution of age and obesity to the number of painful joint sites in individuals reporting osteoarthritis: a population-based study

Objective

To investigate the association of OA risk factors with number of painful joint sites in a representative population sample.

Methods

Analysis of the 2009 Survey on Living with Chronic Diseases in Canada – Arthritis Component (n = 1614) for respondents reporting symptomatic OA. Variables: painful joints sites (hands, wrists, elbows, shoulders, hips, knees, ankles, feet, back, neck), joint symptom duration, sociodemographic characteristics, smoking, comorbidities and BMI. Zero-truncated negative binomial regressions were used to investigate the association between number of painful joint sites and the variables. Generalizability of findings was assessed by a similar analysis in a clinical hip/knee OA sample.

Results

The sample comprised 73% women and 56% were aged <65 years. The mean number of painful joint sites was 3.8: 84% reported pain at ≥2 sites, and 45% at ≥4 sites. Age, BMI, education and smoking were not associated with the number of joint sites. Significant associations were found with being female [rate ratio (RR) = 1.23, 95% CI 1.09, 1.39], having more comorbidities (RR = 1.11, 95% CI 1.07, 1.15) and longer symptom duration (RR = 1.16, 95% CI 1.09, 1.24), although the increase in joint sites with duration was small. Similar regression results were found with the clinical OA sample.

Conclusion

The lack of an association of age and BMI (obesity) with number of painful joint sites in OA raises questions about the role of these risk factors and our understanding of OA as a multi-joint disease. Filling this knowledge gap is critical to making progress with defining OA phenotypes and identifying potential aetiological mechanisms.

Assessment of Common Comorbidity Phenotypes Among Older Adults With Knee Osteoarthritis to Inform Integrated Care Models

Objective

To establish the frequency of concordant, discordant, and clinically dominant comorbidities among Medicare beneficiaries with knee osteoarthritis (KOA) and to identify common concordant condition subgroups.

Participants and Methods

We used a 5% representative sample of Medicare claims data to identify beneficiaries who received a diagnosis of KOA between January 1, 2012, and September 30, 2015, and matched control group without an osteoarthritis (OA) diagnosis. Frequency of 34 comorbid conditions was categorized as concordant, discordant, or clinically dominant among those with KOA and a matched sample without OA. Comorbid condition phenotypes were characterized by concordant conditions and derived using latent class analysis among those with KOA.

Results

The study sample included 203,361 beneficiaries with KOA and 203,361 non-OA controls. The largest difference in frequency between the two cohorts was for co-occurring musculoskeletal conditions (23.7% absolute difference), chronic pain syndromes (6.5%), and rheumatic diseases (4.5%), all with a higher frequency among those with knee OA. Phenotypes were identified as low comorbidity (53% of cohort with classification), hypothyroid/osteoporosis (27%), vascular disease (10%), and high medical and psychological comorbidity (10%).

Conclusions

Approximately 47% of Medicare beneficiaries with KOA in this sample had a phenotype characterized by one or more concordant conditions, suggesting that existing clinical pathways that rely on single or dominant providers might be insufficient for a large proportion of older adults with KOA. These findings could guide development of integrated KOA-comorbidity care pathways that are responsive to emerging priorities for personalized, value-based health care.

The impact of multijoint symptoms on patient-reported disability following surgery for lumbar spine osteoarthritis

BACKGROUND CONTEXT

In the lumbar spine osteoarthritis (LS-OA) population having surgery for lumbar spinal stenosis (LSS) symptoms, a significant proportion of patients experience limited benefit following the intervention. Thus, identifying contributing factors to this is important. Individuals with OA often have multiple joint symptoms, yet this has received limited attention in this population.

PURPOSE

Document the occurrence of joint symptoms among patients undergoing surgery for LS-OA, and investigate the influence of these symptoms on disability postsurgery.

DESIGN

Prospective study of consecutive patients followed to 12-month postsurgery.

PATIENT SAMPLE

Patients undergoing surgery (decompression surgery, with or without fusion) for neurogenic claudication with or without back pain due to LSS with a primary pathology diagnosis of LS-OA.

OUTCOMES MEASURES

Patient self-reported: Oswestry Disability Index (ODI), completed pre- and 12-month postsurgery; and, completed presurgery, age, sex, education, smoking, comorbid conditions, opioid use, short/long-term disability, depression and anxiety symptoms, back and leg pain intensity, presence of spondylolisthesis, procedure, prior spine surgery, and joints with arthritis and "pain/stiffness/swelling most days of the month" indicated on a homunculus (a joint site count was derived).

ASSESSMENTS

Height and weight, used to calculate body mass index; timed-up-and-go performance-based test.

METHODS

Outcome of interest was achieving a clinically important improvement (CII) in ODI by 12-month postsurgery (yes/no). The association between joint site count and achieving a CII was examined by multivariable logistic regression analyses, adjusted for other measures.

