Knee pain as a predictor of structural progression over 4 years: data from the Osteoarthritis Initiative, a prospective cohort study

Short-term variations in trabecular bone texture parameters associated to radio-clinical biomarkers improve the prediction of radiographic knee osteoarthritis progression

The present study aims to examine whether the short-term variations in trabecular bone texture (TBT) parameters, combined with a targeted set of clinical and radiographic data, would improve the prediction of long-term radiographic knee osteoarthritis (KOA) progression. Longitudinal (baseline, 24 and 48-month) data, obtained from the Osteoarthritis Initiative cohort, were available for 1352 individuals, with preexisting OA (1 < Kellgren-Lawrence < 4) at baseline. KOA progression was defined as an increase in the medial joint space narrowing score from the 24-months to the 48-months control point. 16 regions of interest were automatically selected from each radiographic knee and analyzed using fractal dimension. Variations from baseline to 24 months in TBT descriptors as well as selected radiographic and clinical readings were calculated. Different logistic regression models were developed to evaluate the progression prediction performance when associating TBT variations with the selected clinical and radiographic readings. The most predictive model was mainly determined using the area under the receiver operating characteristic curve (AUC). The proposed prediction model including short-term variations in TBT parameters, associated with clinical covariates and radiographic scores, improved the capacity of predicting long-term radiographic KOA progression (AUC of 0.739), compared to models based solely on baseline values (AUC of 0.676, p-value < 0.008).

Inter-joint coordination variability is associated with pain severity and joint loading in persons with knee osteoarthritis

As the lower extremity is a linked-joint system, the contribution of movements at the hip and ankle, in addition to the knee, to gait patterns should be considered for persons with knee osteoarthritis (OA). However, the relationships of joint coordination variability to OA symptoms, particularly knee pain, and joint loading is unknown. The purpose of this study was to determine the relationship of joint coordination variability to knee pain severity and joint loading in persons with knee OA. Thirty-four participants with knee OA underwent gait analysis. Vector coding was used to assess coordination variability during the early, mid, and late stance phase. Hip-knee coupling angle variability (CAV) during midstance was associated with Knee Injury and Osteoarthritis Outcome Score (KOOS) pain (r = -0.50, p = 0.002) and Visual Analog Scale pain (r = 0.36, p = 0.04). Knee-ankle CAV during midstance was associated with KOOS pain (r = -0.34, p = 0.05). Hip-knee CAV during early and midstance were associated with knee flexion moment (KFM) impulses (r = -0.46, p = 0.01). Knee-ankle CAV during early and midstance were associated with peak KFM (r = -0.51, p < 0.01; r = -0.70, p < 0.01). Moreover, knee-ankle CAV during early, mid, and late stance phase were associated with KFM impulses (r = -0.53, p < 0.01; r = -0.70, p < 0.01; r = -0.54, p < 0.01). These findings suggest that joint coordination variability may be a factor that influences pain and knee joint loading in persons with knee OA. Statement of Clinical Significance: Movement coordination of the hip, knee, and ankle should be considered in the clinical management and future research related to knee OA.

Association of Sleep Disturbance With Catastrophizing and Knee Pain: Data From the Osteoarthritis Initiative

OBJECTIVE

To investigate the relationship between sleep disturbance, catastrophizing, and knee pain in middle-aged and older individuals.

METHODS

Data from the Osteoarthritis Initiative cohort from months 48 to 96 were used, where month 48 was treated as baseline. Knee pain (Western Ontario and McMaster Universities Osteoarthritis Index pain scale score ≥5 [range 0-20]), catastrophizing (extracted from Coping Strategies Questionnaire score ≥3 [range 0-6]), and sleep quality (extracted from Center for Epidemiologic Studies Depression Scale [range 1-4]) were assessed annually. We described the association of sleep disturbance with the presence and risk of knee pain and catastrophizing. The mediation effect of knee pain and catastrophizing on the sleep-catastrophizing and sleep-pain association was evaluated, respectively.

RESULTS

Catastrophizing and knee pain were reported in 346 (10%) and 917 (24%) of the 3,813 participants (mean 64.9 years, 58% female) at baseline. Participants with worse sleep disturbance were more likely to have knee pain (prevalence ratio [PR] 1.4-2.0, P for trend <0.001) and catastrophizing (PR 1.4-3.1, P for trend <0.001). Sleep disturbance at baseline predicted the risk of knee pain (risk ratio [RR] 1.1, P for trend <0.001) and catastrophizing (RR 1.2-1.7, P for trend <0.001) during follow-up. No statistically significant interactions between sleep disturbance and knee pain or catastrophizing were observed. Knee pain and catastrophizing mediated the sleep-catastrophizing and sleep-pain association, respectively, at baseline, and knee pain negatively mediated the sleep-catastrophizing association longitudinally.

CONCLUSION

Sleep disturbance was associated with the presence and risk of catastrophizing and knee pain. Sleep interventions may have a universal and independent effect in preventing incident knee pain.

Changes to consultations and diagnosis of osteoarthritis in primary care during the COVID-19 pandemic

OBJECTIVE

General practitioners (GP) are often the first medical professionals to treat musculoskeletal complaints. Yet the impact of COVID-19 on primary care utilisation for musculoskeletal complaints is largely unknown. This study quantifies the impact of the pandemic on primary care utilisation for musculoskeletal complaints and specifically osteoarthritis (OA) in the Netherlands.

DESIGN

We extracted data on GP consultations in 2015-2020 from 118,756 patients over 45 years of age and estimated reductions in consultations in 2020 as compared to 5-year average. Outcomes were GP consultations for: any musculoskeletal complaints, knee and hip OA and complaints, newly diagnosed knee and hip OA/complaints.

