青少年特发性脊柱侧凸主胸弯融合后未融合上胸弯的变化及其与肩部平衡的关系

Changes of the non-fused proximal thoracic curve and its relationship with clinical shoulder balance after main thoracic curve correction in adolescent idiopathic scoliosis

目的：探讨青少年特发性脊柱侧凸（AIS）患者主胸弯融合后未融合上胸弯的变化及其与肩部平衡的关系。方法：回顾性分析2008年1月~2010年12月在我院接受手术治疗的AIS患者，选取年龄10～18岁，Lenke分型为Lenke 1、2、3、4型，右胸弯且Cobb角＜80°，采用后路椎弓根螺钉系统固定矫形，固定融合上端椎在T4或T4以下，随访时间2年以上的患者，排除翻修手术和截骨手术患者。术前根据Lenke分型判断上胸弯是否为结构性，分成结构性上胸弯组和非结构性上胸弯组，统计比较两组术前、术后3个月和末次随访时外观肩部平衡以及影像学各项参数的变化。结果：共有62例患者纳入本研究，平均年龄14.4岁，随访时间24~62个月，平均36.4个月，其中结构性上胸弯组17例，非结构性上胸弯组45例。两组患者术后上胸弯均能自发性矫正，末次随访时，上胸弯Cobb角平均由27.9°减小至19.4°，T1倾斜角由-0.21°增加至4.7°，第一肋倾斜角（FRT）由0.4°增加至3.7°，锁骨角（CA）由-1.5°增加至0.8°，双肩高度差（CSH）由-13.0mm增加至5.2mm，改变均有统计学意义（P=0.000）。Pearson相关性分析显示，T1倾斜角的改变（术后T1倾斜角-术前T1倾斜角）与CSH变化（术后CSH-术前CSH）有较强相关性（r=0.624，P=0.000），术后主胸弯的矫正率和FRT与CSH变化为中等程度相关（r=0.437，0.345，P=0.007，0.006），术前主胸弯Cobb角与CSH变化为弱相关（r=0.262，P=0.040）。上胸弯Cobb角及柔韧性、主胸弯柔韧性、T1倾斜角等参数与CSH变化无统计学相关性。结论：AIS患者结构性与非结构性上胸弯在主胸弯矫正以后均有自发性矫正现象，但T1倾斜角、第一肋倾斜角和双肩高度差均会增加。右胸弯患者左肩被抬高的程度与T1倾斜角增加的程度、主胸弯的矫正率及术后第一肋倾斜角相关。

Objectives： To investigate the change of non-fused upper thoracic curve after correction of main thoracic curve in adolescent idiopathic scoliosis（AIS） patients, and its relationship with the clinical shoulder balance. Methods： A retrospective review of consecutive patients treated with posterior pedicle screw fixation and deformity correction from January 2008 to December 2010 was carried out. This study included the patients with an age from 10 to 18 years old, all cases had a type Lenke 1, 2, 3, 4 with right thoracic curve of less than 80°, and all had upper thoracic instrumented vertebra at or lower than T4. The follow-up was more than two years. Patients underwent osteotomy correction, and revision surgery were excluded. According to the Lenke classification, these patients were subdivided into structure upper thoracic curve（UTC） group and non-structure UTC group. Clinical shoulder height difference（CSH） and radiographic features between two groups were measured and compared at preoperative, 3-month follow-up and final follow-up. Results： 62 patients with an average age of 14.4 years old were included in this study. The follow-up ranged from 24 to 62 months, with a mean of 36.4 months. There were 17 cases in structure UTC group, and 45 cases in non-structure UTC group. At final follow-up, the upper thoracic curve in both groups decreased spontaneously from 27.9° to 19.4°, T1 tilt increased from -0.21° to 4.7°, first rib tilt（FRT） from 0.4° to 3.7°, clavicle angle（CA） from -1.5° to 0.8°, and CSH decreased from -13.0mm to 5.2mm. These changes all had significant differences（P=0.000）. The Pearson′s correlation analysis suggested that there was strong correlation between the change of T1 tilt（post T1 tilt - pre T1 tilt） and the change of CSH（post CSH - pre CSH） （r=0.624, P=0.000）, moderate correlation of correction rate of main thoracic curve and postoperative FRT with the change of CSH（r=0.437, 0.345, P=0.007, 0.006）, only weak correlation between preoperative main thoracic Cobb angle and the change of CSH（r=0.262, P=0.040）. There was no statistically significant correlation of UTC Cobb angle, flexibility, T1 tilt, flexibility of main thoracic curve with the change of CSH. Conclusions： After posterior main curve correction, spontaneous correction occurrs in both structure and non-structure upper thoracic curve. However, the T1 tilt, FRT and CSH difference may increase. There is moderate to strong correlation of the elevation of left shoulder with postoperative T1 tilt change, correction rate of main thoracic curve, FRT.