OBJECTIVE: To investigate the association of quadriceps strength with the presence of knee pain.
METHODS: This cross-sectional study was based on data from the 1999-2000 to 2001-2002 National Health and Nutrition Examination Survey.
METHODS: This was a community-based study.
METHODS: This study included 2619 adults with complete data for knee pain, quadriceps strength, and covariates.
METHODS: Not applicable.
METHODS: Self-reported knee pain.
RESULTS: This study included 2619 individuals, 1287 (52.66%) of whom were women and 1543 (81.66%) identified as Non-Hispanic White. The mean ±standard deviation age was 62.48±9.71 years. After adjusting for covariates, the odds of knee pain decreased with every 20 N/m increase in quadriceps strength (odds ratio, 0.87; 95% confidence interval, 0.81-0.94). Individuals in the upper quartile of quadriceps strength had lower odds of knee pain than those in the lower quartile (Q4 vs Q1 [reference]: odds ratio, 0.28, 95% confidence interval, 0.15-0.52; Ptrend=.006). Nonlinear analyses indicated L-shaped associations for knee pain. The subgroup analyses showed no significant interactions, except for sex (Pinteraction=.046). The significance of the sex interaction indicated a correlation exclusively in women.
CONCLUSIONS: The results demonstrated an inverse association between quadriceps strength and the presence of knee pain. The subgroup analysis by sex showed that this inverse relationship was statistically significant in the women but not in the men subgroup.

OBJECTIVE: To evaluate the safety and efficacy of genicular artery embolization (GAE) in patients with mild-to-severe knee osteoarthritis up to 12 months after GAE.
METHODS: This prospective single-center study included patients who had knee osteoarthritis for >1 year with moderate-to-severe pain after failed conservative treatment for >6 months. Baseline imaging features were evaluated to determine Kellgren-Lawrence (KL) grade and magnetic resonance imaging (MOAKS) scores. GAE was performed using 150-350 μm embolic polyvinyl alcohol particles. The visual analog scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were used to evaluate knee pain, stiffness, and function at baseline and follow-up. The primary endpoints were changes in VAS and WOMAC scores at 12 months.
RESULTS: Thirty-three patients (n = 37 knees) aged 66.6 ± 8.7 years were enrolled. The patients were categorized into two groups: mild-to-moderate osteoarthritis (n = 28, KL grades 2-3) and severe osteoarthritis (n = 9, KL grade 4). GAE was successfully performed in all patients, with no major adverse events. Three to six branches of the genicular artery were embolized. The mean VAS and WOMAC scores in the mild-to-moderate group significantly decreased (6.6 at baseline vs. 3.0 at 12 months and 49.4 vs. 27.4, respectively, all P < 0.001). The mean VAS and WOMAC scores in the severe group significantly decreased at 12 months (7.3 vs. 4.4 and 58.1 vs. 40.6, respectively, all P < 0.001).
CONCLUSIONS: GAE is a well-tolerated and effective treatment that significantly improves pain symptoms and function in patients with mild-to-severe knee osteoarthritis.

OBJECTIVE: To identify and describe existing models for predicting knee pain in patients with knee osteoarthritis.
METHODS: The electronic databases PubMed, EMBASE, CINAHL, Web of Science, and Cochrane Library were searched from their inception to May 2023 for any studies to develop and validate a prediction model for predicting knee pain in patients with knee osteoarthritis. Two reviewers independently screened titles, abstracts, and full-text qualifications, and extracted data. Risk of bias was assessed using the PROBAST. Data extraction of eligible articles was extracted by a data extraction form based on CHARMS. The quality of evidence was graded according to GRADE. The results were summarized with descriptive statistics.
RESULTS: The search identified 2693 records. Sixteen articles reporting on 26 prediction models were included targeting occurrence (n = 9), others (n = 7), progression (n = 5), persistent (n = 2), incident (n = 1), frequent (n = 1), and flares (n = 1) of knee pain. Most of the studies (94%) were at high risk of bias. Model discrimination was assessed by the AUROC ranging from 0.62 to 0.81. The most common predictors were age, BMI, gender, baseline pain, and joint space width. Only frequent knee pain had a moderate quality of evidence; all other types of knee pain had a low quality of evidence.
CONCLUSIONS: There are many prediction models for knee pain in patients with knee osteoarthritis that do show promise. However, the clinical extensibility, applicability, and interpretability of predictive tools should be considered during model development.

