脊柱外科杂志  2017, Vol.15 Issue(6): 331-334   PDF    
椎体次全切除术与椎管扩大椎板成形术术后颈椎矢状位平衡的对比研究
曹鹏, 顾一飞, 周文超, 田野, 袁文     
第二军医大学附属长征医院脊柱外科, 上海 200003
摘要: 目的 对比分析椎体次全切除植骨融合术与椎管扩大椎板成形术术后颈椎矢状位平衡的变化。方法 收集2010年2月-2013年1月本院收治的100例因脊髓性颈椎病伴椎管狭窄症并接受颈椎椎体次全切除植骨融合术(前路组,n=53)或颈椎椎管扩大椎板成形术(后路组,n=47)患者的临床及影像学资料,通过对比术前及末次随访时日本骨科学会(JOA)评分、C2~7 Cobb角、矢状面轴向垂直距离(SVA)、T1倾斜角(T1-slope)的变化,分析不同术式术后患者矢状位平衡的变化。结果 所有手术均顺利完成,随访(25.5±3.2)个月。2组患者术前JOA评分、C2~7 Cobb角、SVA、T1-slope差异无统计学意义(P > 0.05)。末次随访时JOA评分、C2~7 Cobb角、SVA均较术前明显改善,且组间差异有统计学意义(P < 0.05);前路组中,术前高T1-slope患者与低T1-slope患者术后颈椎后凸发生率差异无统计学意义(P > 0.05);后路组中,高T1-slope患者颈椎后凸发生率显著高于低T1-slope患者,差异有统计学意义(P < 0.05)。结论 颈椎前路椎体次全切除术对术后颈椎矢状位平衡的影响优于颈椎后路椎管扩大椎板成形术;当术前患者T1-slope较高时,为减少术后矢状位平衡失代偿,可尽量选择前路手术。
关键词: 颈椎     颈椎病     椎管狭窄     减压术, 外科    
Comparison of cervical sagittal balance after anterior cervical corpectomy and laminoplasty
CAO Peng, GU Yi-fei, ZHOU Wen-chao, TIAN Ye, YUAN Wen     
Department of Spine Surgery, Changzheng Hospital, Second Military Medical University, Shanghai 200003, China
Abstract: Objective To compare the sagittal balance parameters following the procedures of anterior cervical corpectomy and fusion(ACCF) and posterior laminoplasty. Methods Clinical and radiographical data of 100 patients who underwent ACCF(anterior group, n=53) or laminoplasty(posterior group, n=47) from February 2010 to January 2013 were reviewed retrospectively. The pre-and postoperative Japanese Orthopaedic Association(JOA) score, C2-7 Cobb's angles, sagittal vertical axis(SVA) and T1-slope were recorded respectively, and were used to analyzed the postoperative sagittal balance. Results All the operations were successfully completed. The follow-up period was (25.5±3.2)months. There was no significant difference in pre-operative JOA score, C2-7 Cobb's angle, SVA and T1-slope between anterior and posterior groups. At the final follow-up, JOA score, C2-7 Cobb's angles and SVA were significantly improved, and the differences were statistically significant between the 2 groups(P < 0.05). In anterior group, no significant difference in postoperative kyphosis rate was noted between the high T1-slope group and low T1-slope group. In posterior group, a higher rate of kyphosis was observed in high T1-slope group(P < 0.05). Conclusion ACCF is an optimal option for maintaining cervical sagittal balance compared with laminoplasty. In patients with high T1-slope, ACCF should be suggested to avoid postoperative sagittal imbalance.
Key words: Cervical vertebrae     Cervical spondylosis     Spinal stenosis     Decompression, surgical    

颈椎椎体次全切除植骨融合术与颈椎后路椎管扩大椎板成形术是临床治疗多节段脊髓型颈椎病、颈椎后纵韧带骨化及颈椎椎管狭窄症的主要手术方法[1]。目前有部分研究已证实2种术式在神经功能恢复等方面均具有良好疗效[2-3]。但亦有研究提示颈椎后路手术因破坏颈部肌肉-韧带复合体,有可能造成颈椎矢状位失代偿,导致颈椎曲度变直、后凸畸形等严重并发症[4]。本研究拟通过对比椎体次全切除植骨融合术与椎管扩大椎板成形术术后颈椎矢状位平衡变化,明确2种术式对颈椎功能的影响及手术治疗指征间的差异。

