基于年龄和性别的中国正常成年人脊柱-骨盆矢状位形态的多中心研究

Age-and gender-related sagittal spinal-pelvic alignment in Chinese adult population:a multicenter study with 786 asymptomatic subjects

目的建立基于性别与年龄的中国正常成年人脊柱-骨盆矢状位参数正常参考范围,并评估年龄、性别和种族对脊柱-骨盆矢状位参数的影响。方法通过多中心联合前瞻性纳入年龄20~89岁的中国正常成年人共786名。应用EOS低辐射X线机摄站立位全身X线片以评估脊柱-骨盆矢状位形态。测量胸椎后凸角(thoracic kyphosis,TK)、腰椎前凸角(lumbar lordosis,LL)、骨盆入射角(pelvic incidence,PI)、骨盆倾斜角(pelvictilt,PT)、骶骨倾斜角(sacral slope,SS)、下腰椎前凸(L4~S1 lumbar lordosis,LLL)、整体倾斜(global tilt,GT)、T1骨盆角(T1-pelvic angle,TPA)和矢状面平衡(sagittal vertical axis,SVA),并计算PI-LL值和前凸分布指数(LLL/LL,LDI)。采用Oswestry功能障碍指数(Oswestry disability index,ODI)评估患者生活质量。应用相关性系数(intraclass correlation coefficient,ICC)评估观察者内和观察者间测量数据的可信度。比较不同性别与年龄组的脊柱-骨盆参数,并与文献中不同种族人群的结果进行对比分析。结果786名正常成人身体质量指数(body mass index,BMI)为23.7±7.1 kg/m2,ODI为6.9%±2.5%(0~18%)。建立按照年龄和性别分组的矢状位参数,ICC为0.86~0.95,表明可信度较好至优秀。统计结果显示男性与女性间多项矢状面参数的差异有统计学意义(P<0.05),女性PI(45.0°vs.41.4°)、PT(13.9°vs.10.7°)、PI-LL(1.8°vs.-0.5°)和GT(13.5°vs.10.9°)均明显高于男性(P<0.001),而男性LLL(28.6°vs.26.6°)和LDI(0.68 vs.0.63)则明显高于女性(P<0.001)。自40岁组至80岁组PI-LL、SVA、GT和TPA均随着年龄增加而明显升高;而LL、LLL、LDI则逐渐降低,TK随年龄增长缓慢。不同种族间正常成年人脊柱-骨盆矢状面参数的对比显示,中国人PI、SS、TK、LL较美国人小,而PI-LL较高;与日本人相比,中国人PI、SS和LL均较小。随着年龄增长,本研究中国人群与日本、美国人群各矢状面参数保持较为一致的变化趋势。结论成功建立了基于年龄和性别的正常成年中国人脊柱-骨盆矢状面形态参数正常参考范围,不同年龄和性别间的矢状面形态存在明显差异。不同种族人群为维持矢状面平衡的脊柱-骨盆复合体代偿模式也存在差异,因此,评估脊柱畸形以及制定脊柱矫正手术方案时应充分考虑性别、年龄以及种族等因素。

Objective To establish age-and gender-based normative values of sagittal spinal-pelvic alignment in Chinese adult population,and to investigate influence of age,gender and ethnicity on sagittal spinal-pelvic alignment in Chinese normal adults.Methods A total of 786 asymptomatic Chinese adult volunteers aged between 20 and 89 years were prospectively recruited from different spine centers.The inclusion criteria were:1)age between 20 to 89 years old;and 2)Oswestry disability index(ODI)scored lower than 20.The exclusion criteria were:1)previous history of spinal,pelvic or lower limb pathologies that could affect the spine;2)presence of recent and/or regular back pain;3)previous surgeries on spine,pelvic and/or lower limb;and 4)pregnancy.Demographic characteristics of these subjects including age,gender,body weight and height were recorded.During the enrollment of volunteers,16 groups were defined based on the age(20 s,30 s,40 s,50 s,60 s,70 s and 80 s)and gender.Whole body biplanar standing EOS X-ray radiographs were acquired to evaluate the sagittal alignment.Spinal-pelvic parameters including pelvic incidence(PI),pelvic tilt(PT),sacral slope(SS),thoracic kyphosis(T5-T12,TK),lumbar lordosis(L1-S1,LL),lower lumbar lordosis(L4-S1,LLL),global tilt(GT),T1 pelvic angle(TPA)and sagittal vertical axis(SVA)were measured.Values of PI-LL and lordosis distribution index(LLL/LL,LDI)were calculated.Radiographic measurements of 100 subjects were randomly selected to determine the intra-and inter-observer reliabilities using inter-and intra-class correlation coefficients(ICC).The spinal-pelvic parameters were compared among volunteers between different age and gender groups.The comparison was also made among various ethnic population.Results The mean value was 23.7±7.1 kg/m2 for BMI and 6.9%±2.5%(range,0-18%)for ODI score.Each sagittal spinal-pelvic parameter was presented with mean value and standard deviationbased on age and gender.The ICCs of radiographic measurements ranged from 0.89 to 0.95,suggesting good to excellent intra-and inter-observer reliabilities.Significant differences were observed between males and females in multiple sagittal parameters(all P values<0.05).Compared to the male subjects,significantly higher values of PI(41.4°for male vs.45.0°for female,P<0.001),PT(10.7°for male vs.13.9°for female,P<0.001),PI-LL(-0.5°for male vs.1.8°for female,P<0.001),and GT(10.9°for male vs.13.5°for female,P<0.001)were documented in female subjects.Males had significantly higher values of LLL(28.6°for male vs.26.6°for female,P<0.001)and LDI(0.68 for male vs.0.63 for female,P<0.001).PI-LL,SVA,GT and TPA increased with aging from Group 40 s to Group 80 s,while LL,LLL and LDI decreased gradually,and TK decreased slowly with aging.Comparison of sagittal spinal-pelvic parameters between different ethnic subjects showed that Chinese adult population presented lower PI,SS,TK and LL as compared with American population;lower PI,SS and LL as compared with Japanese population.But the variation trend with aging tended to be consistent among different ethnic populations.Conclusion Age-and gender-based normative values of sagittal spinal-pelvic alignment were established in asymptomatic Chinese adult population.Sagittal spinal-pelvic alignment varies with age and gender,and presented different compensation mechanism among different ethnic populations.Therefore,to achieve balanced sagittal alignment,age,gender and ethnicity should be take intoconsideration when planning spine correction surgery.