Evidence for central sensitization in patients with osteoarthritis pain: A systematic literature review

Experimentally induced pain increases absolute but not relative errors and reduces variability in joint repositioning of the knee joint in healthy participants

BACKGROUND

Joint position sense (JPS) plays an important role in knee joint function. Despite the possible influence of pain on the proprioceptive system, the effects of experimental muscle pain on knee JPS have not been studied.

OBJECTIVES

To investigate if experimentally induced muscle pain affects knee JPS in healthy participants.

METHODS

Measurements of knee JPS were conducted before and after the injection of 5.8% sterile hypertonic saline in the vastus medialis muscle of 26 healthy physically active adults. Knee JPS was assessed through a passive/active repositioning paradigm in target angles of 15°, 45° and 60° using an isokinetic dynamometer. Absolute and relative angular errors were calculated. The coefficient of variation analysis was used to assess differences in the angles' variability during the repositioning task.

RESULTS

Absolute angular error increased in all three angles following experimentally induced pain. The difference was statistically significant at 45° (p = 0.003, d = 0.6) and 15° (p = 0.047, d = 0.4) but not at 60° (p = 0.064, d = 0.4). Relative error did not show directional bias at 45° (p = 0.272, d = 0.2), 15° (p = 0.483, d = 0.1) or 60° (p = 0.091, d = 0.3). The coefficient of variation analysis revealed a statistically significant reduction in variability at angles of 60° (p = 0.002, d = 0.7) and 15° (p = 0.031, d = 0.4) after the pain intervention.

CONCLUSION

The presence of experimentally induced muscle pain affects the ability of healthy participants to accurately reposition the knee at two angles of knee flexion and reduces movement variability during the repositioning task. Further research is required to determine if these deficits also impact patients with clinical knee pain.

Thalamocortical dysconnectivity is associated with pain in patients with knee osteoarthritis

Previous studies have suggested that the morphology and function of the thalamus and cortex are abnormal in patients with knee osteoarthritis (KOA). However, whether the thalamocortical network is differentially affected in this disorder is unknown. In this study, we examined functional and effective connectivity between the thalamus and major divisions of the cortex in 27 healthy controls and 27 KOA patients using functional magnetic resonance imaging. We also explored the topological features of the brain via graph theory analysis. The results suggested that patients with KOA had significantly reduced resting-state functional connectivity (rsFC) of the thalamo-sensorimotor pathway; enhanced rsFC of the thalamo-medial/lateral frontal cortex (mFC/LFC), parietal, temporal and occipital pathways; reduced effective connectivity of the left sensorimotor-to-thalamus pathway; and enhanced effective connectivity of the right thalamus-to-sensorimotor pathway compared with healthy controls. The functional connectivity of the thalamo-sensorimotor and thalamo-mFC pathways was enhanced when patients performed the multisource interference task. Moreover, patients with KOA presented altered nodal properties associated with thalamocortical circuits, including the thalamus, amygdala, and regions in default mode networks, compared with healthy controls. The correlation analysis suggested a significant negative correlation between thalamo-mFC rsFC and pain intensity, between thalamo-sensorimotor task-related connectivity and disease duration/depression scores, and a positive correlation between right frontal nodal properties and pain intensity in KOA patients. Taken together, these findings establish abnormal and differential alterations in the thalamocortical network associated with pain characteristics in KOA patients, which extends our understanding of their role in the pathophysiology of KOA.

Diminished vibration perception and greater pressure pain sensitivity are associated with worse knee osteoarthritis outcomes across sex and race

OBJECTIVE

To examine associations of vibration sensitivity and pressure pain sensitivity with knee osteoarthritis (OA) outcomes across sex and race, which may relate to known sex and race disparities in clinical outcomes.

DESIGN

Data were from the 2013-2015 visit of the Johnston County Osteoarthritis Project. Exposures were vibration perception threshold (VPT) measured at the bilateral medial femoral condyle (MFC) and first metatarsophalangeal joint (MTP), and pressure pain threshold (PPT) measured at the bilateral upper trapezius. Outcomes were knee pain severity and presence of knee symptoms, radiographic knee OA, and symptomatic knee OA in each knee. Cross-sectional associations of the exposures with the outcomes were examined using logistic regression models, overall and separately by sex and race.

RESULTS

In the VPT and PPT analyses, 851 and 862 participants (mean age 71 years, 68% female, 33% Black, body mass index 31 kg/m2) and 1585 and 1660 knees were included, respectively. Higher VPT (lower vibration sensitivity) at the MFC and first MTP joint was associated with all outcomes. Lower PPT (greater pressure pain sensitivity) was associated with greater knee pain severity. Associations of VPT and PPT with all outcomes were similar among females and males and Black and White individuals.

CONCLUSIONS

Diminished vibration perception and greater pressure pain sensitivity were cross-sectionally associated with worse knee OA outcomes. Despite differences in VPT and PPT among females and males and Black and White adults, associations with knee OA outcomes did not differ by sex or race, suggesting neurophysiological differences do not relate to established disparities.

The role of obesity and adipose tissue dysfunction in osteoarthritis pain

Obesity has a pivotal and multifaceted role in pain associated with osteoarthritis (OA), extending beyond the mechanistic influence of BMI. It exerts its effects both directly and indirectly through various modifiable risk factors associated with OA-related pain. Adipose tissue dysfunction is highly involved in OA-related pain through local and systemic inflammation, immune dysfunction, and the production of pro-inflammatory cytokines and adipokines. Adipose tissue dysfunction is intricately connected with metabolic syndrome, which independently exerts specific effects on OA-related pain, distinct from its association with BMI. The interplay among obesity, adipose tissue dysfunction and metabolic syndrome influences OA-related pain through diverse pain mechanisms, including nociceptive pain, peripheral sensitization and central sensitization. These complex interactions contribute to the heightened pain experience observed in individuals with OA and obesity. In addition, pain management strategies are less efficient in individuals with obesity. Importantly, therapeutic interventions targeting obesity and metabolic syndrome hold promise in managing OA-related pain. A deeper understanding of the intricate relationship between obesity, metabolic syndrome and OA-related pain is crucial and could have important implications for improving pain management and developing innovative therapeutic options in OA.

Association between widespread pain and psychosocial factors in people with knee osteoarthritis: a cross-sectional study of patients from primary care in Denmark

INTRODUCTION

The relationship between psychosocial factors and bodily pain in people with knee osteoarthritis (KOA) is unclear.

PURPOSE

To examine whether widespread pain was associated with poorer self-efficacy, more anxiety, depression, and kinesiophobia in people with KOA.

METHODS

This was a cross-sectional study based on data from Good Life with osteoArthritis in Denmark (GLA:D®). The association between widespread pain (multiple pain sites) and self-efficacy (Arthritis Self-Efficacy Scale), anxiety and depression (item from the EQ-5D-5 L), and kinesiophobia (yes/no) was examined using multiple linear tobit or logistic regression models.

RESULTS

Among 19,323 participants, 10% had no widespread pain, 37% had 2 pain sites, 26% had 3-4 pain sites, and 27% had ≥5 pain sites. Widespread pain was associated with poorer self-efficacy (-0.9 to -8.3 points), and the association was stronger with increasing number of pain sites (p-value <.001). Significant increasing odds ratios (ORs) were observed for having anxiety or depression with 3-4 pain sites (OR 1.29, 95% CI 1.12; 1.49) and ≥5 pain sites (OR 1.80, 95% CI 1.56; 2.07). Having 2 and 3-4 pain sites were associated with lower odds of kinesiophobia compared to having no widespread pain.

CONCLUSION

Widespread pain was associated with lower self-efficacy and more anxiety and depression but also lower kinesiophobia in people with KOA.

Assessment of potential maladaptive pain in dogs with elbow osteoarthritis using a von Frey aesthesiometer

BACKGROUND

This study aimed to investigate the possible presence of maladaptive pain in the thoracic limbs of dogs with elbow osteoarthritis (OA) using an electronic von Frey aesthesiometer (eVFA).

METHODS

Twenty-eight client- and staff-owned dogs (OA, n = 14; controls, n = 14) were enrolled in the study. Every dog underwent a full orthopaedic examination, and then five von Frey measurements were obtained from each carpal pad of each dog. A maximum test threshold of 400 g was set and approved by an ethics committee.

RESULTS

eVFA thresholds were significantly lower (p < 0.001) in dogs with OA (median 248 g, range 128-369 g) than in control dogs (median 390 g, range 371-400 g). In the OA group, the sensory threshold was significantly lower (p = 0.048) in the more severely affected limb than the less severely affected limb.

LIMITATION

The low maximum threshold required for ethical approval may influence the variability in the control group.

CONCLUSIONS

Dogs with elbow OA had significantly lower sensory thresholds than control dogs, which is compatible with the presence of maladaptive pain, potentially due to central sensitisation. Further research is required to evaluate the potential use of the eVFA for monitoring clinical progression and treatment response in dogs with elbow OA.

Chronic pain as an emergent property of a complex system and the potential roles of psychedelic therapies

Despite research advances and urgent calls by national and global health organizations, clinical outcomes for millions of people suffering with chronic pain remain poor. We suggest bringing the lens of complexity science to this problem, conceptualizing chronic pain as an emergent property of a complex biopsychosocial system. We frame pain-related physiology, neuroscience, developmental psychology, learning, and epigenetics as components and mini-systems that interact together and with changing socioenvironmental conditions, as an overarching complex system that gives rise to the emergent phenomenon of chronic pain. We postulate that the behavior of complex systems may help to explain persistence of chronic pain despite current treatments. From this perspective, chronic pain may benefit from therapies that can be both disruptive and adaptive at higher orders within the complex system. We explore psychedelic-assisted therapies and how these may overlap with and complement mindfulness-based approaches to this end. Both mindfulness and psychedelic therapies have been shown to have transdiagnostic value, due in part to disruptive effects on rigid cognitive, emotional, and behavioral patterns as well their ability to promote neuroplasticity. Psychedelic therapies may hold unique promise for the management of chronic pain.

