Knee Osteoarthritis Changes Research Articles

A Coarse-to-Fine Framework for Automated Knee Bone and Cartilage Segmentation Data from the Osteoarthritis Initiative.

Knee osteoarthritis (OA) is a degenerative joint disease that is prevalent in advancing age. The pathology of OA disease is still unclear, and there are no effective interventions that can completely alter the OA disease process. Magnetic resonance (MR) image evaluation is sensitive for depicting early changes of knee OA, and therefore important for early clinical intervention for relievingthe symptom. Automated cartilage segmentation based on MR images is a vital step in experimental longitudinal studies to follow-up the patients and prospectively define a new quantitative marker from OA progression. In this paper, we develop a deep learning-based coarse-to-fine approach for automated knee bone, cartilage, and meniscus segmentation with high computational efficiency. The proposed method is evaluated using two-fold cross-validation on 507 MR volumes (81,120 slices) with OA from the Osteoarthritis Initiative (OAI)1 dataset. The mean dice similarity coefficients (DSCs) of femoral bone (FB), tibial bone (TB), femoral cartilage (FC), and tibial cartilage (TC) separately are 99.1%, 98.2%, 90.9%, and 85.8%. The time of segmenting each patient is 12s, which is fast enough to be used in clinical practice. Our proposed approach may provide an automated toolkit to help computer-aided quantitative analyses of OA images.

Effects of "knot-loosing" of acupotomy on motor function and morphological changes of knee joint in knee osteoarthritis rabbits

To observe the effect of "knot-loosing method" of acupotomy on morphological changes in knee osteoarthritis (KOA) rabbits, so as to provide experimental basis for clinical acupotomy treatment of KOA. Male New Zealand rabbits were randomly divided into blank control, model and acupotomy groups, with 8 rabbits in each group. By using the modified Videman method, the left hindlimb was immobilized for 6 weeks with a plaster cast to replicate the KOA model. The knot-loosing manipulation of acupotomy was applied to "Hedingci" (located at the attachment of the positive upper margin of the quadriceps tendon and the patella),"Binneixia"（at "Neixiyan" ［EX-LE4］, the medial side of ligamentum patella）, "Binwaixia" （at "Waixiyan" ［ST35］, the lateral side of patellar ligament）, "Chengfeijian" (at the lateral collateral ligament of the knee in the la-teral joint space), "Weiyangci"(at the medial margin of the biceps femoris and the lateral side of the transverse striation), and "Yinlingci"(at the end-point of the medial tibia of the goose foot tendon), respectively, once a week for 4 times. One week after the last intervention, the left knee joint dysfunction severity (pain, maximum walking distance, and some activities of daily living) was evaluated by using modified Lequesne Index score. X-ray and magnetic resonance imaging(MRI)examinations were conducted to assess the articular space size, effusion and cartilage smoothness of the left knee for which the MRI Osteoarthritis Knee Score (MOAKS) was given according to their severity. The histopathologic changes of the cartilage of the left knee were observed by Hematoxylin-eosin (H.E.) staining and light microscope, which Mankin score was given. In addition, the surface of the cartilage was also examined by macroscopic observation. ①Following modeling, the Lequesne Index score, MOAKS, macroscopic observation score and Mankin score were significantly increased in the model group (P<0.05). X-ray and MRI imaging showed a narrower joint space, more effusion, rough cartilage surface; and H.E. staining displayed rough cartilage surface, and disordered arrangement and occasional clusters of the chondrocytes in the left knee joint. ②In comparison with the blank control group, the Lequesne Index, MOAKS, macroscopic observation and Mankin scores were significantly down-regulated in the acupo-tomy group (P<0.05). The abovementioned injury changes shown by X-ray, MRI, macroscopic and microscopic observations were relatively milder in the acupotomy group. Acupotomy loosing based on the "Jingjin theory" of traditional Chinese medicine can effectively improve the motor ability of knee joint and repair pathological changes of the cartilage in KOA rabbits.

Meta-analysis on the association between knee extensor strength and structural changes of knee osteoarthritis.

