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Competitive runners compared with recreational runners have increased odds of osteoarthritis and running-related injury, potentially from different running types. We compared distal anterior femoral cartilage deformation in competitive runners following a continuous and high-intensity interval run (10 × 400 m, 300 m jog) and evaluated the association between running kinetics and cartilage deformation. Twenty-four competitive runners (11 females and 13 males), between 18 and 35 years old underwent femoral cartilage ultrasound imaging before and after both running conditions in a counterbalanced order 2–7 days apart. Footwear was instrumented with force-sensing insoles to extract peak ground reaction force, loading rate, and impulse. A 2 (time) by 2 (condition) ANOVA with repeated measures evaluated the change in cartilage thickness after running between conditions. The lateral cartilage region showed greater deformation after interval compared with continuous running (p = 0.003). A main effect of time was seen where cartilage was thinner after running compared with baseline regardless of condition (1.92 (1.82, 2.02) vs. 1.83 (1.73, 1.93) mm; mean difference = −0.094 (−0.147, −0.042) mm, p = 0.001). No significant associations were found between cartilage deformation and loading rate, peak ground reaction force, or impulse (all r < 0.32, all p > 0.05). Interval running contributed to greater lateral distal anterior femoral cartilage deformation. [ABSTRACT FROM AUTHOR]

Purpose: High body mass index (BMI) is a strong predictor of posttraumatic osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR). Altered gait mechanics are independently affected by BMI and ACLR, and influence OA risk. Yet, evidence directly assessing the impact of high BMI on gait or cartilage characteristics after ACLR are limited. Here, we evaluated if high BMI moderates associations between gait and trochlear cartilage structure in individuals with ACLR. Methods: Treadmill walking biomechanics were evaluated in 40 normal BMI and 24 high BMI participants with ACLR at self-selected speeds. Normalized and absolute peak and cumulative loads (i.e., impulse) were extracted for peak knee flexion and adduction moments (KFM, KAM) and vertical ground reaction force (GRF).Medial and lateral femoral cartilage thickness and medial/lateral thickness ratios were assessed via ultrasound. Results: Those with ACLR and high BMI walked with reduced normalized peak vertical GRFs, and greater absolute peak and cumulative loads compared with normal BMI individuals with ACLR. Those with ACLR and high BMI also exhibited thinner cartilage and greater medial/lateral ratios in ACLR limbs compared with contralateral limbs whereas norma lBMI individuals with ACLR exhibited thicker ACLR limb cartilage. Lastly, greater peak KAM and KAM cumulative load were associated with thicker lateral cartilage and lesser medial/lateral thickness ratios, but only in the high BMI group. Conclusions: We observed those with high BMI after ACLR exhibited trochlear cartilage structural alterations not observed in normal BMI patients, whereas differential associations between loading outcomes and cartilage thickness in ACLR knees were observed between groups. Those with high BMI after ACLR may require different therapeutic strategies to optimize joint health in this subset of patients. [ABSTRACT FROM AUTHOR]

Objective: We sought to measure the deformation of tibiofemoral cartilage immediately following a 3-mile treadmill run, as well as the recovery of cartilage thickness the following day. To enable these measurements, we developed and validated deep learning models to automate tibiofemoral cartilage and bone segmentation from double-echo steady-state magnetic resonance imaging (MRI) scans. Design: Eight asymptomatic male participants arrived at 7 a.m., rested supine for 45 ​min, underwent pre-exercise MRI, ran 3 miles on a treadmill, and finally underwent post-exercise MRI. To assess whether cartilage recovered to its baseline thickness, participants returned the following morning at 7 a.m., rested supine for 45 ​min, and underwent a final MRI session. These images were used to generate 3D models of the tibia, femur, and cartilage surfaces at each time point. Site-specific tibial and femoral cartilage thicknesses were measured from each 3D model. To aid in these measurements, deep learning segmentation models were developed. Results: All trained deep learning models demonstrated repeatability within 0.03 ​mm or approximately 1 ​% of cartilage thickness. The 3-mile run induced mean compressive strains of 5.4 ​% (95 ​% CI ​= ​4.1 to 6.7) and 2.3 ​% (95 ​% CI ​= ​0.6 to 4.0) for the tibial and femoral cartilage, respectively. Furthermore, both tibial and femoral cartilage thicknesses returned to within 1 ​% of baseline thickness the following day. Conclusions: The 3-mile treadmill run induced a significant decrease in both tibial and femoral cartilage thickness; however, this was largely ameliorated the following morning.

Purpose: The correlation of cartilage thickness measured by three‐dimensional (3D) magnetic resonance imaging (MRI) and the medial meniscal coverage ratio (MMCR), which presented pathology of the medial meniscus extrusion (MME) in 3D MRI, has not yet been elucidated. The study's purpose was to retrospectively verify whether the average cartilage thickness calculated by the automatic MRI 3D analysis system for each subregion was correlated with MMCR. Methods: A total of 60 patients underwent medial meniscus repair or high tibial osteotomy to treat their medial knee osteoarthritis. Cartilage thickness and MMCR were automatically calculated using 3D MRI software. The MMCR was defined as the ratio of the area covered by the meniscus within the medial tibial cartilage area to the total medial tibial cartilage area. The association between MMCR and the average cartilage thickness at 15 subregions in the medial femoral condyle (MFC) and medial tibial plateau (MTP) was evaluated using Spearman's rank correlation coefficient. Results: Kellgren–Lawrence grade exhibited a negative correlation with MMCR and a positive correlation with MME width. Cartilage thickness in the MTP had a moderately positive correlation with MMCR at four subregions and a weakly positive correlation at another subregion. Cartilage thickness in the MFC showed a moderately positive correlation with MMCR at five subregions and a weakly positive correlation at one subregion. Conclusions: Cartilage thickness calculated by automatic MRI 3D analysis system had a positive correlation with MMCR for all subregions of the anterior and middle subregions in the MFC and for five regions of nine subregions of the anterior and middle subregions in the MTP. Level of evidence: Level II, cross‐sectional study (diagnosis). [ABSTRACT FROM AUTHOR]

Osteochondral allograft (OCA) transplantation involves grafting of natural hyaline cartilage and supporting subchondral bone into the cartilage defect area to restore its biomechanical and tissue structure. However, differences in biomechanical properties and donor-host matching may impair the integration of articular cartilage (AC). This study analyzed the biomechanical properties of the AC in different regions of different sites of the knee joint and provided a novel approach to OCA transplantation. Intact stifle joints from skeletally mature pigs were collected from a local abattoir less than 8 h after slaughter. OCAs were collected from different regions of the joints. The patella and the tibial plateau were divided into medial and lateral regions, while the trochlea and femoral condyle were divided into six regions. The OCAs were analyzed and compared for Young's modulus, the compressive modulus, and cartilage thickness. Young's modulus, cartilage thickness, and compressive modulus of OCA were significantly different in different regions of the joints. A negative correlation was observed between Young's modulus and the proportion of the subchondral bone (r = − 0.4241, P < 0.0001). Cartilage thickness was positively correlated with Young's modulus (r = 0.4473, P < 0.0001) and the compressive modulus (r = 0.3678, P < 0.0001). During OCA transplantation, OCAs should be transplanted in the same regions, or at the closest possible regions to maintain consistency of the biomechanical properties and cartilage thickness of the donor and recipient, to ensure smooth integration with the surrounding tissue. A 7 mm depth achieved a higher Young's modulus, and may represent the ideal length. [ABSTRACT FROM AUTHOR]

Objective: To investigate the relationship between measures of radiographic joint space width (JSW) loss and magnetic resonance imaging (MRI)-based cartilage thickness loss in the medial weight-bearing region of the tibiofemoral joint over 12–24 months. To stratify this relationship by clinically meaningful subgroups (sex and pain status). Design: We analyzed a subset of knees (n ​= ​256) from the Osteoarthritis Initiative (OAI) likely in early stage OA based on joint space narrowing (JSN) measurements. Natural logarithm transformation was used to approximate near normal distributions for JSW loss. Pearson Correlation coefficients described the relationship between ln-transformed JSW loss and several versions of deep learning-derived MRI-based cartilage thickness loss parameters (minimum, maximum, and mean) in subregions of the femoral condyle, tibial plateau, and combined femoral and tibial regions. Linear mixed-effects models evaluated the associations between the ln-transformed radiographic and MRI-derived measures including potential confounders. Results: We found weak correlations between ln-transformed JSW loss and MRI-based cartilage thickness ranging from R ​= ​−0.13 (p ​= ​0.20) to R ​= ​0.26 (p ​

A 24-year-old male patient complained of mild knee pain after jogging. The subsequent knee MRI demonstrated bilateral lateral thickened tibiofemoral cartilages, evidenced by deformities of the bilateral subchondral bone beneath the lateral femoral condyle cartilage. The corresponding dislocations of almost all the left lateral meniscus and part of the right lateral meniscus to the center of the joint were detected. After excluding diagnoses of congenital ring-shaped meniscus, bucket handle tear of the C-shaped lateral meniscus, and central tear of the discoid meniscus, the displacement of all or part of the lateral meniscus into the intercondylar notch was considered a consequence of congenital thickening of the lateral superior and inferior cartilage. This case may report a new variant of knee joint pathology.