RESULTS

The relative reductions in consultations ranged from 46.7% (95% CI: 43.9-49.3%) (all musculoskeletal consultations) to 61.6% (95% CI: 44.7-73.3%) (hip complaints) at the peak of the first wave, and from 9.3% (95% CI: 5.7-12.7%) (all musculoskeletal consultations) to 26.6% (95% CI: 11.5-39.1%) (knee OA) at the peak of the second wave. The reductions for new diagnoses were 87.0% (95% CI: 71.5-94.1%) for knee OA/complaints, and 70.5% (95% CI: 37.7-86.0%) for hip OA/complaints at the peak of the first wave, and not statistically significant at the peak of the second wave.

CONCLUSION

We observed 47% reduction in GP consultations for musculoskeletal disorders during the first wave and 9.3% during the second wave. For hip and knee OA/complaints, the reductions were over 50% during the first, and 10% during the second wave. This disruption may lead to accumulation of patients with severe OA symptoms and more requests for arthroplasty surgery.

Cushioned Footwear Effect on Pain and Gait Characteristics of Individuals with Knee Osteoarthritis: A Double-Blinded 3 Month Intervention Study

One of the recommendations for individuals with knee osteoarthritis (OA) is the use of specific footwear, such as sturdy or cushioned shoes. However, the long-term use effects of using cushioned shoes on the pain and spatiotemporal gait parameters in individuals with knee OA are yet to be reported. We therefore aimed to compare the efficacy of cushioned sport footwear versus sham shoes on motor functions, pain and gait characteristics of individuals with knee OA who used the shoes for 3 months. In a double-blinded study, we provided 26 individuals with knee OA with cushioned sport shoes and 12 individuals with knee OA with similar sport shoes without cushioning for 3 months. The gait analysis, the timed up and go (TUG) test and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) were conducted and the pain levels were measured at the baseline, 1 month, and 3 months after the baseline. We found that the cushioned shoes reduce the amount of pain (based on WOMAC) in the affected knee and increase functionality in the research group, but not in the control group. Gait velocity and cadence were increased in both groups. Gait spatiotemporal parameters and their symmetry were unaffected during the intervention. We conclude that the use of cushioned shoes should be recommended to individuals with knee OA for alleviating pain.

SUpervised exercise-therapy and Patient Education Rehabilitation (SUPER) versus minimal intervention for young adults at risk of knee osteoarthritis after ACL reconstruction: SUPER-Knee randomised controlled trial protocol

INTRODUCTION

Anterior cruciate ligament injury and reconstruction (ACLR) is often associated with pain, functional loss, poor quality of life and accelerated knee osteoarthritis development. The effectiveness of interventions to enhance outcomes for those at high risk of early-onset osteoarthritis is unknown. This study will investigate if SUpervised exercise-therapy and Patient Education Rehabilitation (SUPER) is superior to a minimal intervention control for improving pain, function and quality of life in young adults with ongoing symptoms following ACLR.

METHODS AND ANALYSIS

The SUPER-Knee Study is a parallel-group, assessor-blinded, randomised controlled trial. Following baseline assessment, 184 participants aged 18-40 years and 9-36 months post-ACLR with ongoing symptoms will be randomly allocated to one of two treatment groups (1:1 ratio). Ongoing symptoms will be defined as a mean score of <80/100 from four Knee injury and Osteoarthritis Outcome Score (KOOS₄) subscales covering pain, symptoms, function in sports and recreational activities and knee-related quality of life. Participants randomised to SUPER will receive a 4-month individualised, physiotherapist-supervised strengthening and neuromuscular programme with education. Participants randomised to minimal intervention (ie, control group) will receive a printed best-practice guide for completing neuromuscular and strengthening exercises following ACLR. The primary outcome will be change in the KOOS₄ from baseline to 4 months with a secondary endpoint at 12 months. Secondary outcomes include change in individual KOOS subscale scores, patient-perceived improvement, health-related quality of life, kinesiophobia, physical activity, thigh muscle strength, knee function and knee cartilage morphology (ie, lesions, thickness) and composition (T2 mapping) on MRI. Blinded intention-to-treat analyses will be performed. Findings will also inform cost-effectiveness analyses.

ETHICS AND DISSEMINATION

This study is approved by the La Trobe University and Alfred Hospital Ethics Committees. Results will be presented in peer-reviewed journals and at international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12620001164987.

Biological Reconstruction of Localized Full-Thickness Cartilage Defects of the Knee: A Systematic Review of Level 1 Studies with a Minimum Follow-Up of 5 Years

OBJECTIVE

The objective of this study was to evaluate the best available mid- to long-term evidence of surgical procedures for the treatment of localized full-thickness cartilage defects of the knee.

DESIGN

Systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines of Level 1 randomized clinical trials (RCTs), meta-analyses of RCTs and systematic reviews with a minimum follow-up of 5 years. Data extracted included patient demographics, defect characteristics, clinical and radiological outcomes, as well as treatment failures.

RESULTS

Six RCTs and 3 Level 1 systematic reviews were included. Two RCTs compared microfracture (MFx) to periosteum-covered autologous chondrocyte implantation (ACI-P), 1 to matrix-associated ACI (M-ACI) and 2 to osteochondral autograft transplantation (OAT). One study compared OAT to collagen membrane covered ACI (ACI-C). The 3 Level 1 systematic reviews/meta-analyses assessed the outcome of MFx, OAT, and various ACI methods in RCTs. OAT showed significantly better outcomes compared with MFx. In the 2 RCTs comparing ACI-P and MFx, no significant differences in clinical outcomes were seen, whereas significantly better outcomes were reported for M-ACI versus MFx in 1 study including patients with larger defects (5 cm²), and for ACI-C versus OAT in terms of Cincinnati Score. Higher failure rates were reported for MFx compared with OAT and for OAT compared with ACI-C, while no significant differences in failure rates were observed for ACI-P compared to MFx.

