海军军医大学学报  2024, Vol. 45 Issue (6): 688-692   PDF    
青少年特发性脊柱侧凸主胸弯悬吊位和矫形术后Cobb角分布差异分析
刘延1, 刘青山1,2, 王梦真3, 韩良丽3, 杨长伟4, 侯藏龙4, 张秋林4     
1. 海军军医大学(第二军医大学)研究生院, 上海 200433;
2. 中国人民解放军联勤保障部队北戴河康复疗养中心, 秦皇岛 066199;
3. 海军军医大学(第二军医大学)第一附属医院麻醉科, 上海 200433;
4. 海军军医大学(第二军医大学)第一附属医院脊柱外科, 上海 200433
摘要: 目的 分析Lenke 1型青少年特发性脊柱侧凸(AIS)患者主胸弯Cobb角分布特征,以及不同节段间悬吊牵引法测得的柔韧性、矫正率、矫正指数的差异。方法 纳入2015年1月至2018年12月于海军军医大学(第二军医大学)第一附属医院行一期脊柱侧凸后路三维矫形融合内固定术的48例Lenke 1型AIS患者。将主胸弯分为近段(T5~T7或T6~T8)、中段(T7~T9或T8~T10)、远段(T9~T11或T10~T12),并测量各段的Cobb角。计算不同节段的侧弯柔韧性、矫正率和矫正指数(术后矫正率/术前侧弯柔韧性)。采用随机区组的方差分析进行统计学分析。结果 患者术前平均年龄为(14.31±2.24)岁,总Cobb角为(51.25±11.86)°,平均Risser分级为2.88±1.93;术后平均随访时间为(38.75±8.82)个月。术前近段Cobb角与远段Cobb角相似[(13.31±5.10)° vs(13.94±5.67)°,P=0.757],中段Cobb角[(24.00±5.61)°]大于近段及远段Cobb角(均P<0.001)。术前近段、中段、远段Cobb角占总Cobb角的比例分别为(25.72±7.97)%、(47.08±5.22)%、(27.20±8.00)%。术前远段侧弯柔韧性高于近段和中段[(64.01±24.18)% vs(35.00±18.02)%、(41.49±17.65)%,均P<0.001]。术后1周,近段、中段、远段矫正率分别为(74.61±15.80)%、(65.66±16.36)%和(73.76±19.41)%,差异无统计学意义(P=0.280);矫正指数分别为2.41±1.20、2.03±1.45和1.49±1.31,近段矫正指数高于远段(P=0.040)。末次随访时,近段、中段、远段矫正率分别为(71.10±14.07)%、(62.39±13.47)%和(69.75±17.53)%,差异无统计学意义(P=0.226);矫正指数分别为2.24±1.10、1.92±1.30和1.39±1.10,近段的矫正指数高于远段(P=0.026)。结论 在Lenke 1型AIS患者中,近段、中段和远段Cobb角分别占主胸弯的25.72%、47.08%、27.20%。悬吊牵引法对远段柔韧性的评估能力最强,即悬吊位下远端节段最灵活,而各节段术后矫正率无明显差异。
关键词: 青少年特发性脊柱侧凸    柔韧性    悬吊牵引法    Cobb角    矫正率    
Differences in distribution of Cobb angles in main thoracic curve suspension position and post-correction in adolescent idiopathic scoliosis
LIU Yan1, LIU Qingshan1,2, WANG Mengzhen3, HAN Liangli3, YANG Changwei4, HOU Canglong4, ZHANG Qiulin4     
1. Graduate School, Naval Medical University (Second Military Medical University), Shanghai 200433, China;
2. Beidaihe Rehabilitation and Recuperation Center, Joint Logistics Support Force of PLA, Qinhuangdao 066199, Hebei, China;
3. Department of Anesthesiology, The First Affiliated Hospital of Naval Medical University (Second Military Medical University), Shanghai 200433, China;
4. Department of Spinal Surgery, The First Affiliated Hospital of Naval Medical University (Second Military Medical University), Shanghai 200433, China
Abstract: Objective To compare the distribution characteristics of the main thoracic curve Cobb angle in Lenke type 1 adolescent idiopathic scoliosis (AIS) patients, and differences in flexibility, correction rate, and correction index measured by different segmental suspension traction methods. Methods Totally 48 Lenke type 1 AIS patients, who underwent one-stage posterior 3-dimensional spinal deformity correction with bone graft fusion and internal fixation in The First Affiliated Hospital of Naval Medical University (Second Military Medical University) from Jan. 2015 to Dec. 2018, were enrolled. The main thoracic curve was divided into proximal (T5-T7 or T6-T8), middle (T7-T9 or T8-T10), and distal (T9-T11 or T10-T12) segments, and Cobb angles were measured for each segment. Flexibility, correction rate, and correction index (correction rate/preoperative flexibility) were calculated for different segments. Statistical analysis was performed using the analysis of variance of randomized block for comparison. Results The preoperative average age was (14.31±2.24) years, the total Cobb angle was (51.25±11.86)°, and the average Risser grade was 2.88±1.93. The average follow-up time was (38.75±8.82) months. The preoperative Cobb angle of the proximal segment was similar to that of the distal segment ([13.31±5.10] ° vs [13.94±5.67] °, P=0.757), and the Cobb angle of the middle segment (24.00±5.61)° was greater than that of the proximal and distal segments (both P < 0.001). The proportions of the proximal, middle and distal Cobb angle to the total Cobb angle were (25.72±7.97)%, (47.08±5.22)% and (27.20±8.00)%, respectively. Preoperative lateral flexion flexibility of the distal segment was significantly higher than that of the proximal and middle segments ([64.01±24.18]% vs [35.00±18.02]%, [41.49±17.65]%, both P < 0.001). The correction rates at 1 week postoperatively were as follows: proximal segment (74.61±15.80)%, middle segment (65.66±16.36)%, and distal segment (73.76±19.41)%, with no significant difference (P=0.280). The correction indexes were as follows: proximal segment 2.41±1.20, middle segment 2.03±1.45, and distal segment 1.49±1.31, and the correction index of the proximal segment was significantly higher than that of the distal segment (P=0.040). At the last follow-up, the correction rates were: proximal segment (71.10±14.07)%, middle segment (62.39±13.47)%, and distal segment (69.75±17.53)%, with no significant difference (P=0.226). The correction indexes were as follows: proximal segment 2.24±1.10, middle segment 1.92±1.30, and distal segment 1.39±1.10, and the correction index of the proximal segment was significantly higher than that of the distal segment (P=0.026). Conclusion In Lenke type 1 AIS patients, the proximal, middle, and distal segments account for 25.72%, 47.08%, and 27.20% of the main thoracic curve Cobb angle, respectively. The suspension traction method has the strongest ability to evaluate the flexibility of the distal segment, that is, the distal segment is most flexible under the suspension position, and the postoperative correction rate of each segment is similar.
Key words: adolescent idiopathic scoliosis    flexibility    suspension traction method    Cobb angle    correction rate    