The Effect of Central Sensitization on Postoperative Neurocognitive Dysfunction in Hospitalized Elderly Patients: A Prospective Cohort Clinical Trial

OBJECTIVE

To investigate whether central sensitization (CS) in elderly patients was a predictive risk factor for postoperative neurocognitive dysfunction (PNCD).

METHODS

One hundred and thirty-three aged patients undergoing total knee arthroplasty (TKA) who received femoral nerve block and general anesthesia were recruited in this research and prospectively assigned into two groups according to the Central Sensitization Inventory (CSI) score: group C (n = 106, CSI score less than 40) and group CS (n = 27, CSI score higher than 40). Scores of Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), Confusion Assessment Method (CAM), Numerical Rating Scale (NRS) and Quality of recovery-40 (QoR-40) questionnaires were assessed. Basic information and clinical records of all participants were also collected.

RESULTS

PNCD occurred in 24 (22.6%) of patients in group C and 16 (59.3%) in group CS (p < .05). Multivariate logistic regression analysis revealed that patients with CSI score ≥40 before surgery exhibited higher risk of PNCD after adjustment for other risk factors (p < .05). Compared to group C, the pre- and post-operative NRS scores, pain duration, the WOMAC score, and propofol consumptions for anesthesia induction were significantly increased in group CS (p < .05).

CONCLUSION

Hospitalized elderly patients with clinical symptoms of CS scores may have increased risk of PNCD following TKA.

Translation, cross-cultural adaptation, and measurement properties of the Arabic version of the pain sensitivity questionnaire

Background

The Pain Sensitivity Questionnaire (PSQ) is a reliable and valid self-reported tool for the assessment of pain sensitivity in clinical practice. The PSQ has been translated, validated, and cross-culturally adapted into multiple languages. However, a validated Arabic version of the PSQ is not available. Thus, this study aims to translate, validate, and cross-culturally adapt the English version of the PSQ into the Arabic language.

Methods and materials

The English version of the PSQ was translated and culturally adapted into Arabic following international guidelines. The psychometric properties of the final version of the PSQ-Arabic (PSQ-A) were tested among 119 patients with different persistent musculoskeletal (MSK) pain.

Findings

The Cronbach's α for the PSQ-A-total, PSQ-A-moderate, and PSQ-C-minor were 0.81, 0.79, and 0.76, respectively. The means for the PSQ-A-total, PSQ-A-moderate, and PSQ-C-minor scores were 5.07 (±1.28), 5.64 (±2.07), and 4.50 (±0.50). The test-retest reliability measured with the interclass correlation coefficient for 68 subjects was 0.80 for the PSQ-A-total, 0.74 for the PSQ-A-moderate, and 0.77 for the PSQ-A-minor. The PSQ-A-total and the PSQ-A-minor showed positive significant correlations with pain catastrophizing scale (PCS) (r = 0.15, 0.17); P ≤ 0.05), respectively. The PSQ-A-total, PSQ-A-moderate, and PSQ-A-minor showed positive significant correlations with the Brief Pain Inventory (BPI)-pain scores (r = 0.47, 0.43, 0.45; P ≤ 0.01), respectively and with the BPI-pain interference scores (r = 0.37, 0.33, 0.34; P ≤ 0.01), respectively.

Conclusions

This study shows that the PSQ-A is a reliable and valid tool to assess individuals with pain sensitivity in Arabic populations. Further studies are recommended to examine the concurrent validity of the PSQ-A against experimental pain sensitivity measures.

Preliminary investigation of the interactive role of physiological arousal and insomnia complaints in gray matter volume alterations in chronic widespread pain

STUDY OBJECTIVES

Brain regions involved in insomnia and chronic pain are overlapping and diffuse. The interactive role of physiological arousal in associations between insomnia symptoms and neural regions is unknown. This preliminary study examined whether arousal interacted with sleep in associations with gray matter volume of frontal (dorsolateral prefrontal cortex, anterior cingulate cortex) and temporal (right/left hippocampus) regions in adults with chronic widespread pain and insomnia complaints.

METHODS

Forty-seven adults with chronic widespread pain and insomnia (mean age = 46.00, standard deviation = 13.88, 89% women) completed 14 daily diaries measuring sleep onset latency (SOL), wake time after sleep onset, and total sleep time (TST), as well as Holter monitor assessments of heart rate variability (measuring physiological arousal), and magnetic resonance imaging. Multiple regressions examined whether average SOL, wake time after sleep onset, or TST were independently or interactively (with arousal/heart rate variability) associated with dorsolateral prefrontal cortex, anterior cingulate cortex, and left/right hippocampus gray matter volumes.

RESULTS

Shorter TST was associated with lower right hippocampus volume. TST also interacted with arousal in its association with right hippocampal volume, Specifically, shorter TST was associated with lower volume at highest and average arousal levels. SOL interacted with arousal in its association with anterior cingulate cortex volume, such that, among individuals with lowest arousal, longer SOL was associated with lower volume.

CONCLUSIONS

Preliminary findings highlight the interactive roles of physiological arousal and insomnia symptoms in associations with neural structure in chronic widespread pain and insomnia. Individuals with the highest physiological arousal may be particularly vulnerable to the impact of shorter TST on hippocampal volume loss. Reducing SOL may only impact anterior cingulate cortex volume in those with lower physiological arousal.

CITATION

Curtis AF, Nair N, Hayse B, et al. Preliminary investigation of the interactive role of physiological arousal and insomnia complaints in gray matter volume alterations in chronic widespread pain. J Clin Sleep Med. 2024;20(2):293-302.

Personalized assessment and management of non-specific low back pain

BACKGROUND AND OBJECTIVE

Low back pain (LBP), and in particular non-specific low back pain (NSLBP), which accounts for approximately 90% of LBP, is the leading cause of years lived with disability worldwide. In clinical trials, LBP is often poorly categorized into 'specific' versus 'non-specific' and 'acute' versus 'chronic' pain. However, a better understanding of the underlying pain mechanisms might improve study results and reduce the number of NSLBP patients.

DATABASES AND DATA TREATMENT

Narrative review.

RESULTS

NSLBP is a multi-dimensional, biopsychosocial condition that requires all contributing dimensions to be assessed and prioritized. Thereby, the assessment of the contribution of nociceptive, neuropathic and nociplastic pain mechanisms forms the basis for personalized management. In addition, psychosocial (e.g. anxiety, catastrophizing) and contextual factors (e.g. work situation) as well as comorbidities need to be assessed and individually weighted. Personalized treatment of NSLBP further requires individually choosing treatment modalities, for example, exercising, patient education, cognitive-behavioural advice, pharmacotherapy, as well as tailoring treatment within these modalities, for example, the delivery of tailored psychological interventions or exercise programs. As the main pain mechanism and psychosocial factors may vary over time, re-assessment is necessary and treatment success should ideally be assessed quantitatively and qualitatively.

CONCLUSIONS

The identification of the main contributing pain mechanism and the integration of the patients' view on their condition, including beliefs, preferences, concerns and expectations, are key in the personalized clinical management of NSLBP. In research, particular importance should be placed on accurate characterization of patients and on including outcomes relevant to the individual patient.

SIGNIFICANCE STATEMENT

Here, a comprehensive review of the challenges associated with the diagnostic label 'non-specific low back pain' is given. It outlines what is lacking in current treatment guidelines and it is summarized what is currently known with respect to individual phenotyping. It becomes clear that more research on clinically meaningful subgroups is needed to best tailor treatment approaches.

The Role of Physical Exercise in Chronic Musculoskeletal Pain: Best Medicine-A Narrative Review

The aim of this paper is to provide a narrative review of the effects of physical exercise in the treatment of chronic musculoskeletal pain. Physical inactivity and sedentary behavior are associated with chronic musculoskeletal pain and can aggravate it. For the management of musculoskeletal pain, physical exercise is an effective, cheap, and safe therapeutic option, given that it does not produce the adverse effects of pharmacological treatments or invasive techniques. In addition to its analgesic capacity, physical exercise has an effect on other pain-related areas, such as sleep quality, activities of daily living, quality of life, physical function, and emotion. In general, even during periods of acute pain, maintaining a minimum level of physical activity can be beneficial. Programs that combine several of the various exercise modalities (aerobic, strengthening, flexibility, and balance), known as multicomponent exercise, can be more effective and better adapted to clinical conditions. For chronic pain, the greatest benefits typically occur with programs performed at light-to-moderate intensity and at a frequency of two to three times per week for at least 4 weeks. Exercise programs should be tailored to the specific needs of each patient based on clinical guidelines and World Health Organization recommendations. Given that adherence to physical exercise is a major problem, it is important to empower patients and facilitate lifestyle change. There is strong evidence of the analgesic effect of physical exercise in multiple pathologies, such as in osteoarthritis, chronic low back pain, rheumatoid arthritis, and fibromyalgia.

