Changes In Cartilage Thickness Research Articles

Loss of patellofemoral cartilage thickness over 5 years following ACL injury depends on the initial treatment strategy: results from the KANON trial

ObjectivesTo evaluate changes in patellofemoral cartilage thickness over 5 years after anterior cruciate ligament (ACL) injury and to determine the impact of treatment strategy.Methods121 adults (ages 18–35 years, 26% women)...

Validation of a novel blinding method for measuring postoperative knee articular cartilage using magnetic resonance imaging

To test PEEK implant-associated MRI artifacts, a method for blinding MRI readers, the repeatability of cartilage thickness measures before and 6weeks after high tibial osteotomy (HTO), and the sensitivity to change of cartilage thickness 12months after HTO. Ten patients underwent HTO using a PEEK implant and 3T-MRI before, 6weeks and 12months after surgery. Masks were applied to hide implant visibility on 48 MRI pairs, which were assessed by 7 readers (blinded to time). One blinded reader measured femorotibial cartilage thickness from masked MRIs. No artifacts were produced. Readers were unable to identify scans by time greater than by chance. Cartilage thickness before and 6weeks after surgery was not significantly different and indicated excellent repeatability. Medial cartilage thickness increases 12M postoperatively approached statistical significance (p=0.06), with no lateral changes observed. Half of the participants had an increase in medial cartilage thickness at 12M that exceeded the minimal detectable change. Standardized response mean values were moderate-to-large. Postoperative measures of cartilage thickness are repeatable, consistent and sensitive to change when artifact is eliminated, and a validated blinding technique is used. These results provide proof of concept for accurately measuring increases in medial knee articular cartilage after medial opening wedge HTO.

Ultrasound detected changes in joint cartilage thickness in juvenile idiopathic arthritis.

The purpose of this study was to investigate the changes in joint cartilage thickness in different subtypes of juvenile idiopathic arthritis (JIA) using ultrasound, comparing them with healthy children and to evaluate the relationship with disease duration and inflammatory markers. We conducted a cross-sectional study comprising of 27 cases of JIA and 54 age- and sex-matched healthy children. Bilateral wrist, knee and ankle joint cartilage thicknesses were measured by ultrasound as per European League Against Rheumatism standard guidelines and compared them between JIA subtypes as well as between cases and control. Descriptive analysis of the whole cohort revealed the mean age of the study population was 8.3±3.2years with mean cartilage thicknesses at the wrist, knee and ankle being 1.40±0.89mm, 1.57±0.78mm and 1.41±0.85mm, respectively. The median cartilage thicknesses of wrist, knee and ankle joints of JIA cases (n=27) and healthy controls (n=54) were 1.01, 1.35, 1.05 and 1.95, 2.00, 1.95, respectively. The joint cartilage thickness was significantly reduced in JIA in comparison to the healthy cohort (P<0.01). Diseased boys suffered greater cartilage damage in knee joints compared to girls; the polyarticular variety of cases had thinner knee cartilage in comparison to the oligoarticular subtype. Further, it was found that joint cartilage destruction is independent of inflammatory markers and disease duration. Significant cartilage thinningin addition was found in JIA children, particularly in the polyarticular subtype, and morein boys than girls, which is independent of disease duration and inflammatory markers, using ultrasound as a primary investigative tool.

Association between changes in molecular biomarkers of cartilage matrix turnover and changes in knee articular cartilage: a longitudinal pilot study