Abstract Purpose The correlation of cartilage thickness measured by three‐dimensional (3D) magnetic resonance imaging (MRI) and the medial meniscal coverage ratio (MMCR), which presented pathology of the medial meniscus extrusion (MME) in 3D MRI, has not yet been elucidated. The study's purpose was to retrospectively verify whether the average cartilage thickness calculated by the automatic MRI 3D analysis system for each subregion was correlated with MMCR. Methods A total of 60 patients underwent medial meniscus repair or high tibial osteotomy to treat their medial knee osteoarthritis. Cartilage thickness and MMCR were automatically calculated using 3D MRI software. The MMCR was defined as the ratio of the area covered by the meniscus within the medial tibial cartilage area to the total medial tibial cartilage area. The association between MMCR and the average cartilage thickness at 15 subregions in the medial femoral condyle (MFC) and medial tibial plateau (MTP) was evaluated using Spearman's rank correlation coefficient. Results Kellgren–Lawrence grade exhibited a negative correlation with MMCR and a positive correlation with MME width. Cartilage thickness in the MTP had a moderately positive correlation with MMCR at four subregions and a weakly positive correlation at another subregion. Cartilage thickness in the MFC showed a moderately positive correlation with MMCR at five subregions and a weakly positive correlation at one subregion. Conclusions Cartilage thickness calculated by automatic MRI 3D analysis system had a positive correlation with MMCR for all subregions of the anterior and middle subregions in the MFC and for five regions of nine subregions of the anterior and middle subregions in the MTP. Level of evidence Level II, cross‐sectional study (diagnosis).

Cartilage thickness change is a well‐documented biomarker of osteoarthritis pathogenesis. However, there is still much to learn about the spatial and temporal patterns of cartilage thickness change in health and disease. In this study, we develop a novel analysis method for elucidating such patterns using a functional connectivity approach. Descriptive statistics are reported for 1186 knees that did not develop osteoarthritis during the 8 years of observation, which we present as a model of cartilage thickness change related to healthy aging. Within the control population, patterns vary greatly between male and female subjects, while body mass index (BMI) has a more moderate impact. Finally, several differences are shown between knees that did and did not develop osteoarthritis. Some but not all significance appears to be accounted for by differences in sex, BMI, and knee alignment. With this work, we present the connectome as a novel tool for studying spatiotemporal dynamics of tissue change. [ABSTRACT FROM AUTHOR]

BackgroundKnee cartilage is the most crucial structure in the knee, and the reduction of cartilage thickness is a significant factor in the occurrence and development of osteoarthritis. Measuring cartilage thickness allows for a more accurate assessment of cartilage wear, but this process is relatively time-consuming. Our objectives encompass using various DL methods to segment knee cartilage from MRIs taken with different equipment and parameters, building a DL-based model for measuring and grading knee cartilage, and establishing a standardized database of knee cartilage thickness.MethodsIn this retrospective study, we selected a mixed knee MRI dataset consisting of 700 cases from four datasets with varying cartilage thickness. We employed four convolutional neural networks—UNet, UNet++, ResUNet, and TransUNet—to train and segment the mixed dataset, leveraging an extensive array of labeled data for effective supervised learning. Subsequently, we measured and graded the thickness of knee cartilage in 12 regions. Finally, a standard knee cartilage thickness dataset was established using 291 cases with ages ranging from 20 to 45 years and a Kellgren–Lawrence grading of 0.ResultsThe validation results of network segmentation showed that TransUNet performed the best in the mixed dataset, with an overall dice similarity coefficient of 0.813 and an Intersection over Union of 0.692. The model’s mean absolute percentage error for automatic measurement and grading after segmentation was 0.831. The experiment also yielded standard knee cartilage thickness, with an average thickness of 1.98 mm for the femoral cartilage and 2.14 mm for the tibial cartilage.ConclusionBy selecting the best knee cartilage segmentation network, we built a model with a stronger generalization ability to automatically segment, measure, and grade cartilage thickness. This model can assist surgeons in more accurately and efficiently diagnosing changes in patients’ cartilage thickness.

To assess (i) the impact of changes in body weight on changes in joint-adjacent subcutaneous fat (SCF) and cartilage thickness over 4 years and (ii) the relation between changes in joint-adjacent SCF and knee cartilage thickness. Individuals from the Osteoarthritis Initiative (total=399) with > 10% weight gain (n=100) and > 10% weight loss (n=100) over 4 years were compared to a matched control cohort with less than 3% change in weight (n=199). 3.0T Magnetic Resonance Imaging (MRI) of the right knee was performed at baseline and after 4 years to quantify joint-adjacent SCF and cartilage thickness. Linear regression models were used to evaluate the associations between the (i) weight change group and 4-year changes in both knee SCF and cartilage thickness, and (ii) 4-year changes in knee SCF and in cartilage thickness. Analyses were adjusted for age, sex, baseline body mass index (BMI), tibial diameter (and weight change group in analysis (ii)). Individuals who lost weight over 4-years had significantly less joint-adjacent SCF (beta range, medial/lateral joint sides: 2.2–4.2 mm, p < 0.001) than controls; individuals who gained weight had significantly greater joint-adjacent SCF than controls (beta range: −1.4 to −3.9 mm, p < 0.001). No statistically significant associations were found between weight change and cartilage thickness change. However, increases in joint-adjacent SCF over 4 years were significantly associated with decreases in cartilage thickness (p = 0.04). Weight change was associated with joint-adjacent SCF, but not with change in cartilage thickness. However, 4-year increases in joint-adjacent SCF were associated with decreases in cartilage thickness independent of baseline BMI and weight change group. [ABSTRACT FROM AUTHOR]

Purpose: Develop a spectroscopic method to assess cartilage thickness during the arthroscopic examination. Methods: Currently, arthroscopy assesses cartilage damage visually; outcomes are based on the surgeon's subjective experience. Light reflection spectroscopy is a promising method for measuring cartilage thickness based on the absorption of light by the subchondral bone. In the presented study, in vivo diffuse optical back reflection spectroscopic measurements were acquired by gently placing an optical fibre probe on different locations of the articular cartilage of 50 patients during complete knee replacement surgery. The optical fibre probe consists of two optical fibers with a diameter of 1 mm to deliver the light and detect back-reflected light from the cartilage. Centre to centre distance between the source and the detector fibers was 2.4 mm. Actual thicknesses of the articular cartilage samples were measured under microscopy using histopathological staining. Results: Using half of the samples in the patient data, a linear regression model was formed to estimate cartilage thicknesses from the spectroscopic measurements. The regression model was then used to predict the cartilage thickness in the second half of the data. The cartilage thickness was predicted with a mean error of 8.7% if the actual thickness was less than 2.5 mm (R2 = 0.97). Conclusion: The outer diameter of the optical fibre probe was 3 mm, which can fit into the arthroscopy channel and can be used to measure the cartilage thickness in real-time during the arthroscopic examination of the articular cartilage. [ABSTRACT FROM AUTHOR]

The aim was to evaluate the effect, if any, of asymptomatic hyperuricemia on distal femoral cartilage thickness through musculoskeletal ultrasonography. A total of 66 participants were evaluated in this prospective, controlled study, including 33 asymptomatic hyperuricemic patients who presented at our outpatient clinic between January and April 2020, and 33 normouricemic subjects matched for age, gender and body mass index. Participants with systemic diseases affecting uric acid level such as chronic renal failure, psoriasis, gout, etc., participants using drugs that can affect uric acid level, and those with knee complaints were excluded from the study. Cartilage thickness measurements were taken using musculoskeletal ultrasonography from the right medial condyle, right lateral condyle, right intercondylar area, left medial condyle, left lateral condyle and left intercondylar area. Distal femoral cartilage thickness was lower in all measurement areas in the asymptomatic hyperuricemia group than in the normouricemic group (p0.05 all). We think that distal femoral cartilages seem to be thinner in participants with asymptomatic hyperuricemia. Longitudinal studies are needed to determine whether asymptomatic hyperuricemia will lead to knee osteoarthritis in individuals, although we believe that people with asymptomatic hyperuricemia should be informed accordingly in order to prevent development of potential knee osteoarthritis.