OBJECTIVE: Metabolic syndrome (MetS) is characterised by the clustering of central obesity with metabolic abnormalities. We aimed to describe the association of MetS and trajectories of MetS over 10-13 years with knee symptoms in general population-based middle-aged adults.
METHODS: Fasting blood biochemistry, waist circumference and blood pressure measures were collected during Childhood Determinants of Adult Health (CDAH)-1 study (year:2004-6; n = 2447; mean age:31.48 ± 2.60) and after 10-13 year at CDAH-3 (year:2014-2019; n = 1549; mean age:44 ± 2.90). Participants were defined as having MetS as per International Diabetes Federation (IDF) definition. Knee symptoms were assessed using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale at CDAH-3 (mid-adulthood).
RESULTS: The prevalence of MetS increased from 8 % at young adulthood (female:52.06 %) to 13 % in mid-adulthood (female:53.78 %) over 10-13 years. Presence of MetS at mid-adulthood was associated with knee symptoms at mid-adulthood [ratio of means (RoM): 1.33; 95%CI:1.27,1.39]. Four MetS trajectories were identified-\'No MetS\' (85.01 %); \'Improved MetS\' (2.14 %), \'Incident MetS\' (8.81 %), and \'Persistent MetS, (4.04 %). Compared to \'No MetS\', \'Persistent MetS\' [RoM:1.15; 95%CI:1.06,1.25], \'Incident MetS\' [RoM:1.56; 95%CI:1.48,1.65], and \'Improved MetS\' [RoM:1.22; 95%CI:1.05,1.41] was associated with higher knee symptoms. Notably, \'Incident MetS\' was strongly associated with knee symptoms [RoM: 1.56; 95%CI:1.48,1.65] and pain [RoM:1.52; 95%CI:1.37,1.70] at mid-adulthood.
CONCLUSIONS: In this sample of middle-aged adults, there was a significant positive association between MetS and knee symptoms. Relative to those without MetS at either life stage, the elevation in mean knee pain scores was more pronounced for those who developed MetS after young adulthood than for those who had MetS in young adulthood.

UNASSIGNED: This study aimed to examine the performance of machine learning models in predicting the progression of knee pain, functional decline, and incidence of knee osteoarthritis (OA) in high-risk individuals, with automated machine learning (AutoML) being used to automate the prediction process.
UNASSIGNED: There were four stages in the process of our AutoML-integrated prediction. Stage 1-Data preparation: The data of 3200 eligible individuals in the Osteoarthritis Initiative (OAI) study who were considered at high risk of knee OA at the baseline visit were extracted and used. Specifically, 1094 variables from the OAI study were used to predict the changes in knee pain, physical function, and incidence of knee OA (i.e. the first occurrence of frequent knee symptoms and definite tibial osteophytes (Kellgren and Lawrence grade ≥2)) over a 9-year period. Stage 2-Model training: The AutoML approach was used to automatically train nine widely used machine learning (ML) models. Stage 3-Model testing: The AutoML approach was used to automatically test the performance of the ML models. Stage 4-Selection of important input variables: The AutoML approach automated the process of computing the importance scores of all input variables and identifying the most important ones, using the technique of permutation feature importance.
UNASSIGNED: Using the AutoML approach, the weighted ensemble model and the CatBoost model showed the best performance among all nine ML models. For the prediction of each outcome in each year, the five most important input variables were identified, most of which were obtained from self-reported questionnaire surveys and radiographic imaging reports.
UNASSIGNED: The AutoML approach has shown potential in automating the process of using ML models to predict long-term changes in knee OA-related outcomes. Its use could support the deployment of ML solutions, facilitating the provision of personalized interventions to prevent the deterioration of knee health and incident knee OA.

Maintaining normal patellar alignment is important for knee health. Altered activation of individual quadriceps muscles have been found related to patellar alignment. However, the relationships between strength and passive stiffness of the quadriceps and patellar alignment remains unexplored.
Participants aged between 60 and 80 years with activity-induced knee pain were recruited. Knee pain was quantified using an 11-point numeric rating scale. Quadriceps strength was assessed using a Cybex dynamometer and passive stiffness of rectus femoris, vastus lateralis, and vastus medialis were measured by shear-wave ultrasound elastography. Patellar alignments were assessed using MR imaging. Linear regression was used to examine relationships between quadriceps properties and patellar alignments with and without controlling for potential covariates.
Ninety-two eligible participants were assessed (71.7% females, age: 65.6 ± 3.8 years; pain scale: 4.6 ± 2.0), most of whom had knee pain during stair climbing (85.9%). We found that 17% of patellar lateral tilt angle could be explained by lower quadriceps strength (adjusted R2 = 0.117; P < 0.001), especially in females (R2 = 0.281; P < 0.001; adjusted R2 = 0.211; P < 0.001). In addition, a higher stiffness ratio of vastus lateralis/medialis accounted for 12% of patellar lateral displacement (adjusted R2 = 0.112; P = 0.008).
Quadriceps strength and relative stiffness of lateral to medial heads are associated with patellar alignment in older adults with knee pain. It suggests that quadriceps weakness and relatively stiffer lateral quadriceps may be risk factors related to patellar malalignments in the elderly.