青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)是一种常见的脊柱疾病,其发病原因不明,早期可无明显症状,而当出现严重脊柱畸形时可能需要接受矫形手术治疗[1-3]。充分的术前准备,包括通过X线片等了解脊柱畸形的严重程度、准确评估侧弯柔韧性,进而选择合适的手术入路、上下固定椎和融合节段等对手术顺利进行具有重要意义[4-5]。柔韧性评估也可以在一定程度上预测术后矫正效果[6]

目前,常用的侧弯柔韧性评估方法主要有仰卧侧屈法、俯卧推挤法、支点侧屈法及悬吊牵引法[5]。其中采用仰卧侧屈法测量Cobb角是评估脊柱侧凸冠状面柔韧性的常用方法[7],但其缺点也显而易见,即在缺少外力的作用下,患者单纯依靠自身力量无法实现最大程度的侧屈。随着三维矫形和椎弓根螺钉内固定技术的应用,通过仰卧侧屈法预测手术的矫正率将不再严谨。不同于仰卧侧屈法,悬吊牵引法则是通过一个背带固定并悬吊患者至下肢离地后拍摄正位X线片,利用重力牵引评估侧弯柔韧性的方法,研究表明其评估术前侧弯柔韧性的准确性较仰卧侧屈法高[8]

虽然目前对脊柱侧凸的柔韧性评估和各型手术矫正率的研究较多,但鲜有研究探讨Cobb角在主胸弯中的分布特征。既往研究表明,AIS患者主胸弯的顶椎与周围椎体具有相似的柔韧性[9]。但对于各分段占整个主胸弯Cobb角的比例、各分段的灵活性等目前尚无相关研究。本研究将Lenke 1型AIS患者的主胸弯分为近段(T5~T7或T6~T8)、中段(T7~T9或T8~T10)、远段(T9~T11或T10~ T12)3个节段,分析Lenke 1型AIS的Cobb角分布特征,比较悬吊牵引法在近、中和远段柔韧性和矫正率方面的差异。