CONCLUSION

Restorative cartilage procedures (ACI-C or M-ACI and OAT) are associated with better long-term clinical outcomes including lower complication and failure rates when compared with reparative techniques (MFx). Among the restorative procedures, OAT seems to be inferior to ACI especially in larger defects after longer follow-up periods.

LEVEL OF EVIDENCE

Level I: Systematic review of Level I studies.

Defining and predicting radiographic knee osteoarthritis progression: a systematic review of findings from the osteoarthritis initiative

PURPOSE

The purposes of this systematic review were to (1) identify the commonly used definitions of radiographic KOA progression, (2) summarize the important associative risk factors for disease progression based on findings from the OAI study and (3) summarize findings from radiographic KOA progression prediction modeling studies regarding the characterization of progression and outcomes.

METHODS

A systematic review was performed by conducting a literature search of definitions, risk factors and predictive models for radiographic KOA progression that utilized data from the OAI database. Radiographic progression was further characterized into "accelerated KOA" and "typical progression," as defined by included studies.

RESULTS

Of 314 studies identified, 41 studies were included in the present review. Twenty-eight (28) studies analyzed risk factors associated with KOA progression, and 13 studies created or validated prediction models or risk calculators for progression. Kellgren-Lawrence (KL) grade based on radiographs was most commonly used to characterize KOA progression (50%), followed by joint space width (JSW) narrowing (32%) generally over 48 months. Risk factors with the highest odds ratios (OR) for progression included periarticular bone mineral density (OR 10.40), any knee injury within 1 year (OR 9.22) and baseline bone mineral lesions (OR 7.92). Nine prediction modeling studies utilized both clinical and structural risk factors to inform their models, and combined models outperformed purely clinical or structural models.

CONCLUSION

The cumulative evidence suggests that combinations of structural and clinical risk factors may be able to predict radiographic KOA progression, particularly in patients with accelerated progression. Clinically relevant and feasible prediction models and risk calculators may provide valuable decision-making support when caring for patients at risk of KOA progression, although standardization in modeling and variable identification does not yet exist.

Pilot comparison of outcome measures across chemical and surgical experimental models of chronic osteoarthritis in the rat (Rattus norvegicus)

Relatively little work has evaluated both the disease of osteoarthritis (OA) and clinically-relevant pain outcome measures across different OA models in rats. The objective of this study was to compare sensitivity, pain, and histological disease severity across chemical and surgical models of OA in the rat. Stifle OA was induced in Sprague-Dawley rats via intraarticular injection of monoiodoacetate (MIA) or surgical transection of anterior cruciate ligament and/or destabilization of medial meniscus (ACL+DMM or DMM alone). Reflexive (e.g., mechanical and thermal stimuli) measures of sensitivity and non-reflexive assays (e.g., lameness, static hindlimb weight-bearing asymmetry, dynamic gait analysis) of pain were measured over time. Joint degeneration was assessed histologically. Six-weeks post OA-induction, the ACL+DMM animals had significantly greater visually observed lameness than MIA animals; however, both ACL+DMM and MIA animals showed equal pain as measured by limb use during ambulation and standing. The MIA animals showed increased thermal, but not mechanical, sensitivity compared to ACL+DMM animals. Joint degeneration was significantly more severe in the MIA model at 6 weeks. Our pilot data suggest both the ACL+DMM and MIA models are equal in terms of clinically relevant pain behaviors, but the MIA model is associated with more severe histological changes over time potentially making it more suitable for screening disease modifying agents. Future work should further characterize each model in terms of complex pain behaviors and biochemical, molecular, and imaging analysis of the sensory system and joint tissues, which will allow for more informed decisions associated with model selection and investigative outcomes.

A Linear Decomposition Approach to Explain Excess Direct Healthcare Expenditures Associated with Pain Among Adults with Osteoarthritis

Objective:

Many patients with osteoarthritis experience pain which can lead to higher healthcare expenditures. It is important to understand the factors that drive the excess expenditures associated with pain in osteoarthritis.

Design:

Cross-sectional.

Study sample:

Our study sample consisted of adults (age ⩾ 18 years) from the Medical Expenditure Panel Survey (MEPS, 2018).

Methods:

Adults who were alive during the calendar year and had pain status were included in this study (N = 2804 weighted N = 32.03 million). Osteoarthritis was identified from the medical conditions file and household file. We used multivariable ordinary least squares regression to identify the statistically significant association of pain with direct healthcare expenditures. The Blinder-Oaxaca post-linear decomposition on log-transformed total direct healthcare expenditures was used to estimate the extent to which differences in characteristics contribute to the excess expenditures associated with pain.

Results:

Adults with osteoarthritis and pain had higher average expenditures ($21 814 vs $10 827, P < .001; 9.318 vs 8.538 in logtransformed expenditures) compared to those without pain. Pooled regression weights explained 62.9% of excess expenditures differences in characteristics between the 2 groups. The 2 main drivers of excess healthcare expenditures among adults with osteoarthritis and pain were (i) comorbidities (diabetes, asthma, chronic obstructive pulmonary disease, depression, heart diseases, cancer, and non-cancer pain conditions and (ii) prescription medications (NSAIDs, opioids, and polypharmacy).