Response to experimental cold-induced pain discloses a resistant category among endurance athletes, with a distinct profile of pain-related behavior and GABAergic EEG markers: a case-control preliminary study

Pain is a major public health problem worldwide, with a high rate of treatment failure. Among promising non-pharmacological therapies, physical exercise is an attractive, cheap, accessible and innocuous method; beyond other health benefits. However, its highly variable therapeutic effect and incompletely understood underlying mechanisms (plausibly involving the GABAergic neurotransmission) require further research. This case-control study aimed to investigate the impact of long-lasting intensive endurance sport practice (≥7 h/week for the last 6 months at the time of the experiment) on the response to experimental cold-induced pain (as a suitable chronic pain model), assuming that highly trained individual would better resist to pain, develop advantageous pain-copying strategies and enhance their GABAergic signaling. For this purpose, clinical pain-related data, response to a cold-pressor test and high-density EEG high (Hβ) and low beta (Lβ) oscillations were documented. Among 27 athletes and 27 age-adjusted non-trained controls (right-handed males), a category of highly pain-resistant participants (mostly athletes, 48.1%) was identified, displaying lower fear of pain, compared to non-resistant non-athletes. Furthermore, they tolerated longer cold-water immersion and perceived lower maximal sensory pain. However, while having similar Hβ and Lβ powers at baseline, they exhibited a reduction between cold and pain perceptions and between pain threshold and tolerance (respectively -60% and - 6.6%; -179.5% and - 5.9%; normalized differences), in contrast to the increase noticed in non-resistant non-athletes (+21% and + 14%; +23.3% and + 13.6% respectively). Our results suggest a beneficial effect of long-lasting physical exercise on resistance to pain and pain-related behaviors, and a modification in brain GABAergic signaling. In light of the current knowledge, we propose that the GABAergic neurotransmission could display multifaceted changes to be differently interpreted, depending on the training profile and on the homeostatic setting (e.g., in pain-free versus chronic pain conditions). Despite limitations related to the sample size and to absence of direct observations under acute physical exercise, this precursory study brings into light the unique profile of resistant individuals (probably favored by training) allowing highly informative observation on physical exercise-induced analgesia and paving the way for future clinical translation. Further characterizing pain-resistant individuals would open avenues for a targeted and physiologically informed pain management.

Exercise therapy for knee osteoarthritis pain: how does it work? A study protocol for a randomised controlled trial

INTRODUCTION

Muscle strengthening training (MST) and behavioural graded activity (BGA) show comparable effects on knee osteoarthritic (KOA) pain, but the mechanisms of action remain unclear. Both exercise-induced anti-inflammation and central sensitisation are promising pathways for pain relief in response to exercise therapy in patients with KOA: MST has the potential to decrease inflammation and BGA has the potential to decrease central sensitisation. Hence, this study aims to examine inflammation and central sensitisation as mediators for the effect of MST and/or BGA on pain in patients with KOA.

METHODS AND ANALYSIS

The Knee OsteoArthritis PAIN trial started on 10 January 2020 (anticipated end: April 2024). The three-arm clinical trial aims to recruit 90 KOA patients who will be randomly allocated to 12 weeks of (1) MST, (2) BGA or (3) care as usual. Assessments will be performed at baseline, 13 and 52 weeks after finishing the intervention. Outcomes, including pain (Knee injury and Osteoarthritis Outcome Score), were chosen in line with the OARSI recommendations for clinical trials of rehabilitation interventions for OA and the IMMPACT/OMERACT recommendations for the assessment of physical function in chronic pain clinical trials. Inflammation as well as features of central sensitisation (including conditioned pain modulation, offset analgesia, temporal summation of pain and event-related potentials following electrical stimulation), will be considered as treatment mediators. A multiple mediators model will be estimated with a path-analysis using structural equation models. In July 2023, all 90 KOA patients have been included and 42 participants already finished the study.

ETHICS AND DISSEMINATION

This study obtained ethics approval (B.U.N. 143201941843). Unravelling the mechanisms of action of exercise therapy in KOA will not only be extremely valuable for researchers, but also for exercise immunology and pain scientists and clinicians.

TRIAL REGISTRATION NUMBER

NCT04362618.

Adaptive Force of hamstring muscles is reduced in patients with knee osteoarthritis compared to asymptomatic controls

BACKGROUND

Quadriceps strength deficits are known for patients with knee osteoarthritis (OA), whereas findings on hamstrings are less clear. The Adaptive Force (AF) as a special neuromuscular function has never been investigated in OA before. The maximal adaptive holding capacity (max. isometric AF; AFisomax) has been considered to be especially vulnerable to disruptive stimuli (e.g., nociception). It was hypothesized that affected limbs of OA patients would show clear deficits in AFisomax.

METHODS

AF parameters and the maximal voluntary isometric contraction (MVIC) of hamstrings were assessed bilaterally comparing 20 patients with knee OA (ART) vs. controls (CON). AF was measured by a pneumatically driven device. Participants were instructed to maintain a static position despite an increasing load of the device. After reaching AFisomax, the hamstrings merged into eccentric action whereby the force increased further to the maximum (AFmax). MVIC was recorded before and after AF trials. Mixed ANOVA was used to identify differences between and within ART and CON (comparing 1st and 2nd measured sides).

RESULTS

AFisomax and the torque development per degree of yielding were significantly lower only for the more affected side of ART vs. CON (p ≤ 0.001). The percentage difference of AFisomax amounted to - 40%. For the less affected side it was - 24% (p = 0.219). MVIC and AFmax were significantly lower for ART vs. CON for both sides (p ≤ 0.001). Differences of MVIC between ART vs. CON amounted to - 27% for the more, and - 30% for the less affected side; for AFmax it was - 34% and - 32%, respectively.

CONCLUSION

The results suggest that strength deficits of hamstrings are present in patients with knee OA possibly attributable to nociception, generally lower physical activity/relief of lower extremities or fear-avoidance. However, the more affected side of OA patients seems to show further specific impairments regarding neuromuscular control reflected by the significantly reduced adaptive holding capacity and torque development during adaptive eccentric action. It is assumed that those parameters could reflect possible inhibitory nociceptive effects more sensitive than maximal strengths as MVIC and AFmax. Their role should be further investigated to get more specific insights into these aspects of neuromuscular control in OA patients. The approach is relevant for diagnostics also in terms of severity and prevention.

Strength Training vs. Aerobic Training for Managing Pain and Physical Function in Patients with Knee Osteoarthritis: A Systematic Review and Meta-Analysis

(1) Background: Strength training (ST) and aerobic training (AT) are the most recommended interventions in patients with knee OA. These recommendations are supported by high-quality evidence, but it is still unknow whether one type of exercise is superior to the other. Thus, the aim was to investigate whether one type of exercise (ST or AT) is superior to the other for improving pain and physical function in patients with knee osteoarthritis. (2) Methods: A systematic review and meta-analysis was carried out following the PRISMA statement. The search strategy was conducted in PubMed, PEDro, Scopus, Web of Science and Cochrane Library databases. Randomized controlled trials comparing ST and AT on pain intensity and physical function in patients with knee osteoarthritis were included. Methodological quality and risk of bias were assessed with a PEDro scale and risk-of-bias tool, respectively. The certainty of evidence was evaluated using GRADE guidelines. (3) Results: Four studies (6 publications) were included. The qualitative and quantitative synthesis showed that ST produces no more improvement in pain intensity (SMD after intervention: 0.02; 95%CI: -0.15, 0.19; I2: 0%; three studies; 426 patients) and physical function (SMD after intervention: 0.07; 95%CI: -0.10, 0.24; I2: 0%; three studies; 426 patients) compared to AT in patients with knee osteoarthritis. The certainty of evidence was rated as very low. (4) Conclusions: Both type of exercises showed clinical benefits in people with knee osteoarthritis, but no differences between ST and AT were found.

Therapeutic Effects of Non-Euphorigenic Cannabis Extracts in Osteoarthritis

Introduction: Osteoarthritis (OA) is disabling and degenerative disease of the joints that is clinically characterized by pain and loss of function. With no disease-modifying treatment available, current therapies aim at pain management but are of limited efficacy. Cannabis products, specifically cannabinoids, are widely used to control pain and inflammation in many diseases with no scientific evidence demonstrating their efficacy in OA. Objective: We investigated the effects of non-euphorigenic cannabis extracts, CBD oil and cannabigerol oil (CBG oil), on pain and disease progression in OA mice. Methods and Results: Twelve-week-old male C57BL/6J mice received either sham or destabilization of the medial meniscus (DMM) surgery. DMM mice were treated with vehicle, CBD oil, or CBG oil. The gait of DMM mice was impaired as early as 2 weeks following surgery and continued deteriorating until week 8, which was restored by CBD oil and CBG oil treatments throughout the disease course. Mechanical allodynia developed in DMM mice, however, was not ameliorated by any of the treatments. On the other hand, both CBD oil and CBG oil ameliorated cold allodynia. In open field test, both oil treatments normalized changes in the locomotor activity of DMM mice. CBD oil and CBG oil treatments significantly reduced synovitis in DMM mice. Only CBG oil reduced cartilage degeneration, chondrocyte loss, and matrix metalloproteinase 13 expression, with a significant increase in the number of anabolic chondrocytes. Subchondral bone remodeling found in vehicle-treated DMM mice was not ameliorated by either CBD or CBG oil. Conclusions: Our results show evidence for the therapeutic efficacy of CBD oil and CBG oil, where both oils ameliorate pain and inflammation, and improve gait and locomotor activity in OA mice, representing clinical pain and function. Importantly, only CBG oil is chondroprotective, which may provide superior efficacy in future studies in OA patients.