1 资料和方法 1.1 研究资料

回顾性分析2015年1月至2018年12月在海军军医大学(第二军医大学)第一附属医院接受一期脊柱侧凸后路三维矫形融合内固定术的Lenke 1型AIS患者48例。纳入标准:(1)诊断明确且有手术指征的Lenke 1型AIS患者,主胸弯包括T5~T11或T6~T12;(2)患者首次接受脊柱侧凸矫形手术治疗;(3)所有手术均由同一位主刀医师实施;(4)患者术前、术后及随访期间的影像学资料保存完整。排除标准:(1)同时行脊柱截骨术;(2)未签署知情同意书;(3)伴有其他脊柱疾病;(4)随访时间较短或失访。本研究通过海军军医大学(第二军医大学)第一附属医院伦理委员会审批,所有患者均签署书面知情同意书。

1.2 影像学评估方法

将Lenke 1型AIS患者的主胸弯分为近段(近端节段,T5~T7或T6~T8)、中段(顶椎区,T7~T9或T8~T10)、远段(远端节段,T9~T11或T10~T12)3段,采用术前、术后1周及末次随访时X线片进行影像学评估[10]。术前拍摄站立位全脊柱正位及悬吊牵引位X线片,测量各节段Cobb角,计算各节段侧弯柔韧性[11-12]。术后1周及末次随访时复查站立位全脊柱正位X线片,测量各节段Cobb角,计算术后矫正率和矫正指数。所有X线片的Cobb角均按标准方式测量,每个参数均由2名脊柱外科医师独立测量2次,取4次测量的平均值进行分析,通过讨论消除可能存在的分歧。

术前侧弯柔韧性(%)=(术前站立位Cobb角-术前悬吊牵引后测得的Cobb角)/ 术前站立位Cobb角×100%。术后矫正率(%)=(术前站立位Cobb角-术后站立位Cobb角)/ 术前站立位Cobb角×100%。矫正指数=术后矫正率/ 术前侧弯柔韧性。

1.3 手术过程

所有手术操作都由同一术者完成。所有患者均在全身麻醉控制性降压(平均动脉压降至60~65 mmHg,1 mmHg=0.133 kPa)下进行脊柱侧凸后路三维矫形融合内固定术。上端固定椎(upper instrumented vertebra,UIV)选择上端椎或T2至稳定椎。UIV一般选择T4或T5,若左肩高则选择T2,若双肩平衡则选择T3。采用全椎弓根螺钉技术,凸侧先置钉,凹侧选择分节段撑开,凸侧加压,同时去旋转矫正脊柱冠状面、矢状面、水平面的三维畸形,最后磨钻去除椎板皮质,植入同种异体骨条。

1.4 统计学处理

采用SPSS 26.0软件对原始数据进行统计分析。计量资料以 x±s表示,采用随机区组的方差分析进行比较。计数资料以例数和百分数表示。检验水准(α)为0.05。

2 结果 2.1 患者一般资料

共纳入48例由同一术者实施手术治疗的Lenke 1型AIS患者,女34例(70.8%)、男14例(29.2%)。手术时患者年龄为11~18(14.31±2.24)岁,平均Risser分级为2.88±1.93。21例患者的病变节段为T5~T11,27例为T6~T12。48例患者术中均未出现脑脊液渗漏、大血管或脊髓损伤等严重的手术相关并发症。术后平均随访时间为(38.75±8.82)个月,未观察到螺钉或钛棒断裂等情况发生。

2.2 术前影像学评估

术前站立位全脊柱正位X线片测得总Cobb角为(51.25±11.86)°,近段Cobb角为(13.31±5.10)°,中段Cobb角为(24.00± 5.61)°,远段Cobb角为(13.94±5.67)°,各分段Cobb角分布差异有统计学意义(P<0.001)。与近段及远段Cobb角相比,中段Cobb角最大(均P<0.001);近段及远段Cobb角差异无统计学意义(P=0.757)。术前各分段Cobb角占总Cobb角的比例为近段(25.72±7.97)%、中段(47.08±5.22)%、远段(27.20±8.00)%。相较于近段及远段Cobb角所占总Cobb角比例,中段Cobb角占总Cobb角的比例最大(均P<0.001);而近段及远段Cobb角占总Cobb角的比例差异无统计学意义(P=0.700)。

悬吊牵引法术前测得近段、中段、远段Cobb角分别为(7.94±2.67)°、(13.94±5.30)°、(5.13±4.27)°,各分段Cobb角分布差异有统计学意义(P<0.001),其中中段Cobb角大于近段和远段Cobb角(均P<0.001),而近段Cobb角也大于远段Cobb角(P=0.031)。近段侧弯柔韧性为(35.00±18.02)%,中段为(41.49±17.65)%,远段为(64.01±24.18)%,其中远段侧弯柔韧性最高,与中段、近段相比差异均有统计学意义(均P<0.001),近段与中段侧弯柔韧性差异无统计学意义(P=0.315)。