This study aimed to perform a meta-analysis to evaluate whether knee extensor (KE) strength weakness was associated with increased structural worsening in knee osteoarthritis (KOA) including joint space narrowing (JSN) and cartilage loss. PubMed, Embase, Scopus, ScienceDirect, Web of Science, and Cochrane library were searched from their inception to May 2020, to identify eligible studies. Odds ratios (ORs) accompanied by 95% confidence intervals (CIs) were calculated for the relationship between KE strength and outcomes. Totally eleven longitudinal studies were included. The pooled crude OR indicated no significant association between KE strength weakness and KOA progression of JSN (OR: 1.13, 95% CI: 0.90, 1.42), and this result duplicated after confounders were adjusted (OR: 1.10, 95% CI: 0.87, 1.39). Subgroup analysis showed the association remained non-significant in sex-specific outcomes and subsets of neutral and malaligned knees, but there was a trend toward increased risk of JSN progression in female knees with low strength (OR: 1.24, 95% CI: 0.87, 1.76, I2 = 82%). The pooled crude OR showed that KE strength weakness was associated with increased risk of cartilage loss (OR:1.43, 95% CI: 1.05, 1.95). After adjustment, we found a non-significant trend that low KE strength could increase the risk of cartilage loss (OR: 1.25, 95% CI: 0.95, 1.64), and this trend was separately observed in tibiofemoral or patellofemoral compartments. This meta-analysis suggested that KE strength weakness was not significantly associated with an increased risk of radiographic structural KOA progression in patients with KOA or known risk factors for KOA. However, there was a trend that women with weaker KE strength displayed a higher risk of JSN worsening and that KE strength weakness had an association with an increased risk of cartilage damage. Key points • Knee extensor strength weakness is not significantly associated with an increased risk of radiographic structural KOA progression in patients with or at risk of knee osteoarthritis. • There is a non-significant trend toward an increased risk of JSN progression in female knees with low knee extensor strength. • There is a trend that low KE strength can increase the risk of cartilage loss no matter in tibiofemoral or patellofemoral compartments, but it's not significant.

Early results of intra-articular micro-fragmented lipoaspirate treatment in patients with late stages knee osteoarthritis: a prospective study

AimTo analyze clinical and functional effects of intra-articular injection of autologous micro-fragmented lipoaspirate (MLA) in patients with late stage knee osteoarthritis (KOA). Secondary aims included classifying cell types contributing to the treatment effect, performing detailed MRI-based classification of KOA, and elucidating the predictors for functional outcomes.MethodsThis prospective, non-randomized study was conducted from June 2016 to February 2018 and enrolled 20 patients with late stage symptomatic KOA (Kellgren Lawrence grade III, n = 4; and IV, n = 16) who received an intra-articular injection of autologous MLA in the index knee joint. At baseline radiological KOA grade and MRI were assessed in order to classify the morphology of KOA changes. Stromal vascular fraction cells obtained from MLA samples were stained with antibodies specific for cell surface markers. Patients were evaluated at baseline and 12-months after treatment with visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Knee Injury and Osteoarthritis Outcome Score (KOOS).ResultsThree patients (15%) received a total knee replacement and were not followed up completely. Seventeen patients (85%) showed a substantial pattern of KOOS and WOMAC improvement, significant in all accounts. KOOS score improved from 46 to 176% when compared with baseline, WOMAC decreased from 40 to 45%, while VAS rating decreased from 54% to 82% (all P values were <0.001). MLA contained endothelial progenitor cells, pericytes, and supra-adventitial adipose stromal cells as most abundant cell phenotypes.ConclusionThis study is among the first to show a positive effect of MLA on patients with late stages KOA.ISRCTN registration ID: ISRCTN13337022.

BMI-related subchondral bone microstructural changes in knee osteoarthritis: overloading or metabolic disturbance?

