Knee Osteoarthritis Group Research Articles

Hip Joint Abnormalities During Midstance in Osteoarthritic Patients.

Osteoarthritis is one of the most debilitating diseases in Europe affecting the lower limb joints, especially the hip and knee, having a bad influence on gait in the long run as well. Rehabilitation physicians use gait in order for the whole body to be seen in ensemble, and through midstance as moment of gait to also take predilection to falls into consideration. Goniometry is the quantifiable measure of a rehabilitation treatment by measuring the range of motion of each treated joint and studied during time. The patients that volunteered to be part of this study have been divided into four groups, depending on the level of osteoarthritis present at the lower limb joints: hip, knee, both hip and knee osteoarthritis or control group with no osteoarthritis, have been asked to walk for a few times and the video recordings were uploaded into the Angles App where we measured the lower limb joint angles during midstance. Patients with knee osteoarthritis present a more extended hip on both dominant and non-dominant sides compared to the ones with hip osteoarthritis, hip and knee osteoarthritis or control group. The results can be explained through the body’s kinematic chains that link the knee and hip, hip and pelvis during the midstance phase in the sagittal plane. A physician can use a video goniometry app in order for him to thoroughly evaluate an osteoarthritic patient as well as follow him or her during the entire course of treatment.

Muscle function, physical function, and gait in older women with and without knee osteoarthritis

Abstract Aim: To compare muscle function of knee extensors, gait parameters, and physical function in older women with and without knee osteoarthritis (KOA) and to associate these parameters to the KOA incidence in this population. Methods: Sixteen older women with KOA (66.9 ± 5.5 years; 74.9 ± 10.0 kg; 157.9 ± 0.9 cm; 30.2 ± 5.0 kg/m2) and fourteen healthy counterparts (control group: CG; 68.8 ± 5.8 years; 68.9 ± 10.5 kg; 158 ± 0.06 cm; 27.4 ± 4.0 kg/m2) participated in this study. Muscle function, physical function, and gait parameters were evaluated in both groups. The Western Ontario and McMaster Index (WOMAC) questionnaire was answered only by the KOA group. A correlation was performed to verify if KOA incidence was associated with muscle function, physical function, and gait parameters. Results: KOA group showed lower peak torque at 60°/s (30%; p = 0.003) and 180°/s (37%; p < 0.001), greater acceleration time at 60°/s (382%; p < 0.001), lower cadence (12.2%; p = 0.002), slower gait speed (19.5%; p < 0.001) and greater stride time (12.5%; p = 0.001) than CG group. However, there was no difference between groups in physical function (p < 0.0045). The KOA incidence presented a negative correlation with peak torque (rho = −0.602; p < 0.001), cadence (rho = −0.533; p = 0.002), gait speed (rho = −0.633; p < 0.001), stride length (rho = −0.517; p = 0.003) and a positive correlation with stride time (rho = 0.533; p = 0.002) and acceleration time (rho = 0.655; p < 0.001). Conclusion: Our findings suggest that knee osteoarthritis may impair the function of the knee extensors muscles and gait parameters. An association between the ability to produce force rapidly and gait speed with the KOA incidence in older women was also observed.

Foot posture assessment in people with primary medial compartment knee osteoarthritis: An observational study

