马拉松运动对膝关节软骨体积及T2弛豫时间的影响

Effects of marathon exercise on knee cartilage volume and T2 relaxation time

目的基于MRI探讨马拉松运动对膝关节软骨体积及T2弛豫时间(T2值)的影响。方法2018年12月至2021年12月招募25名无长跑习惯的健康志愿者和32名长期进行长跑运动的非专业马拉松运动员,行膝关节MRI三维选择性水激发序列(three dimensional water-selective excitation,3D-WATS)和T2 mapping成像,同时提取膝关节5个区的软骨体积和42个亚区软骨T2值进行分析。比较健康志愿者与非专业马拉松运动员膝关节各区软骨体积及其与体表面积比值、各亚区软骨T2值,以及马拉松运动强度与不同区域软骨体积和T2值的相关性。结果与健康志愿者相比,非专业马拉松运动员的各区软骨体积及体积与体表面积比值的差异无统计学意义(P>0.05)。健康志愿者与非专业马拉松运动员的股骨内侧髁中央区中间层[(47.61±5.65)ms和(44.29±6.10)ms]、股骨内侧髁中央区深层[(36.82±9.05)ms和(31.67±7.59)ms]、股骨内侧髁前区深层[(38.37±4.68)ms和(34.09±4.19)ms]、股骨外侧髁中央区浅层[(52.17±11.11)ms和(45.51±7.76)ms]、股骨外侧髁中央区中间层[(49.09±5.08)ms和(45.63±5.04)ms]、股骨外侧髁前区中间层[(45.69±4.68)ms和(42.57±5.77)ms]、股骨外侧髁后区浅层[(55.42±18.41)ms和(47.99±8.39)ms]、胫骨内侧平台前区深层[(33.40±7.76)ms和(29.03±5.69)ms]、胫骨内侧平台后区深层[(31.28±5.02)ms和(27.92±5.99)ms]、髌股关节面髌骨区深层[(35.65±6.99)ms和(32.30±5.28)ms]软骨T2值的差异均有统计学意义(P<0.05)。在非专业马拉松运动员中胫骨内侧平台软骨体积与步频呈负相关(r=-0.371,P=0.035),股骨外侧髁软骨体积与步频呈负相关(r=-0.365,P=0.043),胫骨外侧平台软骨体积与步频呈负相关(r=-0.550,P=0.001);胫骨内侧平台前区中间层软骨T2值与体重呈负相关(r=-0.277,P=0.039)、与体质指数呈负相关(r=-0.290,P=0.030),髌股关节面髌骨区浅层T2值与3个月内跑量呈负相关(r=-0.457,P=0.010),胫骨外侧平台后区浅层T2值与步幅呈负相关(r=-0.437,P=0.014),股骨外侧髁前区中间层软骨T2值与步频呈负相关(r=-0.380,P=0.035)。结论马拉松运动对膝关节软骨体积的影响较小,而对软骨T2值产生一定影响,导致软骨结构改变。步频越高软骨体积越小;体重或体质指数越大、3个月内跑量越大、步幅越大软骨T2值越小。

Objective To investigate the effects of marathon exercise on knee cartilage volume and T2 relaxation time(T2 value)based on MRI.Methods From December 2018 to December 2021,25 healthy volunteers without long-distance running habits and 32 non-professional marathon runners with long-term long-distance running were recruited to undergo knee MRI 3D water-selective excitation(three dimensional water-selective excitation,3D-WATS)and T2 mapping imaging were performed,and the cartilage volumes in 5 knee areas and T2 values in 42 subareas were extracted for analysis.To compare the cartilage volume and its ratio to body surface area of knee joint of healthy volunteers and non-professional marathon runners,the T2 value of cartilage in each subregion,and the correlation between marathon exercise intensity and the volume and T2 value of cartilage in different regions.Results Compared with healthy volunteers,there was no significant difference in cartilage volume or the ratio of body surface area to body volume of non-professional marathon runners(P>0.05).There were significant differences between healthy volunteers and non-professional marathon runners in cartilage T2 values of the median layer of medial condyle of femur(47.61±5.65 ms and 44.29±6.10 ms)and the deep layer of medial condyle of femur(36.82±9.05 ms and 31.67±7.59 ms),deep precondylar area of medial femur(38.37±4.68 ms and 34.09±4.19 ms),shallow area of medial condylar area of femur(52.17±11.11 ms and 45.51±7.76 ms),middle layer of medial condylar area of femur(49.09±5.08 ms and 45.63±5.04 ms),medial layer of anterior condylar region of lateral femur(45.69±4.68 ms and 42.57±5.77 ms),superficial layer of posterior condylar region of lateral femur(55.42±18.41 ms and 47.99±8.39 ms),deep layer of anterior tibial medial plateau(33.40±7.76 ms and 29.03±5.69 ms),deep layer of posterior tibial medial plateau(31.28±5.02 ms and 27.92±5.99 ms),deep layer of patellofemoral surface(35.65±6.99 ms and 32.30±5.28 ms),respectively(P<0.05).In non-professional marathon runners,the medial tibial plateau cartilage volume was negatively correlated with step frequency(r=-0.371,P=0.035),the lateral femoral condylar cartilage volume was negatively correlated with step frequency(r=-0.365,P=0.043),and the lateral tibial plateau cartilage volume was negatively correlated with step frequency(r=-0.550,P=0.001).The T2 value of the medial layer cartilage in the anterior tibial medial plateau region was negatively correlated with body weight(r=-0.277,P=0.039)and body mass index(r=-0.290,P=0.030).The T2 value of the superficial layer of patellofemoral surface was negatively correlated with the amount of running in 3 months(r=-0.457,P=0.010).The superficial T2 value in the posterior lateral plateau of the tibia was negatively correlated with stride length(r=-0.437,P=0.014),and the medial layer cartilage T2 value in the anterior condylar area of the lateral femur was negatively correlated with stride frequency(r=-0.380,P=0.035).Conclusion Marathon exercise had little effect on the knee cartilage volume,but had a certain effect on the cartilage T2 value,resulting in changes in cartilage structure.The higher the step frequency,the smaller the cartilage volume.The greater the body weight or body mass index,the greater the amount of running in 3 months,and the greater the stride length,the lower the cartilage T2 value.