Purpose: Obesity is one of the major risk factors for knee osteoarthritis (KOA), and it may contribute to KOA possibly through two main mechanisms: increased mechanical loading, as well as elevated low-grade systemic inflammation. There has been a growing interest in the relationship between body weight index (BMI), and subchondral trabecular bone (SCTB) microarchitectural changes in KOA, e.g. at the medial compartment. This study aims to fill the research gap, describing the correlation of SCTB microarchitectural changes in lateral compartment with BMI, ultimately to probe the predominant underlying mechanism. Methods: Samples of tibial plateaus from 54 (14 male, 40 female) patients with late stage KOA who were undergoing total knee arthroplasty (TKA) were collected. The samples were divided into three groups, according to the patients’ BMI (lean, BMI < 25; overweight, 25 < BMI < 30; obese, BMI > 30). The region of interest (ROI) was drawn manually for every sample (Figure 1). Three-dimension microarchitectural parameters in both medial and lateral compartments were obtained with the help of micro-CT analysis. Results: In lateral compartment (Figure 2), positive correlations were found between BMI and bone volume fraction (BV/TV) (r = 0.392, p=0.003) and trabecular thickness (Tb.Th) (r = 0.449, p=0.01). Negative correlation was found between BMI and specific bone surface (BS/BV) (r = -0.379, p=0.005) and trabecular pattern factor (Tb.Pf) (r= -0.353, p=0.009). In medial compartment, unlike previous researches, our study did not describe a significant correlation between microarchitectural parameters and BMI. Conclusions: This is the first study showing that BMI is related to microarchitectural changes in lateral compartments of late stage KOA patients. It can be interpreted from the results that bone density and quality increase with BMI. Mechanical loading will increase bone density while low-grade inflammation will erode bone, decreasing its quality and quantity. Our data imply that mechanical loading is a major mechanism to account for the deterioration of SCTB in lateral compartment in the late stage of KOA.The conflicting findings with previous researches in the medial compartment might be due to long waiting list in southern China. Patients usually receive TKA after medial compartment is fully worn out. We assume that in our patients population the KOA is in a critical end-stage, after the collapse of the medial compartment, so the lateral compartment’s mechanical loading is increased, which leads to more severe SCTB sclerosis.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Effects of activity modification in older population having osteoarthritis of knee: a randomized clinical trial

Purpose: The purpose of this study was to assess whether modification of the activities can decrease symptoms, improve functional ability and the quality of life in older adults with knee osteoarthritis (OA) who are accustomed to a traditional lifestyle which includes postures and activities that increase mechanical stress in the knee joints. Methods: In this prospective randomized clinical trial, total 157 adults (both male and female), age between 60-75 years having mechanical pain in the knee joints, difficulty in some of their activities of daily living (due to dysfunction of knee joint) and mild to moderate degree of radio-graphic changes of knee OA were included. All of the participants were previously continuing a traditional lifestyle which includes frequent squatting, climbing stairs, prolong standing, lifting heavy weights, using low sitting stools etc. for last forty to fifty years. They were randomly divided into two groups. Group 1 (n= 77) was treated with shortwave diathermy and Ibuprofen for initial two weeks and exercise and activity modification was continued throughout the whole period of study. Group 2 (n= 80) was treated with shortwave diathermy and Ibuprofen for initial two weeks and exercise was continued throughout the whole period of study. After initial assessment at entry, condition of the patients were assessed further after 3 weeks and 6 weeks, according to pain, functional capacity, and quality of life parameters. Visual analogue scale (VAS) and Western Ontario McMaster osteoarthritis index (WOMAC) of pain score were used to evaluate pain. While WOMAC physical function index was used to measure the functional capacity. Quality of life was assessed by the Nottingham Health Profile questionnaire (NHPQ). 69 from Group 1 and 67 from Group 2 reported timely in the subsequent visits after 3 and 6 weeks of their entry. In Group 1,all of the participants who reported regularly more or less followed the activity modification instructions. Results: After 3 weeks, there was no statistically significant difference of VAS scores and WOMAC pain and physical functional scores in between two groups.Result of the NHPQ also did not show statistically significant difference between the groups. After 6 weeks, VAS scores and WOMAC pain and physical functional scores were statistically lower in Group 1 than in the Group 2 (P<0.001). Result of the NHPQ also showed a statistically significant improvement in the group 1 when compared to the Group 2 (P<0.05). Conclusions: From the findings of this study we conclude that activity modification play an important role in decreasing pain, improving functional capability and providing better quality of life in older population with knee OA.

Comparisons of Neuromuscular Training Versus Quadriceps Training on Gait and WOMAC Index in Patients With Knee Osteoarthritis and Varus Malalignment

ObjectiveThe purpose of this study was to compare the effects of neuromuscular training (NMT) and quadriceps training (QT) on the altered gait patterns and Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index in patients with knee osteoarthritis (OA) and varus malalignment. MethodsSixty-six patients with knee pain ≥2 on 100-mm visual analog scale, radiographic knee OA changes ≥2 on Kellgren-Lawrence grading scale, and genu varum were allocated randomly into either the neuromuscular training group or quadriceps training group. Twelve weeks of supervised exercise protocol was given to the participants of both groups, which included 3 sessions per week. Primary outcomes were gait variables and self-reported physical function (WOMAC index). ResultsOf 66 knee OA patients, only 31 (94%) in the NMT group and 28 (84.8%) in the QT group completed the exercise protocol and were included in the analysis. There was a significant improvement in gait velocity (P = .022), stride length (P = .009), and global WOMAC index (P = .011) in the NMT group compared to the QT group. However, the scores of cadence (P = .226), gait cycle (P = .332), and double limb support (P = .054) were not found significant in the NMT group compared with the QT group. ConclusionThe NMT group showed improvement in some of the gait parameters as well as improvement in pain, stiffness, and functional limitation compared with conventional QT. No additional improvement was found in cadence, gait cycle, and double limb support in patients who received NMT.