暂无摘要。

OBJECTIVE: Frailty is a multisystem syndrome and its relationship with symptomatic osteoarthritis has been reported. We aimed to identify trajectories of knee pain in a large prospective cohort and to describe the effect of frailty status at baseline on the pain trajectories over 9 years.
METHODS: We included 4419 participants (mean age 61.3 years, 58% female) from the Osteoarthritis Initiative cohort. Participants were classified as \"no frailty,\" \"pre-frailty,\" or \"frailty\" at baseline, based on 5 characteristics (ie, unintentional weight loss, exhaustion, weak energy, slow gait speed, and low physical activity). Knee pain was evaluated annually using the Western Ontario and McMaster Universities Osteoarthritis Index pain subscale (0-20) from baseline to 9 years.
RESULTS: Of the participants included, 38.4%, 55.4%, and 6.3% were classified as \"no frailty,\" \"pre-frailty,\" and \"frailty,\" respectively. Five pain trajectories were identified: \"No pain\" (n = 1010, 22.8%), \"Mild pain\" (n = 1656, 37.3%), \"Moderate pain\" (n = 1149, 26.0%), \"Severe pain\" (n = 477, 10.9%), and \"Very Severe pain\" (n = 127, 3.0%). Compared to participants with no frailty, those with pre-frailty and frailty were more likely to have more severe pain trajectories (pre-frailty: odds ratios [ORs] 1.5 to 2.1; frailty: ORs 1.5 to 5.0), after adjusting for potential confounders. Further analyses indicated that the associations between frailty and pain were mainly driven by exhaustion, slow gait speed, and weak energy.
CONCLUSIONS: Approximately two-thirds of middle-aged and older adults were frail or pre-frail. The role of frailty in predicting pain trajectories suggests that frailty may be an important treatment target for knee pain.

UNASSIGNED: To facilitate the older adults with knee pain to perform exercises and improve knee health, we proposed the design of a machine learning-based system for lower-limb exercise training that features three main components: video demonstration of exercises, real-time movement feedback, and tracking of exercise progress. At this early stage of design, we aimed to examine the perceptions of a paper-based prototype among older adults with knee pain and investigate the factors that may influence their perceptions of the system.
UNASSIGNED: A cross-sectional survey of the participants\' (N = 94) perceptions of the system was conducted using a questionnaire, which assessed their perceived effects of the system, perceived ease of use of the system, attitude toward the system, and intention to use the system. Ordinal logistic regression was conducted to examine whether the participants\' perceptions of the system were influenced by their demographic and clinical characteristics, physical activity level, and exercise experience.
UNASSIGNED: The participants\' responses to the perception statements exhibited consensus agreement (≥ 75%). Age, gender, duration of knee pain, knee pain intensity, experience with exercise therapy, and experience with technology-supported exercise programs were significantly associated with the participants\' perceptions of the system.
UNASSIGNED: Our results demonstrate that the system appears promising for use by older adults to manage their knee pain. Therefore, it is needed to develop a computer-based system and further investigate its usability, acceptance, and clinical effectiveness.

BACKGROUND: Knee osteoarthritis (KOA) is a common degenerative joint condition that causes disability and pain in the elderly population. The prevalence of KOA among persons aged 63 or above is approximately 30%. Previous studies have reported the positive effects of Tui-na treatment and the Chinese herbal formula Du-Huo-Ji-Sheng Decoction (DHJSD) for KOA treatment. The current study aims to evaluate the add-on therapeutic effect of oral administration of DHJSD on KOA in addition to Tui-na.
METHODS: We conducted a prospective, randomized, controlled clinical trial. Seventy study subjects with KOA were randomly assigned to the treatment and control groups in a 1:1 ratio. Both two groups received eight sessions of Tui-na manipulation for 4 weeks. The DHJSD was only administered to the study subjects in the treatment group. The primary outcome measure was rated using the WOMAC at the end of treatment (4 weeks). Secondary outcomes were assessed using EQ-5D-5L, a health-related quality of life with 5-level EQ-5D version at end of treatment (week 4) and follow-up (week 8).
RESULTS: No statistically significant difference was found between two groups on WOMAC scores at the end of treatment. The mean WOMAC Pain subscale score was significantly lower in the treatment group than control group at week 8 follow up (mean difference, MD - 1.8, 95% CI - 3.5 to - 0.02, P = 0.048). The mean WOMAC Stiffness subscale score was significantly lower in the treatment group than in the control group at week 2 (MD 0.74, 95% CI 0.05 to 1.42, P = 0.035) and week 8 follow up (MD 0.95, 95% CI 0.26 to 1.65, P = 0.008). The mean EQ-5D index value was significantly improved in the treatment group than in the control group at week 2 (MD 0.17, 95% CI 0.02 to 0.31, P = 0.022). The analysis of WOMAC scores and EQ-5D-5L in both groups showed statistically significant improvement with time. No significant adverse effect was found during the trial.
CONCLUSIONS: DHJSD may have an add-on effect in addition to Tui-na manipulation relieving pain and improving stiffness as well as quality of life (QOL) in patients with KOA. The combined treatment was generally safe and well tolerated. Trial registration The study was registered at the ClinicalTrials.gov (website: https://clinicaltrials.gov/ct2/show/NCT04492670 , registry number: NCT04492670), registered on 30 July 2020.