膝关节软骨负荷运动前后磁共振T_2时间与容积变化研究

目的通过比较分析负荷运动前后膝关节软骨磁共振T2时间和软骨容积变化,探讨利用T2时间和容积变化反映负荷作用下软骨形态变化的可行性。方法选择20例健康志愿者,其中男性16例,女性4例;年龄为20.1~30.4岁,平均年龄25.7岁。在同等运动负荷前后进行软骨T2mapping序列成像,测量股骨内外侧髁、胫骨平台和髌软骨T2时间;以三维脂肪抑制快速扰相梯度回波(3D-FS-SPGR)序列扫描并采用最大信号强度投影法(MIP)重建后测量髌软骨及股骨髁软骨容积。比较负荷前后软骨T2时间变化、软骨容积差异,并分析软骨容积与T2时间变化间的相关性。结果运动前与运动后髌软骨T2时间最长,胫骨外侧平台最短;运动后不同部位软骨T2时间均降低(P=0.000),股骨内侧髁软骨下降幅度最大(t=-27.96,P=0.000);运动后膝关节软骨容积减小(P=0.000),股骨髁软骨容积变化程度(t=-86.71,P=0.000)大于髌软骨(t=-9.42,P=0.000);软骨容积与T2时间变化间无线性相关性(P0.05)。结论运动后膝关节软骨各部位T2时间和局部软骨容积均减少,但软骨容积与T2时间变化间无相关性;软骨T2mapping和软骨容积变化磁共振成像技术对评价负荷作用下软骨形态变化有一定的意义。     

骨性关节炎对膝关节软骨粘弹性影响实验研究

研究了正常国人新鲜尸体膝关节软骨和骨性关节炎膝关节软骨的粘弹性力学性质.对正常和病态膝关节软骨进行一维拉伸应力松弛、蠕变实验,得出了应力松弛、蠕变实验数据和曲线,以回归分析的方法处理应力松弛、蠕变实验数据,得出了归一化应力松弛函数、归一化蠕变函数表达式.以冯元桢教授的准线性理论得出了正常组和病态组膝关节软骨松弛函数表达式,并对实验结果进行了分析讨论.     

骨性关节炎对膝关节软骨力学性质影响的实验研究

目的 研究正常国人新鲜尸体膝关节软骨和骨性关节炎膝关节软骨的生物力学性质,为临床提供生物力学参数。方法 取正常和病变的膝关节软骨在ShimadzuAUTOGRAPH电子万能试验机上进行一维拉伸实验。结果 得出了关节软骨最大载荷、伸长比、应力、应变等数据;用最小二乘法处理应力鄄应变数据,得出了其应力鄄应变关系表达式,拟合出了应力鄄应变曲线。结论 病变组各项力学性质指标均明显低于正常组。     

正常膝关节软骨MRI T_1ρ序列表现初步研究

目的比较正常膝关节软骨MRIT1ρ和三维抑脂扰相梯度回波(3D-FS-SPGR)序列表现,研究T1ρ序列应用于软骨评估的可行性;评估软骨深层与浅层MRIT1ρ值的差异。方法选择经临床和影像确认的26例成年志愿者,其中男性11例,女性15例;年龄15~65岁,平均年龄31.69岁。分析其T1ρ和3D-FS-SPGR序列MRI成像表现。将膝关节软骨划分为髌软骨、髁间窝、股骨内外侧髁、胫骨内外侧平台6个部分。测量相同层面与位置的T1ρ第一回波和3D-FS-SPGR图像上软骨、软骨下骨、背景噪声的信号强度,比较两者的软骨与软骨下骨对比度比(CNR)和软骨信噪比(SNR)。选取6个部位软骨最厚处,把该处软骨厚度等分为深层和浅层,分别测量同像素感兴趣区(ROI)的T1ρ值。对以上数据进行配对t检验,以P0.05为差异有统计学意义。结果①膝关节T1ρ序列第一回波图像上的CNR均值和SNR均值均高于同一部位的3D-FSSPGR序列,CNR 29.88±10.00 vs 12.08±3.08(t=23.09,P=0.000),SNR 34.70±11.16 vs 14.18±3.46(t=23.929,P=0.000);②正常膝关节软骨深层均值(29.12±8.07)ms,浅层均值(43.23±6.78)ms,浅层T1ρ值显著高于深层表现(t=-24.687,P=0.000)。结论 T1ρ序列可用于软骨临床评估,浅层软骨胶原纤维排列较深层更为致密。     