Delayed gadolinium-enhanced MRI of menisci and cartilage (dGEMRIM/dGEMRIC) in obese patients with knee osteoarthritis: Cross-sectional study of 85 obese patients with intra-articular administered gadolinium contrast.

Early cartilage changes in knee osteoarthritis (OA) can be assessed by both intravenous (i.v.) and intra-articular (i.a.) delayed gadolinium-enhanced MRI of cartilage (dGEMRIC). To examine the relationship between i.a. dGEMRIC and delayed gadolinium-enhanced MRI of menisci (dGEMRIM), and to investigate if the approach can be used to assess the morphological degeneration of menisci in obese patients with knee OA. Cross-sectional. Eighty-five obese patients with knee OA. 1.5T. Inversion recovery sequence with four inversion times. T1 relaxation times were calculated for posterior weight-bearing femoral cartilage and the posterior horns of the menisci. Meniscus degeneration sum score (0-2) was assessed as increased signal/no signal (1/0) and tear/no tear (1/0). T1 relaxation times were compared using Student's t-test. Comparison of cartilage and meniscus T1 relaxation times was done by regression analysis. Analysis of variance (ANOVA) was used for comparison of meniscal T1 relaxation times among the three summed morphological scores (0-2). Statistical analyses were performed with a level of significance at 0.05. For lateral menisci, morphology sum scores of 0, 1, and 2 were found in 13, 58, and 14 patients and for medial menisci in 2, 30, and 30 patients, respectively. Mean T1 relaxation times were 441 msec, 480 msec, and 497 msec for cartilage, lateral menisci, and medial menisci, respectively. T1 relaxation times for the menisci were similar (P = 0.53), and a weak correlation was found between dGEMRIC and dGEMRIM in the lateral compartments (R = 0.26). Comparing dGEMRIM between different morphology sum scores showed no differences (P > 0.4). I.a. dGEMRIM showed no correlation between the degree of meniscal degeneration and meniscus T1 relaxation times. I.a. dGEMRIM do not seem to deliver useful information about meniscus degeneration to be suitable for clinical applications, but i.a. dGEMRIC may still be considered an alternative contrast-saving method for cartilage. 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;48:1700-1706.

A study on knee osteoarthritis in physical medicine and rehabilitation department, Rangpur Medical College

Background: Physical Medicine &amp; Rehabilitation (PMR) Department has also been trying to provide services with specialized outdoor (referred patient only) set up for twenty million people of Rangpur division.Objectives: Study is to know the demographic study, clinical grading, examination findings and radiological changes of Knee osteoarthritis.Materials &amp; Methods: It was an observational study. This study was done on referred patients of Knee osteoarthritis in PMR specialized outdoor of RpMCH from 20th September, 2012 to 20th October; 2012. The objective of this study is to know the demographic study, clinical grading, examination findings and radiological changes of knee osteoarthritis (OA). Consecutive sampling technique was adopted and total 34 samples were taken.Results: Among 30 study population, 4 (13.3%) were male, 26 (86.7%) were female and male: female ratio was 0.15 (Table I). The mean age was 52.20±9.572 (standard deviation) and P value was 0.000. Regarding Occupation, 18 (60%) were housewife, 10 (33.3%) were sedentary worker and 2 (6.7%) were businessmen (P value 0.002) (Table IV). Among the study population, 18 (60.0%) had both knee joint OA, 8 (26.7%) had right knee joint OA and 4 (13.3%) had left knee OA. The mean duration of knee joint pain was 25.33 ± 37.570 (standard deviation) month (P value 0.001) (Table VII). Among the study population, 4 (13.3%) had diabetes mellitus, 6 (20.0%) had hypertension, 2 (6.7%) had hypertension with ischemic heart disease and 2 (6.7%) had diabetes mellitus with hypertension with bronchial asthma and 16 (53.3%) were normotensive and nondiabetic (Figure 1). According to clinical grading of knee OA, 2 (6.7%) were in grade-1a, 6 (20%) were in grade-1b, 2 (6.7%) were in grade-2a, 4 (13.3%) were in grade-2b, 8 (26.7%) were in grade-3b, 8 (26.7%) were in grade-4 (P value 0.180 ) (Figure 2).Conclusion: This study reveals that clinically more advanced OA patients actually carrying early radiological changes.KYAMC Journal Vol. 8, No.-2, Jan 2018, Page 18-23