Low central sensitisation inventory score is associated with better post-operative outcomes of osteotomy around the knee

PURPOSE

The purpose of this study was to investigate the potential association between central sensitisation inventory (CSI) scores and post-operative patient-reported outcomes (PROs) in patients underwent osteotomy around the knee (OAK), with a CSI cut-off score specific for knee osteoarthritis.

METHODS

CSI scores were collected from 173 patients who underwent OAK, along with their knee injury and osteoarthritis outcome score (KOOS) and pain numeric rating scale (NRS) scores. Patients were divided into high-CSI score group and low-CSI score group with a cut-off score of 17. Multivariate linear regression was performed to test the association between CSI scores and post-operative outcomes. Pre-surgery KOOS and NRS scores and the rate of attainment of minimal clinically important difference (MCID) of KOOS scores was analysed as secondary outcomes.

RESULTS

Low-CSI score group had significantly higher post-operative KOOS scores and lower pain NRS scores compared to the high-CSI score group (< p = 0.01) after adjusting for confounding factors. For pre-operative scores, only the KOOS-Symptom score was significantly different between the groups (64.7 ± 20.1 when CSI < 17 vs.55.1 ± 19.7 when CSI ≥ 17; p = 0.008). The low-CSI score group had significantly higher MCID achievement rates of KOOS-Pain, Symptom, and ADL than the high-CSI score group (86% vs. 68%; 74% vs. 55%; 86% vs. 67%, respectively; P < 0.05).

CONCLUSIONS

This study established an association between post-operative CSI scores ≥ 17 and poorer outcomes following OAK, highlighting the potential value of the CSI in identifying patients in need of more comprehensive peri-operative pain management.

LEVEL OF EVIDENCE

Level III. Retrospective comparative study.

Frequency of multisite non-hand joint involvement in patients with thumb-base osteoarthritis, and associations with functional and patient-reported outcomes

Purpose

In OA studies, the focus often is on an index-joint; other affected joint sites are often overlooked. In this thumb-base OA study, we documented the frequency of symptomatic non-hand joint sites and investigated whether their count was associated with thumb-specific functional and patient-reported outcome measures.

Design

Patients seeking care for thumb-base OA (conservative or surgical) were included. A patient-completed questionnaire captured sociodemographic and health characteristics, symptomatic hand and non-hand joint sites, and outcome measures (thumb-base pain intensity, symptoms and disability (TASD) and upper-extremity disability/symptoms (quickDASH)). Grip and pinch strength were measured. Linear regressions examined the association between each outcome and symptomatic joint site count, adjusted for several covariates.

Results

The mean age of the 145 patients was 62 years, 72% were female. Mean symptomatic non-hand joint site count was 3.6. Ten percent reported only their hands as symptomatic; 30% reported 2-3 other symptomatic sites, and 49% reported 4+. From cross-sectional multivariable analyses, a higher symptomatic non-hand joint site count was associated with worse scores for all patient-reported outcomes and grip strength. Every unit increase in joint site count (49% had a 4+ count) was associated with a 2.1-3.3 unit increase (worse) in patient-reported outcome scores (all p ​< ​0.02).

Conclusions

In this sample, nearly 80% of patients had 2+ symptomatic non-hand joint sites. These symptoms were associated with worse thumb- and hand-specific outcomes, suggesting a need for awareness of whole body OA burden, with implications for outcome score interpretations, study designs, and provision of care in thumb-base OA.

Investigation for Factors Affecting Body Perception Disturbance in Patients with Low Back Pain by Mechanism-Based Classification of Pain: A Cross-Sectional Study

Background

Central sensitization is a pathophysiological cause of chronic low back pain and is linked with psychosocial factors. The association between central sensitization (CS) and body perception disturbance is currently unclear, and no prior studies have investigated this relationship in patients with acute or subacute low back pain. The objective of this study was to investigate potential factors that influence body perception disturbance using a mechanistic classification of low back pain.

Methods

This cross-sectional study was conducted at the time of initial physical therapy in patients with low back pain. During the study period, 169 patients were recruited. Pain intensity, disease duration, disability, CS, and body perception disturbance were evaluated. Patients were divided into three groups according to the pathology of low back pain, and multivariate analysis was used to examine factors affecting body perception disturbance. The dependent variable was Fremantle Back Awareness Questionnaire (FreBAQ); the independent variables were age, gender, BMI, VAS, disease duration, RDQ, and CS Inventory-9 (CSI-9).

Results

A total of 117 patients were included in our analysis. According to the mechanistic classification of pain, 66 (56.4%), 36 (30.8%), and 15 (12.8%) patients were categorized as having nociceptive pain (NP), peripheral neuropathic pain (PNP), and CS pain (CSP), respectively. Patients with PNP or CSP were significantly older than those with NP (p  <  0.01). FreBAQ and RDQ scores were significantly higher in patients with CSP than those with NP (p  <  0.05). The results of multiple regression analyses indicated that CSI-9 scores were significantly associated with FreBAQ (p  <  0.01).

Conclusion

Patients with CS syndrome and low back pain tend to have higher CSI-9 scores and be older. Body perception disturbance is influenced by CS or CS syndrome, regardless of the stage of low back pain, suggesting that patients with chronic low back pain tend to have low body image.

Exploration of the clinical course and longitudinal correlations in frozen shoulder: The role of autonomic function, central pain processing, and psychological variables. A longitudinal multicenter prospective observational study

BACKGROUND

Altered central pain processing (CPP) and dysautonomia might play a role in the clinical course of frozen shoulder and psychological factors, like pain catastrophizing and hypervigilance, might influence clinical variables in frozen shoulder.

OBJECTIVES

To explore the clinical course of frozen shoulder regarding CPP, dysautonomia, pain catastrophizing, and hypervigilance and to explore whether longitudinal correlations between these outcomes and pain intensity were present.

DESIGN

prospective longitudinal observational study.

METHOD

Participants with frozen shoulder were recruited at hospitals and general practitioner practices and followed for 9 months. They completed six questionnaires (about demographics, shoulder pain and disability, pain intensity, pain catastrophizing, pain hypervigilance, and autonomic symptoms) and underwent tactile sensitivity (allodynia), pressure pain thresholds (hyperalgesia), temporal summation, and conditioned pain modulation during four timeframes (3-month intervals).

RESULTS

Initially, 149 participants with frozen shoulder were recruited and 88 completed all the measurements. An improvement from baseline to at least one follow-up measurement was found for shoulder pain and disability, pain intensity, pain catastrophizing, hypervigilance, and dysautonomia. A fair longitudinal correlation was found between pain intensity and catastrophizing and hypervigilance (r = 0.301-0.397). Poor longitudinal correlations were found between pain intensity and allodynia and hyperalgesia (r = -0.180-0.193), between pain catastrophizing and dysautonomia (r = 0.209) and between hypervigilance and hyperalgesia (r = -0.159).

CONCLUSION

Patients with frozen shoulder showed an early improvement that flattened with time in several pain and psychological variables over the course of 9 months. However, autonomic symptoms rather showed a late improvement over 9 months.

Does the painDETECT questionnaire identify impaired conditioned pain modulation in people with musculoskeletal pain? - a diagnostic accuracy study

BACKGROUND

People with neuropathic-like symptoms had more unfavourable pain features than people with nociceptive. Moreover, deficient conditioned pain modulation is common in people with neuropathic-like symptoms. PainDETECT questionnaire have been used to assess the central sensitisation sign and symptoms. However, whether the painDETECT questionnaire can identify the conditioned pain modulation's impairment is still unknown. Therefore, the current study aimed to evaluate the diagnostic accuracy of the painDETECT questionnaire in detecting the impairment of conditioned pain modulation in people with musculoskeletal pain.

METHODS

We conducted a diagnostic accuracy comparing the painDETECT questionnaire (index method) with the cold pressor test, the psychophysical test used to assess the conditioned pain modulation (reference standard). We determined diagnostic accuracy by calculating sensitivity, specificity, predictive values, and likely hood ratios.

RESULTS

We retrospectively enrolled 308 people with musculoskeletal pain in outpatient departments. Most participants were female (n 20 = 220, 71.4%) and had a mean age of 52.2 (± 15.0) years. One hundred seventy-three (56.1%) participants were classified as nociceptive pain, 69 (22.4%) as unclear, and 66 (21.4%) as neuropathic-like symptoms. According to the cold pressor test, 60 (19.4%) participants presented impairment of conditioned pain modulation. The cutoff point of 12 of the painDETECT questionnaire showed values of diagnostic accuracy below 70% compared to the cold pressor test, except for a negative predictive value [76.9 95% Confidence Interval (CI) 71.7 to 81.5]. The cutoff point 19 showed high specificity (78.6%, 95% CI 73.0 to 83.5), high negative predictive value (80.5%, 95% CI 78.1 to 82.7), and accuracy of 67.5% compared to the cold pressor test.

CONCLUSION

The painDETECT questionnaire seems valuable for ruling out people with musculoskeletal pain and impairment of conditioned pain modulation.

Role of autophagy in the pathogenesis and regulation of pain

Pain is a ubiquitous and highly concerned clinical symptom, usually caused by peripheral or central nervous injury, tissue damage, or other diseases. The long-term existence of pain can seriously affect daily physical function and quality of life and produce great torture on the physiological and psychological levels. However, the complex pathogenesis of pain involving molecular mechanisms and signaling pathways has not been fully elucidated, and managing pain remains highly challenging. As a result, finding new targets to pursue effective and long-term pain treatment strategies is required and urgent. Autophagy is an intracellular degradation and recycling process that maintains tissue homeostasis and energy supply, which can be cytoprotective and is vital in maintaining neural plasticity and proper nervous system function. Much evidence has shown that autophagy dysregulation is linked to the emergence of neuropathic pain, such as postherpetic neuralgia and cancer-related pain. Autophagy has also been connected to pain caused by osteoarthritis and lumbar disc degeneration. It is worth noting that in recent years, studies on traditional Chinese medicine have also proved that several traditional Chinese medicine monomers involve autophagy in the mechanism of pain relief. Therefore, autophagy can serve as a potential regulatory target to provide new ideas and inspiration for pain management.