Objective: Longitudinal weight-bearing radiographic joint space width (JSW) and non-weight-bearing MRI-based cartilage thickness changes often show weak correlations. The current objective was to investigate these correlations, and to explore the influence of different factors that could contribute to longitudinal differences between the two methods. Methods: The current study included 178 participants with medial osteoarthritis (OA) out of the 297 knee OA participants enrolled in the IMI-APPROACH cohort. Changes over 2 years in medial JSW (ΔJSWmed), minimum JSW (ΔJSWmin), and medial femorotibial cartilage thickness (ΔMFTC) were assessed using linear regression, using measurements from radiographs and MRI acquired at baseline, 6 months, and 1 and 2 years. Pearson R correlations were calculated. The influence of cartilage quality (T2 mapping), meniscal extrusion (MOAKS scoring), potential pain-induced unloading (difference in knee-specific pain scores), and increased loading (BMI) on the correlations was analyzed by dividing participants in groups based on each factor separately, and comparing correlations (slope and strength) between groups using linear regression models. Result: Correlations between ΔMFTC and ΔJSWmed and ΔJSWmin were statistically significant (p < 0.004) but weak (R < 0.35). Correlations were significantly different between groups based on cartilage quality and on meniscal extrusion: only patients with the lowest T2 values and with meniscal extrusion showed significant moderate correlations. Pain-induced unloading or BMI-induced loading did not influence correlations. Conclusions: While the amount of loading does not seem to make a difference, weight-bearing radiographic JSW changes are a better reflection of non-weight-bearing MRI cartilage thickness changes in knees with higher quality cartilage and with meniscal extrusion. [ABSTRACT FROM AUTHOR]

This study aimed to assess the preliminary outcomes of kinematically aligned robot-assisted total knee arthroplasty (TKA) with patient-specific cartilage thickness measurement. Patients who underwent kinematically aligned robot-assisted TKA were included in this study. Robot-assisted total knee arthroplasties were performed by NAVIO Surgical System (Smith & Nephew, Memphis, USA), an image-free handheld robotic system. The kinematic alignment technique was performed according to our intraoperative cartilage thickness measurement technique. Hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), joint-line orientation angle (JLOA), and joint-line convergence angle (JLCA) were measured through standing full-length anteroposterior radiographs. Knee Injury and Osteoarthritis Outcome Score, Oxford score, VAS pain and satisfaction score, and Forgotten Joint Score were used to assess clinical outcomes. A total of 142 knees of 109 patients (92 females and 17 males) were evaluated in this study. There was a significant correction in HKA, JLCA, and mMPTA postoperatively (p ≤0.001, < 0.001, and 0.029, respectively). We observed no significant change in mLDFA and JLOA measurements. All clinical scores significantly increased at the latest follow-up. Our results demonstrated that kinematically aligned robot-assisted TKA with patient-specific cartilage thickness measurement demonstrated no significant change in mLDFA and JLOA, as expected; however, significantly corrected the deformity in HKA, mMPTA, and JLCA measurements. [ABSTRACT FROM AUTHOR]

Objective: Therapy for osteoarthritis ideally aims at preserving structure before radiographic change occurs. This study tests: a) whether longitudinal deterioration in cartilage thickness and composition (transverse relaxation-time T2) are greater in radiographically normal knees “at risk” of incident osteoarthritis than in those without risk factors; and b) which risk factors may be associated with these deteriorations. Design: 755 knees from the Osteoarthritis Initiative were studied; all were bilaterally Kellgren Lawrence grade [KLG] 0 initially, and had magnetic resonance images available at 12- and 48-month follow-up. 678 knees were “at risk”, whereas 77 were not (i.e., non-exposed reference). Cartilage thickness and composition change was determined in 16 femorotibial subregions, with deep and superficial T2 being analyzed in a subset (n ​= ​59/52). Subregion values were used to compute location-independent change scores. Results: In KLG0 knees “at risk”, the femorotibial cartilage thinning score (−634 ​± ​516 ​μm) over 3 years exceeded the thickening score by approximately 20%, and was 27% greater (p ​

Objective: To employ novel methodologies to identify phenotypes in knee OA based on variation among three baseline data blocks: 1) femoral cartilage thickness, 2) tibial cartilage thickness, and 3) participant characteristics and clinical features. Methods: Baseline data were from 3321 Osteoarthritis Initiative (OAI) participants with available cartilage thickness maps (6265 knees) and 77 clinical features. Cartilage maps were obtained from 3D DESS MR images using a deep-learning based segmentation approach and an atlas-based analysis developed by our group. Angle-based Joint and Individual Variation Explained (AJIVE) was used to capture and quantify variation, both shared among multiple data blocks and individual to each block, and to determine statistical significance. Results: Three major modes of variation were shared across the three data blocks. Mode 1 reflected overall thicker cartilage among men, those with higher education, and greater knee forces; Mode 2 showed associations between worsening Kellgren-Lawrence Grade, medial cartilage thinning, and worsening symptoms; and Mode 3 contrasted lateral and medial-predominant cartilage loss associated with BMI and malalignment. Each data block also demonstrated individual, independent modes of variation consistent with the known discordance between symptoms and structure in knee OA and reflecting the importance of features such as physical function, symptoms, and comorbid conditions independent of structural damage. Conclusions: This exploratory analysis, combining the rich OAI dataset with novel methods for determining and visualizing cartilage thickness, reinforces known associations in knee OA while providing insights into the potential for data integration in knee OA phenotyping.

Purpose: Kinematically aligned total knee arthroplasty (KA TKA), as a pure resurfacing procedure, is based on matching implant thickness with bone cut and kerf thickness, plus cartilage wear. However, the assumption of a consistent 2 mm femoral cartilage thickness remains unproven. This study aimed to systematically review the available literature concerning magnetic resonance imaging (MRI) assessment of femoral cartilage thickness in non-arthritic patients. Our hypothesis was that cartilage thickness values would vary significantly among individuals, thereby challenging the established KA paradigm of 'one-cartilage-fits-all'., Methods: Systematic literature searches (Pubmed, Scopus and Cochrane Library) followed PRISMA guidelines. English-language studies assessing distal and posterior femoral cartilage thickness using MRI in non-arthritic adults were included. Studies lacking numerical cartilage thickness data, involving post-operative MRI, considering total femoro-tibial cartilage thickness, or failing to specify the compartment of the knee being studied were excluded., Results: Overall, 27 studies comprising 8170 MRIs were analysed. Weighted mean femoral cartilage thicknesses were: 2.05 ± 0.62 mm (mean range 1.06-2.6) for the distal medial condyle, 1.95 ± 0.4 mm (mean range 1.15-2.5) for the distal lateral condyle, 2.44 ± 0.5 mm (mean range 1.37-2.6) for the posterior medial condyle and 2.27 ± 0.38 mm (mean range 1.48-2.5) for the posterior lateral condyle., Discussion: Femoral cartilage thickness varies significantly across patients. In KA TKA, relying on a fixed thickness of 2 mm may jeopardize the accurate restoration of individual anatomy, leading to errors in implant coronal and rotational alignment. An intraoperative assessment of cartilage thickness may be advisable to express the KA philosophy at its full potential., Level of Evidence: Level IV., (© 2024 European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Objective: Ex vivo nanoindentation measurement has reported that elastic modulus decreases as cartilage degenerates, but no method has been established to macroscopically evaluate mechanical properties in vivo. The objective of this study was to evaluate the elastic modulus of knee joint cartilage based on macroscopic methods and to compare it with gross and histological findings of degeneration., Design: Osteochondral sections were taken from 50 knees with osteoarthritis (average age, 75 years) undergoing total knee arthroplasty. The elastic modulus of the cartilage was measured with a specialized elasticity tester. Gross findings were recorded as International Cartilage Repair Society (ICRS) grade. Histological findings were graded as Mankin score and microscopic cartilage thickness measurement., Results: In ICRS grades 0 to 2 knees with normal to moderate cartilage abnormalities, the elastic modulus of cartilage decreased significantly as cartilage degeneration progressed. The elastic modulus of cartilage was 12.2 ± 3.8 N/mm for ICRS grade 0, 6.3 ± 2.6 N/mm for ICRS grade 1, and 3.8 ± 2.4 N/mm for ICRS grade 2. Similarly, elastic modulus was correlated with Mankin score ( r = -0.51, P < 0.001). Multiple regression analyses showed that increased Mankin score is the most relevant factor associated with decreased elastic modulus of the cartilage ( t -value, -4.53; P < 0.001), followed by increased histological thickness of the cartilage ( t -value, -3.15; P = 0.002)., Conclusions: Mechanical properties of damaged knee cartilage assessed with new macroscopic methods are strongly correlated with histological findings. The method has potential to become a nondestructive diagnostic modality for early cartilage damage in the clinical setting., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: The production of the indentation probe used in this study was supported by Tech-Gihan (Kyoto, Japan).