Potential pharmaceutic effect of Shilajit (mumie) on experimental osteoarthritis in rat

Osteoarthritis (OA) is a worldwide joint disease with clinically loss of motion and pain in human. The conventional treatments are associated with essential side effects. In folk medicine, Shilajit is applied for treatment of arthritis and bone fractures. The present study evaluated effect of Shilajit on the osteoarthritis in rat model. Thirty-six adult male rats were randomly divided into two groups including OA and treated with Shilajit groups. OA was induced by injection of monosodium iodoacetate in the articular space of femorotibial joint. Aqueous extract of Shilajit was given to the treatment group by gavage as daily during experimental course until 21 days. The joint samples were investigated 7, 14, and 21 days post induction. The main macroscopic changes in the affected joints were swelling and congestion at early stages. Histopathologic study showed surface irregularity, erosion and fissures, necrotic chondrocytes, depletion of toluidine blue staining, and lysis of subchondral bone in both OA and Shilajit groups after 7 and 14 days. Synovium revealed synovial cells hyperplasia and inflammatory cells infiltration. Moderate to advanced OA was seen in both groups without significant difference. After 21 days, histopathologic scores of destructive damages and synovitis were reduced in the Shilajit group and showed significant difference in compare to OA group. The present study shows that aqueous extract of Shilajit decreased cartilage degenerative changes in knee osteoarthritis. Also, it reduced inflammatory reactions in synovial membrane.

Radiographic Knee Osteoarthritis and Knee Pain: Cross-sectional study from Five Different Racial/Ethnic Populations

The weak correlation between pain and structural changes in knee osteoarthritis is widely reported. In a previous within-person, knee-matched case-control study among Caucasians, the severity of radiographic osteoarthritis (ROA) was strongly associated with both the presence of frequent knee pain and pain severity. We studied the association between ROA and knee pain in five racial/ethnic populations by using the same method. Subjects were selected from China; Japan; Korea and the United States. Among subjects with knees discordant for either frequent knee pain or pain severity, we examined the relationship between ROA and the presence of frequent knee pain using conditional logistic regression, and between ROA and pain severity using a stratified proportional odds model with an amalgamating conditional likelihood. In total, 252 urban Chinese, 221 rural Chinese, 297 Japanese, 122 Korean, 1,735 Caucasian, and 394 African-American patients were included. There was a strong dose-response relationship between the severity of ROA and the prevalence of frequent knee pain in all five racial/ethnic populations. Even mild ROA was significantly associated with frequent knee pain. In addition, ROA was also strongly associated with the severity of knee pain. These results show that structural pathology is associated with knee pain in different ethnic populations.

Knee Osteoarthritis Functional Classification Scheme - Validation of Time Dependent Treatment Effect. One Year Follow - Up of 518 Patients

Objective: The purpose of the current study was to validate time dependent changes of a novel functional classification for patients with knee osteoarthritis (KOA), following a home-based biomechanical treatment (HBBT).Methods: A retrospective analysis of 518 patients with KOA was conducted. All patients were classified using a novel knee osteoarthritis functional grade (KOFG) classification for KOA, based on spatio-temporal gait analysis. Patients were re-classified after 3 months and 1 year of HBBT to examine and validate this classification using timedependant changes. The time dependent changes in the classification were compared to gold-standard selfassessment questionnaires, WOMAC and short form 36 (SF-36).Results: The changes in KOFG were demonstrated over time, with most changes occurring after 3 months of treatment with consolidation of the effect at 12 months. For example, of 427 patients that were classified in KOFG 2-4 grade at baseline, 44.9% and 51.5% had lower (better) KOFG grades at 3 and 12 months of treatment, respectively. The changes in KOFG were validated with WOMAC and SF-36 questionnaires showing a significant correlation between KOFG changes and changes in WOMAC and SF-36. SF-36 pain sub-scale showed an improvement of 33.0% and 38.0% following 3 months and 12 months of treatment, respectively (p values <0.0001).Conclusions: The results of the current study validate the knee osteoarthritis functional grade classification scheme as a tool to assess time dependant changes in KOA as well as its sensitivity to assess treatment effect. The KOFG can offer a more robust mode of reporting clinical results in describing the natural history and time-dependent treatment results of patients suffering from knee OA and should be considered as an additional outcome measure in future studies.