BackgroundAn early detection of Osteoarthritis is urgently needed and still not possible until today. The aim of the study was to assess whether molecular biomarkers of cartilage turnover are associated with longitudinal change in knee cartilage thickness during a 2 year period in individuals with increased risk of developing knee osteoarthritis. A secondary aim was to assess whether prior knee injury or subjective patient-reported outcomes at baseline (BL) were associated with articular cartilage changes. Nineteen volleyball players (mean age 46.5 ± 4.9 years, 47% male) with a 30-year history of regular high impact training were recruited. The serum biomarkers Cpropeptide of type II procollagen (CPII), cartilage oligomeric matrix protein (COMP), collagenase generated carboxy-terminal neoepitope of type II collagen (sC2C), cartilage intermediate layer protein 2 (CILP-2), and the urine biomarkers C-telopeptide of type II collagen (CTX-II) and collagenase-generated peptide(s) of type II collagen (C2C-HUSA) were assessed at BL and at 2 year follow up (FU). Femorotibial cartilage thinning, thickening and absolute thickness change between BL and FU was evaluated from magnetic resonance imaging. Subjective clinical status at BL was evaluated by the International Knee Documentation Committee Subjective Knee Form and the Short-Form 36 Physical Component Score.ResultsCILP-2 was significantly higher at FU and linearly associated with the absolute cartilage thickness change during the experimental period. Prior injury was a predictor of increased absolute cartilage thickness change.ConclusionMeasuring the change in the cartilage biomarker CILP-2 might be a valid and sensitive method to detect early development of knee osteoarthritis as CILP-2 appears to be related to cartilage thickness loss in certain individuals with increased risk of developing knee osteoarthritis. Prior knee injury may be predictive of increased articular cartilage thickness change.

Longitudinal Changes in the Total Knee Joint Moment After Anterior Cruciate Ligament Reconstruction Correlate With Cartilage Thickness Changes.

This study investigated associations between changes in the total joint moment (TJM) at the knee and changes in cartilage thickness after anterior cruciate ligament reconstruction (ACLR). Seventeen subjects (five males; age: 29.6 ± 7.3 years) with unilateral ACLR underwent gait analysis and magnetic resonance imaging at baseline (2.2 ± 0.3 years post-ACLR) and at long-term follow-up (7.7 ± 0.7 years post-ACLR). Knee loading was assessed using the TJM, and differences in loading were analyzed using repeated measures analysis of variance. Pearson correlation coefficients assessed associations between changes in TJM and changes in (medial-to-lateral) M/L femoral cartilage thickness ratios in the ACLR limb. Bilaterally, there was no significant change in the magnitude of the TJM first peak (TJM1), however, there was a significant increase in the percent contribution of the knee flexion moment (KFM) (p < 0.001) and decrease in the percent contribution of the knee adduction moment (KAM) to TJM1 (p < 0.001). The change in the percent contributions of KFM and KAM to TJM1 were associated with changes in M/L femoral cartilage thickness in the ACLR limb. Specifically, subjects with smaller increases in KFM contribution (R = 0.521, p = 0.032) and smaller decreases in KAM contribution (R = -0.521, p = 0.032) had a reduction in the M/L ratio in the central femoral subregion over the follow-up period, with similar trends in the external femoral subregion. The study results provide new insight into changes in the loading environment at the knee joint prospectively following ACL reconstruction and give evidence that there are modifiable gait metrics that are associated with cartilage changes after ACLR. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1546-1554, 2019.

Acute Effects of Walking on the Deformation of Femoral Articular Cartilage in Older Adults.