RESULTS

In all, 165 patients were included. The mean age was 67 years (range: 44-90) and 47% were female. Seventy-seven percent reported 1+ joint site other than the back, 62% reported 2+, and 25% reported 4+. Among those achieving a CII, 21% had 4+ joint sites, compared with 31% among those not achieving a CII. Adjusted analyses: Increasing joint site count was associated with increasing risk (odds ratio [OR]: 1.32, 95% confidence interval [CI]: 1.05, 1.66) of not achieving a CII; for those with 4+ joints, adjusted probability of not achieving a CII exceeded 50%. Also associated with an increased risk of not achieving a CII was presurgery anxiety (OR: 2.97, 95% CI: 1.02, 8.65), opioid use (OR: 2.89, 95% CI: 1.07, 7.82), and worse back pain intensity score (OR: 1.27, 95% CI: 1.05, 1.53).

CONCLUSIONS

Multijoint involvement was highly prevalent in this LS-OA surgical sample. Its association with poorer postsurgery outcome supports a comprehensive approach to OA management and care. Knowledge of multijoint symptoms should inform patient education, shared decision-making, and recommendations for postsurgical rehabilitation and self-management strategies.

Long-Term Pain Management and Health Care Resource Use Among an Employed Population in Japan with Knee Osteoarthritis Combined with Low Back Pain

Objective

Assess long-term comorbidity burden and pain management patterns among working-age patients with knee osteoarthritis (KOA) only without low back pain (LBP) (KOA-noLBP) and patients with KOA plus LBP (KOA+LBP) in Japan.

Methods

Retrospective claims data analyses were conducted on data from the Japan Medical Data Center (JMDC) database. Adult patients (≥40 years) with a diagnosis of knee osteoarthritis (KOA) (January 1, 2011–December 31, 2012) and 5 years of follow-up were evaluated. The first claim with a KOA diagnosis defined the index date. Longitudinal pain management patterns were assessed in both cohorts.

Results

Overall, 1,828 patients met study criteria (717 with KOA-noLBP; 1,111 with KOA+LBP). The mean age of patients with KOA-noLBP was 52.1 years, and that of patients with KOA+LBP was 53.1 years, with more females in the KOA+LBP cohort (49.4% vs. 55.0%). Regardless of cohort, >90% of patients received pharmacological intervention during the 5-year follow-up period. The most common regimen first received was either topical or oral nonsteroidal anti-inflammatory drugs. A higher mean number of pharmaceutical treatments were received by patients in the KOA+LBP cohort (3.6) than by patients in the KOA-noLBP cohort (2.7) during the follow-up period. Regardless of cohort, most of the direct medical cost was derived from medication.

Conclusion

This study demonstrates that a greater proportion of the JMDC population of working individuals with KOA were comorbid with LBP and received pain-related treatment in the long-term perspective relative to patients with KOA without LBP. Appropriate pain management for both KOA and LBP would be key for effective resource utilization in an aging society facing socioeconomic burdens

Facilitating Activity and Self-management for people with Arthritic knee, hip or lower back pain (FASA): A cluster randomised controlled trial

BACKGROUND

Chronic musculoskeletal pain including osteoarthritis (OA) can significantly limit the functional independence of individuals. The spine and hip and knee are predominantly affected; management guidelines for each recommend exercise and education to support self-management.

OBJECTIVES

This study investigated the effectiveness of a generic exercise and self-management intervention for people over-50 with hip/knee OA and/or lower back pain compared to continued GP management.

DESIGN

Single blind, cluster randomised controlled trial.

METHOD

Participants who had previously consulted with hip/knee OA and/or chronic lower back pain were recruited from 45 GP practices in SW England. Practices were randomly allocated to receive continued GP care (control) or continued GP care and a 6-week group exercise and self-management intervention facilitated by a physiotherapist and located in a community-based physiotherapy department. The primary outcome measure was the Dysfunction Index of the Short Musculoskeletal Functional Assessment (DI-SMFA) measured at six month post-rehabilitation.

RESULTS

349 participants were recruited and allocated to the intervention (n = 170) or control (n = 179) arms; the attrition rate was 13% at the 6 month primary end-point. One minor adverse event in the intervention group that required no medical input was reported. Intervention arm participants reported better function at 6 months compared with continued GP management alone (-3.01 difference in DI-SMFA [95%CI -5.25, -0.76], p = 0.01).

CONCLUSIONS

A generic exercise and self-management intervention resulted in statistically significant changes in function after six-months compared with GP management alone, but clinical significance of these findings is less clear. This may be an effective way of managing group interventions for lower limb OA and chronic lower back pain.

What General and Pain-associated Psychological Distress Phenotypes Exist Among Patients with Hip and Knee Osteoarthritis?

BACKGROUND

Psychological distress can negatively influence disability, quality of life, and treatment outcomes for individuals with hip and knee osteoarthritis (OA). Clinical practice guidelines recommend a comprehensive disease management approach to OA that includes the identification, evaluation, and management of psychological distress. However, uncertainty around the best psychological screening and assessment methods, a poor understanding of the heterogeneity of psychological distress in those with OA, and lack of guidance on how to scale treatment have limited the growth of OA care models that effectively address individual psychological needs.