Levels of preoperative cerebrospinal fluid pro-inflammatory mediators and chronic pain after total knee arthroplasty surgery

BACKGROUND

Patients undergoing total knee arthroplasty (TKA) surgery are at high risk of chronic postsurgical pain (CPSP). Accumulating evidence suggests an active role of neuroinflammation in chronic pain. However, its role in the progression to CPSP following TKA surgery remains unanswered. Here, we examined the associations between preoperative neuroinflammatory states and pre- and postsurgical chronic pain in TKA surgery.

METHODS

The data of 42 patients undergoing elective TKA surgery for chronic knee arthralgia at our hospital were analyzed in this prospective study. Patients completed the following questionnaires: brief pain inventory (BPI), hospital anxiety and depression scale, painDETECT, and pain catastrophizing scale (PCS). Cerebrospinal fluid (CSF) samples were collected preoperatively and concentrations of IL-6, IL-8, TNF, fractalkine, and CSF-1 were measured by electrochemiluminescence multiplex immunoassay. CPSP severity was ascertained, using the BPI, 6 months postsurgery.

RESULTS

While no significant correlation was observed between the preoperative CSF mediator levels and preoperative pain profiles, the preoperative fractalkine level in the CSF showed a significant correlation with CPSP severity (Spearman's rho = -0.525; p = .002). Furthermore, multivariate linear regression analysis revealed that the preoperative PCS score (standardized β coefficient [β]: .11; 95% confidence interval [CI]: 0.06-0.16; p < .001) and CSF fractalkine level (β: -.62; 95% CI: -1.10 to -0.15; p = .012) were independent predictors of CPSP severity 6 months after TKA surgery.

CONCLUSIONS

We identified the CSF fractalkine level as a potential predictor for CPSP severity following TKA surgery. In addition, our study provided novel insights into the potential role of neuroinflammatory mediators in the pathogenesis of CPSP.

Psychophysical assessment of pain in adults with moderate and severe haemophilia: A cross-sectional study

BACKGROUND

Joint pain is the hallmark of haemophilia; therefore it seems clinically rather a musculoskeletal than a bleeding disorder. Although joint pain in people with haemophilia (PwH) is a complex and multidimensional problem, pain assessment remains primarily focused on the structural evaluation of their joints. Whereas, only few data are available on the potential implication of psychophysical and psychological factors.

OBJECTIVE

This study aimed to perform a psychophysical pain assessment including quantitative sensory testing (QST) and an evaluation of psychological factors in a large sample of PwH, to get insight into the individuals' pain system.

METHODS

Ninety-nine adults (36.9 ± 13.5 years) with moderate/severe haemophilia A/B and 46 healthy controls filled in self-reported pain and psychological questionnaires and underwent a QST evaluation including static and dynamic tests. Static tests focused on the determination of thermal detection and pain thresholds and mechanical pressure pain thresholds. Dynamic tests evaluated pain facilitation and the efficacy of endogenous pain inhibition. Besides comparing PwH and healthy controls, between-subgroup differences were studied in PwH based on their pain distribution.

RESULTS

The study revealed increased thermal and mechanical pain sensitivity and the presence of unhelpful psychological factors such as anxiety/depression in PwH. Among the subgroups, especially PwH with widespread pain showed altered somatosensory functioning. Enhanced pain facilitation and impaired efficacy of endogenous pain inhibition in PwH could not be observed.

CONCLUSION

Altered somatosensory functioning and unhelpful psychological factors, appear to play an important role in the pathophysiology of pain in PwH, especially in PwH with widespread pain.

Investigation of factors influencing low physical activity levels in community-dwelling older adults with chronic pain: a cross-sectional study

Low levels of physical activity in individuals with chronic pain can lead to additional functional impairment and disability. This study aims to investigate the predictors of low physical activity levels in individuals with chronic pain, and to determine the accuracy of the artificial neural network used to analyze these predictors. Community-dwelling older adults with chronic pain (n = 103) were surveyed for their physical activity levels and classified into low, moderate, or high physical activity level groups. Chronic pain-related measurements, physical function assessment, and clinical history, which all influence physical activity, were also taken at the same time. Logistic regression analysis and analysis of multilayer perceptron, an artificial neural network algorithm, were performed. Both analyses revealed that history of falls was a predictor of low levels of physical activity in community-dwelling older adults. Multilayer perceptron analysis was shown to have excellent accuracy. Our results emphasize the importance of fall prevention in improving the physical activity levels of community-dwelling older adults with chronic pain. Future cross-sectional studies should compare multiple analysis methods to show results with improved accuracy.

Is there a difference in the analgesic response to intra-articular bupivacaine injection in people with knee osteoarthritis pain with or without central sensitisation? Protocol of a feasibility randomised controlled trial

INTRODUCTION

Pain is the main symptom of osteoarthritis (OA) with approximately 50% of patients reporting moderate-to-severe pain. Total knee replacement (TKR) is the ultimate treatment option to alleviate pain in knee OA. Nevertheless, TKR does not provide complete relief for all as approximately 20% of patients experience chronic postoperative pain. Painful peripheral stimuli may alter the central nociceptive pathways leading to central sensitisation that can influence treatment response in patients with OA. Currently, there is no objective protocol for detecting whether a patient will respond to a given treatment. Therefore, there is a need for a better mechanistic understanding of individual factors affecting pain relief, consequently informing personalised treatment guidelines. The purpose of this research is to examine the feasibility of conducting a full-scale mechanistic clinical trial in painful knee OA investigating the analgesic response to intra-articular bupivacaine between those with or without evidence of central sensitisation.

METHODS AND ANALYSIS

The Understanding Pain mechanisms in KNEE osteoarthritis (UP-KNEE) study is a feasibility, double-blinded, placebo-controlled randomised parallel study in participants with radiographically defined knee OA and with self-reported chronic knee pain. The study involves the following assessments: (1) a suite of psychometric questionnaires; (2) quantitative sensory testing; (3) magnetic resonance imaging (MRI) scan of the knee and brain; (4) a 6-minute walk test; and (5) an intra-articular injection of bupivacaine or placebo (sodium chloride 0.9%) into the index knee. Assessments will be repeated post intra-articular injection apart from the MRI scan of the knee. Our aim is to provide proof of concept and descriptive statistics to power a future mechanistic trial.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Health Research Authority (HRA) (REC: 20/EM/0287). Results will be disseminated via peer-reviewed journals and scientific conferences. The results will also be shared with lay audiences through relevant channels, such as Pain Centre Versus Arthritis website and patient advocacy groups.

TRIAL REGISTRATION NUMBER

NCT05561010.

Early Knee Osteoarthritis Classification and Clinical Evolution: A Longitudinal Observational Pilot Study

Knee osteoarthritis (KOA) is one of the main problems of an aging society in terms of incidence, impairment to the quality of daily living (QOL), and economics. The main aim of this study was to verify the usefulness, in practical terms, of applying the existing diagnostic criteria of early knee osteoarthritis (EKOA). The secondary objective of this project was to evaluate the clinical progression of healthy subjects (HS) at risk of osteoarthritis and of patients with diagnosed EKOA. A cross-sectional longitudinal pilot study was carried out, in which 105 participants were classified as EKOA patients or HS according to the diagnostic criteria. Measures of disability, pain, and self-reported variables were assessed. Two follow-ups were performed in order to assess the diagnoses and radiological progression, and the clinical progression was evaluated using self-reported measures. Following the current diagnostic criteria, the participants were divided into EKOA and HS. Most of the participants did not present changes in their classification, although some subjects were reclassified as EKOA or HS in the follow-ups which were performed. The current classification criteria for EKOA based on self-reported measures, radiological findings, and clinical conditions such as pain could lead to a misdiagnosis of this process, as fluctuations in the classifications of patients according to their conditions were found during follow up.

Clinical phenotypes and prognostic factors in persons with hip osteoarthritis undergoing total hip arthroplasty: protocol for a longitudinal prospective cohort study (HIPPROCLIPS)

BACKGROUND

Large heterogeneity exists in the clinical manifestation of hip osteoarthritis (OA). It is therefore not surprising that pain and disability in individuals with hip OA and after total hip arthroplasty (THA) cannot be explained by biomedical variables alone. Indeed, also maladaptive pain-related cognitions and emotions can contribute to pain and disability, and can lead to poor treatment outcomes. Traumatic experiences, mental disorders, self-efficacy and social support can influence stress appraisal and strategies to cope with pain, but their influence on pain and disability has not yet been established in individuals with hip OA undergoing THA. This study aims (1) to determine the influence of traumatic experiences and mental disorders on pain processing before and shortly after THA (2) to identify preoperative clinical phenotypes in individuals with hip OA eligible for THA, (3) to identify pre- and early postoperative prognostic factors for outcomes in pain and disability after THA, and (4) to identify postoperative clinical phenotypes in individuals after THA.