Although discomfort during walking is a common complaint in individuals with knee osteoarthritis (OA), how an acute bout of walking affects femoral cartilage remains unclear. Current literature has suggested that frontal plane knee malalignment (ie, varus and valgus) is associated with the initiation and/or progression of knee OA. However, the association between knee alignment and femoral cartilage deformation after an acute bout of loading has not yet been investigated. This study was aimed to compare the acute effects of walking on femoral cartilage deformation between older adults with and without knee OA. We also examined the association between frontal plane knee alignment and loading-induced femoral cartilage deformation. Ten persons without OA (Kellgren Lawrence grading = 0 or 1; 5 females and 5 males; 55.0 [1.8] years of age; 78.8 [14.1] kg; 1.8 [0.2] m) and 9 persons with OA (Kellgren Lawrence grading ≥2; 4 females and 5 males; 55.6 [4.5] years of age; 97.4 [15.0] kg; 1.7 [0.1] m) participated. Each participant underwent magnetic resonance imaging before and immediately after 30 minutes of fast walking at 3 to 4 miles per hour. To obtain cartilage deformation postwalking, the medial and lateral femoral cartilage of the weight-bearing areas was segmented on participants' magnetic resonance imaging. Cartilage thickness was quantified by computing the average perpendicular distance between opposing voxels defining the edges of the femoral cartilage. Cartilage deformation of the medial and lateral femurs was defined as the percent changes in cartilage thickness after walking. Frontal plane knee alignment was obtained by measuring the angle between the long axes of femur and tibia. Independent t tests were used to compare cartilage deformation between the 2 groups. Pearson correlation coefficients were used to assess the association between cartilage deformation and knee alignment. There was no significant difference in cartilage deformation between the OA and control groups in lateral (P = .69) or medial (P = .87) femur. A significant correlation was found between lateral femoral cartilage deformation and increased knee valgus alignment (r = 0.497; P = .03). No difference was found between medial femoral cartilage deformation and frontal plane knee alignment (r = 273; P = .26). This is the first study comparing the acute effects of walking on femoral cartilage deformation between older adults with and without knee OA. Although there was not a difference in walking-induced femoral cartilage deformation between the OA and control groups, knee valgus was related to lateral femoral cartilage deformation after walking. Our findings suggested that walking exercises may be used safely in older adults without knee malalignment.

Structural progressor thresholds of femorotibial cartilage change over 1 to 4-years for different MRI orientations and contrasts – data from the osteoarthritis initiative

Structural progressor thresholds of femorotibial cartilage change over 1 to 4-years for different MRI orientations and contrasts – data from the osteoarthritis initiative

Influence of sex on tibiofemoral cartilage response to running in young healthy men and women

Purpose: Women are more likely to experience greater degeneration and more severe symptoms related to osteoarthritis (OA) than men. It is unknown whether sex influences the acute response of cartilage in the knee to loading. Identifying sex-differences, if present, may improve our understanding of the differences in OA experienced between men and women at a tissue level. The purpose of this study was to determine if there is an influence of sex on loading-induced changes in regional tibiofemoral cartilage thickness as measured by magnetic resonance imaging (MRI) following running in young men and women. Methods: Young healthy men (N=15, 25.6±4.1 y, 23.7±2.7 kg/m2) and women (N=15, 26.1±3.4 y, 23.1±3.1 kg/m2) were recruited. Participants were excluded if they were unfit to participate in physical activity as captured by the Get Active! Questionnaire, scored below 74 on the Lower-Extremity Functional Scale, self-reported lower-limb injuries in the last 3 months, had orthopaedic surgery in the limb of interest (right), or had contraindications to MRI. Participants were asked to attend one MRI imaging session in the morning. Participants then rested supine for 30 minutes to mitigate effects of morning loading activities (i.e., walking) on the cartilage. Pre-activity scans were acquired with a 3.0T MR750 Discovery MRI scanner. Specifically, sagittal 3D fat-saturated fast-spoiled gradient recalled (FSPGR) scans were obtained to clearly delineate articular cartilage from surrounding tissues (FOV: 160 mm, Matrix: 512 x 512, In-Plane Resolution: 0.3125 x 0.3125 mm, Slice Spacing: 1 mm, TR: 17.388 ms, TE: 5.832 ms, Frequency: 127.78 MHz, Flip Angle: 18 degrees). Following pre-activity scans, participants ran on a treadmill adjacent to the MRI scanning room for 15 minutes. Then, participants immediately completed post-activity imaging (FSPGR). Tibiofemoral cartilage were segmented from pre- and post-activity FSPGR scans using a convolutional neural network (NeuralSeg). Medial and lateral tibial, and medial and lateral weight-bearing femoral cartilage were extracted and analyzed separately. Thickness maps were created by finding the minimum Euclidean distance from each bone-cartilage interface voxel to the articular surface. These maps were then flattened and warped to the same dimensions for further analyses. Pixelwise statistical parametric mapping using F-statistics was completed to examine the influence of sex on cartilage response to exercise. First, maps were smoothed using a Gaussian kernel filter with a full-width half maximum of 4 mm. Next, pixelwise F-statistic maps were generated for the factors of Sex, Exercise, and the interaction of Sex and Exercise (Sex#Exercise). F-maps were thresholded at a corresponding alpha level of p=0.01. Finally, the significance of thresholded clusters was determined using Gaussian random field (GRF) theory at an alpha level of p=0.001. Results: A minimum cluster size of 20 pixels was determined as a significant change. For the factor of Sex, significant clusters were identified for all four tissues, indicating that female sex was associated with overall thinner cartilage. These clusters of thinner cartilage in women in the medial and lateral tibia were located centrally, aligning approximately with the location of articulation of the femur with the tibia (Fig 1). Similarly, significant medial and lateral weight-bearing femoral clusters were located at the approximate location of the articulation with the tibia. The effect of exercise caused significant clusters for the lateral tibia only, suggesting cartilage thinning following exercise. This cluster was located centrally. The interaction Sex#Exercise did not contain significant clusters. Conclusions: This study compared cartilage thickness changes in young healthy men and women. Consistent with previous literature, women had thinner cartilage; the clustering analysis emphasizes that this thinner cartilage appears in the weight-bearing regions of the knee among women. Running produced systematic deformation patterns in cartilage of the lateral tibia. Finally, no interaction of sex and exercise was found, suggesting that sex does not cause distinct cartilage deformation patterns in response to running. Future work should aim to include other factors that may affect cartilage response to loading, such as age or disease.