QUESTIONS/PURPOSES

(1) Across which general and pain-related psychological distress constructs do individuals seeking conservative care for hip or knee OA report higher scores than the general population of individuals seeking conservative care for musculoskeletal pain conditions? (2) What common psychological phenotypes exist among nonsurgical care-seeking individuals with hip or knee OA?

METHODS

The sample included participants from the Duke Joint Health Program (n = 1239), a comprehensive hip and knee OA care program, and the Optimal Screening for Prediction of Referral and Outcome (OSPRO) cohort studies (n = 871) comprising individuals seeking conservative care for knee, shoulder, low back, or neck pain. At the initial evaluation, patients completed the OSPRO Yellow Flag (OSPRO-YF) Assessment Tool, which assesses 11 general and pain-related psychological distress constructs (depression, anxiety, fear of movement, self-efficacy for managing one's own pain). We used OSPRO-YF scores to compare levels of psychological distress between the cohorts. Cohen's d effect sizes were calculated to determine the magnitude of differences between the groups, with d = 0.20, d = 0.50, and d = 0.80 indicating small, medium, and large effect sizes, respectively. We used a latent class analysis to derive psychological distress phenotypes in people with OA based on the 11 OSPRO-YF psychological distress indicators. Psychological distress phenotypes are characterized by specific mood, belief, and behavioral factors that differentiate subgroups within a population. Phenotyping can help providers develop scalable treatment pathways that are better tailored to the common needs of patients.

RESULTS

Patients with OA demonstrated higher levels of general and pain-related psychological distress across all psychological constructs except for trait anxiety (that is, anxiety level as a personal characteristic rather than as a response to a stressful situation, like surgery) with small-to-moderate effect sizes. Characteristics with the largest effect sizes in the OA and overall OSPRO cohort were (Cohen's d) general anxiety (-0.66, lower in the OA cohort), pain catastrophizing (the tendency to ruminate over, maginfiy, or feel helpless about a pain experience, 0.47), kinesiophobia (pain-related fear of movement, 0.46), pain self-efficacy (confidence in one's own ability to manage his or her pain, -0.46, lower in the OA cohort), and self-efficacy for rehabilitation (confidence in one's own ability to perform their rehabilitation treatments, -0.44, lower in the OA cohort). The latent class analysis yielded four phenotypes (% sample): high distress (52%, 647 of 1239), low distress (26%, 322 of 1239), low self-efficacy and acceptance (low confidence in managing and willingness to accept pain) (15%, 186 of 1239), and negative pain coping (exhibiting poor pain coping skills) (7%, 84 of 1239). The classification error rate was near zero (2%), and the median of posterior probabilities used to assign subgroup membership was 0.99 (interquartile range 0.98 to 1.00), both indicating excellent model performance. The high-distress group had the lowest mean age (61 ± 11 years) and highest levels of pain intensity (6 ± 2) and disability (HOOS JR: 50 ± 15; KOOS JR: 47 ± 15), whereas the low-distress group had the highest mean age (63 ± 10 years) and lowest levels of pain (4 ± 2) and disability (HOOS JR: 63 ± 15; KOOS JR: 60 ± 12). However, none of these differences met or exceeded anchor-based minimal clinically important difference thresholds.

CONCLUSIONS

General and pain-related psychological distress are common among individuals seeking comprehensive care for hip or knee OA. Predominant existing OA care models that focus on biomedical interventions, such as corticosteroid injection or joint replacement that are designed to directly address underlying joint pathology and inflammation, may be inadequate to fully meet the care-related needs of many patients with OA due to their underlying psychological distress. We believe this because biomedical interventions do not often address psychological characteristics, which are known to influence OA-related pain and disability independent of joint pathology. Healthcare providers can develop new comprehensive hip and knee OA treatment pathways tailored to these phenotypes where services such as pain coping skills training, relaxation training, and psychological therapies are delivered to patients who exhibit phenotypes characterized by high distress or negative pain coping. Future studies should evaluate whether tailoring treatment to specific psychological phenotypes yields better clinical outcomes than nontailored treatments, or treatments that have a more biomedical focus.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Determining the feasibility of a trial to evaluate the effectiveness of phototherapy versus placebo at reducing pain during physical activity for people with knee osteoarthritis: a pilot randomized controlled trial

BACKGROUND

Although practice guidelines recommend physical activity and exercise for the management of knee osteoarthritis, pain is a common barrier to participation. Phototherapy has been shown to reduce pain intensity for people with knee osteoarthritis, but it is unclear if it reduces pain during physical activity or contributes to improved rehabilitation outcomes.

OBJECTIVE

The aim of this study is to assess the feasibility of performing a fully powered randomized controlled trial (RCT) comparing an active phototherapy intervention versus placebo on pain during physical activity for people with knee osteoarthritis.