BACKGROUND: Foot postures are integral to the biomechanical alignment and the dynamic function of the lower extremity. This study compared foot postures in people with primary medial compartment osteoarthritis (OA) and age-, gender-, and body mass index (BMI)-matched controls using various foot measures. Grade-wise variations were also assessed. AIM: The aim of the study was to assess the foot postures in people with primary medial compartment knee OA. METHODS: This was an observational, analytical study and the subjects were recruited by convenient sampling from tertiary hospitals in Pune. The target population were primary knee OA who were clinically and radiologically diagnosed for their severity based on the Kellgren–Lawrence grading, a severity classification based on radiographic evidence. The Centre of Rheumatic Diseases version of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Foot Function Index (FFI) which are both self-report questionnaires were duly filled by the knee OA subjects for the pain and dysfunction of the knee and foot, respectively. The control group consisted of age-, gender-, and BMI-matched asymptomatic healthy subjects. Foot postures of all subjects namely, the OA (n=48) and controls (n = 33) were assessed using the foot posture index (FPI), arch index, and navicular drop test. The FPI as well as the navicular drop test categorized the subjects into 3 groups: pronated, neutral, and supinated. The arch index was calculated from the inked imprint of the foot of the affected limb where higher values indicated dropped arch. STATISTICAL ANALYSIS AND RESULTS: Independent samples Mann–Whitney U-test and unpaired t-test were used to investigate the differences between the two groups in the foot characteristics. The Spearman's rho was used to analyze the correlation of FPI with the grades of OA and of WOMAC with the FFI within the OA group. The study included 48 medial knee OA subjects (48 knees and the corresponding foot) and 33 age-, gender-, and BMI-matched healthy controls. The percentages of foot postures (neutral, pronated and highly pronated) of both groups were 71%, 25% and 4% respectively in the OA group and 92%, 2% and 6% respectively in the control group. Comparative study of foot postures between the two groups showed more pronated feet in the OA group (P CONCLUSION: The foot postures were altered in the knee OA group as compared to healthy controls, with the OA group showing more pronated foot type.

Associations between the radiographic phenotypes and the presence of metabolic syndrome in patients with knee osteoarthritis.

We aimed to investigate the associations between the radiographic phenotypes and the presence of metabolic syndrome (MetS) in patients with knee osteoarthritis (OA). We evaluated women age 40 and over who presented to our outpatient clinics with knee pain and fulfilled the clinical and radiographic criteria for the classification of idiopathic OA of the knee. Patients were categorized into two groups concerning dominant radiographic phenotype. We included consecutive 50 patients in each group. All patients were evaluated in terms of MetS according to the revised diagnostic criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III), as well as the World Health Organization (WHO). Overall, MetS prevalence was found to be 79% according to the NCEP ATP III-MetS criteria and 65% according to the WHOMetS criteria. Prevalence of MetS was higher in the joint space narrowing (JSN)-dominant group compared to the osteophyte (O)- dominant knee OA group, but the difference did not reach statistical significance. However, in subgroup analysis (54 patients) in which we excluded patients with a past medical history of type 2 diabetes mellitus (DM), the prevalence of NCEP ATP III-MetS was statistically significantly higher in the JSN-dominant group compared to the O-dominant group [22 (75.9%) vs. 12 (48%), respectively, p = 0.03]. Logistic regression analysis in the subgroup demonstrated that the presence of NCEP ATP III-MetS was an independent risk factor for JSN-dominant knee OA phenotype [OR and 95% CI = 3.48 (1.09-11.13)]. The prevalence of MetS is quite high in patients with knee OA and is particularly pronounced in patients with JSNdominant radiographic phenotype. Moreover, our results suggest that MetS is an independent risk factor for JSN-dominant knee OA in patients with no past medical history of DM.

Trajectory of excess healthcare consultations, medication use, and work disability in newly diagnosed knee osteoarthritis: a matched longitudinal register-based study

To estimate the excess healthcare use and work disability attributable to knee osteoarthritis (OA) in the first 5years following diagnosis. Among individual aged 40-80 years who resided in Skåne on 31st December 2008, we identified those with a main diagnosis of knee OA during 2009-2014 and no previous diagnosis of any OA from 1998 (n=16,888). We created a comparison cohort matched (1:1) by sex, age, and municipality from individuals with no OA diagnosis (at any site) during 1998-2016. We compared healthcare use and net disability days for 60 months following diagnosis between the two groups. We applied a survival-adjusted regression technique controlling for sociodemographic characteristics as well as pre-diagnosis outcome and comorbidity. The estimated 5-year incremental effects of knee OA per-patient were 16.8 (95% CI: 15.8, 17.7) healthcare consultations, 0.7 (0.4, 1.1) inpatient days, 420 (372, 490) defined daily dose of prescribed medications, and 21.8 (15.2, 30.0) net disability days. Primary care consultations constituted about 73% of the excess healthcare consultations. Most of these incremental effects occurred in the first year after diagnosis. Better survival in the knee OA group accounted for 0.7 (95% CI: 0.5, 0.8) and 1.4 (0.7, 2.6) of the excess healthcare consultations and net disability days, respectively. Both estimated total and incremental resources use were generally greater for women than men with knee OA. Knee OA was associated with considerable excess healthcare use and work disability independent of pre-diagnosis resources use, comorbidity, and sociodemographic characteristics.