COX-2在膝关节骨性关节炎软骨中表达及临床意义

目的研究环氧化酶-2基因在膝关节骨性关节炎（osteoarthritis,OA）患者软骨组织的表达及其临床意义。方法对40例膝关节骨性关节炎取患者软骨组织设为OA组和7例膝关节正常软骨组织设为对照组。分别提取两组软骨组织RNA和总蛋白,通过RT-PCR检测各组COX-2mRNA转录水平以及COX-2基因表达蛋白Westernblot分析。结果 RT-PCR结果显示OA组出现大小约700bp条带,对照组扩增条带不明显;Western blot分析结果OA组COX-2基因表达蛋白明显,两组间灰度比有显著差异（〈0.05）。结论 COX-2基因及其表达蛋白在膝关节骨性关节炎软骨组织损害过程中起到重要作用。     

髌软骨T2 mapping与膝关节骨性关节炎临床症状间的 关系及影响因素

目的 探讨膝骨关节炎患者髌软骨T2 mapping与临床症状、关节软骨缺损及骨髓病变间的关系。方法 回顾性选取2017年1月~7月本院32例符合1986年美国风湿学会症状性膝关节骨性关节炎患者,行膝关节MRI检查,包括T2WI、3D FSPGR和T2 mapping,评估髌软骨缺损及骨髓病变分级,在T2 mapping图像上勾画ROI,测量髌软骨T2值,以T2值中位数为区分标准,作各项指标的两组间比较,Logistic回归分析骨髓病变、软骨缺损与T2值间的相关性,行方差分析观察软骨缺损及骨髓水肿与T2值间的关系。结果 软骨缺损及骨髓病变在两组间有统计学差异,P值均＜0.05。Logistic回归分析发现软骨缺损及骨髓病变与T2值是否高于中位数相关,P值分别为0.003及0.032;不同等级关节软骨缺损及骨髓病变间T2值不同,且呈现增高趋势,P值均＜0.05。结论 不同等级的软骨缺损及骨损伤具有不同的T2值,且随着等级的增高,T2值亦呈现增高趋势。     

3D-FS-SPGR序列在膝关节软骨病变的临床应用研究

目的　利用3D-FS-SPGR序列测量各期膝关节OA软骨厚度,探讨OA膝关节软骨厚度与病变进展的关系。 方法　62例OA患者行膝关节MRI检查,用3D-FS-SPGR序列测量不同部位关节软骨的厚度,并与20名对照组膝关节MRI检查结果进行比较。 结果　轻度OA组关节软骨厚度与正常组之间无统计学差异（P＞0.05）,而重度OA组大部分软骨区域软骨厚度与正常组有统计学差异（P＜0.05）。软骨厚度的改变可能受到多方面因素的影响,年龄、体重及BMI等与软骨厚度改变之间存在负相关。 结论　关节软骨负重面大部分区域随着OA病情的加重,其软骨厚度变薄,软骨厚度改变可能还受到体重、年龄及性别等因素的影响。     