Conclusion:

Need factors such as comorbid conditions, and prescription treatment explained the excess healthcare expenditures among adults with osteoarthritis and pain. The study findings suggest that reducing polypharmacy and appropriate management of comorbid conditions may be a pathway to reduce excess expenditures among adults with osteoarthritis and pain.

Cohort profile: the Halland osteoarthritis (HALLOA) cohort-from knee pain to osteoarthritis: a longitudinal observational study in Sweden

PURPOSE

The overall objective in this study is to investigate the early development of radiographic knee osteoarthritis (OA) and its association with hand or/and knee OA, metabolic diseases, biomarkers, chronic pain, physical function and daily physical activity types.

PARTICIPANTS

The Halland osteoarthritis (HALLOA) cohort is a longitudinal cohort study that includes individuals with knee pain in the southwest of Sweden. Enrolment took place from 2017 to 2019. The inclusion criteria were current knee pain, with no former known radiographic knee OA and no cruciate ligament rupture or rheumatological disorder. The participants were recruited: (1) when seeking care for knee pain in primary healthcare or (2) by advertisements in local newspapers. There are 306 individuals included in the study, mean age (SD) 51.7 (8.7) years and 69% are women. The baseline and follow-ups include clinical tests, radiographical examinations, blood samples, metabolic measures, pain pressure thresholds, tests of physical functions, daily physical activity types and patient-reported outcomes.

FINDINGS TO DATE

There were associations between metabolic factors and radiographic knee OA, even in those with normal body mass index at baseline. In addition, clinical hand OA was positively associated with fasting plasma glucose. We also found that modifiable factors as increased visceral fat and total body fat were associated with increased pain sensitivity among individuals with knee pain.

FUTURE PLANS

By studying possible pathophysiological mechanisms of OA over time, we aim to provide new insights on OA progression, identify usable preventive measures helping the clinicians in the management of the disease and improve health for the patients. It is also important to study the development of chronic pain in OA, to get tools to identify individuals at risk and to be able to offer them treatment.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT04928170).

Quadriceps muscle strength at 2 years following anterior cruciate ligament reconstruction is associated with tibiofemoral joint cartilage volume

PURPOSE

Quadriceps strength deficits following anterior cruciate ligament reconstruction (ACLR) are linked to altered lower extremity biomechanics, tibiofemoral joint (TFJ) space narrowing and cartilage composition changes. It is unknown, however, if quadriceps strength is associated with cartilage volume in the early years following ACLR prior to the onset of posttraumatic osteoarthritis (OA) development. The purpose of this cross-sectional study was to examine the relationship between quadriceps muscle strength (peak and across the functional range of knee flexion) and cartilage volume at ~ 2 years following ACLR and determine the influence of concomitant meniscal pathology.

METHODS

The involved limb of 51 ACLR participants (31 isolated ACLR; 20 combined meniscal pathology) aged 18-40 years were tested at 2.4 ± 0.4 years post-surgery. Isokinetic knee extension torque generated in 10° intervals between 60° and 10° knee flexion (i.e. 60°-50°, 50°-40°, 40°-30°, 30°-20°, 20°-10°) together with peak extension torque were measured. Tibial and patellar cartilage volumes were measured using magnetic resonance imaging (MRI). The relationships between peak and angle-specific knee extension torque and MRI-derived cartilage volumes were evaluated using multiple linear regression.

RESULTS

In ACLR participants with and without meniscal pathology, higher knee extension torques at 60°-50° and 50°-40° knee flexion were negatively associated with medial tibial cartilage volume (p < 0.05). No significant associations were identified between peak concentric or angle-specific knee extension torques and patellar cartilage volume.

CONCLUSION

Higher quadriceps strength at knee flexion angles of 60°-40° was associated with lower cartilage volume on the medial tibia ~ 2 years following ACLR with and without concomitant meniscal injury. Regaining quadriceps strength across important functional ranges of knee flexion after ACLR may reduce the likelihood of developing early TFJ cartilage degenerative changes.

LEVEL OF EVIDENCE

III.

Effect of Neuromuscular Electrical Stimulation During Walking on Pain Sensitivity in Women With Obesity With Knee Pain: A Randomized Controlled Trial

OBJECTIVE

To assess the extent to which pain sensitivity is altered in women with obesity with frequent knee symptoms who walk with either a hybrid training system (HTS) that provides antagonist muscle electrical stimulation vs sensory transcutaneous electrical nerve stimulation (TENS).

DESIGN

Randomized, double-blinded, controlled trial.

SETTING

University-based fitness center.

PARTICIPANTS

Twenty-eight women (N=28) with obesity, aged 40-70 years, with daily knee symptoms.

INTERVENTIONS

Participants were randomized to 12 weeks of biweekly 30-minute walking exercise with either HTS (HTSW group) or sensory TENS (control group).

MAIN OUTCOME MEASURES

Pressure pain thresholds (PPTs) at the more symptomatic knee (local PPT) and PPT at the ipsilateral pain-free wrist (remote PPT).

RESULTS

After adjustment for preintervention values and body mass index (BMI), there was a statistically significant improvement in local PPT in the HTSW group compared with the control group (P=.039). After adjustment for pretraining value, age, and BMI, changes in remote PPT when comparing groups did not reach statistical significance, although the HTS group tended to demonstrate increased remote PPT (P=.052) compared with the control group. Moreover, after adjustment for pretraining value, knee pain, and quality of life, comparing groups did not reach statistical significance, although the HTS group tended to demonstrate decreased knee pain (P=.069) compared with the control group.

CONCLUSIONS

Augmentation of walking exercise with HTS was more effective than application of sensory TENS in improving local pain sensitivity at the knee but not at the wrist in women with obesity with frequent knee symptoms.