Spatial distribution of longitudinal cartilage thickness change in anterior and posterior cruciate ligament injury compared to healthy athletic controls

Spatial distribution of longitudinal cartilage thickness change in anterior and posterior cruciate ligament injury compared to healthy athletic controls

Radiographic-based measurement of tibiofemoral joint space width and magnetic resonance imaging derived articular cartilage thickness are not related in subjects at risk for post traumatic arthritis of the knee.

Joint space width (JSW), measured as the distance between the femoral and tibial subchondral bone margins on two-dimensional weight-bearing radiographs, is the initial imaging modality used in clinical settings to diagnose and evaluate the progression of osteoarthritis (OA). While, JSW is the only structural outcome approved by the FDA for studying the treatment of this disease in phase III clinical trials, recent reports suggest that magnetic resonance imaging (MRI)-based measurements of OA changes are superior due to increased sensitivity and specificity to the structural changes associated with progression of this disease. In the current study, we examined the relationship between radiographic JSW and MRI-derived articular cartilage thickness in subjects 4 years post anterior cruciate ligament reconstruction (ACLR) who were at increased risk for the onset and early progression of post-traumatic OA, and in uninjured subjects with normal knees (Control). In both ACLR and Control groups, there were large measurement biases, wide limits of agreement, and poor correlation between the two measurement techniques. Clinical significance: The finding from this study suggest that the two methods of examining changes associated with the onset and early progression of PTOA either characterize different structures about the knee and should not be used interchangeably, or two-dimensional JSW measurements are not sensitive to small changes in articular cartilage thickness. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Moderate Physical Activity and Prevention of Cartilage Loss in People With Knee Osteoarthritis: Data From the Osteoarthritis Initiative.

To examine the impact of physical activity on cartilage thickness loss in knee osteoarthritis (OA). A total of 689 participants with radiographic knee OA at baseline (Kellgren/Lawrence grade ≥2) from the Osteoarthritis Initiative completed the Physical Activity Scale for the Elderly (PASE) questionnaires at annual intervals over 4 years. Magnetic resonance imaging-based cartilage thickness change in the medial femorotibial compartment (MFTC) over 4 years was the main outcome. The impact of PASE tertiles (low, moderate, or high) on changes in MFTC cartilage thickness was estimated using a mixed-effects model adjusted for baseline characteristics. Furthermore, stratification by sex was performed for secondary analyses. Structural progression of MFTC cartilage loss of -0.20 mm (95% confidence interval [95% CI] -0.22, -0.17) was observed in the entire cohort, with no significant difference between physical activity levels after adjustment for baseline characteristics. An interaction between sex and physical activity was observed in the adjusted analysis (P = 0.02). Stratification by sex showed that women with low physical activity had a statistically greater cartilage loss than women with moderate physical activity (adjusted between-group difference -0.09 mm [95% CI -0.16, 0.02]), whereas no significant differences were observed in men. While physical activity was not associated with cartilage thickness loss in the whole cohort, this relationship significantly differed between sexes. In women, but not in men, moderate physical activity may slow down structural disease progression compared to low physical activity levels. For both men and women, high physical activity levels do not appear to be more detrimental than lower physical activity levels for cartilage thickness loss.

