Musculoskeletal Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States.
Department of Physical Therapy, California State University, Sacramento, CA, USA.
Osteoarthritis Cartilage. 2016 Sep;24(9):1554-64. doi: 10.1016/j.joca.2016.04.006. Epub 2016 Apr 12.
This study aimed to investigate the associations between patellofemoral cartilage T1ρ and T2 relaxation times and knee flexion moment (KFM) and KFM impulse during gait.
Knee magnetic resonance (MR) images were obtained from 99 subjects with and without patellofemoral joint (PFJ) osteoarthritis (OA), using fast spin-echo, T1ρ and T2 relaxation time sequences. Patellar and trochlear cartilage relaxation times were computed for the whole cartilage, and superficial and deep layers (laminar analysis). Subjects also underwent three-dimensional (3D) gait analysis. Peak KFM and KFM impulse were calculated during the stance phase. Linear regressions were used to examine whether cartilage relaxation times were associated with knee kinetics during walking while adjusting age, sex, body mass index (BMI) and walking speed.
Higher peak KFM and KFM impulse were significantly related to higher T1ρ and T2 relaxation times of the trochlear and patellar cartilage, with standardized regression coefficients ranging from 0.21 to 0.28. Laminar analysis showed that overall the superficial layer of patellofemoral cartilage showed stronger associations with knee kinetics. Subgroup analysis revealed that in subjects with PFJ OA, every standard deviation change in knee kinetics was related to greater increases in PFJ cartilage T1ρ and T2 (standardized coefficients: 0.29 to 0.41). Conversely, in subjects without OA, weaker relationships were observed between knee kinetics and PFJ cartilage T1ρ and T2.
Our findings suggest that increased peak KFM and KFM impulse were related to worse cartilage health at the PFJ. This association is more prominent in superficial layer cartilage and cartilage with morphological lesions.
本研究旨在探讨髌股关节（PFJ）骨关节炎（OA）患者与非 OA 患者髌股软骨 T1ρ 和 T2 弛豫时间与步态时膝关节弯曲力矩（KFM）和 KFM 冲量之间的关系。
使用快速自旋回波、T1ρ 和 T2 弛豫时间序列，从 99 例伴有和不伴有 PFJ OA 的受试者中获得膝关节磁共振（MR）图像。计算整个软骨、浅层和深层（层状分析）的髌骨和滑车软骨弛豫时间。受试者还进行了三维（3D）步态分析。在站立阶段计算峰值 KFM 和 KFM 冲量。线性回归用于检验在调整年龄、性别、体重指数（BMI）和行走速度后，软骨弛豫时间是否与行走时的膝关节动力学相关。
更高的峰值 KFM 和 KFM 冲量与滑车和髌骨软骨的 T1ρ 和 T2 弛豫时间升高显著相关，标准化回归系数范围为 0.21 至 0.28。层状分析表明，髌股软骨的浅层总体上与膝关节动力学的相关性更强。亚组分析显示，在 PFJ OA 患者中，膝关节动力学的每一个标准偏差变化都与 PFJ 软骨 T1ρ 和 T2 的增加相关（标准化系数：0.29 至 0.41）。相反，在非 OA 患者中，膝关节动力学与 PFJ 软骨 T1ρ 和 T2 之间的关系较弱。
我们的研究结果表明，峰值 KFM 和 KFM 冲量的增加与 PFJ 软骨健康状况较差有关。这种相关性在浅层软骨和形态学病变的软骨中更为明显。