METHODS

A pilot RCT was conducted to test the feasibility of a trial comparing 8-sessions (4 weeks) of active phototherapy versus placebo. People were able to participate if they (1) were an English speaking adult (> 18 years of age), (2) had received a diagnosis of knee osteoarthritis from a physician, and (3) self-reported experiencing pain and disability related to their knee osteoarthritis for > 3 months. Primary outcomes were the feasibility of participant recruitment, retention, assessment procedures, and maintaining high treatment fidelity. Secondary outcomes piloted for a full trial included pain during physical activity (primary outcome of full trial); self-reported pain severity, physical function, stiffness, adherence to prescribed exercise, global rating of change, patient satisfaction, and adverse events; 6-min walk test; and pressure pain threshold.

RESULTS

Twenty participants (4 men; 16 women) with knee osteoarthritis and a mean age of 63.95 (SD: 9.27) years were recruited over a 3-week period (6.7 participants per week). Fifteen out of 20 (75%) of participants completed the primary outcome assessment at 4 weeks and 19/20 (95%) of participants were retained and completed the final 16-week assessment. Overall, 89% of all assessment items were completed by participants across all time-points. Fifteen out of 20 participants (75%) completed all 8 treatment sessions. Treatment fidelity was 100% for all completed treatment sessions. No adverse events were reported by participants in either group.

CONCLUSIONS

Results suggest that the trial methodology and intervention are feasible for implementation in a fully powered randomized controlled trial to determine the effectiveness of phototherapy at reducing pain during physical activity for people with knee osteoarthritis.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT04234685 , January 21, 2020-Retrospectively registered.

Examination of the changes in lower extremities related to progression of adult spinal deformity: a longitudinal study of over 22 years

This longitudinal observational study investigated the relationship between changes in spinal sagittal alignment and changes in lower extremity coronal alignment. A total of 58 female volunteers who visited our institution at least twice during the 1992 to 1997 and 2015 to 2019 periods were investigated. We reviewed whole-spine radiographs and lower extremity radiographs and measured standard spinal sagittal parameters including pelvic incidence [PI], lumbar lordosis [LL], pelvic tilt [PT], sacral slope [SS] and sagittal vertical axis [SVA], and coronal lower extremity parameters including femorotibial angle (FTA), hip–knee–ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA) and mechanical lateral distal tibial angle (mLDTA). Lumbar spondylosis and knee osteoarthritis were assessed using the Kellgren–Lawrence (KL) grading system at baseline and at final follow-up. We investigated the correlation between changes in spinal sagittal alignment and lower extremity alignment and changes in lumbar spondylosis. The mean age [standard deviation (SD)] was 48.3 (6.3) years at first visit and 70.2 (6.3) years at final follow-up. There was a correlation between changes in PI-LL and FTA (R = 0.449, P < 0.001) and between PI-LL and HKA (R = 0.412, P = 0.001). There was a correlation between changes in lumbar spondylosis at L3/4 (R = 0.383, P = 0.004) and L4/5 (R = 0.333, P = 0.012) and the knee joints. Changes in lumbar spondylosis at L3/4 and L4/5 were related to changes in KOA. Successful management of ASD must include evaluation of the state of lower extremity alignment, not only in the sagittal phase, but also the coronal phase.

Effect of Comorbid Chronic Low Back Pain on Patient-Reported Outcome and Gait Parameters in Patients With Symptomatic Knee Osteoarthritis

Knee osteoarthritis and chronic low back pain are common and often coexist. There are limited studies on the impact of coexisting musculoskeletal disorders on gait parameters and its association with self-assessed functional outcome. This study compared gait parameters, self-assessed functional outcome measurements, and quality-of-life scales between patients with knee osteoarthritis against those with coexisting knee osteoarthritis and chronic low back pain using gait analysis, Western Ontario and McMaster Osteoarthritis Index, and Short Form-36. Three hundred sixty-seven patients underwent gait analysis after the question-based functional outcome measurement. Pain, function, and quality of life were worse in the coexisting knee osteoarthritis and chronic low back pain group (n = 197) compared with the knee osteoarthritis only group (n = 170, P = 0.017, P = 0.004, P < 0.001, P = 0.004, respectively). The coexisting knee osteoarthritis and chronic low back pain group had significantly lower gait velocity and cadence than the knee osteoarthritis group (P = 0.028 and P = 0.003). The Western Ontario and McMaster Osteoarthritis Index Pain subscore was associated with gait velocity (P < 0.001) in the knee osteoarthritis group, whereas Short Form-36 physical composite was associated with gait velocity (P < 0.001) in the coexisting knee osteoarthritis and chronic low back pain group. Comorbid chronic low back pain in patients with knee osteoarthritis was associated with worse pain, function, quality of life, gait velocity, and cadence. Compared with the Western Ontario and McMaster Osteoarthritis Index, Short Form-36 may be a more suitable tool to track mobility outcome measure, such as gait velocity, in the management of the coexisting knee osteoarthritis and chronic low back pain.

The WOMAC Pain Scale and Crosstalk From Co-occurring Pain Sites in People With Knee Pain: A Causal Modeling Study

OBJECTIVE

The Western Ontario and McMaster Universities Osteoarthritis (WOMAC) pain scale quantifies knee pain severity with activities of daily living, but the potential impact of pain in other body regions on WOMAC pain scores has not been explored using a causal modeling approach. The purpose of this study was to determine if pain in other areas of the body impact WOMAC pain scores, a phenomenon referred to as "crosstalk."