Cartilage loss in radiographically normal knees depends on radiographic status of the contralateral knee – data from the Osteoarthritis Initiative

To test whether radiographically normal knees with contralateral radiographic knee osteoarthritis (OA), but without contralateral trauma history, display greater cartilage thickness loss than knees from subjects with bilaterally radiographically normal knees. 828 radiographically normal knees (Kellgren Lawrence grade [KLG] 0) from the Osteoarthritis Initiative [OAI] were studied; 150 case knees displayed definite radiographic knee OA (KLG≥2) contralaterally, and had MRI double echo steady state (DESS) images available at 12 and 48 month follow-up. 678 reference knees displayed KLG0 at the contralateral side. Cartilage thickness change was determined in femorotibial subregions and location-independent cartilage thinning scores were computed. Case and reference knees were compared using ANCOVA. Of the 150 KLG0 case knees, 108 had a contralateral KLG2 knee (50 without, and 58 with joint space narrowing [JSN]), 31 a KLG3 and 11 a KLG4 knee. The cartilage thinning score tended to be greater in case than reference knees; the cartilage thinning score in KLG0 case knees with contralateral radiographic JSN (-858μm; [95% confidence interval-1016,-701μm]) was significantly greater (P=0.0012) than that in bilaterally KLG0 reference knees (-634μm; [-673,-596μm]), whereas KLG0 knees with contralateral KLG2 without JSN only showed relatively small thinning scores (-530μm, [-631,-428μm]). Region-specific analysis suggested greater rates of cartilage loss in case than in reference knees in the lateral, rather than medial, femorotibial compartment. Radiographically normal knees with contralateral JSN may serve as a human model of early OA, for testing disease modifying drugs in clinical trials designed to prevent cartilage loss before the onset of radiographic change. CLINICALTRIALS. NCT00080171.

Effects of Anterior Cruciate Ligament Deficiency on Tibiofemoral Cartilage Thickness and Strains in Response to Hopping

Background: Changes in knee kinematics after anterior cruciate ligament (ACL) injury may alter loading of the cartilage and thus affect its homeostasis, potentially leading to the development of posttraumatic osteoarthritis. However, there are limited in vivo data to characterize local changes in cartilage thickness and strain in response to dynamic activity among patients with ACL deficiency. Purpose/Hypothesis: The purpose was to compare in vivo tibiofemoral cartilage thickness and cartilage strain resulting from dynamic activity between ACL-deficient and intact contralateral knees. It was hypothesized that ACL-deficient knees would show localized reductions in cartilage thickness and elevated cartilage strains. Study Design: Controlled laboratory study. Methods: Magnetic resonance images were obtained before and after single-legged hopping on injured and uninjured knees among 8 patients with unilateral ACL rupture. Three-dimensional models of the bones and articular surfaces were created from the pre- and postactivity scans. The pre- and postactivity models were registered to each other, and cartilage strain (defined as the normalized difference in cartilage thickness pre- and postactivity) was calculated in regions across the tibial plateau, femoral condyles, and femoral cartilage adjacent to the medial intercondylar notch. These measurements were compared between ACL-deficient and intact knees. Differences in cartilage thickness and strain between knees were tested with multiple analysis of variance models with alpha set at P < .05. Results: Compressive strain in the intercondylar notch was elevated in the ACL-deficient knee relative to the uninjured knee. Furthermore, cartilage in the intercondylar notch and adjacent medial tibia was significantly thinner before activity in the ACL-deficient knee versus the intact knee. In these 2 regions, thinning was significantly influenced by time since injury, with patients with more chronic ACL deficiency (>1 year since injury) experiencing greater thinning. Conclusion: Among patients with ACL deficiency, the medial femoral condyle adjacent to the intercondylar notch in the ACL-deficient knee exhibited elevated cartilage strain and loss of cartilage thickness, particularly with longer time from injury. It is hypothesized that these changes may be related to posttraumatic osteoarthritis development. Clinical Relevance: This study suggests that altered mechanical loading is related to localized cartilage thinning after ACL injury.