METHODS

This prospective longitudinal cohort study will investigate 200 individuals undergoing THA for hip OA. Phenotyping variables and candidate prognostic factors include pain-related fear-avoidance behaviour, perceived injustice, mental disorders, traumatic experiences, self-efficacy, and social support. Peripheral and central pain mechanisms will be assessed with thermal quantitative sensory testing. The primary outcome measure is the hip disability and osteoarthritis outcome score. Other outcome measures include performance-based measures, hip muscle strength, the patient-specific functional scale, pain intensity, global perceived effect, and outcome satisfaction. All these measurements will be performed before surgery, as well as 6 weeks, 3 months, and 12 months after surgery. Pain-related cognitions and emotions will additionally be assessed in the early postoperative phase, on the first, third, fifth, and seventh day after THA. Main statistical methods that will be used to answer the respective research questions include: LASSO regression, decision tree learning, gradient boosting algorithms, and recurrent neural networks.

DISCUSSION

The identification of clinical phenotypes and prognostic factors for outcomes in pain and disability will be a first step towards pre- and postoperative precision medicine for individuals with hip OA undergoing THA.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05265858. Registered on 04/03/2022.

Tactile acuity and left/right judgment performance in patients with knee osteoarthritis: A cross-sectional study

BACKGROUND

Left/right judgment task (LRJT) performance and tactile acuity are impaired in chronic pain conditions, however, evidence is limited for knee osteoarthritis (OA).

OBJECTIVE

To compare LRJT performance and the two-point discrimination threshold (TPDT) of chronic knee OA patients with asymptomatic knee and pain-free controls.

DESIGN

Cross-sectional study.

METHODS

Fifty knee OA patients and 50 age and gender-matched pain-free controls were assessed using the Recognize® application by displaying knee images and a digital caliper for the TPDT of the medial and lateral knee joint line.

RESULTS

TPDTs over the lateral joint line in symptomatic (mean difference [MD]: 13.59 mm; 95% confidence interval [CI]: 8.72, 18.46; d = 1.40) and asymptomatic knee (MD: 10.15 mm; 95% CI: 5.08, 15.22; d = 0.99) were significantly increased compared to pain-free controls. Similarly, TPDTs of the medial joint line were significantly increased in symptomatic (MD: 12.19 mm; 95% CI: 7.59, 16.79; d = 1.31) and asymptomatic knee (MD: 7.64 mm; 95% CI: 3.64, 11.64; d = 1.31) compared to pain-free controls. Patients with knee OA were less accurate (MD: 7.80%; 95% CI: 15.32, -0.27; d = 0.52) recognizing images of their symptomatic knee. No correlation was found between pain severity, pain duration, LRJT performance, and TPDTs. Post-hoc analysis revealed no differences in LRJT and TPDTs between patients with and without clinically relevant symptoms of central sensitization.

CONCLUSION

Chronic knee OA is associated with increased TPDT for medial and lateral knee joint lines and decreased recognition accuracy performance which should be considered during treatment process.

Central Sensitization and Chronic Pain Personality Profile: Is There New Evidence? A Case-Control Study

BACKGROUND

Personality traits are relevant for pain perception in persistent pain disorders, although they have not been studied in depth in sensitized and nonsensitized patients with knee osteoarthritis (OA).

OBJECTIVE

To explain and compare the personality profile of patients with OA, with and without central sensitization (CS), and fibromyalgia (FM).

SETTING

Participants were selected at the Rheumatology Department in two major hospitals in Spain.

PARTICIPANTS

Case-control study where the sample consists of 15 patients with OA and CS (OA-CS), 31 OA without CS (OA-noCS), 47 FM, and 22 controls. We used a rigorous and systematic process that ensured the sample strictly fulfilled all the inclusion/exclusion criteria, so the sample is very well delimited.

PRIMARY OUTCOME MEASURES

Personality was assessed by the Temperament and Character Inventory of Cloninger.

RESULTS

The percentile in harm-avoidance dimension for the FM group is higher compared to OA groups and controls. The most frequent temperamental profiles in patients are cautious, methodical, and explosive. Patients with FM are more likely to report larger scores in harm-avoidance, with an increase in logistic regression adjusted odds ratio (ORadj) between 4.2% and 70.2%.

CONCLUSIONS

Harm-avoidance seems to be the most important dimension in personality patients with chronic pain, as previously found. We found no differences between OA groups and between sensitized groups, but there are differences between FM and OA-noCS, so harm-avoidance might be the key to describe personality in patients with CS rather than the presence of prolonged pain, as found in the literature before.

Mechanisms of Peripheral and Central Sensitization in Osteoarthritis Pain

Pain, the primary symptom of osteoarthritis (OA), reduces both the quality and quantity of life for patients. The pathophysiology of OA pain is complex and often difficult to explain solely by radiological structural changes. One reason for this discrepancy is pain sensitization (peripheral sensitization [PS] and central sensitization [CS]) in OA. Thus, an understanding of pain sensitization is important when considering treatment strategies and development for OA pain. In recent years, pro-inflammatory cytokines, nerve growth factors (NGFs), and serotonin have been identified as causative agents that induce peripheral and central sensitization and are becoming therapeutic targets for OA pain. However, the characteristics of the clinical manifestations of pain sensitization elicited by these molecules remain unclear, and it is not well understood who among OA patients should receive the therapeutic intervention. Thus, this review summarizes evidence on the pathophysiology of peripheral and central sensitization in OA pain and the clinical features and treatment options for this condition. While the majority of the literature supports the existence of pain sensitization in chronic OA pain, clinical identification and treatment of pain sensitization in OA are still in their infancy, and future studies with good methodological quality are needed.

Extracutaneous features and complications of the Ehlers-Danlos syndromes: A systematic review

Introduction

The Ehlers-Danlos syndromes (EDS) comprise a group of inherited connective tissue disorders presenting with variable fragility to skin, soft tissue, and certain internal organs, which can cause significant complications, particularly arterial rupture, bowel perforation and joint difficulties. Currently, there are 14 proposed subtypes of EDS, with all except one subtype (hypermobile EDS) having an identified genetic etiology. An understanding of the extracutaneous features and complications within each subtype is key to maximizing clinical care and reducing the risk of further complications.

Methods

A systematic review of EDS-related extracutaneous features and complications was undertaken.

Results

We identified 839 EDS cases that met the inclusion criteria. We noted a high prevalence of joint hypermobility amongst kyphoscoliotic (39/39, 100%), spondylodysplastic (24/25, 96.0%), and hypermobile (153/160, 95.6%) EDS subtypes. The most common musculoskeletal complications were decreased bone density (39/43, 90.7%), joint pain (217/270, 80.4%), and hypotonia/weakness (79/140, 56.4%). Vascular EDS presented with cerebrovascular events (25/153, 16.3%), aneurysm (77/245, 31.4%), arterial dissection/rupture (89/250, 35.5%), and pneumothorax/hemothorax. Chronic pain was the most common miscellaneous complication, disproportionately affecting hypermobile EDS patients (139/157, 88.5%). Hypermobile EDS cases also presented with chronic fatigue (61/63, 96.8%) and gastrointestinal complications (57/63, 90.5%). Neuropsychiatric complications were noted in almost all subtypes.

Discussion

Understanding the extracutaneous features and complications of each EDS subtype may help diagnose and treat EDS prior to the development of substantial comorbidities and/or additional complications.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022308151, identifier CRD42022308151.

Activity-related pain predicts pain and functional outcomes in people with knee osteoarthritis: A longitudinal study

Knee Osteoarthritis (OA) is a prevalent musculoskeletal condition, commonly resulting in pain and disability. However, pain and disability in this population are poorly related with the degree of structural joint damage. Underlying pain mechanisms, including activity-related pain and sensitization assessed via Quantitative Sensory Testing (QST), may better predict pain and functional outcomes of those with knee OA. Therefore, the aim of this study was to explore whether activity-related pain and sensitization assessed via QST predict future pain, function, fatigue, physical performance and quality of life outcomes in those living in the community with knee OA. Eighty-six participants with knee OA were recruited in Dunedin, New Zealand. Those eligible to participate underwent baseline testing including QST as well as measures of activity-related pain including Movement-evoked Pain (MEP) and Sensitivity to Physical Activity (SPA). Outcome measures exploring pain, function, fatigue and quality of life outcomes were collected at baseline, and two follow-up periods (two and nine weeks). Univariable linear regression models were developed followed by multivariable linear regression models for each prognostic marker adjusting for age, gender, BMI, OA duration, baseline pain intensity and socioeconomic status. Activity-related measures of pain, including MEP and SPA, demonstrated predictive associations with pain and functional outcomes prospectively in those with knee OA. Therefore, those demonstrating activity-related pain are at future risk of greater pain, disability and reduced quality of life. Larger, externally validated longitudinal studies are required which include individuals with more severe knee OA.

A Two-Step, Trajectory-Focused, Analytics Approach to Attempt Prediction of Analgesic Response in Patients with Moderate-to-Severe Osteoarthritis

INTRODUCTION

We sought to predict analgesic response to daily oral nonsteroidal anti-inflammatory drugs (NSAIDs) or subcutaneous tanezumab 2.5 mg (every 8 weeks) at week 16 in patients with moderate-to-severe osteoarthritis, based on initial treatment response over 8 weeks.

METHODS

Data were derived from three randomized controlled trials of osteoarthritis. A two-step, trajectory-focused, analytics approach was used to predict patients as responders or non-responders at week 16. Step 1 identified patients using a data-element combination method (based on pain score at baseline, pain score at week 8, pain score monotonicity at week 8, pain score path length at week 8, and body site [knee or hip]). Patients who could not be identified in step 1 were predicted in step 2 using a k-nearest neighbor method based on pain score and pain response level at week 8.