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

ObjectiveTo 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. DesignPerformance 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. ResultsWe 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. ConclusionsThe 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.

Adapted protocol of rate of force development and relaxation scaling factor for neuromuscular assessment in patients with knee osteoarthritis

BackgroundThe linear relationship between muscle torque and rate of torque rise/relaxation during rapid muscle contractions has been recently introduced as a novel measure of muscle quickness, termed rate of torque development/relaxation scaling factor (RTD-SF/RTR-SF). Because the standard assessment protocol includes potentially painful muscle contractions, the first purpose of this study was to validate an adapted RTD-SF/RTR-SF protocol for knee extensor muscles that utilizes lower submaximal intensities and can be used in knee osteoarthritis patients. MethodsA cross-sectional study was performed on a group of healthy controls (n = 24) who underwent the standard RTD-SF/RTR-SF protocol (20–80% of maximum) and the knee osteoarthritis group (n = 24) who underwent the adapted protocol (20–60% of maximum). We calculated the RTD-SF, RTR-SF and the linearity (r2) for both relationships, based on both protocols in controls. ResultsThe validity of the adapted protocol was acceptable (intraclass correlation coefficient = 0.77–0.93), with low within-participant variation (coefficient of variability <10%) for both outcome measures. Compared with the control group, the knee osteoarthritis group had similar RTD-SF, but lower linearity of RTD-SF (0.90 vs. 0.82). The RTR-SF (8.0/s vs. 6.7/s) and its linearity (0.87 vs. 0.73) were significantly reduced. Comparing the affected and the unaffected leg in the knee osteoarthritis group, the unaffected leg had greater maximal torque (96.2 vs. 84.1 Nm) and higher linearity for RTD-SF (0.86 vs. 0.80) and RTR-SF (0.82 vs. 0.73). ConclusionsWe confirmed the validity of the adapted RTD/RTR-SF protocol and its sensitivity to impairments associated with knee osteoarthritis.

The condition of the contralateral knee may induce different degrees of knee extensor strength asymmetry and affect functionality in individuals with unilateral or bilateral osteoarthritis

BackgroundLoss of knee extensor strength in individuals with knee osteoarthritis (KOA) may induce inter-limb strength asymmetries and alter functionality. The aims were to analyse whether the condition of the uninvolved knee (advanced to severe KOA or no affection) may induce different degrees of knee extensor strength asymmetry in individuals with KOA and to study whether functionality may differ in cases of unilateral or bilateral KOA. MethodsSixty-eight subjects with advance-to-severe KOA were categorized into two groups (unilateral or bilateral KOA). The knee extensor strength ratio (KESR), and self-reported and performance-based functionality were analysed and compared. Sex and age were independent factors. One- and two-way analysis of variance assessed for significant between-group differences (95% confidence interval (CI)). ResultsParticipants with unilateral KOA presented with 20% knee extensor strength asymmetry. The mean difference with the bilateral KOA group in terms of Knee Extensors Strength Ratio was 0.2 (95% CI 0–0.3; P = 0.021), of the Oxford Knee Scale score was 4.2 (95% CI 3.4–5.1; P = 0.037), and of the Timed Up and Go was 1.3 s (95% CI 0.5–2.2; P > 0.05). There were significant sex and age interactions (P < 0.05). ConclusionsIndividuals with unilateral or bilateral KOA present with different degrees of knee extensor strength asymmetry. The non-affected knee seems to help to better develop functional tasks in cases of unilateral condition. The findings may help the design of tailored strengthening interventions in which each knee condition in individuals with KOA should be considered.