Knee symptom but not radiographic knee osteoarthritis increases the risk of falls and fractures: results from the Osteoarthritis Initiative

OBJECTIVE

To describe the effect of knee symptoms and radiographic osteoarthritis (ROA) on the risk of falls, recurrent falls, and fractures.

DESIGN

Participants from the Osteoarthritis Initiative were classified as having 'no', 'unilateral' or 'bilateral' knee symptoms (≥19 on a 0-96 Western Ontario and McMaster Universities Osteoarthritis Index) and ROA (Kellgren-Lawrence grade ≥2) for each visit. Self-reported falls and fractures in the past 12 months were extracted at baseline and follow-up visits until month 96. Recurrent falls were defined as having ≥2 falls in the past 12 months. Hazard ratios (HR) with 95% confidence intervals (CI) were estimated using mixed-effects complementary log-log regression.

RESULTS

Of 4465 participants, 3145 (70%), 1681 (38%), and 806 (18%) experienced at least one fall, recurrent fall, and fracture, respectively, over 96 months. Compared to participants without symptomatic knee, unilateral and bilateral knee symptoms were associated with a 17% increased risk of falls and a 36-46% increased risk of recurrent falls, and bilateral knee symptoms increased the risk of fractures (HR 1.45, 95%CI 1.17 to 1.81). Compared to participants with no ROA in either knee, bilateral ROA was associated with a reduced risk of falls (HR 0.87, 95%CI 0.77 to 0.99) and fractures (HR 0.78, 95%CI 0.64 to 0.96). No statistically significant interactions between knee symptoms and ROA were observed.

CONCLUSIONS

This large population-based study showed that knee symptoms but not ROA increased the risk of falls, recurrent falls, and fractures, and that adults with bilateral ROA may have a lower risk of falls and fractures.

High Estimated 24-Hour Urinary Sodium Excretion Is Related to Symptomatic Knee Osteoarthritis: A Nationwide Cross-Sectional Population-Based Study

OBJECTIVES

High salt intake results in various harmful effects on human health including hypertension, cardiovascular disease, and reduced bone density. Despite this, there are very few studies in the literature that have investigated the association between sodium intake and osteoarthritis (OA). Therefore, we aimed to explore these associations in a Korean population.

METHODS

This study used cross-sectional data from adult subjects aged 50-75 years from two consecutive periods of the Korean National Health and Nutrition Examination Survey V-VII (2010-2011 and 2014-2016). The estimated 24-hour urinary sodium excretion (24HUNa) was used as a surrogate marker of salt intake. In the 2010-2011 dataset, knee OA (KOA) was defined as the presence of the radiographic features of OA and knee pain. The association between KOA and salt intake was analysed using univariable and multivariable logistic regression methods. For the sensitivity analysis, the same procedures were conducted on subjects with self-reported OA (SR-OA) with knee pain in the 2010-2011 dataset and any site SR-OA in the 2014-2016 dataset.

RESULTS

Subjects with KOA had significantly lower energy intake, but higher 24HUNa than those without KOA. The restricted cubic spline plots demonstrated a J-shaped distribution between 24HUNa and prevalent KOA. When 24HUNa was stratified into five groups (<2, 2-3, 3-4, 4-5 and ≥5 g/day), subjects with high sodium intake (≥5 g/day) had a higher risk of KOA (odds ratio [OR] = 1.64, 95% confidence interval [CI] 1.03-2.62) compared to the reference group (3-4 g/day) after adjusting for covariates. The sensitivity analysis based on SR-OA with knee pain showed that high sodium intake was also significantly associated with increased prevalence of OA (OR = 1.84, 95% CI 1.10-3.10) compared with the reference group. Regarding SR-OA at any site in the 2014-2016 dataset, estimated 24HUNa showed a significantly positive association with the presence of SR-OA after adjusting for potential confounders.

CONCLUSIONS

This nationwide Korean representative study showed a significant association between symptomatic KOA and high sodium intake (≥5 g/day). Avoidance of a diet high in salt might be beneficial as a non-pharmacologic therapy for OA.

A Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial Assessing Efficacy and Safety of a Novel Low-Dose Turmeric Extract Formulation in Healthy Adults with Chronic Knee Pain

Background

Knee pain causes functional limitations, eventually compromising the quality of life. We evaluated the efficacy of our water-dispersible turmeric formulation (60% natural curcuminoids, TurmXTRA 60N^®—WDTE60N), which exhibited better PK profile at low dose (250 mg) than standard turmeric extract, in alleviating symptoms of chronic knee pain.

Methods

In this randomized, double-blind, placebo-controlled trial, subjects received either 250 mg WDTE60N capsule (150 mg curcuminoids; n = 53) or appearance-matched placebo capsule (n = 53) once daily for 90 days. Primary endpoint was change in pain score on the visual analogue scale (VAS) after 80-m fast-paced walk test.

Results

A total of 96 subjects completed the study. WDTE60N reduced VAS score from baseline (5.4 ± 0.9) to day 90 (3.8 ± 0.8) with greater mean reduction than placebo (−1.5 ± 0.7 vs −0.6 ± 0.8, p < 0.0001; 2.5 times). It also significantly improved the time taken for 80-m fast-paced walk test and 9-step stair-climb test; and improved all biomarkers compared to placebo (p > 0.05). Three adverse events occurred but were unrelated to study products.

Conclusion

WDTE60N 250 mg administered once daily for 3 months, alleviated knee pain, improved joint function in healthy subjects with chronic knee pain, was well tolerated and safe.