选择性切断膝关节神经支对膝骨性关节炎模型兔关节软骨超微结构的影响

目的观察选择性切断膝关节神经支对兔膝骨性关节炎模型关节软骨超微结构的影响。方法采用Huhh法复制兔膝骨性关节炎模型,通过外科显微镜下选择性切断兔膝关节神经支,对关节软骨等结构进行形态学观察,运用TUNEL法检测软骨细胞的凋亡,并应用透射电镜观察关节软骨超微结构的变化。结果模型组兔膝关节软骨出现退变的表现,软骨细胞过度凋亡,其凋亡指数（31．25±6．83）明显高于正常组（3．16±0．65;P〈0．05）。模型组关节软骨超微结构明显受损,软骨细胞出现核固缩,线粒体肿胀,粗面内质网扩张、脱颗粒;软骨基质内胶原纤维断裂溶解,结构模糊。治疗组兔膝关节软骨退变有明显改善,细胞凋亡指数（15．43±3．72）明显低于模型组（P〈0．05）,关节软骨超微结构较模型组有明显改善。结论选择性切断膝关节神经支对膝骨性关节炎模型兔关节软骨细胞凋亡有抑制作用,并能改善关节软骨的超微结构。     

膝关节骨性关节炎的发病因素及治疗进展研究

膝关节骨性关节炎是一种老年性关节炎,会引起多种临床症状及并发症,对患者的生活带来严重的影响。本文通过对膝关节骨性关节炎的发病因素分析,从非药物治疗、药物治疗以及手术治疗分别讲述各自的特点,适用情况,为膝关节骨性关节炎的发病因素的临床治疗提供理论依据。     

膝关节骨性关节炎治疗研究

膝关节骨性关节炎发病年龄段较广,男女均可发布,常见于中老年患者.当前治疗KOA的方法很多,主要有健康教育、物理疗法、药物疗法、运动疗法、手术治疗、基因疗法等,但疗效不一.本文从非手术治疗和手术治疗两个方面进行论述,以供参考.     

红姜提取物保护早期膝骨关节炎模型大鼠的关节软骨

BACKGROUND: Studies have reported that the combined use of ginger extract to reduce the levels of serum pro-inflammatory cytokines, including interleukin-1β, interleukin-6, tumor necrosis factor-α, is related to the reduction of cartilage injury in knee osteoarthritis. OBJECTIVE: To observe the protective effect of red ginger extract on articular cartilage and the expression of serum interleukin-1β, interleukin-6, tumor necrosis factor-α and cartilage tissue type II collagen α1 mRNA in rats with early knee osteoarthritis, and to explore the protective effect of red ginger extract on articular cartilage of rats with early knee osteoarthritis and its possible mechanism. METHODS: Fifty SPF Sprague-Dawley rats were randomly divided into blank group, model group, low-dose red ginger, high-dose red ginger and positive control group (n=10 per group). Except for the blank group, the rats in the other four groups were used to prepare knee osteoarthritis models by intraarticular injection of 4% papain 0.2 mL+0.03 mol/L L-cysteine mixed solution. The rats in the blank and model groups were fed routinely, and the low-dose red ginger, high-dose red ginger and positive control groups were given 50 mg/kg red ginger extract aqueous solution, 100 mg/kg red ginger extract aqueous solution and 18 mg/kg celecoxib capsule aqueous solution respectively. All the interventions were conducted once a day, for 4 continuous weeks. Four weeks after treatment, the rats in each group were killed and the knee joints were stained with safranin O-fast green. The articular cartilage was scored by Mankin scoring. The expression levels of interleukin-1β, interleukin-6, tumor necrosis factor-α in serum and type II collagen α1 mRNA in cartilage were detected. The study protocol was approved by the Animal Ethics Committee of Guangzhou University of Chinese Medicine, with an approval No. 20190917002. RESULTS AND CONCLUSION: The pathological section of knee cartilage showed that there was cartilage matrix loss in the model and each treatment group, and the Mankin score of each treatment group was significantly higher than that of the blank group (P < 0.05) and lower than that of the model group (P < 0.05). There was no significant difference between the high-dose group and the positive control group (P > 0.05), but the scores of the two groups were lower than that of the low-dose group. The levels of interleukin-1β, interleukin-6, and tumor necrosis factor-α were upregulated in the positive control group, high-dose red ginger group and low-dose red ginger group compared with the blank group and down-regulated compared with the model group (P < 0.05). Moreover, and the levels of these cytokines were ranked as follows: positive control group < high-dose red ginger group < low-dose red ginger group (P < 0.05). The level of type II collagen α1 mRNA in cartilage showed no significant difference between the blank group and the high-dose red ginger group and the positive control group (P > 0.05), whereas the expression of type II collagen α1 mRNA was significantly increased in the model group and low-dose red ginger group compared with the other three groups (P < 0.05). To conclude, red ginger extract may protect the articular cartilage of knee osteoarthritis by inhibiting interleukin-1β, interleukin-6, and tumor necrosis factor-α, thereby delaying the development of knee osteoarthritis. Compared with the low-dose group, high-dose red ginger extract has better anti-inflammatory effect. © 2021, Journal of Clinical Rehabilitative Tissue Engineering Research. All rights reserved.     