Purpose: The purpose of this study was to evaluate the changes in joint space width (JSW) over time after medial opening-wedge high tibial osteotomy (MOWHTO) and identify risk factors for deterioration of JSW using anteroposterior (AP) and Rosenberg views. Methods: We retrospectively analyzed changes in JSW of 104 MOWHTO patients whose preoperative osteoarthritis (OA) grade was K-L grade 3 or less on AP and Rosenberg views. Serial changes in JSW were assessed from preoperatively to at least 3 years postoperatively. Patients were divided into two groups according to JSW change patterns on each of AP and Rosenberg views: non-deterioration group had either unchanged or increased JSW, and deterioration group had decreased JSW. Clinical outcomes were compared using Western Ontario and McMaster Universities OA Index (WOMAC) score between groups. Multivariate logistic regression analysis was performed to identify risk factors for deterioration of JSW. Results: JSW on average for all patients increased 0.5 mm and 0.8 mm on AP and Rosenberg views, respectively (p < 0.05). Non-deterioration group showed significant improvement based on patient-reported outcomes (WOMAC) than deterioration group (all p < 0.05). Undercorrection was an independent risk factor for failure to achieve maintained or increased JSW on both AP (OR 6.885, 95% CI 1.976–23.986, p = 0.002) and Rosenberg (OR 12.756, 95% CI 2.952–55.129, p = 0.001) views. Conclusion: JSW increased gradually and continuously on standing AP and Rosenberg views until postoperative 3 years after MOWHTO. Deterioration of JSW following MOWHTO was closely related to the undercorrection and affected clinical outcomes. Level of evidence: Level III, case control study. [ABSTRACT FROM AUTHOR]

Objective To explore morphological characteristics of patellofemoral joint surface of patients with patellar instability by adopting the MRI‐based method. Methods A retrospective analysis was performed from March 2016 to January 2020 to assess morphological characteristics of the patellofemoral joint surface by Magnetic Resonance Imaging (MRI) scanning knees of 30 patients (24 females, six males) with patellar instability and trochlear dysplasia and knees of 30 subjects from a randomly selected control group (25 females, five males). The control group was matched as per age and sex. All participants had undergone MRI scans in the supine position and keep knees in or near full extension. Six parts were measured in total, including thickness of trochlear cartilage, thickness of patella cartilage, cartilaginous sulcus angle, cartilaginous Wiberg angle, contact range and frequency and distributions of the mean difference measurement of the femoral trochlea, to evaluate the difference of trochlear and patellar morphology between the patient group and the control group. The threshold for statistical significance was set at P

We combined mobile biplane X‐ray imaging and magnetic resonance imaging to measure the regions of articular cartilage contact and cartilage thickness at the tibiofemoral and patellofemoral joints during six functional activities: standing, level walking, downhill walking, stair ascent, stair descent, and open‐chain (non‐weight‐bearing) knee flexion. The contact centers traced similar paths on the medial and lateral femoral condyles, femoral trochlea, and patellar facet in all activities while their locations on the tibial plateau were more varied. The translations of the contact centers on the femur and patella were tightly coupled to the tibiofemoral flexion angle in all activities (r2 > 0.95) whereas those on the tibia were only moderately related to the flexion angle (r2 > 0.62). The regions of contacting cartilage were significantly thicker than the regions of non‐contacting cartilage on the patella, femoral trochlea, and the medial and lateral tibial plateaus in all activities (p < 0.001). There were no significant differences in thickness between contacting and non‐contacting cartilage on the medial and lateral femoral condyles in all activities, except open‐chain knee flexion. Our results provide partial support for the proposition that cartilage thickness is adapted to joint load and do not exclude the possibility that other factors, such as joint congruence, also play a role in regulating the structure and organization of healthy cartilage. The data obtained in this study may serve as a guide when evaluating articular contact motion in osteoarthritic and reconstructed knees. [ABSTRACT FROM AUTHOR]

The relationship between knee moments and markers of knee osteoarthritis progression has not been examined in different knee osteoarthritis subtypes. The objective was to examine relationships between external knee moments during gait and tibiofemoral cartilage thickness in patients with nontraumatic and posttraumatic knee osteoarthritis. For this cross‐sectional study, participants with knee osteoarthritis were classified into two groups: nontraumatic (n = 22; mean age 60 years) and posttraumatic (n = 19; mean age 56 years, history of anterior cruciate ligament rupture). Gait data were collected with a three‐dimensional motion capture system sampled at 100 Hz and force plates sampled at 2000 Hz. External knee moments were calculated using inverse dynamics. Cartilage thickness was determined with magnetic resonance imaging (T1‐weighted, 3D sagittal gradient‐echo sequence). Linear regression analyses examined relationships between cartilage thickness with knee moments, group, and their interaction. A higher knee adduction moment impulse was negatively associated with medial to lateral cartilage thickness ratio (B = −1.97). This relationship differed between participants in the nontraumatic osteoarthritis group (r = −0.56) and posttraumatic osteoarthritis group (r = −0.30). A higher late stance knee extension moment was associated with greater medial femoral condyle cartilage thickness (B = −0.86) and medial to lateral cartilage thickness (B = −0.73). These relationships also differed between participants in the nontraumatic osteoarthritis group (r = −0.61 and r = −0.51, respectively) and posttraumatic osteoarthritis group (r = 0.10 and r = 0.25, respectively). Clinical Significance: The relationship between knee moments with tibiofemoral cartilage thickness differs between patients with nontraumatic and posttraumatic knee osteoarthritis. The potential influence of mechanical knee loading on articular cartilage may also differ between these subtypes. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to assess quantitatively articular cartilage volume, thickness, and T2 value alterations in meniscus tear patients. Materials and methods: The study included 32 patients with meniscus tears (17 females, 15 males; mean age: 40.16 ± 11.85 years) and 24 healthy controls (12 females; 12 males; mean age: 36 ± 9.14 years). All subjects were examined by 3 T magnetic resonance imaging (MRI) with 3D dual-echo steady-state (DESS) and T2 mapping images. All patients underwent diagnostic arthroscopy and treatment. Cartilage thickness, cartilage volume and T2 values of 21 subregions of knee cartilage were measured using the prototype KneeCaP software (version 2.1; Siemens Healthcare, Erlangen, Germany). Mann-Whitney-U tests were utilized to determine if there were any significant differences among subregional articular cartilage volume, thickness and T2 value between patients with meniscus tear and the control group. Results: The articular cartilage T2 values in all subregions of the femur and tibia in the meniscus tear group were significantly higher (p< 0.05) than in the healthy control group. The cartilage thickness of the femoral condyle medial, femur trochlea, femur condyle lateral central, tibia plateau medial anterior and patella facet medial inferior in the meniscus tear group were slightly higher than in the control group (p< 0.05). In the femur trochlea medial, patella facet medial inferior, tibia plateau lateral posterior and tibia plateau lateral central, there were significant differences in relative cartilage volume percentage between the meniscus tear group and the healthy control group (p< 0.05). Nineteen patients had no cartilage abnormalities (Grade 0) in the meniscus tear group, as confirmed by arthroscopic surgery, and their T2 values in most subregions were significantly higher (p< 0.05) than those of the healthy control group. Conclusion: The difference in articular cartilage indexes between patients with meniscus tears and healthy people without such tears can be detected by using quantitative MRI. Quantitative T2 values enable early and sensitive detection of early cartilage lesions. [ABSTRACT FROM AUTHOR]