Changes in gait characteristics of women with early and established medial knee osteoarthritis: Results from a 2-years longitudinal study

BackgroundDespite the large number of cross-sectional studies on gait in subjects with knee osteoarthritis, there are scarcely any longitudinal studies on gait changes in knee osteoarthritis. MethodsGait analysis was performed on 25 women with early and 18 with established medial knee osteoarthritis, as well as a group of 23 healthy controls. Subjects were asked to walk at their comfortable speed. Kinematic and kinetic data were measured at baseline and after 2years follow-up. FindingsResults indicated that the early osteoarthritis group, similar to established osteoarthritis group, showed significantly higher maximum knee adduction angles compared to the controls during the early stance phase of gait. None of the kinematic or kinetic measures, changed over two years in the early osteoarthritis group. In the established osteoarthritis group, at the time of entry, an increased first and second peak knee adduction moment, as well as higher mid-stance knee adduction moment and knee adduction moment impulse, were present compared to the control and the early osteoarthritis groups. Mid-stance knee adduction moment and knee adduction moment impulse, further increased over two years only in the established osteoarthritis group. For all three groups, the peak knee flexion angle during the stance phase decreased significantly over time. InterpretationIncreased maximum knee adduction angle during stance phase was the only alteration in the gait pattern of subjects with early knee osteoarthritis compared to the controls. This suggests that, unlike in the later stages of the disease, gait is rather stable over two years in early osteoarthritis.

A structural study of bone changes in knee osteoarthritis by synchrotron-based X-ray fluorescence and X-ray absorption spectroscopy techniques

Osteoarthritis (OA) is characterized by degeneration of articular cartilage and thickening of subchondral bone. The present study investigated the changing of biochemical components of cartilage and bone compared between normal and OA people. Using Synchrotron-based X-ray fluorescence (SR-XRF) and X-ray absorption spectroscopy (XAS) techniquesincluding X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) were employed for the bone changes in kneeosteoarthritisstudies. The bone samples were collected from various osteoarthritis patients with both male and female in the ages range between 20 and 74 years old. SR-XRF results excited at 4240 eV for Ca elements show a majority three main groups, based on their XRF intensities, 20–36 years, 40–60 years and over 70 years, respectively. By employing XAS techniques, XANES features can be used to clearly explain in term of electronic transitions occurring in bone samples which are affected from osteoarthritis symptoms. Moreover, a structural change around Ca ions in bone samples is obviously obtained by EXAFS results indicating an increase of Ca-amorphous phase when the ages increase.

Associations between proximal tibiofibular joint (PTFJ) types and knee osteoarthritic changes in older adults.

To describe the cross-sectional associations between proximal tibiofibular joint (PTFJ) type configurations and knee joint structural abnormalities in older adults. A total of 967 community-based participants were studied. T1-weighted fat-suppressed magnetic resonance image (MRI) with spoiled gradient recalled echo sequence was utilized to assess the PTFJ type configurations. Knee cartilage volume, cartilage defects, bone marrow lesions and osteophytes were measured. Linear regression and binary logistic regression analyses were used to examine the associations between PTFJ type configurations and knee joint cartilage volume as well as knee structural abnormalities, respectively, after adjustment for potential confounders. Seven PTFJ types including plane (49.4%), trochoid (31.9%), double trochoid (4.3%), saddle (5.4%), condylar (5.3%), trochlear (3.5%) and ball & socket (0.2%) were observed. Plane type was used as the comparator. In multivariable analyses, irregular joint types (comprising the five uncommon joint types) were associated negatively with cartilage volume, and positively with knee cartilage defects, bone marrow lesions and osteophytes in the lateral (but not medial) compartments. In contrast, trochoid type was only associated with reduced femoral cartilage volume, but not with knee cartilage defects, bone marrow lesions and osteophytes. Irregular PTFJ joint shapes are associated with osteoarthritic changes in the lateral, but not medial, tibiofemoral compartment in older adults. The causal relationship needs to be examined in future longitudinal studies.