Matrix changes in articular cartilage in the knee of patients with rheumatoid arthritis after biological therapy: 1-year follow-up evaluation by T2 and T1ρ MRI quantification

To estimate the morphological changes in the articular cartilage of the knees of patients with rheumatoid arthritis treated with biological disease-modifying anti-rheumatic drugs (bDMARDs). Cartilage-specific magnetic resonance imaging (MRI) results, including T2 and T1ρ mapping of the femorotibial joint of 17 patients, were obtained before and 1 year after starting treatment with bDMARDs. Regions of interest were selected on the sagittal images of the cartilage of the medial and lateral femoral condyles (MFC, LFC) and the tibial plateau (MTP, LTP). Cartilage thickness, T2, and T1ρ were measured, and the correlations of their changes were evaluated. The mean changes in cartilage thickness tended to decrease in all four condyles, and the rate was significant in the MFC. T2 and T1ρ tended to increase, and T2 in the MFC significantly increased. Changes in cartilage thickness after 1 year showed a moderate correlation with the baseline T2 in the MFC as well as changes in T2 in the MTP. Decreasing cartilage thickness and matrix changes appeared in the MFC after 1 year of treatment with bDMARDs. Microstructural damage of the cartilage at baseline is a predictor for further cartilage damage in the knee joint, even if treatment with bDMARDs is effective.

Progression of Post-Traumatic Osteoarthritis in rat meniscectomy models: Comprehensive monitoring using MRI

Knee injury often triggers post-traumatic osteoarthritis (PTOA) that affects articular cartilage (AC), subchondral bone, meniscus and the synovial membrane. The available treatments for PTOA are largely ineffective due to late diagnosis past the “treatment window”. This study aimed to develop a detailed understanding of the time line of the progression of PTOA in murine models through longitudinal observation of the femorotibial joint from the onset of the disease to the advanced stage. Quantitative magnetic resonance microimaging (µMRI) and histology were used to evaluate PTOA-associated changes in the knee joints of rats subjected to knee meniscectomy. Systematic longitudinal changes in the articular cartilage thickness, cartilage T2 and the T2 of epiphysis within medial condyles of the tibia were all found to be associated with the development of PTOA in the animals. The following pathogenesis cascade was found to precede advanced PTOA: meniscal injury → AC swelling → subchondral bone remodelling → proteoglycan depletion → free water influx → cartilage erosion. Importantly, the imaging protocol used was entirely MRI-based. This protocol is potentially suitable for whole-knee longitudinal, non-invasive assessment of the development of OA. The results of this work will inform the improvement of the imaging methods for early diagnosis of PTOA.

Decreased medial compartment loading and increased medial femorotibial articular cartilage thickness 12 months after limb realignment surgery