Oxidant-Antioxidant Status in Patients with Knee Osteoarthritis in Duhok City, Kurdistan Region of Iraq

The major famous degenerative joint disease is osteoarthritis (OA), which leads to disability, reduced motion, pain, swelling, and crepitus. Thus, this research aimed to determine the statuses of oxidative stress (OS) and antioxidants in blood patients with primary OA and to compare serum levels of some inflammatory markers between control and knee OA patients groups. In this case-control study, 126 knee OA patients and 49 control individuals were taken, who visited the Center of Rheumatoid in Duhok city, Kurdistan region of Iraq. For the participant’s information, a study questionnaire was employed. Serum total bilirubin (TBIL), uric acid (UA), catalase, peroxynitrite (PN), malondialdehyde (MDA), and ceruloplasmin (CP) were evaluated. Some inflammatory markers were measured, including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Also, body mass index (BMI) was measured. In the present study, the % of the control group was 28% and patients groups were 29.71, 28, and 14.29% for mild, moderate, and severe cases, respectively. The mean values of MDA and CP showed significant differences between knee OA and control groups. On the other hand, the mean values of catalase, PN, UA, and TBIL showed no significant differences among control and knee OA groups. A significant difference was found among control and knee OA groups for ESR, but CRP was non-significant. In the current study, elevated levels of lipid-peroxidation and CP in patients with knee OA were observed. OS may be involved in OA.

Gait initiation and lateral wedge insole for individuals with early knee osteoarthritis

BackgroundPeople with knee osteoarthritis are at higher risk of postural deficits and locomotor adaptations which could be manifested in transient tasks like gait initiation. To better understand the effect of early knee osteoarthritis on gait initiation, we measured the gait initiation in two groups of early knee osteoarthritis and healthy age-matched controls and assessed the effect of lateral wedge insole in knee osteoarthritis group. MethodsTwenty-one individuals with early knee osteoarthritis, mean (SD) age = 53.1 (7.4, years), and 19 age- and sex-matched asymptomatic healthy individuals, mean (SD) age = 47.5 (11.2, years), participated. Centre of pressure trajectories were used to quantify the two phases of gait initiation in barefoot condition: anticipatory postural adjustment, and locomotor phase. The immediate and four-week effect of lateral wedge insole and shod condition were also compared for individuals in knee osteoarthritis group. FindingsLonger duration of anticipatory postural adjustment phase (P = 0.046), locomotor phase (P = 0.049), and total duration of gait initiation (P = 0.035) with lower length and velocity of the center of pressure trajectories in anticipatory postural adjustment phase (P = 0.002, and 0.008, respectively) were observed in knee osteoarthritis group compared to controls. Lateral wedge insole could increase the length and velocity of the centre of pressure in locomotor phase compared to barefoot condition (P = 0.001, and 0.002, respectively). InterpretationOur study outlined that people with early knee osteoarthritis adopt different gait initiation strategies mainly in postural preparation phase. The potential effect of lateral wedge insole was shown with better performance of the locomotor phase. Clinical trial registry numberIRCT2016060628310N1.

BALANCE POSTURAL ASSESSMENTS AND FUNCTIONAL MOBILITY IN SUBJECTS WITH KNEE OSTEOARTHRITIS

INTRODUCTION: Knee Osteoarthritis (KOA) affects joint cartilage causing pain, musculoskeletal and proprioceptive disorder that may favor the occurrence of postural balance disorders during activities of daily living. OBJECTIVE: To analyze the clinical variables, the balance profile and the functional mobility of subjects with KOA with and without a history of falls. METHODS: Sixty-four women, 50 to 75 years of age, were separated into three different groups: KOAF group (18 subjects with KOA and previous history of falls); KOANF (24 subjects with KOA and no previous history of falls) and control group - CG (22 healthy subjects). The Womac questionnaire was used to analyze functional disability. For the functional evaluation of the balance, two instruments were used, the Berg’s Balance Scale (BBS) and the Timed Up and Go test (TUG). For static balance evaluation, was used the stabilization diffusion analysis method (SDA) and analysis of the balance stabilizer of center of pressure (COP). RESULTS: It was evidenced that the BBS and WOMAC scores were significantly lower for the KOA group. The functional evaluation of the balance showed that the TUG test time and BBS score were significantly lower in subjects with KOA than in CG. The KOA groups (KOAF and KOANF) presented a greater displacement of the COP, anterior-posterior (AP) direction, and ellipse area than CG, in the closed-eyes condition. The KOAF group showed higher average speed of COP than CG. In the analysis of stabilogram diffusion, for both visual conditions, the KOA groups presented higher values in the short-term interval, long-term interval and critical point position than CG in the AP direction. CONCLUSION: The results imply that subjects with KOA, regardless of the previous history of falls, show a deficit of balance, increasing the risk of falls in this population.