A cross-sectional study on the correlation between MRI signal for IPFP and knee osteoarthritis

To investigate the correlation between MRI signal for infrapatellar fat pad (IPFP) and pathological changes in knee osteoarthritis (KOA), and to analyze the role of IPFP in the development of knee osteoarthritis. Methods: A total of 114 subjects (without special knee disease) were enrolled for this study. The intensity of MRI signal for IPFP was determined by fat-suppressed proton-density-weighted turbospin-echo magnetic resonance imaging. Based on the cartilage defects and osteophytes of knee joint, the subjects were divided into a KOA group and a control group. The difference of MRI signal for IPFP between two groups was analyzed. Results: After excluding the potential confounders of age, gender and BMI, the intensity of MRI signal for IPFP was positively correlated with defections in patellar, medial femur, lateral tibial or knee joint (OR 1.333 to 2.168, P 0.006 to 0.023); the intensity of MRI signal for IPFP was also positively correlated with osteophytes in patellar, medial femur, lateral tibial or knee joint (OR 1.309 to1.781, P 0.004 to 0.046); the intensity of MRI signal for IPFP in the KOA group was significantly higher than that in the control group (P=0.028). Conclusion: The increase in the density of MRI signal for IPFP is an imaging manifestation for knee degeneration. IPFP inflammation and endocrine abnormalities may play an important role in KOA.

Risk prediction model for knee pain in the Nottingham community: a Bayesian modelling approach

BackgroundTwenty-five percent of the British population over the age of 50 years experiences knee pain. Knee pain can limit physical ability and cause distress and bears significant socioeconomic costs. The objectives of this study were to develop and validate the first risk prediction model for incident knee pain in the Nottingham community and validate this internally within the Nottingham cohort and externally within the Osteoarthritis Initiative (OAI) cohort.MethodsA total of 1822 participants from the Nottingham community who were at risk for knee pain were followed for 12 years. Of this cohort, two-thirds (n = 1203) were used to develop the risk prediction model, and one-third (n = 619) were used to validate the model. Incident knee pain was defined as pain on most days for at least 1 month in the past 12 months. Predictors were age, sex, body mass index, pain elsewhere, prior knee injury and knee alignment. A Bayesian logistic regression model was used to determine the probability of an OR >1. The Hosmer-Lemeshow χ2 statistic (HLS) was used for calibration, and ROC curve analysis was used for discrimination. The OAI cohort from the United States was also used to examine the performance of the model.ResultsA risk prediction model for knee pain incidence was developed using a Bayesian approach. The model had good calibration, with an HLS of 7.17 (p = 0.52) and moderate discriminative ability (ROC 0.70) in the community. Individual scenarios are given using the model. However, the model had poor calibration (HLS 5866.28, p < 0.01) and poor discriminative ability (ROC 0.54) in the OAI cohort.ConclusionsTo our knowledge, this is the first risk prediction model for knee pain, regardless of underlying structural changes of knee osteoarthritis, in the community using a Bayesian modelling approach. The model appears to work well in a community-based population but not in individuals with a higher risk for knee osteoarthritis, and it may provide a convenient tool for use in primary care to predict the risk of knee pain in the general population.

Hypointense signals in the infrapatellar fat pad assessed by magnetic resonance imaging are associated with knee symptoms and structure in older adults: a cohort study.

BackgroundThere are few clinical and epidemiological studies reporting the association between abnormal changes within the IPFP and knee osteoarthritic changes. This study aims to describe the associations between hypointense signals in the infrapatellar fat pad (IPFP) and knee structural change and symptoms in older adults.MethodsParticipants (n = 874) were selected randomly from local community and followed up 2.7 years later (range 2.6–3.3 years). T1- or T2-weighted fat-suppressed magnetic resonance imaging (MRI) was assessed for IPFP hypointense signal, cartilage volume, cartilage defects, and bone marrow lesions (BMLs). Knee pain was assessed by self-administered Western Ontario and McMaster Osteoarthritis Index (WOMAC) questionnaire. Radiographic osteoarthritis was assessed using the OARSI atlas.ResultsCross-sectionally, hypointense signals in the IPFP were significantly associated with a higher risk of knee cartilage defects at all sites, tibiofemoral BMLs and knee pain in multivariable analyses. Longitudinally, baseline signal abnormalities were significantly and positively associated with increases in knee cartilage defects (OR: 2.27, 95 % CI: 1.61–3.21), BMLs (OR: 1.91, 95 % CI: 1.39–2.62), and knee pain (OR: 1.36, 95 % CI: 1.05–1.76) in multivariable analyses. The associations with cartilage defects remained significant after adjustment for BMLs, but the associations with BMLs and knee pain decreased in magnitude or became non-significant after further adjustment for cartilage defects.ConclusionsHypointense signals in the IPFP were associated primarily with increased knee cartilage defects and also with BMLs and knee symptoms in cross-sectional and longitudinal analyses, suggesting the abnormality represented by this signal has a potentially important role in osteoarthritis progression.Electronic supplementary materialThe online version of this article (doi:10.1186/s13075-016-1130-y) contains supplementary material, which is available to authorized users.