Purpose: High tibial osteotomy (HTO) is a limb realignment surgery for patients with medial compartment knee osteoarthritis (OA) and varus alignment. The surgery is proposed to improve aberrant knee joint loading and thereby alter disease progression. The purposes of the present study were to explore changes after HTO in: [1] MRI-based measures of articular cartilage thickness and [2] 3D gait analysis-based measures of medial-to-lateral knee load distribution (the external knee adduction moment (KAM) and angular impulse (KAAI)). Methods: Patients with clinical and radiographic evidence of medial compartment knee OA were recruited from an orthopaedic clinic specializing in HTO. Participants were included if they had varus malalignment, early to moderate disease severity (defined using Kellgren and Lawrence Grades 1–3) and knee pain localized to the medial compartment. All patients received an HTO plate and screws made of polyetheretherketone (PEEK) that does not create artifact on MRI. MR images were assessed preoperatively, 6 weeks postoperatively to determine any immediate changes due to surgery, then again at 12 months postoperatively to assess the effects of long-term altered loads. Gait analysis was performed preoperatively and 12 months postoperatively. MR images were acquired on a 3T scanner using sagittal double-echo steady state (DESS) imaging. The medial and lateral femorotibial cartilage compartments were segmented manually and the reader was blinded to disease severity (including masking all but the articular surfaces on the MRIs), alignment, and the order of image acquisition (baseline, 6 weeks and 12 months). The sums of the mean thickness in the medial tibia (MT) and central weight-bearing region of the medial femoral condyle (cMF), and the lateral tibia (LT) and central weight-bearing region of the lateral femoral condyle (cLF), were used to calculate the cartilage thickness in the medial (MFTC) and lateral femorotibial compartments (LFTC) respectively. 3D gait analysis was performed and the external knee moment in the frontal plane was calculated using inverse dynamics to represent medial-to-lateral knee load distribution. The mean changes with 95% confidence intervals (95%CI) were calculated for each follow-up time point, minus baseline. The number of individual patients achieving previously suggested smallest detectable changes (SDC) in medial articular cartilage thickness and peak knee adduction moments were also determined. Results: The demographic and clinical characteristics for eight participants are presented in Table 1. Changes in articular cartilage thickness at 6 weeks and 12 months after surgery are shown in Fig. 1. At 12 months, the KAM decreased 1.3%BWxHt (95%CI: −1.8 to −0.7) and had a moderate-to-high correlation (r = −0.64) with the observed increases in articular cartilage thickness. Similar results were found when the KAM was replaced with the KAAI (−0.7%BWxHts; 95%CI: −1.1 to −0.4; r = −0.76). At the 12-month follow-up, 75% of participants (6 of 8) had an increase in medial articular cartilage thickness greater than the smallest detectable change (SDC) threshold in MFTC (111 μm) previously reported for cartilage thickness loss. Similarly, 63% of participants (5 of 8) had a decrease in KAM greater than the previously reported SDC threshold (1%BWxHt). Conclusions: This is the first study to quantify increases in medial femorotibial articular cartilage thickness that are correlated to decreases in medial knee loading after limb realignment surgery.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Quantitative cartilage thickness change in radiographically normal knees with and without OA risk factors – data from the OAI

