目的 对比研究不同海拔地区新兵在高海拔地区体能训练各阶段致膝关节损伤的MRI表现特点,为减少其发生提供理论依据。方法 120名新兵,分为低海拔组和高海拔组,在新训的第1、2、3个月行右膝关节MRI扫描,观察各阶段的膝关节骨质(骨髓、骨皮质、关节软骨)、半月板、韧带、软组织及关节腔损伤情况。结果 (1)低海拔组新兵第1阶段骨髓水肿及关节腔积液检出率(85.0%、65.0%)高于高海拔组新兵检出率(46.7%、33.3%;P<0.01);低海拔组新兵第2阶段骨髓水肿及关节腔积液检出率(91.7%、86.7%)高于高海拔组新兵检出率(71.7%、65.0%;P<0.01);(2)低海拔组新兵第2、3阶段半月板损伤检出率(16.7%、20.0%)高于同阶段高海拔组新兵检出率(1.7%、3.3%;P<0.01);(3)两组新兵各阶段骨皮质、关节软骨、韧带及软组织损伤检出率差异均无统计学意义。结论 低海拔地区新兵新训期膝关节损伤率高于高海拔地区,应该根据新兵来源地区的海拔高度制定正确施训策略和防护措施,以减少其发生。

Objective To study comparatively the MRI features of knee injuries caused by physical training at high altitudes in different stage in recruits coming from different altitudes and provide a theoretical basis for reducing the incidence of knee injuries. Methods 120 recruits were divided into two groups: low-altitude group and high-altitude group. Then, we observed the lesions of their right knees’ joint in different stages including cortical bone, bone marrow, cartilage, meniscus, ligaments and articular cavity by examining with 1.5T MRI in the first three months of training. Results (1) The detectable rate of low-altitude group’s bone marrow edema and joint effusion in the first stages and second stages(first stage 85% and 65%,second stage 91.7% and 86.7%) were all higher than that of high-altitude group’s (first stage 46.7% and 33.3%,second stage 71.7%and 65%;P<0.01).(2)The detectable rate of low-altitude group’s meniscus injury in the second and third stages (second stage 16.7%,third stage 20%)were all higher than that of high-altitude group’s (second stage 1.7%,third stage 3.3%;P<0.01). (3)The differences in the detectable rates of both groups’ cortical bone, cartilage, ligaments and soft tissue injury in different stages were not statistically significant. Conclusions The injury rate in recruits from low altitude is higher than that in recruits from high altitude. Therefore, it is necessary to develop protective and scientific strategies to reduce the chances of injury’s occurrence.