METHODS

Cross-sectional datasets were built from public use data available from the Osteoarthritis Initiative (OAI) and the Multicenter Osteoarthritis Study (MOST). The WOMAC Pain Scale and generic hip, knee, ankle, foot and back pain measures were included. Three nested regression models grounded in causally based classical test theory determined the extent of crosstalk. Improvements in the coefficient of determination across the 3 models were used to determine the presence of crosstalk.

RESULTS

Causal modeling provided evidence of crosstalk in both OAI and MOST datasets. For example, in OAI, multiple statistical models demonstrated significant increases in coefficient of determination values (P < .0001) as additional pain areas were added to the models.

CONCLUSIONS

Crosstalk appears to be a clinically important source of error in the WOMAC Pain Scale, particularly for patients with a larger number of painful body regions and when contralateral knee joint pain is more severe.

IMPACT STATEMENT

This study has important implications for arthritis research. It also should raise clinician awareness of the threat to score interpretation and the need to consider the extent of pain in other body regions when interpreting WOMAC pain scores.

Misconceived expectations: Patient reflections on the total knee replacement journey

INTRODUCTION

Fifty per cent of patients consent for total knee replacement (TKR) with unrealistic expectations about what it involves and can achieve. A framework is needed to help surgeons identify key knowledge gaps and misconceptions that can be targeted during the informed consent process. In this qualitative study, we explored knowledge gaps and misconceptions by asking patients to reflect on their expectations along the TKR journey.

METHODS

Eligible adults were ≥18 years, 12-month post-TKR and had completed a validated expectations questionnaire pre-TKR as part of a joint replacement registry. To capture a variety of perspectives, people with a range of pre-TKR expectation scores were invited. In interviews, participants reflected on anticipated and actual experiences and unexpected experiences they had along the way. Transcripts were analysed through inductive thematic analysis. Recruitment ceased when thematic saturation was reached.

ETHICS APPROVAL

Ethical approval for this study was granted by the St Vincent's Hospital Melbourne Ethics Committee (LRR 077/18).

RESULTS

In the final sample (n = 20; 50% female; median age = 72 years; contralateral TKR = 11), all participants described instances where their anticipated and actual experiences diverged, including high expectations of improvements in pain/function (pre-surgical optimism), lacking awareness about anaesthetic procedures (perioperative misunderstandings), feeling unprepared for the length of the recovery period (post-operative misestimations) and trying to make sense of ongoing functional limitations (long-term misattributions).

DISCUSSION AND CONCLUSION

These findings are captured in a preliminary framework of therapeutic misconception. Although future research is needed to test this framework prospectively in larger, more generalisable samples, surgeons can consider these key knowledge gaps and misconceptions when consenting for TKR.

Musculoskeletal pain in other body sites is associated with new-onset low back pain: a longitudinal study among survivors of the great East Japan earthquake

Background

Low back pain (LBP) is a common health problem experienced after natural disasters. LBP is often concurrent with other musculoskeletal pain; however, the effects of preexisting musculoskeletal pain on the development of LBP are not clear. The purpose of this study was to elucidate the association of musculoskeletal pain in other body sites with new-onset LBP among survivors of the Great East Japan Earthquake (GEJE).

Methods

A longitudinal study was conducted with survivors of the GEJE. The survivors who did not have LBP at the 3 year time period after the GEJE were followed up 1 year later (n = 1782). Musculoskeletal pain, such as low back, hand and/or foot, knee, shoulder, and neck pain, were assessed with self-reported questionnaires. The outcome of interest was new-onset LBP, which was defined as LBP absent at 3 years but present at 4 years after the disaster. The main predictor was musculoskeletal pain in other body sites 3 years after the GEJE, which was categorized according to the number of pain sites (0, 1, ≥ 2). Multiple regression analyses were performed to calculate the odds ratio (OR) and 95% confidence interval (CI) for new-onset LBP due to musculoskeletal pain in other body sites.

Results

The incidence of new-onset LBP was 14.1% (251/1782). Musculoskeletal pain in other body sites was significantly associated with new-onset LBP. Including people without other musculoskeletal pain as a reference, the adjusted OR and 95% CI for new-onset LBP were 1.73 (1.16–2.57) for people with one musculoskeletal pain site and 3.20 (2.01–5.09) for people with ≥ 2 sites (p <  0.001).

Conclusions

Preexisting musculoskeletal pain in other body sites was associated with new-onset LBP among survivors in the recovery period after the GEJE.

The Prevalence and Clinical Implications of Comorbid Back Pain in Shoulder Instability: A Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability Cohort Study

Background:

Understanding predictors of pain is critical, as recent literature shows that comorbid back pain is an independent risk factor for worse functional and patient-reported outcomes (PROs) as well as increased opioid dependence after total joint arthroplasty.