Diet-induced obesity leads to behavioral indicators of pain preceding structural joint damage in wild-type mice

Introduction

Obesity is one of the largest modifiable risk factors for the development of musculoskeletal diseases, including intervertebral disc (IVD) degeneration and back pain. Despite the clinical association, no studies have directly assessed whether diet-induced obesity accelerates IVD degeneration, back pain, or investigated the biological mediators underlying this association. In this study, we examine the effects of chronic consumption of a high-fat or high-fat/high-sugar (western) diet on the IVD, knee joint, and pain-associated outcomes.

Methods

Male C57BL/6N mice were randomized into one of three diet groups (chow control; high-fat; high-fat, high-sugar western diet) at 10 weeks of age and remained on the diet for 12, 24, or 40 weeks. At endpoint, animals were assessed for behavioral indicators of pain, joint tissues were collected for histological and molecular analysis, serum was collected to assess for markers of systemic inflammation, and IBA-1, GFAP, and CGRP were measured in spinal cords by immunohistochemistry.

Results

Animals fed obesogenic (high-fat or western) diets showed behavioral indicators of pain beginning at 12 weeks and persisting up to 40 weeks of diet consumption. Histological indicators of moderate joint degeneration were detected in the IVD and knee following 40 weeks on the experimental diets. Mice fed the obesogenic diets showed synovitis, increased intradiscal expression of inflammatory cytokines and circulating levels of MCP-1 compared to control. Linear regression modeling demonstrated that age and diet were both significant predictors of most pain-related behavioral outcomes, but not histopathological joint degeneration. Synovitis was associated with alterations in spontaneous activity.

Conclusion

Diet-induced obesity accelerates IVD degeneration and knee OA in mice; however, pain-related behaviors precede and are independent of histopathological structural damage. These findings contribute to understanding the source of obesity-related back pain and the contribution of structural IVD degeneration.

COVID-19-related cancellation of elective orthopaedic surgery caused increased pain and psychosocial distress levels

PURPOSE

Health care systems in most European countries were temporarily restructured to provide as much capacity as possible for the treatment of coronavirus disease 2019 (COVID-19) patients. Subsequently, all elective surgeries had to be cancelled and postponed for months. The aim of the present study was to assess the pretreatment health status before and after COVID-19-related cancellation and the psychosocial distress caused by the cancellation.

METHODS

For this study, a questionnaire was developed collecting sociodemographic data and information on health status before and after the cancellation. To assess psychosocial distress, the validated depression module of the Patient Health Questionnaire (PHQ-9), was implemented. PHQ-9-Scores of 10 and above were considered to indicate moderate or severe depressive symptoms. In total, 119 patients whose elective orthopaedic surgery was postponed due to the COVID-19 pandemic were surveyed once at least 8 weeks after the cancellation.

RESULTS

Seventy-seven patients (65%; 34 female, 43 male) completed the questionnaire and were included. The predominant procedures were total knee arthroplasty (TKA), hip arthroscopy and foot and ankle surgery. The mean pain level significantly increased from 5.5 ± 2.2 at the time of the initially scheduled surgery to 6.2 ± 2.5 at the time of the survey (p < 0.0001). The pain level before cancellation of the surgery was significantly higher in female patients (p = 0.029). An increased analgetic consumption was identified in 46% of all patients. A mean PHQ-9 score of 6.1 ± 4.9 was found after cancellation. PHQ-9 scores of 10 or above were found in 14% of patients, and 8% exhibited scores of 15 points or above. Significantly higher PHQ-9 scores were seen in female patients (p = 0.046). No significant differences in PHQ-9 scores were found among age groups, procedures or reasons for cancellation.

CONCLUSION

Cancellation of elective orthopaedic surgery resulted in pain levels that were significantly higher than when the surgery was scheduled, leading to increased analgesic use. Additionally, significant psychosocial distress due to the cancellation was identified in some patients, particularly middle-aged women. Despite these results, confidence in the national health care system and in the treating orthopaedic surgeons was not affected.

LEVEL OF EVIDENCE

Level III.

Determining individual trajectories of joint space loss: improved statistical methods for monitoring knee osteoarthritis disease progression

OBJECTIVES

Knee osteoarthritis (KOA) progression is frequently monitored by calculating the change in knee joint space width (JSW) measurements. Such differences are small and sensitive to measurement error. We aimed to assess the utility of two alternative statistical modelling methods for monitoring KOA.

MATERIAL AND METHODS

We used JSW on radiographs from both the control arm of the Strontium Ranelate Efficacy in Knee Osteoarthritis trial (SEKOIA), a 3-year multicentre, double-blind, placebo-controlled phase three trial, and the Osteoarthritis Initiative (OAI), an open-access longitudinal dataset from the USA comprising participants followed over 8 years. Individual estimates of annualised change obtained from frequentist linear mixed effect (LME) and Bayesian hierarchical modelling, were compared with annualised crude change, and the association of these parameters with change in WOMAC pain was examined.

RESULTS

Mean annualised JSW changes were comparable for all estimates, a reduction of around 0.14 mm/y in SEKOIA and 0.08 mm/y in OAI. The standard deviation (SD) of change estimates was lower with LME and Bayesian modelling than crude change (SEKOIA SD = 0.12, 0.12 and 0.21 respectively; OAI SD = 0.08, 0.08 and 0.11 respectively). Estimates from LME and Bayesian modelling were statistically significant predictors of change in pain in SEKOIA (LME P-value = 0.04, Bayes P-value = 0.04), while crude change did not predict change in pain (P-value = 0.10).

CONCLUSIONS

Implementation of LME or Bayesian modelling in clinical trials and epidemiological studies, would reduce sample sizes by enabling all study participants to be included in analysis regardless of incomplete follow up, and precision of change estimates would improve. They provide increased power to detect associations with other measures.