Rapid volumetric gagCEST imaging of knee articular cartilage at 3 T: evaluation of improved dynamic range and an osteoarthritic population

Chemical exchange saturation transfer of glycosaminoglycans, gagCEST, is a quantitative MR technique that has potential for assessing cartilage proteoglycan content at field strengths of 7 T and higher. However, its utility at 3 T remains unclear. The objective of this work was to implement a rapid volumetric gagCEST sequence with higher gagCEST asymmetry at 3 T to evaluate its sensitivity to osteoarthritic changes in knee articular cartilage and in comparison with T₂ and T_1ρ measures. We hypothesize that gagCEST asymmetry at 3 T decreases with increasing severity of osteoarthritis (OA). Forty‐two human volunteers, including 10 healthy subjects and 32 subjects with medial OA, were included in the study. Knee Injury and Osteoarthritis Outcome Scores (KOOS) were assessed for all subjects, and Kellgren‐Lawrence grading was performed for OA volunteers. Healthy subjects were scanned consecutively at 3 T to assess the repeatability of the volumetric gagCEST sequence at 3 T. For healthy and OA subjects, gagCEST asymmetry and T₂ and T_1ρ relaxation times were calculated for the femoral articular cartilage to assess sensitivity to OA severity. Volumetric gagCEST imaging had higher gagCEST asymmetry than single‐slice acquisitions (p = 0.015). The average scan‐rescan coefficient of variation was 6.8%. There were no significant differences in average gagCEST asymmetry between younger and older healthy controls (p = 0.655) or between healthy controls and OA subjects (p = 0.310). T₂ and T_1ρ relaxation times were elevated in OA subjects (p < 0.001 for both) compared with healthy controls and both were moderately correlated with total KOOS scores (rho = ?0.181 and rho = ?0.332 respectively). The gagCEST technique developed here, with volumetric scan times under 10 min and high gagCEST asymmetry at 3 T, did not vary significantly between healthy subjects and those with mild‐moderate OA. This further supports a limited utility for gagCEST imaging at 3 T for assessment of early changes in cartilage composition in OA.     

Cutoff points of T1 rho/T2 mapping relaxation times distinguishing early-stage and advanced osteoarthritis