RESULTS

Our approach predicted response with high accuracy in NSAID-treated (83.2-90.2%, n = 931) and tanezumab-treated (84.6-91.0%, n = 1430) patients regardless of the efficacy measure used to assess pain, or the threshold used to define response (20%, 30%, or 50% improvement from baseline). Accuracy remained high using 50% or 20% response thresholds, with 50% and 20% yielding generally slightly better negative and positive predictive value, respectively, relative to 30%. Accuracy was slightly better in patients aged ≥ 65 years relative to younger patients across most efficacy measure/response threshold combinations.

CONCLUSIONS

Analyzing initial 8-week analgesic responses using a two-step, trajectory-based approach can predict future response in patients with moderate-to-severe osteoarthritis treated with NSAIDs or 2.5 mg tanezumab. These findings demonstrate that prediction of treatment response based on a single dose of a novel therapeutic is possible and that predicting future outcomes based on initial response offers a way to potentially advance the approach to clinical management of patients with osteoarthritis.

CLINICALTRIALS

GOV IDENTIFIERS

NCT02528188, NCT02709486, NCT02697773.

Development of a Clinical Prediction Rule for Treatment Success with Transcranial Direct Current Stimulation for Knee Osteoarthritis Pain: A Secondary Analysis of a Double-Blind Randomized Controlled Trial

The study’s objective was to develop a clinical prediction rule that predicts a clinically significant analgesic effect on chronic knee osteoarthritis pain after transcranial direct current stimulation treatment. This is a secondary analysis from a double-blind randomized controlled trial. Data from 51 individuals with chronic knee osteoarthritis pain and an impaired descending pain inhibitory system were used. The intervention comprised a 15-session protocol of anodal primary motor cortex transcranial direct current stimulation. Treatment success was defined by the Western Ontario and McMaster Universities’ Osteoarthritis Index pain subscale. Accuracy statistics were calculated for each potential predictor and for the final model. The final logistic regression model was statistically significant (p < 0.01) and comprised five physical and psychosocial predictor variables that together yielded a positive likelihood ratio of 14.40 (95% CI: 3.66−56.69) and an 85% (95%CI: 60−96%) post-test probability of success. This is the first clinical prediction rule proposed for transcranial direct current stimulation in patients with chronic pain. The model underscores the importance of both physical and psychosocial factors as predictors of the analgesic response to transcranial direct current stimulation treatment. Validation of the proposed clinical prediction rule should be performed in other datasets.

Experimental models to study osteoarthritis pain and develop therapeutics

Pain is the predominant symptom of osteoarthritis (OA) that drives patients to seek medical care. Currently, there are no pharmacological treatments that can reverse or halt the progression of OA. Safe and efficacious medications for long-term management of OA pain are also unavailable. Understanding the mechanisms behind OA pain generation at onset and over time is critical for developing effective treatments. In this narrative review, we first summarize our current knowledge on the innervation of the knee joint, and then discuss the molecular mechanism(s) currently thought to underlie OA pain. In particular, we focus on the contribution of each joint component to the generation of pain. Next, the current experimental models for studying OA pain are summarized, and the methods to assess pain in rodents are presented. The potential application of emerging microphysiological systems in OA pain research is especially highlighted. Lastly, we discuss the current challenge in standardizing models and the selection of appropriate systems to address specific questions.

Efficacy of Adductor Canal Block on Medial Knee Pain in Patients with Knee Osteoarthritis: A Randomized Single-Blind Placebo-Controlled Study

BACKGROUND

This study aimed to confirm the efficacy of ultrasound-guided adductor canal block (ACB) as a treatment option for medial knee pain caused by knee osteoarthritis (KOA).

METHODS

In total, 31 participants with medial knee pain due to KOA were randomized to either the ACB (ultrasound-guided ACB, n = 15) or placebo group (1 mL of 1% lidocaine, n = 16). The primary outcome was a numerical rating scale (NRS) for knee pain intensity comparing before and 4 weeks after injection. The secondary outcomes were the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), average daily number of analgesics consumed, average daily opioid consumption, and Timed Up and Go (TUG) test results before and 4 weeks after injection.

RESULTS

Participants' baseline characteristics were not significantly different between the groups, except for age. At 4 weeks post-injection, the NRS score in the ACB group significantly improved compared to that in the placebo group (p = 0.009). However, the WOMAC, average daily number of analgesics consumed, average daily opioid consumption, and TUG test results did not show significant differences.

CONCLUSION

ACB can be an effective treatment for reducing medial knee pain in patients with KOA.

Presence of Night Pain, Neuropathic Pain, or Depressive Disorder Does Not Adversely Affect Outcomes After Total Knee Arthroplasty: A Prospective Cohort Study

BACKGROUND

A considerable proportion of patients warranting total knee arthroplasty (TKA) have night pain, neuropathic pain, and/or depressive disorder, which may not be resolved by TKA. This prospective, longitudinal cohort study aimed to document the prevalence of night pain, neuropathic pain, and depressive disorder in patients with advanced knee osteoarthritis undergoing TKA and to determine whether the specific coexisting pain and/or disorder at the time of TKA adversely affected postoperative outcomes.

METHODS

In this study, 148 patients undergoing TKA were longitudinally evaluated. The presence of night pain, neuropathic pain (determined using Douleur Neuropathique 4 [DN4]) and depressive disorder (determined using the Patient Health Questionnaire-9 [PHQ-9]) was determined before and 6 weeks, 3 months and 1 year after TKA. In addition, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and EuroQol-5 Dimension (EQ-5D) scores were assessed before and 1 year after TKA. Potential associations of night pain, neuropathic pain, and/or depressive disorder with pre- and postoperative WOMAC and EQ-5D scores were examined in subgroup analyses.

RESULTS

Preoperatively, 72% (n = 106) of patients reported night pain, and the prevalences of neuropathic pain and depressive disorder were 15% and 17%, respectively. Preoperatively, compared with patients without night pain, those with night pain had significantly poorer preoperative WOMAC scores, but no significant difference was seen between groups 1 year after TKA. Preoperatively, the WOMAC, EQ-5D, and EQ-5D health scores of patients with neuropathic pain were not significantly different from those of patients without neuropathic pain, and there was no difference in clinical outcome scores 1 year after TKA between these groups. Preoperatively, the patients with depressive disorder showed significantly poorer preoperative WOMAC, EQ-5D, and EQ-5D health scores than those without depressive disorder, but no significant differences in scores were observed 1 year after TKA between these groups.

CONCLUSION

This study revealed a considerable prevalence of night pain, neuropathic pain, and depressive disorder in patients undergoing TKA and that patients with these specific conditions reported poorer functional and quality of life scores preoperatively. However, such adverse effects disappeared after TKA. Our study findings suggest that TKA can provide satisfactory outcomes for patients with these specific conditions.

Autonomic Nervous System Function and Central Pain Processing in People With Frozen Shoulder: A Case-control Study

OBJECTIVES

The pathophysiology of a frozen shoulder (FS) is thought to be related to chronic inflammation. Chronic inflammation may disturb the immune system and consequently the nervous system as part of an overarching system. The aim of this study was to determine the presence of disturbed autonomic nervous system function and altered central pain processing (CPP) in patients with FS. Secondarily, the presence of psychological variables (catastrophizing and hypervigilance) and self-reported associated symptoms of altered CPP in patients with FS were investigated.

METHODS

Patients with FS and healthy controls completed the Composite Autonomic Symptom Score (autonomic function) and underwent quantitative sensory testing to assess tactile sensitivity (ie, allodynia), pressure pain thresholds (PPTs, ie, hyperalgesia), temporal summation of pain, and Conditioned Pain Modulation (CPM). Psychological issues were explored with the Pain Catastrophizing Scale and the Pain Vigilance and Awareness Questionnaire, and self-reported symptoms associated with altered CPP were determined with the Central Sensitization Inventory.

RESULTS

Thirty-two patients with FS and 35 healthy controls were analyzed in the study. Patients with FS showed more self-reported autonomic symptoms and symptoms of altered CPP, higher levels of pain catastrophizing and hypervigilance, and are more sensitive to tactile touches and mechanical pressure compared with controls.

DISCUSSION

On the basis of the effect sizes, between-group differences in allodynia, hyperalgesia, catastrophizing, and hypervigilance were clinically relevant, but only local allodynia, hyperalgesia, catastrophizing, and hypervigilance were statistically different. Therefore, obvious altered CPP was not present at the group level in patients with FS compared with controls.

A Randomised Controlled Trial of YOGa and Strengthening Exercise for Knee OsteoArthritis: Protocol for a Comparative Effectiveness Trial (YOGA Trial)

Osteoarthritis (OA) is a common joint disorder for which there is no cure. Current treatments are suboptimal. Exercise is a core treatment for knee OA, with muscle strengthening exercise commonly recommended. Yoga is a mind-body exercise intervention that can improve flexibility, muscle strength, balance, and fitness and potentially reduce symptoms of OA. However, there is a scarcity of robust, high-quality conclusive evidence on the efficacy of yoga in knee OA. We are currently conducting the first randomised comparative effectiveness and cost-effectiveness trial of a yoga program compared with a strengthening exercise program in patients with symptomatic knee OA. This study protocol describes the design and conduct of this trial. The YOGA study is a phase III, single-centre, parallel, superiority, randomised, active-controlled trial which will be conducted in Hobart, Australia. One hundred and twenty-six participants (63 in each arm) aged over 40 years with symptomatic knee OA will be recruited from the community and randomly allocated to receive either a 24-week yoga program (3×/week) or a strengthening exercise program (3×/week). The primary outcome will be change in knee pain over 12 weeks, assessed using a 100 mm visual analogue scale (VAS). The secondary outcomes include change in knee pain, patient global assessment, physical function, quality of life, gait speed, biomarkers, and others over 12 and 24 weeks. We will also assess whether the presence of neuropathic pain moderates the effects of yoga compared to strengthening exercise. Additional data, such as cost and resource utilization, will be collected for the cost-effectiveness analysis. The primary analysis will be conducted using an intention-to-treat approach. Adverse events will be monitored throughout the study. Once completed, this trial will contribute to the knowledge of whether yoga can be used as a simple, effective, low-cost option for the management of knee OA, thus saving economic costs in the healthcare system.