Dynamic ultrasonography of the medial meniscus during walking in knee osteoarthritis

BackgroundMedial meniscal extrusion (MME) is a risk factor for the progression of knee osteoarthritis (OA). MME evaluation is crucial and it is commonly performed using magnetic resonance imaging (MRI) or static ultrasonography. We developed a prototype flat-shaped ultrasound transducer to visualize the actual meniscal movements during walking. ObjectiveThe aim of this study was to investigate whether it is feasible to visualize and evaluate the meniscal movements during walking using the novel flat-shaped ultrasound transducer for dynamic ultrasonography. MethodsSix participants who were diagnosed with primary unilateral or bilateral tibiofemoral knee OA on radiography (mean age, 67.1 ± 9.9 years; males/females, 4/2) and six healthy volunteers without any symptoms in their knees (mean age, 26.3 ± 4.0 years; males/females, 4/2) were enrolled in this study. The movement of the medial meniscus during walking was visualized using the novel transducer and the gait motion was recorded as video images that were synchronized with the ultrasonogram. MME and ΔMME (the difference between the minimum and maximum MME during the stance phase of the gait cycle) were evaluated in those with OA and compared with those in healthy volunteers. ResultsIn both groups, MME was visualized clearly in the stance phase. The mean values of MME and ΔMME in the knee OA group were significantly greater than those in the control group (P < .01). ConclusionsDynamic meniscal movement during gait can be evaluated with the specially developed novel ultrasound transducer. Our approach will be helpful in unveiling unknown pathological mechanisms in knee OA.

Serum levels of leptin, osteopontin, and sclerostin in patients with and without knee osteoarthritis.

To investigate the relationship between leptin, osteopontin (OPN), sclerostin (SOST) and severity of knee osteoarthritis (KOA). The study included 148 consecutive patients with knee OA and 101 non-KOA subjects enrolled in this cross-sectional study. All patients fulfilled the American College of Rheumatology criteria for primary knee OA. Severity of the disease was assessed using plain radiography of the affected knee, according to the Kellgren and Lawrence classification. Fasting blood samples were obtained from all patients and controls; the serum samples were kept at - 80°C before assessment of leptin, OPN, and SOST using a multiplex particle-based flow cytometric assay. KOA patients group compared with the control group, serum leptin (KOA, 26581.7 ± 2011.5pg/ml, vs control,6936.4 ± 702.2pg/ml),OPN (KOA, 4908.3 ± 769.4pg/ml, vs control, 2182.5 ± 217.8pg/ml), and SOST (KOA, 2481.9 ± 543.5pg/ml, vs control, 1288.9 ± 267.7pg/ml) in the KOA group were higher than control group; there were also differences in three bone metabolic factors between male and female in the KOA group; meanwhile, there was correlation between each factor and the incidence of KOA. Our study of 249 serum samples was conducted. Serum leptin, OPN, and SOST were significantly increased in KOA patients, and there was an internal correlation; these findings could, at best, contribute to the identification of novel targets for medical interventions. Key Points • The aim of this study was to assess the relationships of radiographic knee OA with altered serum levels of leptin, OPN, and SOST. Our study of 249 serum samples was conducted. Serum leptin, OPN, and SOST were significantly increased in KOA patients compared with control group. There were gender differences in the concentration of three serum bone turnover factors in KOA group and control group. Serum SOST concentration increased with Kellgren-Lawrence (K-L) grading. We found that serum leptin, OPN, and SOST were significantly increased in KOA patients, and there was an internal correlation. Leptin had a remarkable diagnostic value in the incidence of KOA.

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

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

Effect of Cholecystectomy on the Occurrence of Knee Osteoarthritis.