IntroductionThe histopathology grading system is the gold standard post-operative method to evaluate cartilage degeneration in knee osteoarthritis (OA). Magnetic resonance imaging (MRI) T1 rho/T2 mapping imaging can be used for preoperative detection. An association between histopathology and T1 rho/T2 mapping relaxation times was suggested in previous research. However, the cutoff point was not determined among different histopathology grades. Our study aimed to determine the cutoff point of T1 rho/T2 mapping.Material and methodsT1 rho/T2 mapping images were acquired from 80 samples before total knee replacements. Then the histopathology grading system was applied.ResultsThe mean T1 rho/T2 mapping relaxation times of 80 samples were 39.17 ms and 37.98 ms respectively. Significant differences were found in T1 rho/T2 mapping values between early-stage and advanced OA (p < 0.001). The cutoff point for T1 rho was 33 ms with a sensitivity of 94.12 (95% CI: 80–99.3) and a specificity of 91.30 (95% CI: 79.2–97.6). The cutoff point for T2 mapping was suggested as 35.04 ms with a sensitivity of 88.24 (95% CI: 72.5–96.7) and specificity of 97.83 (95% CI: 88.5–99.9). After bootstrap simulation, the 95% CI of the T1 rho/T2 mapping cutoff point was estimated as 29.36 to 36.32 ms and 34.8 to 35.04 ms respectively. The area under the PR curve of T1 rho/T2 mapping was 0.972 (95% CI: 0.925–0.992) and 0.949 (95% CI: 0.877–0.989) respectively.ConclusionsThe cutoff point of T1 rho relaxation times, which was suggested as 33 ms, could be used to distinguish early-stage and advanced OA.     

Morphological MRI and T2 mapping of cartilage repair tissue after mosaicplasty with tissue-engineered cartilage in a pig model

The aim of this study was to evaluate the efficacy of mosaicplasty with tissue-engineered cartilage for the treatment of osteochondral defects in a pig model with advanced MR technique. Eight adolescent miniature pigs were used. The right knee underwent mosaicplasty with tissue-engineered cartilage for treatment of focal osteochondral defects, while the left knee was repaired via single mosaicplasty as controls. At 6, 12, 18 and 26 weeks after surgery, repair tissue was evaluated by magnetic resonance imaging （MRI） with the cartilage repair tissue （MOCART） scoring system and T2 mapping. Then, the results of MRI for 26 weeks were compared with findings of macroscopic and histologic studies. The MOCART scores showed that the repaired tissue of the tissue-engineered cartilage group was statistically better than that of controls （P 〈 0.001）. A significant correlation was found between macroscopic and MOCART scores （P 〈 0.001）. Comparable mean T2 values were found between adjacent cartilage and repair tissue in the experimental group （P 〉 0.05）. For zonal T2 value evaluation, there were no significant zonal T2 differences for repair tissue in controls （P 〉 0.05）. For the experimental group, zonal T2 variation was found in repair tissue （P 〈 0.05）. MRI, macroscopy and histology showed better repair results and bony incorporation in mosaicplasty with the tissue-engi- neered cartilage group than those of the single mosaicplasty group. Mosaicplasty with the tissue-engineered cartilage is a promising approach to repair osteochodndral defects. Morphological MRI and T2 mapping provide a non-invasive method for monitoring the maturation and integration of cartilage repair tissue in vivo.     

Individual and cumulative measures of knee joint load associate with T2 relaxation times of knee cartilage in young,uninjured individuals: A pilot study

BackgroundArticular cartilage structure and chondrocyte health are sensitive and reliant on dynamic joint loading during activities. The purpose of this pilot study was to determine the association between measures of individual and cumulative knee joint loading with T2 relaxation times in the knee cartilage of young individuals without knee injury.MethodsTwelve participants (17–30 years old) without history of knee injury or surgery completed MRI, physical activity (PA), and biomechanical gait testing. T2 relaxation times were calculated in the cartilage within the patella and lateral and medial compartments. Accelerometry was used to measure mean daily step counts, minutes of PA, and % sedentary time over 7 days. Vertical ground reaction force, external knee joint moments and peak knee flexion angle were measured during stance phase of gait using three-dimensional motion capture. Cumulative knee joint loading was calculated as daily step count by external knee joint moment impulse. The relationship between measures of knee joint loading and T2 relaxation times was assessed using Pearson correlations.ResultsHigher T2 relaxation times in the femoral and tibial cartilage were consistently correlated to greater body mass, daily step counts, moderate and vigorous PA, and peak knee joint moments (r = 0.10–0.84). Greater cumulative knee flexion and adduction loading was associated with higher T2 relaxation times in the femoral and tibial cartilage (r = 0.16–0.65).ConclusionPreliminary findings suggest that individual loading factors and cumulative knee joint loading are associated with higher T2 relaxation times in the articular cartilage of young, healthy knees.     