Abstract Background Among school-age children, the decrease of cartilage thickness (Cth) with increasing age is well known. However, the influence of body mass index (BMI), height or weight on Cth has not been revealed. Here in, we aim to establish an age- and gender-specific Cth standard reference among Asians and investigate the possible prestige of BMI, height and weight. Methods A cross-sectional study was performed in healthy Asian children. Bilateral knees, ankles, wrists, second metacarpophalangeals (MCPs) and proximal interphalangeals (PIPs) were measured using ultrasound. The children’s height, weight and BMI were also recorded for later adjustment. Results A total of 200 school age Asian children (including 86 girls and 114 boys, aged between 5 to 13 years-old) were investigated. Cth differences were observed in the knees, ankles, wrists, MCPs and PIPs between sexes (p

Background: The aim of this study was to evaluate lower extremity cartilage thickness in axial spondyloarthritis (SpA) patients and healthy controls using ultrasound (US) and to determine the relationship between the indices, quality of life, enthesopathy, and cartilage thickness of patients with axial SpA. Materials and Methods: This study included 73 axial SpA patients and 30 healthy controls. The patients with axial SpA were divided into two groups as with and without heel enthesitis. Demographic data, disease duration, and medical treatments of patients were recorded. The cartilage (hip, talar, and knee), plantar fascia, and Achilles tendon thicknesses of both healthy controls and axial SpA patients were measured by US. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Functional Index (BASFI), patient global assessment (PGA), and Ankylosing Spondylitis Quality of Life (ASQoL) scores of patients were evaluated. Results: There was no difference between the groups in terms of demographic data and body mass index. The axial SpA groups with and without heel enthesitis were similar in terms of medical treatment and disease duration. The axial SpA patients with heel enthesitis had thinner cartilages than those without heel enthesitis (P < 0.05). The axial SpA patients without heel enthesitis had thinner cartilage thicknesses than the healthy control group (P < 0.05). There were statistically significant differences between the two groups in terms of the BASDAI, BASFI, BASMI, and ASQoL scores. These indices were negatively correlated with cartilage thickness (P < 0.05; r: −0.420). Conclusion: Lower extremity cartilage thickness is associated with disease activity, quality of life, and spinal mobility in patients with axial SpA.

Biomechanical factors (e.g., joint loading) have a significant role in the progression of osteoarthritis (OA). However, some relationships between in vivo joint loading indices and tibial cartilage thickness are conflicting. This study investigated relationships between pre‐operative in vivo external knee joint moments, joint alignment and regional tibial cartilage thickness using micro‐CT in subjects with end‐stage knee OA. Tibial plateaus from 25 patients that underwent knee replacement for OA were micro‐CT scanned (17 µm/voxel). Prior to surgery, subjects underwent gait analysis to calculate external knee moments. The mechanical axis deviation (MAD) was obtained from pre‐operative radiographs. Cartilage thickness (Cart.Th) was analyzed from micro‐CT images, in anteromedial, anterolateral, posteromedial and posterolateral subregions of interest. Medial‐to‐lateral Cart.Th ratios were also explored. Relationships between Cart.Th and joint loading indices were examined using Pearson's correlations. Significant correlations were found between Cart.Th and joint loading indices, positive anteromedially with the first peak knee adduction moment (r = 0.55, p < 0.01) and external rotation moment (ERM; r = 0.52, p < 0.01), and negative with MAD (r = −0.76, p < 0.001). In the lateral regions, these correlations had opposite signs. The medial‐to‐lateral Cart.Th ratio correlated strongly with ERM (r = 0.63, p = 0.001) and MAD (r = −0.75, p < 0.001). Joint loading indices correlated with regional cartilage thickness values and their medial‐to‐lateral ratios in end‐stage knee OA subjects, with higher regional loads corresponding to thinner cartilage. These relationships have the opposite sign compared to the subchondral bone microarchitecture found in our previous study on the same specimens, which may suggest a complementary bone–cartilage interplay in response to loading. [ABSTRACT FROM AUTHOR]

To develop a semi‐automatic framework for quantitative analysis of biochemical properties and thickness of femur cartilage using magnetic resonance (MR) images and evaluate its potential for femur cartilage classification into asymptomatic (AS), early osteoarthritis (OA), and advanced OA groups. In this study, knee joint MRI data (fat suppressed‐proton density‐weighted and multi‐echo T2‐weighted images) of eight AS‐volunteers (data acquired twice) and 34 OA patients including 20 early OA (16 Grade‐I and 4 Grade‐II), 14 advanced‐OA (Grade‐III) were acquired at 3.0T MR scanner. Modified Outerbridge classification criteria was performed for the clinical evaluation of data by an experienced radiologist. Cartilage segmentation, T2‐mapping, 2D‐WearMap generation, and subregion analysis were performed semi‐automatically using in‐house developed algorithms. The intraclass correlation coefficient (ICC) and coefficient of variation (CV) were computed for testing the reproducibility of T2 values. One‐way analysis of variance with Tukey–Kramer post hoc test was performed for evaluating the differences among the groups. The performance of individual T2 and thickness, as well as their combination using logistic regression, were evaluated with receiver operating characteristics (ROC) curve analysis. The interscan agreement based on the ICC index was 0.95 and the CV was 2.45 ± 1.33%. T2 mean of values greater than 75th percentile showed sensitivity and specificity of 94.1% and 81.3% (AUC = 0.93, cut‐off value = 47.9 ms) in differentiating AS volunteers versus OA group, while sensitivity and specificity of 90.0% and 81.3% (AUC = 0.90, cut‐off value = 47.9 ms) in differentiating AS volunteers versus early OA groups, respectively. In the differentiation of early OA versus advanced‐OA group, ROC results of combination (T2 and thickness) showed the highest sensitivity and specificity of 85.7%, and 70.0% (AUC = 0.79, cut‐off value = 0.39) compared with individual T2 and thickness features, respectively. A computer‐aided quantitative evaluation of femur cartilage degeneration showed promising results and can be used to assist clinicians in diagnosing OA. [ABSTRACT FROM AUTHOR]

Objectives Knee joint distraction (KJD) has been shown to result in long-term clinical improvement and short-term cartilage restoration in young OA patients. The objective of the current study was to evaluate MRI cartilage thickness up to 10 years after KJD treatment, using a 3D surface-based approach. Methods Twenty end-stage knee OA patients were treated with KJD. MRI scans (1.5 T) were performed before and at 1, 2, 5, 7, and 10 years after treatment. Tibia and femur cartilage segmentation and registration to a canonical surface were performed semi-automatically. Statistical parametric mapping with linear mixed models was used to analyse whole-joint changes. The influence of baseline patient characteristics was analysed with statistical parametric mapping using linear regression. Relevant weight-bearing parts of the femur were selected to obtain the average cartilage thickness in the femur and tibia of the most- (MAC) and least-affected compartment. These compartmental changes over time were analysed using repeated measures ANOVA; missing data was imputed. In all cases, P <0.05 was considered statistically significant. Results One and 2 years post-treatment, cartilage in the MAC weight-bearing region was significantly thicker than pre-treatment, gradually thinning after 5 years, but still increased at 10 years post-treatment. Long-term results showed that areas in the least-affected compartment were significantly thicker than pre-treatment. Male sex and more severe OA at baseline somewhat predicted shorter-term benefit (P >0.05). Compartmental analyses showed significant short- and long-term thickness increase in the tibia and femur MAC (all P <0.05). Conclusion KJD results in significant short- and long-term cartilage regeneration, up to 10 years post-treatment. Trial registration Netherlands Trial Register, https://www.trialregister.nl , NL419. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Subclinical inflammation is still a controversial issue in inflammatory diseases. There is no reliable, easy, and cheap inflammation marker in daily clinical practices currently. This study aims to predict clinical remission using cartilage and tendon thicknesses. METHODS: Eleven patients with Familial Mediterranean Fever (FMF) who had musculoskeletal involvement before and 11 patients with Enthesitis-Related Arthritis (ERA) were included in this study. They were on remission with clinical and laboratory evaluations for at least three months. Demographic and clinical features of the subjects, including age, sex, body mass index, disease duration, age at onset, medical treatment, and laboratory evaluations, were all noted. Healthy children of the same age were included as the control group. The thicknesses of the bilateral knee, second metacarpophalangeal and ankle joints cartilages, quadriceps, superior and inferior patellar, and the Achilles tendons were measured with a linear probe. A total of 198 joint and 264 tendon thicknesses were measured. RESULTS: The thicknesses of metacarpophalangeal, knee, and ankle cartilages were higher in the FMF group than in the others. In the FMF group, the quadriceps tendon thickness was higher than in the ERA group, and the superior patellar tendon thickness was higher than in the control group (p