Purpose: Quantitative cartilage thickness change, as measured by MRI, has been intensively explored as an imaging biomarker of structural progression in knee OA, and its sensitivity has been reported for various radiographic baseline disease severity strata. However, whether significant femorotibial cartilage change occurs in knees without radiographic knee OA, and whether it differs between knees from persons with and without common risk factors for knee OA, is unknown. The purpose of this work hence was 1) To explore location-independent and region-specific measures of quantitative cartilage thickness change by MRI in knees without any evidence of radiographic knee OA in either knee; 2) To test the hypothesis that knees from persons with common risk factors for knee OA display significantly greater cartilage thinning (and thickening) than knees from persons without risk factors. Methods: In the Osteoarthritis Initiative, a longitudinal cohort study of knee OA, we assessed the right knees of participants without any signs of radiographic knee OA (bilaterally KLG0; centralized readings). Of 755 knees, 77 were from healthy reference OAI participants (no pain, no risk factors for knee OA, 60% female; age 55.4 ± 7.3 y; BMI 24.4 ± 3.2 kg/m2) and 678 from incident cohort participants (various levels of pain and risk factors of knee OA, 57% female; age 59.6 ± 8.8 y; BMI 26.7 ± 4.2 kg/m2). The femoro-tibial cartilages were segmented and subregional thickness change was computed from year 1 and 4 (Y1/Y4) follow-up MRI data, using the sagittal DESS sequence and Chondrometrics software. Thinning (and thickening) scores were computed by summarizing all negative (and positive) subregion changes in each participant (primary analysis). Subregions and ordered values (OV) of subregional change were included as exploratory outcomes. Changes were reported including 95% CIs; statistical comparisons between both groups were made using the unpaired Welch t-test and Cohen D. Results: In KLG0 knees with risk factors (risk cohort), the cartilage thinning score over 3 years exceed the thickening score by approx. 20% and was significantly greater than the thinning score in healthy reference cohort knees. (Fig. 1; Table 1: P = 0.002). Cartilage thickening scores, however, were similar between both Groups (Fig. 1). 9 (of 16) OVs suggested greater thinning in the “risk cohort” compared with the reference cohort (Table 1; Fig. 2), whereas only 2 subregions (cLT; icMF) suggested greater thinning, and 2 regions (iMT, ccMF) less thickening in “risk cohort” than in reference cohort knees (data not shown). Conclusions: Among individuals without radiographic evidence of OA in either knee, knees from persons at higher risk for OA experienced significantly greater cartilage thinning than those from persons without risk factors for knee OA, whilst the observed magnitude of cartilage thickening was similar between groups. Greater thinning in KLG0 knees with risk factors was most prominent in the (central) lateral compartment; yet, location-independent analysis was superior to region-specific analysis in elucidating these subtle between-group differences.Table 13-year cartilage thickness change in KLG0 knees without and with risk factors for knee OA[μm]Healthy kneesRisk kneesP-ValueEffect sizeMeanSD95% CIMeanSD95% CIT-TestCohen's DThinn. Score−634516(−673, −596)−501319(−573, −429)<0.01−0.27Thick. Score529366(501, 556)537308(467, 607)0.83−0.02OV 1−166121(−175, −157)−14291(−163, −122)0.04−0.20OV 2−11685(−122, −109)−9855(−110, −85)0.01−0.22OV 3−8869(−94, −83)−7548(−86, −64)0.03−0.20OV 1614380(137, 149)14474(127, 160)0.970.00 Open table in a new tab

3D meniscal position predicts knee replacement in fast progressing knee osteoarthritis

3D meniscal position predicts knee replacement in fast progressing knee osteoarthritis

Does radiographic status of the contralateral knee impact cartilage thickness change in radiographically normal knees – data from the osteoarthritis initiative

Does radiographic status of the contralateral knee impact cartilage thickness change in radiographically normal knees – data from the osteoarthritis initiative

Changes in the structural features of osteoarthritis in a year of weight loss

In patients undergoing bariatric surgery or medical management for obesity, we assessed whether those experiencing substantial weight loss had changes in innervated knee structures or in cartilage. Severely obese patients (body mass index (BMI) ≥35) with knee pain on most days were seen before bariatric surgery or medical weight management and at 1-year follow-up. Examinations included 3T MRI acquired at both time points for semi-quantitative scoring of bone marrow lesions (BML), synovitis, cartilage damage, and for quantitative measurement of cartilage thickness. Association of ≥20% vs <20% weight loss with change in semi-quantitative scores was evaluated using linear mixed-effects models, and that with cartilage thickness change used non-parametric and parametric methods. Sensitivity analyses tested different thresholds for weight loss, weight loss as a continuous measure, examined those with and without bariatric surgery, and with worse osteoarthritis (OA). 75 subjects (median age 49 years, 92% women) were included. At baseline, 61 subjects (81%) had Kellgren and Lawrence (KL) grade >0, and 16 (21%) had KL grade ≥3; 69 (92%) had cartilage damage. For BML, synovitis, and cartilage damage, the majority of knees had change in semi-quantitative scores of 0, and there was no difference between those with and without ≥20% weight loss. Similarly, in terms of cartilage thickness loss, in 14 of 16 sub-regions thickness loss was not associated with weight loss. Sensitivity analyses showed similar findings. In middle-aged persons with mostly mild radiographic OA, structural features changed little over a year and weight loss was not associated with effects on structural changes.