Associations between the properties of the cartilage matrix and findings from quantitative MRI in human osteoarthritic cartilage of the knee

The aim of this study was to investigate the associations between the properties of the cartilage matrix and the results of T2 mapping and delayed gadolinium-enhanced magnetic resonance imaging (dGEMRIC) in human knee osteoarthritic cartilage. Osteochondral samples were harvested from the middle part of the femoral condyle and tibial plateaus of 20 patients with knee osteoarthritis (OA) during total knee arthroplasty. Sagittal T2 mapping, T1pre, and T1Gd were performed using 7.0T magnetic resonance imaging (MRI). Gycosaminoglycan (GAG) distribution was evaluated by OARSI, collagen anisotropy was assessed by polarized light microscopy (PLM), and biochemical analyses measured water, GAG, and collagen content. Associations between properties of the cartilage matrix and T2 and ΔR1 (1/T1Gd-1/T1pre) values were explored using correlation analysis. T2 and ΔR1 values were significantly correlated with the degree of cartilage degeneration (OARSI grade; Ρ = 0.53 and 0.77). T2 values were significantly correlated with water content (r = 0.69; P < 0.001), GAG content (r = -0.43; P < 0.001), and PLM grade (r = 0.47; P < 0.001), but not with collagen content (r = -0.02; P = 0.110). ΔR1 values were significantly correlated with GAG content (r = -0.84; P < 0.001) and PLM grade (r = 0.41; P < 0.001). Taken together, T2 mapping and dGEMRIC results were correlated with the properties of the cartilage matrix in human knee osteoarthritic cartilage. Combination T2 mapping and dGEMRIC represents a potential non-invasive monitoring technique to detect the progress of knee OA.     

Uncompromised MRI of knee cartilage while incorporating sensitive sodium MRI

Sodium imaging is able to assess changes in ion content, linked to glycosaminoglycan content, which is important to guide orthopeadic procedures such as articular cartilage repair. Sodium imaging is ideally performed using double tuned RF coils, to combine high resolution morphological imaging with biochemical information from sodium imaging to assess ion content. The proton image quality of such coils is often harshly degraded, with up to 50% of SNR or severe acceleration loss as compared to single tuned coils. Reasons are that the number of proton receive channels often severely reduced and double tuning will degrade the intrinsic sensitivity of the RF coil on at least one of the nuclei. However, the aim of this work was to implement a double‐tuned sodium/proton knee coil setup without deterioration of the proton signal whilst being able to achieve acquisition of high SNR sodium images. A double‐tuned knee coil was constructed as a shielded birdcage optimized for sodium and compromised for proton. To exclude any compromise, the proton part of the birdcage is used for transmit only and interfaced to RF amplifiers that can fully mitigate the reduced efficiency. In addition, a 15 channel single tuned proton receiver coil was embedded within the double‐resonant birdcage to maintain optimal SNR and acceleration for proton imaging. To validate the efficiency of our coil, the designed coil was compared with the state‐of‐the‐art single‐tuned alternative at 7 T. B1+ corrected SNR maps were used to compare both coils on proton performance and g‐factor maps were used to compare both coils on acceleration possibilities. The newly constructed double‐tuned coil was shown to have comparable proton quality and acceleration possibilities to the single‐tuned alternative while also being able to acquire high SNR sodium images.     