Purpose/Hypothesis:

The purpose of this study was to evaluate whether comorbid back pain would be predictive of pain or self-reported instability symptoms at the time of stabilization surgery. We hypothesized that comorbid back pain will correlate with increased pain at the time of surgery as well as with worse scores on shoulder-related PRO measures.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

As part of the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort, patients consented to participate in pre- and intraoperative data collection. Demographic characteristics, injury history, preoperative PRO scores, and radiologic and intraoperative findings were recorded for patients undergoing surgical shoulder stabilization. Patients were also asked, whether they had any back pain.

Results:

The study cohort consisted of 1001 patients (81% male; mean age, 24.1 years). Patients with comorbid back pain (158 patients; 15.8%) were significantly older (28.1 vs 23.4 years; P < .001) and were more likely to be female (25.3% vs 17.4%; P = .02) but did not differ in terms of either preoperative imaging or intraoperative findings. Patients with self-reported back pain had significantly worse preoperative pain and shoulder-related PRO scores (American Shoulder and Elbow Surgeons score, Western Ontario Shoulder Instability Index) (P < .001), more frequent depression (22.2% vs 8.3%; P < .001), poorer mental health status (worse scores for the RAND 36-Item Health Survey Mental Component Score, Iowa Quick Screen, and Personality Assessment Screener) (P < .01), and worse preoperative expectations (P < .01).

Conclusion:

Despite having similar physical findings, patients with comorbid back pain had more severe preoperative pain and self-reported symptoms of instability as well as more frequent depression and lower mental health scores. The combination of disproportionate shoulder pain, comorbid back pain and mental health conditions, and inferior preoperative expectations may affect not only the patient’s preoperative state but also postoperative pain control and/or postoperative outcomes.

Comparing the association of widespread pain, multi-joint pain and low back pain with measures of pain sensitization and function in people with knee osteoarthritis

INTRODUCTION/OBJECTIVES

To compare 1. measures of pain sensitization (PS) in people with widespread pain (WSP), multi-joint pain, low back pain (LBP) and knee osteoarthritis (KOA) only, in people with knee OA and 2. results of self-reported function and physical performance tests amongst these sub groups.

METHODOLOGY

Patients with knee OA consulting an orthopaedic surgeon were recruited from three Montreal area hospitals. A body homunculus was used to identify the presence of WSP (Y/N), multi-joint pain using a joint count (≥ 2 joints) and LBP (Y/N). Tests included pressure pain thresholds (PPT), temporal summation (TS), conditioned pain modulation and three physical performance tests. The Knee Injury and Osteoarthritis Outcome Score (KOOS) assessed self-reported function. Means were compared with Welch's ANOVA, post hoc tests and multiple regression analysis were performed.

RESULTS

Two hundred twenty-one participants were evaluated (mean age: 63.4 ± 9.9 years, females n = 135 (61.1%)). Those with WSP significantly differed from those with LBP on PPT mean - 1.4, 95%CI (- 2.4, - 0.4), TS 10.3 (2.1, 18.5) and the stair climb test (SCT) 5.6 (1.3, 9.9). Those with WSP significantly differed from those with KOA only on TS 9.5 (1.0, 18.1), SCT 6.3 (2.0, 10.6) and KOOS - 14.2 (- 26.5, - 2.0).

CONCLUSION

In patients with knee OA, those with WSP demonstrated greater degrees of PS compared with those with knee OA only, LBP and multi-joint pain. They also demonstrated a slower SCT compared with those with KOA only and LBP and decreased self-reported function compared with those with KOA only. These results should be confirmed in a longitudinal study.Key Points• In people with knee OA and widespread pain, measures of sensitization, self-reported function and physical performance were poorer compared with those with knee OA and LBP, knee OA and multi-joint pain or knee OA only.• Clinicians can consider these outcomes when planning management for these subgroups planning a comprehensive treatment program for this subgroup.

Clinical and Statistical Validation of a Probabilistic Prediction Tool of Total Knee Arthroplasty Outcome

BACKGROUND

Predicting patients at risk of a poor outcome would be useful in patient selection for total knee arthroplasty (TKA). Existing models to predict outcome have seen limited functional implementation. This study aims to validate a model and shared decision-making tool for both clinical utility and predictive accuracy.

METHODS

A Bayesian belief network statistical model was developed using data from the Osteoarthritis Initiative. A consecutive series of consultations for osteoarthritis before and after introduction of the tool was used to evaluate the clinical impact of the tool. A data audit of postoperative outcomes of TKA patients exposed to the tool was used to evaluate the accuracy of predictions.

RESULTS

The tool changed consultation outcomes and identified patients at risk of limited improvement. After introduction of the tool, patients booked for surgery reported worse Knee Osteoarthritis and Injury Outcome Score pain scores (difference, 15.2; P < .001) than those not booked, with no significant difference prior. There was a 27% chance of not improving if predicted at risk, and a 1.4% chance if predicted to improve. This gives a risk ratio of 19× (P < .001) for patients not improving if predicted at risk.