The Path Forward for Digital Measures: Suppressing the Desire to Compare Apples and Pineapples

Digital measures are becoming more prevalent in clinical development. Methods for robust evaluation are increasingly well defined, yet the primary barrier for digital measures to transition beyond exploratory usage often relies on a comparison to the existing standards. This article focuses on how researchers should approach the complex issue of comparing across assessment modalities. We discuss comparisons of subjective versus objective assessments, or performance-based versus behavioral measures, and we pay particular attention to the situation where the expected association may be poor or nonlinear. We propose that, rather than seeking to replace the standard, research should focus on a structured understanding of how the new measure augments established assessments, with the ultimate goal of developing a more complete understanding of what is meaningful to patients.

Noncoding RNAs in subchondral bone osteoclast function and their therapeutic potential for osteoarthritis

Osteoclasts are the only cells that perform bone resorption. Noncoding RNAs (ncRNAs) are crucial epigenetic regulators of osteoclast biological behaviors ranging from osteoclast differentiation to bone resorption. The main ncRNAs, including miRNAs, circRNAs, and lncRNAs, compose an intricate network that influences gene transcription processes related to osteoclast biological activity. Accumulating evidence suggests that abnormal osteoclast activity leads to the disturbance of subchondral bone remodeling, thus initiating osteoarthritis (OA), a prevalent joint disease characterized mainly by cartilage degradation and subchondral bone remodeling imbalance. In this review, we delineate three types of ncRNAs and discuss their related complex molecular signaling pathways associated with osteoclast function during bone resorption. We specifically focused on the involvement of noncoding RNAs in subchondral bone remodeling, which participate in the degradation of the osteochondral unit during OA progression. We also discussed exosomes as ncRNA carriers during the bone remodeling process. A better understanding of the roles of ncRNAs in osteoclast biological behaviors will contribute to the treatment of bone resorption-related skeletal diseases such as OA.

Towards classification criteria for early-stage knee osteoarthritis: A population-based study to enrich for progressors

OBJECTIVE

To facilitate a greater likelihood of favorable response to new disease-modifying therapies, recruitment of patients at an earlier stage of their disease into clinical trials may be an attractive strategy. Hence, there is a need to develop widely accepted classification criteria for early-stage knee osteoarthritis (OA). We have proposed a set of classification criteria for early-stage knee OA (2018 classification criteria) now being further refined. Here, we test the draft criteria for enrichment for clinical and structural progression.

DESIGN

Performance of the 2018 classification criteria for early stage knee OA was tested using data from the Osteoarthritis Initiative (OAI). The OAI comprises data of 4796 men and women aged 45-79 years with or at risk for knee OA at baseline. Based on the 2018 classification criteria, a knee with Kellgren & Lawrence (K&L) grade of 0-I, two out of four Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales equal or less than 85, and presence of at least one of joint line tenderness or crepitus, was considered as early-stage knee OA. Knees with K&L grade 0-I that did not fulfill the 2018 criteria, were considered as controls. Logistic regression analysis was used to evaluate the predictive performance of the criteria set for structural as well as clinical progression. We further explored the discriminatory capability of criteria by including the average KOOS₄ score, and relevant clinical examination findings such as the presence of effusion and/or Heberden's nodes.

RESULTS

We identified 1315 (27%) knees from OAI fulfilling the 2018 early-stage knee OA classification criteria. The female to male ratio was higher in the early knee OA group compared to controls. The early-stage knee OA group were on average slightly younger and had higher body mass index vs controls (mean [SD] age: 59.2 [8.9] years vs. 60.2 [9.1] and mean [SD] BMI 28.3 [7.0] vs. 26.8 [6.0]). By applying the 2018 criteria, there was a substantial enrichment compared to controls at 48 and 96 months for both structural (OR=1.1-1.4, and AUC=0.72-0.74) and clinical progressors (OR=2.1-2.5, 95% and AUC=0.66). Expanding the clinical examination findings by including joint effusion and/or Heberden's nodes improved the enrichment for both structural and clinical progressors (OR=4.2, 95% confidence interval=3.2-5.5 and OR=3.3, 95% confidence interval=2.8-3.5, respectively). Replacing scoring of the 4 separate KOOS domains by a KOOS₄ score performed comparably.

CONCLUSIONS

The proposed 2018 early-stage knee OA classification criteria showed encouraging performance characteristics with regard to an enrichment for structural and clinical progression using longitudinal OAI data. Our results indicate that the addition of clinical findings improves the performance of previous criteria to define early-stage disease and risk for progression.

Setting up distinctive outcome measures for each osteoarthritis phenotype

Osteoarthritis (OA) is an evolving chronic joint disease with a huge global impact. Given the intricate nature of the etiopathogenesis and subsequent high heterogeneity in the clinical course of OA, it is crucial to discriminate between etiopathogenic endotypes and clinical phenotypes, especially in the early stages of the disease. In this sense, we propose that an OA phenotype should be properly assessed with a set of outcome measures including those specifically related to the main underlying pathophysiological mechanisms. Thus, each OA phenotype can be related to different and clinically meaningful outcomes. OA phenotyping would lead to an adequate patient stratification in well-designed clinical trials and the discovery of precise therapeutic approaches. A significant effort will be required in this field in light of inconclusive results of clinical trials of tissue-targeting agents for the treatment of OA.

Longitudinal study of the relationship between physical activity and knee pain and functional limitation in community-dwelling older adults

AIMS

To describe the associations between interindividual (between-person) and intraindividual (within-person) variability in physical activity (PA) and knee pain and functional limitation among older adults. We also investigated the potential bidirectional association of between-person and within-person variability in knee pain and functional limitation with PA.