Sodium relaxation times in the knee joint in vivo at 7T

The sodium concentration correlates directly with the concentration of proteoglycans (PG) in cartilage, the loss of which is an early signature of osteoarthritis (OA). As a result, quantitative sodium MRI is a promising technique for assessing the degradation of articular cartilage in patients with OA. Sodium relaxation times can also provide information on the degradation of cartilage: it has already been shown on bovine cartilage that T(1) and T2long are longer and T2short shorter when the PG concentration decreases. In this study, sodium T(1), T2*short and T2*long relaxation maps were measured in vivo at 7 T on 8 healthy volunteers and in 4 different regions of the cartilage in the knee joint. The patellar, femoro-tibial medial, lateral, and femoral condyle cartilage have an average T(1)~20 ms, but different T2*short (from 0.5 ms to 1.4 ms) and T2*long (from 11.4 ms to 14.8 ms). Statistically significant differences in T(1), T2*short and T2*long were observed between the different regions in cartilage (p < 10(- 5)). Statistical differences in T(1) were also observed between male and female data (p < 10(- 5)). These relaxation times measurements can further be applied as correction factors for sodium concentration maps in vivo and can also be useful as complementary information to quantitative sodium MRI in the quest for detecting early OA. These measurements were done on low resolution sodium images in order to acquire sufficient quality data for fitting (5 images for T(1) and 9 images for T2*) while keeping the total time of acquisition of the data reasonable for the volunteer's comfort (1 h 15 min).     

Evaluation of enzymatic proteoglycan loss and collagen degradation in human articular cartilage using ultrashort echo time-based biomarkers: A feasibility study

The objective of the current study was to investigate the feasibility of quantitative 3D ultrashort echo time (UTE)-based biomarkers in detecting proteoglycan (PG) loss and collagen degradation in human cartilage. A total of 104 cartilage samples were harvested for a trypsin digestion study (n = 44), and a sequential trypsin and collagenase digestion study (n = 60), respectively. Forty-four cartilage samples were randomly divided into a trypsin digestion group (tryp group) and a control group (phosphate-buffered saline [PBS] group) (n = 22 for each group) for the trypsin digestion experiment. The remaining 60 cartilage samples were divided equally into four groups (n = 15 for each group) for sequential trypsin and collagenase digestion, including PBS + Tris (incubated in PBS, then Tris buffer solution), PBS + 30 U col (incubated in PBS, then 30 U/ml collagenase [30 U col] with Tris buffer solution), tryp + 30 U col (incubated in trypsin solution, then 30 U/ml collagenase with Tris buffer solution), and tryp + Tris (incubated in trypsin solution, then Tris buffer solution). The 3D UTE-based MRI biomarkers included T₁, multiecho T₂*, adiabatic T_1ρ (AdiabT_1ρ), magnetization transfer ratio (MTR), and modeling of macromolecular proton fraction (MMF). For each cartilage sample, UTE-based biomarkers (T₁, T₂*, AdiabT_1ρ, MTR, and MMF) and sample weight were evaluated before and after treatment. PG and hydroxyproline assays were performed. Differences between groups and correlations were assessed. All the evaluated biomarkers were able to differentiate between healthy and degenerated cartilage in the trypsin digestion experiment, but only T₁ and AdiabT_1ρ were significantly correlated with the PG concentration in the digestion solution (p = 0.004 and p = 0.0001, respectively). In the sequential digestion experiment, no significant differences were found for T₁ and AdiabT_1ρ values between the PBS + Tris and PBS + 30 U col groups (p = 0.627 and p = 0.877, respectively), but T₁ and AdiabT_1ρ values increased significantly in the tryp + Tris (p = 0.031 and p = 0.024, respectively) and tryp + 30 U col groups (both p < 0.0001). Significant decreases in MMF and MTR were found in the tryp + 30 U col group compared with the PBS + Tris group (p = 0.002 and p = 0.001, respectively). It was concluded that AdiabT_1ρ and T₁ have the potential for detecting PG loss, while MMF and MTR are promising for the detection of collagen degradation in articular cartilage, which could facilitate earlier, noninvasive diagnosis of osteoarthritis.