CONCLUSION

For a prediction tool to be clinically useful, it needs to provide a better understanding of the likely clinical outcome of an intervention than existed without its use when the clinical decisions are made. The tool presented here has the potential to direct patients to surgical or nonsurgical pathways on a patient-specific basis, ensuring patients who will benefit most from TKA surgery are selected.

Musculoskeletal Symptomatic Areas After Total Knee Replacement for Osteoarthritis

Objective

The objective of this study was to measure cumulative incidence and incidence rate and identify factors associated with new musculoskeletal (MSK) symptomatic areas after total knee replacement (TKR) for osteoarthritis (OA).

Methods

Using data from a randomized controlled trial of patients undergoing elective TKR for OA, we assessed for MSK symptomatic areas by region (neck, hands/wrists/arms/shoulders, back, hips, nonindex knee, and ankles/feet) at baseline (pre‐TKR), and at 3, 6, 12, 24, 36, and 48 months post‐TKR. Cumulative incidence and incidence rates were calculated for each region. Factors associated with incident MSK symptomatic areas were identified using generalized linear mixed models. Time to incident symptomatic area was assessed using Cox proportional hazards regression.

Results

Among 293 subjects, the cumulative incidence of any new MSK symptomatic area over 4 years was 45%; the incidence rate was 19.2 per 100 person‐years. Body site–specific cumulative incidence and incidence rates were highest for nonindex knee and back. Predictors of incident MSK symptomatic areas included female sex (relative risk [RR] 1.64; 95% confidence interval [CI] 1.15‐2.34), body mass index of 35 or higher (RR 1.27; 95% CI 0.88‐1.85), Charlson Comorbidity Index 2 or more (RR 1.28; 95% CI 0.92‐1.78), baseline index knee Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score greater than 40 (RR 1.39; 95% CI 0.99‐1.95), and anxiety/depression (measured by the five‐item Mental Health Index) (RR 1.70; 95% CI 1.20‐2.40).

Conclusion

Incident MSK symptomatic areas occurred in roughly half of recipients of TKR in the 4 years after the operation. Further study is needed to examine the long‐term impact of MSK symptomatic areas on postoperative pain, function, and quality of life.

The association between insomnia, c-reactive protein, and chronic low back pain: cross-sectional analysis of the HUNT study, Norway

BACKGROUND AND AIMS

Chronic low back pain (chronic LBP) is the number one cause for years lived with disability among 301 diseases and injuries analyzed by The Global Burden of Disease study 2013. Insomnia is highly prevalent among people with chronic LBP. To explain the sleep-pain relationship, theoretical models propose that insomnia symptoms may be associated with increased basal inflammation, operationalized as c-reactive protein (CRP) and lead to further pain and disrupted sleep. We aimed to determine the associations between insomnia, chronic LBP, and inflammation (operationalized as CRP), whilst controlling for age, body mass index, smoking, physical activity, depression, anxiety and osteoarthritis.

METHODS

A cross-sectional analysis of the third Nord-Trøndelag Health Study (2006-2008), a rural population survey of 50,666 participants in Norway aged 20-96 years. Insomnia (dichotomous) was defined according to the Diagnostic and Statistical Manual of Mental Disorders 5th Edition, and chronic LBP (dichotomous) as low back pain or stiffness lasting at least 3 months. Data for CRP were obtained from non-fasting serum samples and assessed via latex immunoassay methodology. We excluded participants with the following self-reported chronic somatic diseases: chronic heart failure, chronic obstructive pulmonary disease, rheumatoid arthritis, fibromyalgia or ankylosing spondylosis. Possible associations between presence of insomnia and presence of chronic LBP (dependent), and the level of CRP and presence of chronic LBP (dependent), were assessed using logistic regression models. The possible association between insomnia and CRP (dependent) was assessed using linear regression. Multivariable analyses were conducted adjusting for confounders stated in our aim that achieved p ≤ 0.2 in univariate regressions. We performed stratified analyses for participants with "Normal" (<3 mg/L) "Elevated" (3-10 mg/L) and "Very High" (>10 mg/L) levels of CRP.

RESULTS

In our total included sample (n = 30,669, median age 52.6, 54% female), 6.1% had insomnia (n = 1,871), 21.4% had chronic LBP (n = 6,559), and 2.4% had both (n = 719). Twenty four thousand two hundred eighty-eight (79%) participants had "Normal" CRP, 5,275 (17%) had "Elevated" CRP, and 1,136 (4%) had "Very High" CRP. For participants with "Normal" levels of CRP, insomnia was associated with higher levels of CRP (adjusted B = 0.04, 95%CI [0.00-0.08], p = 0.046), but not for people with "Elevated" or "Very High" levels of CRP. There was an association between CRP and presence of chronic LBP in the total sample (adjusted OR = 1.01, [1.00-1.01], p = 0.013) and for people with "Normal" CRP (1.05, [1.00-1.10, p = 0.034]. Insomnia was associated with the presence of chronic LBP in the total sample (adjusted OR = 1.99, 95%CI [1.79-2.21], <0.001) and for people with "Normal", "Elevated" and "Very High".