METHOD

Participants (N = 1064; 51% women; mean age 63 ± 7.4 years) were measured at baseline, 2.5, and 5 years. PA was measured using pedometers. Knee pain and functional limitation were assessed using the WOMAC scale. A two-part hurdle model, with adjustment for confounders, estimated the association of between-person and within-person variability in PA with knee pain/functional limitation (as the outcome). Linear mixed effect regression models described the association of between-person and within-person variability in knee pain and functional limitation with PA (as the outcome).

RESULTS

Between-person effects showed that participants with a higher 5-year average PA had lower average WOMAC scores (β= -1.17, 95% CI: -1.82, -0.51). Within-person effects showed that at time-points when participants had a higher PA level than average, they also had lower WOMAC scores (β= -0.85, 95% CI: -1.36, -0.35). Conversely, both between-person (β= -15.6, 95% CI: -22.5, -8.8) and within-person increase (β= -7.4, 95% CI: -13.5, -1.4) in WOMAC scores were associated with lower PA.

CONCLUSION

These findings suggest that PA and knee pain/dysfunctional contribute to the development of one another. Pain can lead to changes in inter- and intraindividual PA levels, but the reverse is also possible - changes in PA results in changes in inter- and intraindividual pain/dysfunctional levels.

Osteoarthritis year in review 2019: imaging

OBJECTIVE

To provide a narrative review of original articles on osteoarthritis (OA) imaging published between April 1, 2018 and March 30, 2019.

METHODS

All original research articles on OA imaging published in English between April 1, 2018 and March 30, 2019 were identified using a PubMed database search. The search terms of "Osteoarthritis" or "OA" were combined with the search terms "Radiography", "X-Rays", "Magnetic Resonance Imaging", "MRI", "Ultrasound", "US", "Computed Tomography", "Dual Energy X-Ray Absorptiometry", "DXA", "DEXA", "CT", "Nuclear Medicine", "Scintigraphy", "Single-Photon Emission Computed Tomography", "SPECT", "Positron Emission Tomography", "PET", "PET-CT", or "PET-MRI". Articles were reviewed to determine relevance based upon the following criteria: 1) study involved human subjects with OA or risk factors for OA and 2) study involved imaging to evaluate OA disease status or OA treatment response. Relevant articles were ranked according to scientific merit, with the best publications selected for inclusion in the narrative report.

RESULTS

The PubMed search revealed a total of 1257 articles, of which 256 (20.4%) were considered relevant to OA imaging. Two-hundred twenty-six (87.1%) articles involved the knee joint, while 195 (76.2%) articles involved the use of magnetic resonance imaging (MRI). The proportion of published studies involving the use of MRI was higher than previous years. An increasing number of articles were also published on imaging of subjects with joint injury and on deep learning application in OA imaging.

CONCLUSION

MRI and other imaging modalities continue to play an important role in research studies designed to better understand the pathogenesis, progression, and treatment of OA.

Chondroprotective Factors in Osteoarthritis: a Joint Affair

PURPOSE OF THE REVIEW

Osteoarthritis is widely regarded as a spectrum of conditions that affect all joint tissues, typified by a common entity: cartilage loss. Here, we review recent progress and challenges in chondroprotection and discuss new strategies to prevent cartilage loss in osteoarthritis.

RECENT FINDINGS

Advances in clinical, molecular, and cellular characterization are enabling improved stratification of osteoarthritis subtypes. Integration of next-generation sequencing and "omics" approaches with clinically relevant readouts shows promise in delineating both subtypes of disease and meaningful trial end points. Novel delivery strategies are enabling joint-specific delivery. Chondroprotection requires a whole joint approach, stratification of patient groups, and use of patient-relevant end points. Drug development should continue to explore new targets, while using modern technologies and recent knowledge to re-visit unsuccessful therapeutics from the past. The overarching goal for chondroprotection is to provide the right treatment(s) for the right patient at the right time.

[What factors affect the effectiveness of long - term analgesic therapy for osteoarthritis? Data analysis of the multi - center 3-month PARACELSUS study]

There are factors that can affect the effectiveness of treatment of osteoarthritis (OA). Aim to identify factors affecting the effectiveness of long - term analgesic therapy in OA. Materials and methods. The study included 6448 patients (70.9% female and 29.1% male), middle age 57.8±10.2 years, with severe pain [≥40 mm on the visual analog scale]. All patients received the preparation of avocado - soybean unsaponifiables (ASU) 300 mg/day. For pain relief at the beginning and during the study, the drug Ketoprofen lysine salt (KLS) 320 mg/day was used. The efficiency criterion was pain reduction ≥50% and satisfaction with treatment ≥4 on a 5-point scale. The influence of a number of factors on the result of treatment was evaluated. Results. For 3 months of treatment, the pain decreased from 63.7±12.0 to 14.2±11.7 mm VAS. The result was evaluated as "good" or "excellent" 81.7% of patients. Adverse reactions were rare. In total, a good response to therapy was noted in 87.4% of patients. Gender, body mass index ≥30 kg/m2, type 2 diabetes mellitus, poor effect of non - steroidal anti - inflammatory drugs (NSAIDs) and Symptomatic Slow-Acting Drugs in Osteoarthritis (SYSADOA) in history did not affect the result. The effect was lower in persons >65 years [odds ratio (OR) 0.418; 95% confidence interval (CI) 0.342-0.509, p2 by Kellgren-Lawrence (OR 0.556; 95% CI 0.298-0.738, p.