ObjectiveTo evaluate the effect of cholecystectomy on the occurrence of knee osteoarthritis (KOA).MethodsThe present study was a case‐control study with a retrospective, cross‐sectional, and longitudinal study design. The clinical data for knee osteoarthritis in the Second Hospital of Shanxi Medical University from January 2016 to September 2018 was analyzed. Clinical data, including gender, age, height, weight, smoking, alcohol abuse, prior medical history, and previous surgical history, were recorded. A logistic regression model was used for the univariate and multivariate analysis.ResultsA total of 1659 patients with KOA (KOA group) and 1195 limb fracture patients (control group) were included in this study. Among the 1659 patients with KOA, 388 patients were male and 1271 were female, while among the 1195 patients in the control group, 638 patients were male and 557 patients were female. The period between cholecystectomy and knee osteoarthritis onset ranged from 0.5 years to 17 years; the average interval time was 8.73 ± 2.11 years. The age at disease onset was significantly older when compared to the control group, while the body mass index in the KOA group was significantly higher when compared to the control group (P < 0.05). There were 97 patients undergoing cholecystectomy in the KOA group and there were 15 patients undergoing cholecystectomy in the control group. The proportion of cholecystectomy in the two groups was statistically significant. After the univariate analysis, there was a statistically significant difference in distribution between the two groups (P < 0.05). The multivariate logistic regression analysis revealed that there was a significant difference in the distribution of these two groups (P < 0.05), indicating that cholecystectomy is associated with the occurrence of KOA.ConclusionThere is a close relationship between cholecystectomy and KOA. However, the specific mechanism remains unknown and should be further researched.

Identification of lncRNA and mRNA Biomarkers in Osteoarthritic Degenerative Meniscus by Weighted Gene Coexpression Network and Competing Endogenous RNA Network Analysis.

Background Long noncoding RNAs (lncRNAs) play a crucial role in varieties of biological processes. This study is aimed at investigating meniscal degeneration-specific lncRNAs and mRNAs and their related networks in knee osteoarthritis (KOA). Methods The dataset GSE98918, which included 24 meniscus samples and related clinical data, was downloaded from the Gene Expression Omnibus database. The differentially expressed lncRNAs and mRNAs in the meniscus between KOA and control groups were identified. Based on the enriched differentially expressed lncRNAs and mRNAs, we constructed the coexpression network using WGCNA (weighted correlation network analysis) and identified the critical module related to KOA. For mRNAs in the key module, gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were carried out using the DAVID database. A competing endogenous RNA network (ceRNA) based on the screened mRNAs, lncRNAs, and related miRNAs was constructed to reveal presumptive biomarkers further. Finally, the hub lncRNAs and mRNAs were screened, and the diagnostic value was evaluated using a receiver operating characteristic (ROC) curve. Hub mRNAs were validated using the dataset GSE113825. Results We screened 208 significantly differentially expressed lncRNAs and mRNAs in menisci between the KOA and non-KOA samples, which were enriched in sixteen modules using WGCNA, especially the green module. Coexpression network based on the enriched differentially expressed lncRNAs and mRNAs in the green module uncovered 5 lncRNAs and 56 mRNAs. The lncRNA-miRNA-mRNA ceRNA network revealed that lnc-HLA-DQA1-5, lnc-RP11-127H5.1.1-1, lnc-RTN2-1, IGFBP4 (insulin-like growth factor binding protein 4), and KLF2 (Kruppel-like factor 2) were significantly correlated with the meniscus degeneration of KOA. ROC curve analysis revealed that these hub lncRNAs and mRNAs showed excellent diagnostic value for KOA. Conclusions These hub lncRNAs and mRNAs were potential prognostic biomarkers for the meniscus degeneration of KOA. Further studies are required to validate these new biomarkers and better understand the pathological process of the meniscus degeneration of KOA.

Composite quantitative knee structure metrics predict the development of accelerated knee osteoarthritis: data from the osteoarthritis initiative