Abstract Purpose Surgical techniques for total knee arthroplasty (TKA) require femoral rotational corrections that alter the position of the surface of the posterior femoral joint especially in kinematic alignment. However, preoperative planning of TKA based on computed tomography (CT), without knowing the femoral cartilage thickness, may cause post-surgery failures in femoral rotation. Therefore, this study aimed to evaluate the effects of posterior condyle cartilage thickness on rotational alignment in the femoral component. Methods Three-dimensional magnetic resonance imaging (MRI) scans were obtained for 139 male and 531 female osteoarthritis patients. The angles defined by the femoral posterior condylar axis (PCA) and the surgical transepicondylar axis (TEA) were evaluated with respect to the presence of cartilage. Additionally, these effects were evaluated with respect to patient gender and varus/valgus condition. Results In all patients, the angle between the TEA and PCA was significantly greater in the presence of cartilage than in the absence of cartilage. This result was also seen in female patients. However, there was no difference in the TEA/PCA angle in male patients based on the presence of cartilage. The TEA/PCA angle was significantly greater in the presence of cartilage than in the absence of cartilage in the female varus group. However, there were no differences in the TEA/PCA angle based on the presence of cartilage in the male varus/valgus and female valgus groups. Cartilage thickness in the posterior femoral condyle was significantly greater on the lateral side than on the medial side in all and male patients. However, there was no difference between the genders regarding cartilage thickness. Conclusion Surgical planning for TKA based on CT does not consider articular cartilage and could lead to external malrotation of the femoral implant. Therefore, the effect of the remaining posterior condylar cartilage should be considered by surgeons to prevent over-rotation of the femoral component, especially in female varus knees.

ObjectiveTo assess the difference between the posterior condylar angle (PCA) and the mechanical lateral distal femoral angle (mLDFA) in the osseous and cartilaginous contours in a non-arthritic Chinese population.MethodsComputed tomography (CT) and magnetic resonance imaging (MRI) were obtained from 83 patients with knee injuries before arthroscopy, and femur and distal femoral cartilage three-dimensional (3D) models were constructed. The 3D cartilage model was arranged to share physical space with the 3D femoral model, and then PCA and mLDFA were measured on the osseous and cartilaginous contours, respectively. The differences between the measurements with and without cartilage were evaluated.ResultsThe average PCA with cartilage was 2.88 ± 1.35° and without was 2.73 ± 1.34°. The difference was significant in all patients and females but not in males. The average mLDFA with cartilage was 84.73 ± 2.15° and without cartilage was 84.83 ± 2.26°, but the difference was statistically insignificant in all groups.ConclusionPCA on the osseous and cartilaginous contours significantly differed with and without cartilage in the female group, suggesting that cartilage thickness should be considered during preoperative femoral rotational resection planning.

Background: The purposes of this study were to determine (1) if cartilage thicknesses on the talar dome and medial/lateral surfaces of the talus were similar, (2) whether there was sufficient donor cartilage surface area on the medial and lateral talar surfaces to repair talar dome cartilage injuries of the talus, and (3) whether the cartilage surface could be increased following anterior talofibular ligament (ATFL) and sectioning of the tibionavicular and tibiospring portion of the anterior deltoid. Methods: Medial and lateral approaches were utilized in 8 cadaveric ankles to identify the accessible medial, lateral, and talar dome cartilage surfaces in 3 conditions: (1) intact, (2) ATFL release, and (3) superficial anterior deltoid ligament release. The talus was explanted, and the cartilage areas were digitized with a coordinate measuring machine. Cartilage thickness was quantified using a laser scanner. Results: The mean cartilage thickness was 1.0 ± 0.1 mm in all areas tested. In intact ankles, the medial side of the talus showed a larger total area of available cartilage than the lateral side (152 mm2 vs 133 mm2). ATFL release increased the available cartilage area on the medial and lateral sides to 167 mm2 and 194 mm2, respectively. However, only the lateral talar surface had sufficient circular graft donor cartilage available for autologous osteochondral transplantation (AOT) procedures of the talus. After ATFL and deltoid sectioning, there was an increase in available graft donor cartilage available for AOT procedures. Conclusion: The thickness of the medial and lateral talar cartilage surfaces is very similar to that of the talar dome cartilage surface, which provides evidence that the medial and lateral surfaces may serve as acceptable AOT donor cartilage. The surface area available for AOT donor site grafting was sufficient in the intact state; however, sectioning the ATFL and superficial anterior deltoid ligament increased the overall lateral talar surface area available for circular grafting for an AOT procedure that requires a larger graft. These results support the idea that lateral surfaces of the talus may be used as donor cartilage for an AOT procedure since donor and recipient sites are similar in cartilage thickness, and there is sufficient cartilage surface area available for common lesion sizes in the foot and ankle. Clinical Relevance: This anatomical study investigates the feasibility of talar osteochondral autografts from the medial or lateral talar surfaces exposed with standard approaches. It confirms the similar cartilage thickness of the talar dome and the ability to access up to an 8- to 10-mm donor graft from the lateral side of the talus after ligament release. This knowledge may allow better operative planning for use of these surfaces for osteochondral lesions within the foot and ankle, particularly in certain circumstances of a revision microfracture. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to evaluate lower extremity cartilage thickness in axial spondyloarthritis (SpA) patients and healthy controls using ultrasound (US) and to determine the relationship between the indices, quality of life, enthesopathy, and cartilage thickness of patients with axial SpA. Materials and Methods: This study included 73 axial SpA patients and 30 healthy controls. The patients with axial SpA were divided into two groups as with and without heel enthesitis. Demographic data, disease duration, and medical treatments of patients were recorded. The cartilage (hip, talar, and knee), plantar fascia, and Achilles tendon thicknesses of both healthy controls and axial SpA patients were measured by US. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Functional Index (BASFI), patient global assessment (PGA), and Ankylosing Spondylitis Quality of Life (ASQoL) scores of patients were evaluated. Results: There was no difference between the groups in terms of demographic data and body mass index. The axial SpA groups with and without heel enthesitis were similar in terms of medical treatment and disease duration. The axial SpA patients with heel enthesitis had thinner cartilages than those without heel enthesitis (P < 0.05). The axial SpA patients without heel enthesitis had thinner cartilage thicknesses than the healthy control group (P < 0.05). There were statistically significant differences between the two groups in terms of the BASDAI, BASFI, BASMI, and ASQoL scores. These indices were negatively correlated with cartilage thickness (P < 0.05; r: −0.420). Conclusion: Lower extremity cartilage thickness is associated with disease activity, quality of life, and spinal mobility in patients with axial SpA. [ABSTRACT FROM AUTHOR]