Serum levels of interleukin-17 and adiponectin are associated with infrapatellar fat pad volume and signal intensity alteration in patients with knee osteoarthritis.

BackgroundIn the present study, we sought to generate hypotheses regarding the associations of serum levels of interleukin (IL)-17, adiponectin, and resistin with magnetic resonance imaging-measured infrapatellar fat pad (IPFP) size and signal intensity alterations in patients with knee osteoarthritis (OA).MethodsA total of 170 subjects with symptomatic knee OA (mean age 55.4 years, range 34–74, 88.2 % females) were included. IPFP volume was measured on T1-weighted spoiled gradient-recalled acquisition in the steady state images and was computed by using a software program. IPFP high signal intensity (grades 0–3) was assessed on T2-weighted fast spin echo images. Serum IL-17, adiponectin, and resistin levels were measured using an enzyme-linked immunosorbent assay.ResultsIn multivariable analyses, serum IL-17 was negatively associated with IPFP volume (β = −0.185, 95 % CI −0.337 to −0.034) but positively associated with the severity of IPFP signal intensity alteration (OR 1.23, 95 % CI 1.06–1.42) after adjustment for age, sex, weight, and height. Serum adiponectin was positively associated with IPFP volume (β = 0.016, 95 % CI 0.001–0.032) but negatively associated with IPFP signal intensity alteration (OR 0.99, 95 % CI 0.98–1.00) after adjustment for covariates. Resistin was positively associated with IPFP signal intensity alteration (OR 1.13, 95 % CI 1.04–1.23) but not with IPFP volume. The significant associations of adiponectin or resistin disappeared after further adjustment for IL-17; in contrast, the significant associations of IL-17 remained after further adjustment for adiponectin.ConclusionsWhile serum IL-17 and resistin were associated with reduced IPFP volume and/or increased abnormal signal intensity alteration, serum adiponectin had opposite associations that were largely through IL-17. These findings suggest that serum adipocytokines may have a role to play in IPFP changes of knee OA.

Aging Promotes Sirtuin 3-Dependent Cartilage Superoxide Dismutase 2 Acetylation and Osteoarthritis.

To quantify functional age-related changes in the cartilage antioxidant network in order to discover novel mediators of cartilage oxidative stress and osteoarthritis (OA) pathophysiology. We evaluated histopathologic changes of knee OA in 10-, 20-, and 30-month-old male F344BN rats and analyzed cartilage oxidation according to the ratio of reduced to oxidized glutathione. Antioxidant gene expression and protein abundance were analyzed by quantitative reverse transcription-polymerase chain reaction and selected reaction-monitoring mass spectrometry, respectively. Superoxide dismutase 2 (SOD2) activity and acetylation were analyzed by colorimetric enzyme assays and Western blotting, respectively. We examined human OA cartilage to evaluate the clinical relevance of SOD2 acetylation, and we tested age-related changes in the mitochondrial deacetylase sirtuin 3 (SIRT-3) in rats and mice. Cartilage oxidation and OA severity in F344BN rats increased with age and were associated with an increase in SOD2 expression and protein abundance. However, SOD2-specific activity decreased with age due to elevated posttranslational lysine acetylation. Consistent with these findings, SIRT-3 levels decreased substantially with age, and treatment with SIRT-3 increased SOD2 activity in an age-dependent manner. SOD2 was also acetylated in human OA cartilage, and activity was increased with SIRT-3 treatment. Moreover, in C57BL/6J mice, cartilage SIRT-3 expression decreased with age, and whole-body deletion of SIRT-3 accelerated the development of knee OA. Our results show that SIRT-3 mediates age-related changes in cartilage redox regulation and protects against early-stage OA. These findings suggest that mitochondrial acetylation promotes OA and that restoration of SIRT-3 in aging cartilage may improve cartilage resistance to oxidative stress by rescuing acetylation-dependent inhibition of SOD2 activity.