BackgroundWe aimed to determine if composite structural measures of knee osteoarthritis (KOA) progression on magnetic resonance (MR) imaging can predict the radiographic onset of accelerated knee osteoarthritis.MethodsWe used data from a nested case-control study among participants from the Osteoarthritis Initiative without radiographic KOA at baseline. Participants were separated into three groups based on radiographic disease progression over 4 years: 1) accelerated (Kellgren-Lawrence grades [KL] 0/1 to 3/4), 2) typical (increase in KL, excluding accelerated osteoarthritis), or 3) no KOA (no change in KL). We assessed tibiofemoral cartilage damage (four regions: medial/lateral tibia/femur), bone marrow lesion (BML) volume (four regions: medial/lateral tibia/femur), and whole knee effusion-synovitis volume on 3 T MR images with semi-automated programs. We calculated two MR-based composite scores. Cumulative damage was the sum of standardized cartilage damage. Disease activity was the sum of standardized volumes of effusion-synovitis and BMLs. We focused on annual images from 2 years before to 2 years after radiographic onset (or a matched time for those without knee osteoarthritis). To determine between group differences in the composite metrics at all time points, we used generalized linear mixed models with group (3 levels) and time (up to 5 levels). For our prognostic analysis, we used multinomial logistic regression models to determine if one-year worsening in each composite metric change associated with future accelerated knee osteoarthritis (odds ratios [OR] based on units of 1 standard deviation of change).ResultsPrior to disease onset, the accelerated KOA group had greater average disease activity compared to the typical and no KOA groups and this persisted up to 2 years after disease onset. During a pre-radiographic disease period, the odds of developing accelerated KOA were greater in people with worsening disease activity [versus typical KOA OR (95% confidence interval [CI]): 1.58 (1.08 to 2.33); versus no KOA: 2.39 (1.55 to 3.71)] or cumulative damage [versus typical KOA: 1.69 (1.14 to 2.51); versus no KOA: 2.11 (1.41 to 3.16)].ConclusionsMR-based disease activity and cumulative damage metrics may be prognostic markers to help identify people at risk for accelerated onset and progression of knee osteoarthritis.

Age-specific changes in collagen remodelling in a healthy population

Purpose: There is a need to investigate the age characteristics and natural history of collagen turnover biomarkers to maximize their potential use in osteoarthritis (OA) (Tables 1 and 2). Collagen turnover is an essential part of growth and can vary as a function of age and disease. Several collagen turnover biomarkers, such as the formation of type II collagen (hsPRO-C2), matrix metalloproteinase-degradation of type II collagen (C2M) and degradation of type X collagen (C10C) are currently utilized as research tools in the OA field: hsPRO-C2 and C10C have both showed the ability to separate OA patients from healthy individuals, while C2M is elevated in knee OA patients compared to pain-free controls and was associated with KL-2 score and levels of chronic inflammation in the knee OA group.

Neuromuscular alterations in knee osteoarthritis: a systematic review and meta-analysis