Many studies have validated cartilage thickness as a biomarker for knee osteoarthritis (OA); however, few studies investigate beyond cross‐sectional observations or comparisons across two timepoints. By characterizing the trajectory of cartilage thickness changes over 8 years in healthy individuals from the OA initiative data set, this study discovers associations between the dynamics of cartilage changes and OA incidence. A fully automated cartilage segmentation and thickness measurement method were developed and validated against manual measurements: mean absolute error = 0.11–0.14 mm (n = 4129 knees) and automatic reproducibility = 0.04–0.07 mm (n = 316 knees). The mean thickness for the medial and lateral tibia (MT, LT), central weight‐bearing medial and lateral femur (cMF, cLF), and patella (P) cartilage compartments were quantified for 1453 knees at seven timepoints. Trajectory subgroups were defined per cartilage compartment such as stable, thinning to thickening, accelerated thickening, plateaued thickening, thickening to thinning, accelerated thinning, or plateaued thinning. For tibiofemoral compartments, the stable (22%–36%) and plateaued thinning (22%–37%) trajectories were the most common, with an average initial velocity (μm/month), acceleration (μm/month2) for the plateaued thinning trajectories LT: −2.66, 0.0326; MT: −2.49, 0.0365; cMF: −3.51, 0.0509; and cLF: −2.68, 0.041. In the patella compartment, the plateaued thinning (35%) and thickening to thinning (24%) trajectories were the most common, with an average initial velocity, acceleration for each −4.17, 0.0424; 1.95, −0.0835. Knees with nonstable trajectories had higher adjusted odds of OA incidence than stable trajectories: accelerated thickening, accelerated thinning, and plateaued thinning trajectories of the MT had adjusted odds ratio (OR) of 18.9, 5.48, and 1.47, respectively; in the cMF, adjusted OR of 8.55, 10.1, and 2.61, respectively. [ABSTRACT FROM AUTHOR]

Objective To explore morphological characteristics of patellofemoral joint surface of patients with patellar instability by adopting the MRI‐based method. Methods: A retrospective analysis was performed from March 2016 to January 2020 to assess morphological characteristics of the patellofemoral joint surface by Magnetic Resonance Imaging (MRI) scanning knees of 30 patients (24 females, six males) with patellar instability and trochlear dysplasia and knees of 30 subjects from a randomly selected control group (25 females, five males). The control group was matched as per age and sex. All participants had undergone MRI scans in the supine position and keep knees in or near full extension. Six parts were measured in total, including thickness of trochlear cartilage, thickness of patella cartilage, cartilaginous sulcus angle, cartilaginous Wiberg angle, contact range and frequency and distributions of the mean difference measurement of the femoral trochlea, to evaluate the difference of trochlear and patellar morphology between the patient group and the control group. The threshold for statistical significance was set at P < 0.05. Results: There were significant differences in four values between the two groups (P < 0.05). The cartilage thickness two‐third along the lateral condyle in the patient group was significantly lower than that in the control group (LCT2,1.80 ± 0.37 vs 2.06 ± 0.52, 1.92 ± 0.36 vs 2.17 ± 0.50), but there was no significant difference in other sites. There was no significant difference in patella thickness between the patient group and the control group. The cartilaginous sulcus angle in the patient group was larger than that in the control group (157.90 ± 6.64 vs 142.23 ± 3.95, P < 0.001), but there was no significant difference in cartilaginous Wiberg angle. The patient group had a larger initial contact ratio (59.47 ± 6.13 vs 46.50 ± 3.67, P < 0.001), and a smaller contact range (16.55 ± 4.14 vs 27.55 ± 4.09, P < 0.001). The deepest part of the intercondylar suclus appears more often in the lateral of the deepest part of the osseous concavity of the femoral trochlea. Among the patient group, 18 cases (60%) were found with the deepest part of the intercondylar suclus lateral to the deepest point of the osseous concavity of the femoral trochlea while among the control group only 4 cases (13.33%) were found. The distribution of trochlear dysplasia of Dejour grades was type B (n = 22), type C (n = 5), and type D (n = 3). Conclusion: Thickness of partial lateral trochlear cartilage decreases in patients with patellar instability and the trochlear cartilage develops abnormal morphological characteristics. Moreover, it also suggests that MRI can be used to further present the morphology of cartilage for the convenience of surgical planning. [ABSTRACT FROM AUTHOR]

Background: Among school-age children, the decrease of cartilage thickness (Cth) with increasing age is well known. However, the influence of body mass index (BMI), height or weight on Cth has not been revealed. Here in, we aim to establish an age- and gender-specific Cth standard reference among Asians and investigate the possible prestige of BMI, height and weight. Methods: A cross-sectional study was performed in healthy Asian children. Bilateral knees, ankles, wrists, second metacarpophalangeals (MCPs) and proximal interphalangeals (PIPs) were measured using ultrasound. The children's height, weight and BMI were also recorded for later adjustment. Results: A total of 200 school age Asian children (including 86 girls and 114 boys, aged between 5 to 13 years-old) were investigated. Cth differences were observed in the knees, ankles, wrists, MCPs and PIPs between sexes (p < 0.05), with girls having thinner cartilage thickness. While Cth decreases with increasing age (p < 0.0001, 0.039, 0.001, 0.023, 0.091 in girls' knees, ankles, wrists, MCPs and PIPs and p = 0.002, 0.001, < 0.0001, 0.001, 0.045 in boys', respectively). Our data showed that weight, height and BMI are not the main factors contributing to Cth. A formula to calculate gender-specific cartilage thickness for Asian school age children is suggested. There was no difference in Cth after adjusting for height or weight between Asian or Caucasian group. Conclusions: A formula to calculate gender-specific cartilage thickness for Asian school age children is suggested. Height, weight and BMI were not the major contributor for Cth among school age children. [ABSTRACT FROM AUTHOR]

Purpose: The correlation between cartilage thickness evaluated by 3D MRI and knee alignment has not been elucidated. The study's purpose was to retrospectively verify whether average cartilage thickness calculated by the automatic MRI 3D analysis system for each subregion was correlated with knee alignment., Methods: A total of 53 patients underwent medial meniscus repair or high tibial osteotomy for medial knee osteoarthritis. Cartilage thickness was automatically calculated using 3D MRI software. Knee alignment, weight-bearing line ratio (WBLR), joint line convergence angle (JLCA), medial proximal tibial angle (MPTA), and lateral distal femoral angle (LDFA) were calculated on a weight-bearing long-leg radiograph using digital planning software. The association between knee alignment and the average cartilage thickness at 18 subregions in the medial femoral condyle (MFC) and medial tibial plateau (MTP) was evaluated using Spearman's rank correlation coefficient., Results: Cartilage thickness of the MFC had moderately positive correlations with WBLR at four subregions and weak correlations at two subregions. Cartilage thickness of the MTP had moderately positive correlations with WBLR at four subregions. Cartilage thickness of the MFC had moderately negative correlations with JLCA at six subregions. Cartilage thickness of the MTP had moderately negative correlations with JLCA at four subregions and a weak correlation at one subregion. Conversely, cartilage thickness had weak correlations with MPTA or LDFA., Conclusions: In knees with pathological conditions in the medial compartment, cartilage thicknesses by 3D MRI had positive correlations with WBLR and JLCA at almost all subregions of the MFC and at the anterior-middle and central-external of the MTP. Treatment strategies should be considered in light of these regions., Level of Evidence: Cross-sectional study (diagnosis); Level of evidence, 2., Competing Interests: Declaration of competing interest FUJIFILM Corporation. The corresponding author received the funding from FUJIFILM corporation., (Copyright © 2024 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.)

Abstract Background Ultrasonography is a fast and patient-friendly modality to assess cartilage thickness. However, inconsistent results regarding accuracy have been reported. Therefore, we asked what are (1) the accuracy, (2) reproducibility, and (3) reliability of ultrasonographic cartilage thickness measurement using contrast-enhanced micro-CT for validation? Methods A series of 50 cartilage–bone plugs were harvested from fresh bovine and porcine joints. Ultrasonic cartilage thickness was determined using an A-mode, 20-MHz hand-held ultrasonic probe with native (1580 m/s) and adjusted speed of sound (1696 m/s). All measurements were performed by two observers at two different occasions. Angle of insonation was controlled by tilting the device and recording minimal thickness. Retrieval of exact location for measurement was facilitated by aligning the circular design of both cartilage–bone plug and ultrasonic device. There was no soft tissue interference between cartilage surface and ultrasonic probe. Ground truth measurement was performed using micro-CT with iodine contrast agent and a voxel size of 16 μm. The mean cartilage thickness was 1.383 ± 0.402 mm (range, 0.588–2.460 mm). Results Mean accuracy was 0.074 ± 0.061 mm (0.002–0.256 mm) for native and 0.093 ± 0.098 mm (0.000–0.401 mm) for adjusted speed of sound. Bland–Altman analysis showed no systematic error. High correlation was found for native and adjusted speed of sound with contrast-enhanced micro-CT (both r = 0.973; p

