骨盆入射角与退变性脊柱侧凸患者脊柱-骨盆矢状位平衡调节的关系

The correlation between pelvic incidence and the sagittal spinopelvic balance in degenerative lumbar scoliosis

目的：探讨骨盆入射角（PI）与退变性脊柱侧凸患者脊柱-骨盆矢状位平衡调节的关系。方法采用回顾性病例对照研究方法,共纳入2008年1月—2014年12月河北医科大学第三医院脊柱外科136例退变性脊柱侧凸患者作为观察组,120例同年龄段、同性别组成的健康体检者作为对照组。依据 PI 的不同,将观察组和对照组分为：低 PI 值组（PI 〈45。）、中 PI 值组（PI 45。~60。）、高PI 值组（PI 〉60。）。于脊柱全长侧位 X 线片测量 C7铅垂线与 S1后上角的水平距离（ SVA）、胸椎后凸角（TK）、胸腰段角度（TLJ）、腰椎前凸角（LL）、PI、骶骨倾斜角（SS）、骨盆倾斜角（PT）。分别比较3组PI 值受试者中观察组与对照组脊柱-骨盆矢状位参数的差异,分析观察组与对照组中脊柱-骨盆矢状位参数之间的相关性。结果观察组中低、中、高 PI 值的受试者,分别为38例（27.9%）、50例（36.8%）、48例（35.3%）,对照组中分别为52例（43.3%）、41例（34.2%）、27例（22.5%）。在观察组中,高 PI 值患者相比于低 PI 值患者表现出较大的 LL、PT、SS 和较小的 SVA（P 值均〈0.01）；与中 PI 值相比,低 PI 值 SS 显著降低（P 〈0.01）,而 PT 则无明显变化（P 〉0.05）；与中 PI 值相比,高PI 值 PT 显著增大（P 〈0.01）,而 SS 则无明显变化（P 〉0.05）。在观察组和对照组中,PI 值与骨盆参数（PT、SS）及脊柱矢状位参数（LL、TLJ）具有相关性,SS 和 LL 之间以及 SS 和 TLJ 之间均具有相关性（P 值均〈0.05）；在观察组中,PT 和 SVA 之间具有相关性（P 〈0.05）。在低、中、高 PI 值中,观察组患者相比于对照组受试者,均表现出 SS 减小和 PT 增大,TK、LL 以及 TLJ 减小（P 值均〈0.01）。结论在退变性脊柱侧凸患者中,骨盆对于 LL 减小的代偿机制因 PI 的不同而存在着差异,PI 较大者的代偿以骨盆后倾为主,而 PI 较小者的代偿以骶骨水平化为主,退变性脊柱侧凸的手术矫形方案制定及术中 LL 重建应考虑到 PI 的大小。

Objective To explore the correlation between pelvic incidence（PI） and the sagittal spinopelvic balance in degenerative lumbar scoliosis （DLS）. Methods From Jan 2008 to Dec 2014, 136 cases of DLS were enrolled as experimental group, 120 healthy age-and gender-matched adults were enrolled as control group. All the participants were divided into three goups according to the PI value： low （PI less than 45. ）, middle （PI between 45. and 60. ）, and high PI group （PI more than 60. ）. Sagittal balance was determined by measuring the sagittal vertical axis （ SVA）, thoracic kyphosis （ TK）, thoracolumbar junction （TLJ）, lumbar lordosis （LL）, PI, sacral slope （SS）, pelvic tilt （PT） were measured at a full spine lateral radiograph, sagittal spinopelvic parametersr were compared between the DLS patients and asymptomatic adults in each PI group. The correlations between spinopelvic parameters were determined using the Pearson correlation coefficient. Results The number of DLS patients with low, middle, and high PI were 38 （27. 9% ）, 50 （36. 8% ）, and 48 （35. 3% ）, respectively. In the Control group, the number of low, middle, and high PI patients were 52 （43. 3% ）, 41 （34. 2% ）, and 27 （22. 5% ）, respectively. In the Experimental group, patients with high PI always presented with large LL, PT, SS and smaller SVA（all P values 〈 0. 01）, the SS was small in low PI than that in middle PI（P 〉 0. 05） and the PT was large in high PI than that in middle PI（ P 〈 0. 01）. In the control group and DLS group, PI determined pelvic orientation（PT, SS） and sagittal spinal patameters（LL, TLJ）. In terms of correlation between SS and LL,＆amp;nbsp;between SS and TLJ, both DLS and control groups showed significant correlations（all P values 〈 0. 05）. In terms of correlation between PT and SVA, only the DLS group showed a significant correlation（P 〈 0. 05）. Compared with the asymptomatic adults, DLS patients showed a high PT and low SS as well as lumbar hypolordosis, thoracic hypokyphosis and decreased TLJ in all PI groups（all P values 〈 0. 01）. Conclusions The compensatory mechanisms of the spine and pelvis in DLS patients depend on PI, the increased PT in high PI and the increased SS in low PI are often observed respectively, surgical planning and lumbar curve restoration should be also dependent on the value of PI.