2.3 术后1周影像学评估结果

术后1周站立位全脊柱正位X线片测得近段、中段、远段Cobb角分别为(3.56±2.56)°、(8.50±5.60)°、(3.50± 2.39)°,差异有统计学意义(P<0.001);术后1周中段Cobb角大于近段及远段Cobb角(均P<0.001),而近段与远段术后Cobb角差异无统计学意义(P=0.950)。在术后矫正率方面,近段矫正率为(74.61±15.80)%,中段为(65.66±16.36)%,远段为(73.76±19.41)%,差异无统计学意义(P=0.280)。近段、中段和远段矫正指数分别为2.41±1.20、2.03±1.45和1.49±1.31,近段矫正指数高于远段(P=0.040)。

2.4 末次随访时影像学评估结果

末次随访时,近段(3.81±2.34)°、中段(9.19±5.02)°和远段(4.00±2.10)℃obb角差异有统计学意义(P<0.001),其中中段Cobb角最大,与近段、远段相比差异均有统计学意义(均P=0.001);而近段与远段Cobb角之间差异无统计学意义(P= 0.818)。此外,主胸弯的近段、中段、远段矫正率分别为(71.10±14.07)%、(62.39±13.47)% 和(69.75±17.53)%,差异无统计学意义(P= 0.226)。近段、中段和远段的矫正指数分别为2.24±1.10、1.92±1.30和1.39±1.10,近段的矫正指数高于远段(P=0.026)。

3 讨论

AIS是一种原因不明的脊柱三维畸形,针对Lenke 1型AIS的侧弯位置、结构特征和自然病史的研究已经非常广泛[13-14]。研究表明,在顶椎上下4个椎体水平,柔韧性等特征存在相似性[9]。随着手术技术的革新、矫正理念的演进及新一代三维矫正器械的出现,脊柱侧凸的矫正有了更多的手术选择。目前临床使用较多的几种评估脊柱畸形柔韧性的方法都存在局限性,仰卧侧屈法因个体差异无法预测最佳的矫正效果,支点侧屈法的问题则在于患者因局部侧屈受力产生疼痛引起的不自主肌肉收缩会影响矫正效果[15-17]。悬吊牵引法的主要优势在于能够通过自身重量减小侧弯角度,也存在瘦弱的青少年患者不易配合的问题,但这不影响融合节段的选择[18]。在本研究中,Lenke 1型AIS患者的Cobb角分布处于近乎自然对称状态,其近段与远段所占总Cobb角的比例相似,而中段(包括较刚性侧凸和结构性侧凸的顶椎节段)Cobb角占总Cobb角的比例最大。

从悬吊牵引的柔韧性分布来看,远段的柔韧性最好,而中段与近段之间的柔韧性无显著差异,这可能是由不同节段椎间盘的活动度不同造成的。一般来说,椎间盘节段越低,其可活动性越高[9]。研究表明,更高的柔韧性往往意味着更高的矫正率[19]。然而,本研究结果显示近段、中段和远段的术后矫正率没有显著差异,表明目前可用的评估脊柱侧凸柔韧性的方法可能无法预测椎弓根螺钉内固定的矫正效果[5]。Vora等[20]提出矫正指数的概念,即使用各节段矫正率与术前柔韧性的比值来评估矫正效果。利用矫正指数,可以较好地评价和比较不同方法之间的矫正效果。从术后矫正指数来看,近段矫正指数大于远段,矫正指数越接近1代表预测越准,也提示悬吊牵引法对远段柔韧性的评估更具价值,而对近段和中段的评估价值相对较低。造成这种结果的原因可能是由于较刚性侧凸和结构性侧凸的顶椎节段的存在。此外,外科医师经常倾向使用多种技术,如局部松解、牵张和压迫技术来实施矫正。尽管本研究的病例没有进行脊柱截骨,但可以推断远段并不需要进行脊柱截骨。

研究表明,在采用脊柱后路矫形手术治疗轻中度AIS时,不需要在每个椎体植入椎弓根螺钉,在不影响矫正效果的情况下使用更少的螺钉也能有较好的手术效果[21-23]。然而,目前尚无选择螺钉植入位置的依据,本研究结果可为减少椎弓根螺钉的使用提供参考。既往研究发现,悬吊牵引可以更好地评估脊柱侧凸曲线的重力稳定性,并且能够更好地确定下端固定椎的数量[24-25]。据此,本团队未来将开展相关研究,以验证在柔韧性更佳的远段是否可以减少植入螺钉的数量。

综上所述,在Lenke 1型AIS患者中,近段、中段和远段Cobb角分别占主胸弯的25.72%、47.08%、27.20%。悬吊牵引法所测得的柔韧性数据表明,远端节段最灵活,其评价远端节段矫正的效果较好。术后近段、中段和远段矫正率差异无统计学意义。

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