This study compared quantitative cartilage ultrasound metrics between people with (n = 12) and without (n = 12) arthroscopic cartilage damage after anterior cruciate ligament injury (age, 24.9 ± 3.7 y; sex, 33% female, 67% male; days since injury = 50 ± 52). A transverse suprapatellar ultrasound assessment imaged the femoral cartilage in participants' injured knees before a clinical arthroscopy. A custom program automatically separated a manual cartilage segmentation into standardized medial and lateral femoral regions and calculated mean thickness (i.e., cross-sectional area/length of cartilage-bone interface), mean echo intensity and echo-intensity heterogeneity. An orthopedic surgeon assessed arthroscopic cartilage damage in the medial and lateral femoral condyles using the Outerbridge grading system (cartilage damage = Outerbridge ≥ 1). Separate logistic regressions for medial and lateral femoral cartilage were used to determine the association between each ultrasound metric and arthroscopic cartilage damage. In medial femoral cartilage, for every 1 standard deviation decrease in echo-intensity mean and heterogeneity, there is, respectively, a 91% (adjusted odds ratio, 0.09; 95% confidence interval, 0.01-0.69) and 97% (adjusted odds ratio, 0.03; 95% confidence interval, 0.002-0.50) increase in the odds of having arthroscopic cartilage damage. Lateral cartilage ultrasound metrics are not associated with lateral arthroscopic cartilage damage. This study provides preliminary evidence that femoral cartilage ultrasound echo intensity is a non-invasive measure associated with medial femoral cartilage health after anterior cruciate ligament injury. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Subclinical inflammation is still a controversial issue in inflammatory diseases. There is no reliable, easy, and cheap inflammation marker in daily clinical practices currently. This study aims to predict clinical remission using cartilage and tendon thicknesses. METHODS: Eleven patients with Familial Mediterranean Fever (FMF) who had musculoskeletal involvement before and 11 patients with Enthesitis-Related Arthritis (ERA) were included in this study. They were on remission with clinical and laboratory evaluations for at least three months. Demographic and clinical features of the subjects, including age, sex, body mass index, disease duration, age at onset, medical treatment, and laboratory evaluations, were all noted. Healthy children of the same age were included as the control group. The thicknesses of the bilateral knee, second metacarpophalangeal and ankle joints cartilages, quadriceps, superior and inferior patellar, and the Achilles tendons were measured with a linear probe. A total of 198 joint and 264 tendon thicknesses were measured. RESULTS: The thicknesses of metacarpophalangeal, knee, and ankle cartilages were higher in the FMF group than in the others. In the FMF group, the quadriceps tendon thickness was higher than in the ERA group, and the superior patellar tendon thickness was higher than in the control group (p<0.05). CONCLUSION: According to our preliminary findings, an increased thickness of the cartilage and tendon in FMF patients may be an indicator of subclinical inflammation. Increased thickness of the enthesis in FMF patients may also indicate that enthesitis-related arthritis will also develop in the future. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The purpose of this study was to compare the differences of degenerative characteristics of medial, lateral regions, femoral, patellar, and tibia parts of the knee joint in the early-stage of knee osteoarthritis (OA). PATIENTS AND METHODS: A total of 66 patients with early stage knee OA and 22 healthy volunteers who have no knee-related clinical symptoms were enrolled in this cross-sectional study. T2 mapping and 3D dual-echo images were acquired with a 3.0T MR scanner. The degenerative changes of the articular cartilage were quantified by a T2 mapping and cartilage thicknesses analysis. Any structural changes were conducted using the Whole Organ Magnetic Resonance Imaging Score (WORMS). RESULTS: In patients with knee OA, the thicknesses of medial cartilages were significantly thinner than lateral ones (2.13 mm vs. 2.34 mm, p<0.0001), but with higher T2 values (40.38 ms vs. 38.4 ms, p<0.0001) and WORMS scores (12.12 vs. 0.47, p=0.004). No significant differences were observed between medial and lateral cartilage in the healthy volunteers. The T2 values of the femoral (p<0.001) and patellar (p=0.012) cartilages of OA patients were higher than that of the healthy controls. Within OA group, the T2 values of femoral (p<0.0001) and patellar (p<0.0001) cartilages were higher than tibial ones. Moreover, the WORMS scores of femoral (p=0.001) and patellar (p<0.0001) cartilages were higher than that of the tibial ones. CONCLUSIONS: This study demonstrates that the medial compartment and patellofemoral knee joint degenerate more severely in patients with early-stage knee OA. [ABSTRACT FROM AUTHOR]

Background: Traditional quantitative analysis of cartilage with MRI averages measurements (eg, thickness) across regions-of-interest (ROIs) which may reduce responsiveness.Purpose: To validate and describe clinical application of a semiautomated surface-based method for analyzing cartilage relaxation times ("composition") and morphology on MRI, 3D cartilage surface mapping (3D-CaSM).Study Type: Validation study in cadaveric knees and prospective observational (cohort) study in human participants.Population: Four cadaveric knees and 14 participants aged 40-60 with mild-moderate knee osteoarthritis (OA) and 6 age-matched healthy volunteers, imaged at baseline, 1, and 6 months.Field Strength/sequence: 3D spoiled gradient echo, T1 rho/T2 magnetization-prepared 3D fast spin echo for mapping of T1 rho/T2 relaxation times and delayed gadolinium enhanced MRI of cartilage (dGEMRIC) using variable flip angle T1 relaxation time mapping at 3T.Assessment: 3D-CaSM was validated against high-resolution peripheral quantitative computed tomography (HRpQCT) in cadaveric knees, with comparison to expert manual segmentation. The clinical study assessed test-retest repeatability and sensitivity to change over 6 months for cartilage thickness and relaxation times.Statistical Tests: Bland-Altman analysis was performed for the validation study and evaluation of test-retest repeatability. Six-month changes were assessed via calculation of the percentage of each cartilage surface affected by areas of significant change (%SC), defined using thresholds based on area and smallest detectable difference (SDD).Results: Bias and precision (0.06 ± 0.25 mm) of 3D-CaSM against reference HRpQCT data were comparable to expert manual segmentation (-0.13 ± 0.26 mm). 3D-CaSM demonstrated significant (>SDD) 6-month changes in cartilage thickness and relaxation times in both OA participants and healthy controls. The parameter demonstrating the greatest 6-month change was T2 relaxation time (OA median %SC [IQR] = 8.8% [5.5 to 12.6]).Data Conclusion: This study demonstrates the construct validity and potential clinical utility of 3D-CaSM, which may offer advantages to conventional ROI-based methods.Level Of Evidence: 2.Technical Efficacy Stage: 2. J. Magn. Reson. Imaging 2020;52:1139-1151. [ABSTRACT FROM AUTHOR]

Objective: Evaluate associations between 2-year change in radiographic or quantitative magnetic resonance imaging (qMRI) structural measures, and knee replacement (KR), within a subsequent 7-year follow-up period.Method: Participants from the Osteoarthritis Initiative were selected based on potential eligibility criteria for a disease-modifying osteoarthritis (OA) drug trial: Kellgren-Lawrence grade 2 or 3; medial minimum joint space width (mJSW) ≥2.5 mm; knee pain at worst 4-9 in the past 30 days on an 11-point scale, or 0-3 if medication was taken for joint pain; and availability of structural measures over 2 years. Mean 2-year change in structural measures was estimated and compared with two-sample independent t-tests for KR and no KR. Area under the receiver operating characteristic curve (AUC) was estimated using 2-year change in structural measures for prediction of future KR outcomes.Results: Among 627 participants, 107 knees underwent KR during a median follow-up of 6.7 years after the 2-year imaging period. Knees that received KR during follow-up had a greater mean loss of cartilage thickness in the total femorotibial joint and medial femorotibial compartment on qMRI, as well as decline in medial fixed joint space width on radiographs, compared with knees that did not receive KR. These imaging measures had similar, although modest discrimination for future KR (AUC 0.62, 0.60, and 0.61, respectively).Conclusions: 2-year changes in qMRI femorotibial cartilage thickness and radiographic JSW measures had similar ability to discriminate future KR in participants with knee OA, suggesting that these measures are comparable biomarkers/surrogate endpoints of structural progression. [ABSTRACT FROM AUTHOR]