Purpose: Neuromuscular alterations are commonly reported in knee osteoarthritis (OA) patients and neuromuscular training is being suggested as a first-line treatment. It is crucial to completely understand these alterations, including neural, structural and functional changes, to optimize interventions for knee OA patients. The aim of this systematic review was to systematically evaluate and determine the current evidence on the neuromuscular alterations of periarticular muscles in patients with knee OA when compared to age- and sex-matched healthy controls. Methods: We searched five databases (Pubmed, Embase, Web of Science, Scopus, Cochrane Central Register of Controlled Trials) for studies comparing neuromuscular alterations of periarticular muscles (i.e. quadriceps, hamstring, gastrocnemius, soleus, popliteus) in a knee OA population to an age- and sex-matched asymptomatic control group. We did not accept contralateral knee as the control group, as there is evidence of bilateral changes in unilateral disease presence. We only included studies reporting structural severity of the OA patients. Outcomes included normalized isokinetic strength, voluntary activation, cortical and spinal-reflex excitability, muscle morphology, and electromyography. Only moderate- and high-quality studies are included assessed by a modified Downs and Black checklist. We performed meta-analyses with random-effects model, grouping on radiographic OA severity, for outcome measures reported by two or more studies. Level of evidence is decided based on van Tulder et al. (2003). We also created an evidence gap-map to show which outcomes need more research. Results: We identified and included 7 high- and 37 medium-quality studies. One prospective cohort and 43 case-control studies reported data for 1643 OA patients and 1532 healthy controls. OA definitions hugely differed among studies in terms of structural severity. There was a high risk of selection bias in the included studies and blinding was not performed in most (n=40/44). Most studies reported quadriceps or hamstring muscle strength (n=24/44), while neural or structural alterations have been of less interest. Studies generally measured quadriceps (n=43/44) or hamstring muscles (n=23/44), while gastrocnemius (n=10/44), soleus (n=1/44) or popliteus (n=0/44) have been of less interest. Our findings indicated deficits in quadriceps (-0.72 [-0.95, -0.50], I2=72%, moderate evidence) and hamstring strength (-0.51 [-0.69, -0.33], I2=0%, moderate evidence) in knee OA patients. We also found lower quadriceps voluntary activation (-0.58 [-0.92, -0.23], I2=36%, moderate evidence) in knee OA group. No change was seen in quadriceps torque variability (0.43 [-0.60, 1.46], I2=84, limited evidence). Structural changes within the muscle focused on muscle volume and intermuscular fat for quadriceps. Results indicated no change in quadriceps muscle volume (0.10 [-0.03, 0.23], I2=0, strong evidence) but increased quadriceps intermuscular fat volume (0.39 [0.26, 0.52], I2=0, strong evidence) in knee OA population. For muscle activation, patients with knee OA showed increased muscle co-contraction for vastus medialis/medial gastrocnemius (0.88 [0.45, 1.30], I2=0%, moderate evidence) but not for vastus medialis/medial hamstring (0.23 [-0.18, 0.64], I2=0%, moderate evidence) during functional tasks. Conclusions: Our findings indicated that deficits in quadriceps and hamstring muscle strength in concurrence with quadriceps voluntary activation deficits are evident in knee OA patients. The lack of deficits of the quadriceps volume indicates that quadriceps weakness may be the result of neural inhibition more than muscle atrophy. This may support the use of neuromuscular training exercises in knee OA populations to increase neural drive. We also found increased co-contraction levels for vastus medialis and medial gastrocnemius muscles but not for vastus medialis and medial hamstring muscles. This interesting finding indicates that the interaction of quadriceps-gastrocnemius muscles may be more relevant than quadriceps-hamstring muscles in knee OA patients. Co-contractions differences may alter the loading of the knee joint; therefore, future studies optimizing the interventions for these co-contraction alterations in knee OA patients may be beneficial to avoid further degeneration. Despite huge number of studies being published in knee OA research, there are still very low evidence levels and poorly reported outcomes in studies measuring neuromuscular manifestations of the disease. High-quality studies with matched healthy control groups are still needed to understand neuromuscular alterations associated with knee OA. Better definition of OA following current guidelines and clearer participant selection processes are needed in future studies to increase evidence level.

Matrix metalloproteinase-13, NF-κB p65 and interleukin-1β are associated with the severity of knee osteoarthritis.

Knee osteoarthritis (KOA) is a prevalent disease, especially in the elderly. The present study examined the expression of matrix metalloproteinase-13 (MMP-13), NF-κBp65 and interleukin (IL)-lβ in the synovial tissues of KOA patients and the role of MMP-13 and the NF-κBp65 signalling pathway in KOA pathogenesis. A total of 100 KOA patients were enrolled in our hospital from December 2015 to December 2017 and were classified into either a mild KOA group (Outerbridge grade 1 and 2) or a severe KOA group (Outerbridge grade 3 and 4). Non-OA patients were included as controls. Synovial tissues from patients in both groups were collected for detection of the mRNA and protein expression of MMP-13, NF-κBp65 and IL-lβ. Synovial tissue slices were subjected to haematoxylin and eosin staining and immunohistochemistry (SP method). Cartilage tissues were observed under a light microscope after Safranin O-fast green staining. Reverse transcription-quantitative PCR and western blot analyses demonstrated that the expression of MMP-13, NF-κBp65 and IL-lβ in the mild and severe groups were substantially upregulated compared with the control group (all P<0.05). A positive correlation between MMP-13 and NF-κBp65 expression in the KOA synovial tissues was identified (P<0.05). Immunohistochemistry revealed that the expression of MMP-13 and NF-κBp65 was related to the severity of KOA (MMP-13: severe, 92.54%; moderate, 76.52%; control: 32.14%; and NF-κBp65: severe, 85.56%; moderate, 48.12%; control: 28.32%). This evidence indicated that the severity of KOA was related to MMP-13 and NF-κBp65 expression. The NF-κB signalling pathway may be activated during OA progression, which could upregulate the expression of MMP-13 and IL-1β and accelerate the deterioration of articular cartilage.