Preoperative Predictors of Complex Regional Pain Syndrome Outcomes in the 6 Months Following Total Knee Arthroplasty

This prospective observational study evaluated preoperative predictors of complex regional pain syndrome (CRPS) outcomes in the 6 months following total knee arthroplasty (TKA). Participants were n = 110 osteoarthritis patients (64.5% female) undergoing unilateral TKA with no prior CRPS history. Domains of negative affect (depression, anxiety, catastrophizing), pain (intensity, widespread pain, temporal summation of pain [TSP]), pain interference, sleep disturbance, and pro-inflammatory status (tumor necrosis factor-alpha [TNF-a]) were assessed preoperatively. CRPS outcomes at 6-week and 6-month follow-up included the continuous CRPS Severity Score (CSS) and dichotomous CRPS diagnoses (2012 IASP criteria). At 6 months, 12.7% of participants met CRPS criteria, exhibiting a "warm CRPS" phenotype. Six-week CSS scores were predicted by greater preoperative depression, anxiety, catastrophizing, TSP, pain intensity, sleep disturbance, and TNF-a (P's < .05). Provisional CRPS diagnosis at 6 weeks was predicted by higher preoperative TSP, sleep disturbance, and TNF-a (P's < .05). CSS scores at 6 months were predicted by more widespread and intense preoperative pain, and higher preoperative TSP, pain interference, and TNF-a (P's < .01). CRPS diagnosis at 6 months was predicted only by more widespread and intense pain preoperatively (P's < .05). Risk for CRPS following TKA appears to involve preoperative central sensitization and inflammatory mechanisms. Preoperative negative affect is unlikely to directly influence long-term CRPS risk. PERSPECTIVE: This article identifies preoperative predictors of CRPS features at 6 months following total knee arthroplasty, including more widespread pain and higher pain intensity, temporal summation of pain, pain interference, and tumor necrosis factor-alpha levels. Findings suggest the importance of central sensitization and inflammatory mechanisms in CRPS risk following tissue trauma.

The Benefits of Adding Manual Therapy to Exercise Therapy for Improving Pain and Function in Patients With Knee or Hip Osteoarthritis: A Systematic Review With Meta-analysis

OBJECTIVE: To evaluate if there was an additional benefit of combining manual therapy (MT) and exercise therapy over exercise therapy alone on pain and function in patients with hip or knee osteoarthritis. DESIGN: Intervention systematic review LITERATURE SEARCH: We (1) searched 4 databases from inception to June 20, 2021; (2) hand searched a reference list of included trials and relevant systematic reviews; and (3) contacted 2 researchers in the field. STUDY SELECTION CRITERIA: We included randomized controlled trials that compared MT and exercise therapy to similar exercise therapy programs alone in patients with hip or knee osteoarthritis. DATA SYNTHESIS: The data were combined using random-effects meta-analyses where appropriate. The certainty of evidence for each outcome was judged using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework. RESULTS: We included 19 trials. There was very low to moderate certainty of evidence that MT added benefit in the short term for pain, and combined pain, function, and stiffness (WOMAC global scale), but not for performance-based function and self-reported function. In the medium term, there was low- to very-low-certainty evidence that MT added benefit for performance-based function and WOMAC global score, but not for pain. There was high-certainty evidence that MT provided no added benefit in the long term for pain and function. CONCLUSION: There was very low to moderate certainty of evidence supporting MT as an adjunct to exercise therapy for pain and WOMAC global scale, but not function in patients with knee or hip osteoarthritis in the short term. There was high certainty of evidence of no benefit for additional MT over exercise therapy alone in the long term. J Orthop Sports Phys Ther 2022;52(10):675-684. Epub: 27 July 2022. doi:10.2519/jospt.2022.11062.

Lysophosphatidylcholine 16:0 mediates chronic joint pain associated to rheumatic diseases through acid-sensing ion channel 3

ABSTRACT

Rheumatic diseases are often associated to debilitating chronic pain, which remains difficult to treat and requires new therapeutic strategies. We had previously identified lysophosphatidylcholine (LPC) in the synovial fluids from few patients and shown its effect as a positive modulator of acid-sensing ion channel 3 (ASIC3) able to induce acute cutaneous pain in rodents. However, the possible involvement of LPC in chronic joint pain remained completely unknown. Here, we show, from 2 independent cohorts of patients with painful rheumatic diseases, that the synovial fluid levels of LPC are significantly elevated, especially the LPC16:0 species, compared with postmortem control subjects. Moreover, LPC16:0 levels correlated with pain outcomes in a cohort of osteoarthritis patients. However, LPC16:0 do not appear to be the hallmark of a particular joint disease because similar levels are found in the synovial fluids of a second cohort of patients with various rheumatic diseases. The mechanism of action was next explored by developing a pathology-derived rodent model. Intra-articular injections of LPC16:0 is a triggering factor of chronic joint pain in both male and female mice, ultimately leading to persistent pain and anxiety-like behaviors. All these effects are dependent on ASIC3 channels, which drive sufficient peripheral inputs to generate spinal sensitization processes. This study brings evidences from mouse and human supporting a role for LPC16:0 via ASIC3 channels in chronic pain arising from joints, with potential implications for pain management in osteoarthritis and possibly across other rheumatic diseases.

In the Shoulder or in the Brain? Behavioral, Psychosocial and Cognitive Characteristics of Unilateral Chronic Shoulder Pain with Symptoms of Central Sensitization

The recognition of central sensitization (CS) is crucial, as it determines the results of rehabilitation. The aim of this study was to examine associations between CS and catastrophizing, functionality, disability, illness perceptions, kinesiophobia, anxiety, and depression in people with chronic shoulder pain (SP). In this cross-sectional study, 64 patients with unilateral chronic SP completed a few questionnaires including the Central Sensitization Inventory, the Oxford Shoulder Score, the Tampa Scale for Kinesiophobia, the Hospital Anxiety and Depression Scale, the Pain Catastrophizing Scale, the Brief Illness Perception Questionnaire and the “arm endurance” test. On the basis of three constructed linear regression models, it was found that pain catastrophizing and depression (model 1: p < 0.001, R = 0.57, R2 = 0.33), functionality (model 2: p < 0.001, R = 0.50, R2 = 0.25), and helplessness (model 3: p < 0.001, R = 0.53, R2 = 0.28) were significant predictors for CS symptoms in chronic SP. Two additional logistic regression models also showed that depression (model 4: p < 0.001, Nagelkerke R2 = 0.43, overall correct prediction 87.5%) and functionality (model 5: p < 0.001, Nagelkerke R2 = 0.26, overall correct prediction 84.4%) can significantly predict the classification of chronic SP as centrally sensitized. Patients who were classified as centrally sensitized (n = 10) were found to have significantly worse functionality, psychological factors (anxiety, depression, kinesiophobia, catastrophizing), and pain intensity (p < 0.05). Catastrophizing, depression, and functionality are predictive factors of CS symptoms in patients with chronic shoulder pain. Health care providers should adopt a precision medicine approach during assessment and a holistic rehabilitation of patients with unilateral chronic SP.

Association between chronic pain with presarcopenia and central sensitization in Japanese community-dwelling older adults: A cross-sectional study

Older people with chronic pain are at higher risk of developing sarcopenia. Central sensitization (CS) has been implicated in chronic pain among community-dwelling older adults. However, a relationship between CS and chronic pain with sarcopenia has not been established. This cross-sectional study aimed to clarify the relationship between chronic pain with sarcopenia or presarcopenia and CS among community-dwelling older adults. We assessed chronic pain and sarcopenia in 104 older adults participating in community health checks. We defined sarcopenia using the Asian Working Group for Sarcopenia (AWGS) consensus recommendations based on the following outcomes: low muscle mass, low muscle strength, and slow gait speed. Pain-related assessments included pain intensity, the Pain Catastrophizing Scale, the CS Inventory-9, the pressure pain threshold, the Tampa Scale of Kinesiophobia-11, and the EuroQol 5-dimension 5-level (EQ5D-5L). Chronic pain was defined by related symptoms within the month prior to the health check that had continued for ≥ 3 months and corresponded to a numerical rating scale score of ≥ 1 at the site of maximum pain. The prevalence of chronic pain was 43.3%. In addition, the prevalence of chronic pain with sarcopenia or presarcopenia was 29.8%. A logistic regression analysis revealed that the pressure pain threshold (odds ratio: 0.82, 95% CI: 0.95-1.02) and the EQ5D-5L (odds ratio: 0.58, 95% CI: 0.36-0.76) were significantly associated with the presence of chronic pain with sarcopenia or presarcopenia. Chronic pain with sarcopenia or presarcopenia was affected by central sensitization. Therefore, CS should be evaluated in the elderly.