CONCLUSIONS

Individuals with insomnia have twice the odds of reporting chronic LBP. Insomnia, CRP and chronic LBP appear to be linked but the role of CRP appears to be limited. Longitudinal studies may help further explore the causal inference between insomnia chronic LBP, and inflammation.

IMPLICATIONS

Given the strong relationship between insomnia and chronic LBP, screening and management of comorbid insomnia and chronic LBP should be considered in clinical practice. Further longitudinal studies are required to explore whether the presence of insomnia and increased inflammation affects the development of chronic LBP.

Relationship Between Varus Thrust During Gait and Low Back Pain in Individuals With Knee Osteoarthritis

OBJECTIVE

To test the hypothesis that varus thrust visualized during gait is associated with a higher prevalence of low back pain (LBP) in individuals with knee osteoarthritis (OA).

METHODS

Individuals with knee OA (Kellgren/Lawrence grade ≥1) underwent a gait observation to assess varus thrust. The participants identified LBP and its severity using questionnaires. Logistic regression analyses were performed to examine the association between varus thrust and LBP.

RESULTS

We included 205 participants (mean age 68.19 years; 72.20% women). A total of 45 participants (22.0%) showed varus thrust in their painful knee, in whom 31 (68.89%) and 18 (40.00%) were identified as having any LBP and moderate-to-severe LBP (numerical rating scale ≥4 points), respectively. Patients with varus thrust demonstrated a 3.6-fold higher risk of the presence of moderate-to-severe LBP (95% confidence interval [95% CI] 1.62-8.10). In patients with LBP, the presence of varus thrust was associated with more severe LBP intensity (proportional odds ratio 2.25 [95% CI 1.02-4.96]).

CONCLUSION

This study highlights the novel relationship between varus thrust and LBP, which supports the idea of a biomechanical link, the so-called knee-spine syndrome. These findings provide new insight for clarifying the pathogenesis of LBP related to knee OA.

Evaluation of a Cost-Effective Novel Diagnostic Method for Lumbar Herniated Disc with Knee-Osteoarthritis: A Randomized Sample Study

The aim of this study was to determine a cost-effective diagnostic method for lumbar herniated disc with knee osteoarthritis (LHD-KOA) based on aberrant outcome measures, levels of biomarkers, and examination of the lower-extremity. Data were separately analyzed for each cohort suffering with LHD-KOA (n=108; 59.82±7.15years) and without LHD-KOA (n=108; 58.81±7.61years), and findings were confirmed with radiological images. The aberrant-leg-features (bilateral: knee gaps between the short head of biceps femoris and the surface of the bed, diameters of calves and thighs, angles of straight leg raising, knee-flexion and -extension in a supine position) and biochemical parameters (Interleukin-10, Tumor necrosis factor-alpha, C-reactive protein, creatine kinase-muscle, and Aldolase-A), and outcome measures, Western Ontario and McMaster Universities osteoarthritis index (WOMAC), knee-injury osteoarthritis outcomes scale (KOOS), Oswestry disability index (ODI), and body mass index (BMI)for participants with and without LHD-KOA were evaluated with appropriate techniques. All the subjects underwent standardized physical examination and completed a questionnaire. The risk ratios and mean± standard deviations of biomarkers, anatomical features, and outcome measures of the experimental subjects were highly significant compared to controls (p<0.0001). Results suggest that monitoring the studied aberrant outcome measures, biomarkers, and lower-anatomical features may be a cost-effective diagnostic tool for LHD-KOA. Further research is recommended for an alternative treatment protocol for LHD-KOA.

Proximal gait adaptations in individuals with knee osteoarthritis: A systematic review and meta-analysis

Clarifying proximal gait adaptations as a strategy to reduce knee joint loading and pain for individuals with knee osteoarthritis (OA) contributes to understanding the pathogenesis of multi-articular OA changes and musculoskeletal pain in other joints. We aimed to determine whether biomechanical alterations in knee OA patients during level walking is increased upper trunk lean in the frontal and sagittal planes, and subsequent alteration in external hip adduction moment (EHAM) and external hip flexion moment (EHFM). A literature search was conducted in PubMed, PEDro, CINAHL, and Cochrane CENTRAL through May 2018. Where possible, data were combined into a meta-analysis; pooled standardized mean differences (SMD) of between knee OA patients and healthy adults were calculated using a random-effect model. In total, 32 articles (2037 participants, mean age, 63.0 years) met inclusion criteria. Individuals with knee OA had significantly increased lateral trunk lean toward the ipsilateral limb (pooled SMD: 1.18; 95% CI: 0.59, 1.77) along with significantly decreased EHAM. These subjects also displayed a non-significantly increased trunk/pelvic flexion angle and EHFM. The GRADE approach judged all measures as "very low." These results may indicate that biomechanical alterations accompanying knee OA are associated with increased lateral trunk lean and ensuing alterations in EHAM. Biomechanical alterations in the sagittal plane were not evident. Biomechanical adaptations might have negative sequelae, such as secondary hip abductor muscle weakness and low back pain. Thus, investigations of negative sequelae due to proximal gait adaptations are warranted.