1 资料与方法 1.1 一般资料

回顾性分析2010年2月—2013年1月本院收治的因颈椎椎管狭窄症接受椎体次全切除植骨融合术(前路组)或椎管扩大椎板成形术(后路组)患者的临床及影像学资料。纳入标准:经病史、症状、体征及影像学检查证实为多节段脊髓性颈椎病伴椎管狭窄者。排除标准:既往有颈椎手术史;合并肿瘤、结核或创伤等疾病。满足纳入条件者共100例,前路组53例,男32例、女21例,年龄(51.3±8.4)岁;后路组47例,男29例、女18例,年龄(52.1±9.1)岁。2组患者性别、年龄构成组间差异无统计学意义(P > 0.05)。

1.2 手术方式

前路组:患者全身麻醉,取仰卧位,颈部自然后伸。采用常规颈前外侧切口,显露病变节段并定位后切除椎体上下相邻椎间盘,摘除变性髓核组织,达后纵韧带。逐步切除椎体骨质,保留椎体后壁约2 mm,用撑开器撑开,沿椎间隙扩大减压,并切断后纵韧带,摘除脱出的髓核组织。碎骨填充钛网,并置入减压槽,钛网尽量置入椎体深部,使其与椎体后壁相接触,予钢板固定。

后路组:患者全身麻醉,取俯卧位,后正中入路显露病变节段,纵行依次切开皮肤、皮下组织,剥离显露棘突、双侧椎板及关节突内侧部。在两侧椎板的关节突内侧缘开槽,一侧作为门轴侧,磨除外层皮质骨及部分松质骨,保留内层皮质;另一侧为开门侧,完全磨除至内层皮质。将开门侧椎板向门轴侧掀开,并以小钢板固定。

术后予颈托保护6周,尽早恢复功能锻炼。

1.3 观察指标

术前及术后随访均行颈椎正侧位X线检查。以日本骨科学会(JOA)评分[5]及其改善率评价神经功能。由本科室2位未参与本研究者对所有患者X线片进行数据测量,取测量结果的均值。测量数据包括术前及末次随访时2组患者C2~7 Cobb角、矢状面轴向垂直距离(SVA)、T1倾斜角(T1-slope)。其中C2~7 Cobb角为C2椎体下缘连线与C7椎体下缘连线的夹角,当Cobb角 < 0°时认为存在后凸畸形(图 1a);SVA为C1前结节的垂线与经C7椎体后上角垂线的距离(图 1b);T1-slope为T1椎体上缘连线与水平线的夹角(图 1a)。并按术前T1-slope值将2组患者再分为高T1-slope亚组(T1-slope≥25°)和低T1-slope亚组(T1-slope < 25°)。其中前路组中高T1-slope亚组17例,低T1-slope亚组36例;后路组中高T1-slope亚组14例,低T1-slope亚组33例。

a:C2~7 Cobb角与T1-slope b:SVA a:C2-7 Cobb's angle and T1-slope b:SVA 图 1 颈椎矢状位参数 Figure 1 Cervical sagittal parameters
1.4 统计学处理

采用SPSS 17.0软件对数据进行统计学分析。对手术前后各影像学指标及JOA评分进行秩和检验。以P < 0.05为差异有统计学意义。

2 结果

所有患者随访(25.5±3.2)个月。2组患者术前JOA评分、C2~7 Cobb角、SVA、T1-slope差异无统计学意义(P > 0.05,表 1)。末次随访时,JOA评分2组较术前有所改善,且前路组优于后路组,2组间差异有统计学意义(P < 0.05,表 1);末次随访时C2~7 Cobb角2组较术前有所改善,且前路组优于后路组,2组间差异有统计学意义(P < 0.05,表 1);末次随访时SVA 2组较术前有所改善,且前路组优于后路组,2组间差异有统计学意义(P < 0.05,表 1)。

表 1 统计数据 Table 1 Statistical data

JOA评分改善率:前路组术前高T1-slope患者与低T1-slope患者相比差异无统计学意义(P > 0.05,表 2);后路组术前高T1-slope患者低于低T1-slope患者,差异有统计学意义(P < 0.05,表 2);术前高T1-slope患者,前路组高于后路组,差异有统计学意义(P < 0.05,表 2);术前低T1-slope患者,2组间差异无统计学意义(P > 0.05,表 2)。术后后凸畸形发生率:前路组术前高T1-slope患者与低T1-slope患者相比差异无统计学意义(P > 0.05,表 2);后路组术前高T1-slope患者高于低T1-slope患者,差异有统计学意义(P < 0.05,表 2);术前高T1-slope患者,后路组高于前路组,差异有统计学意义(P < 0.05,表 2);术前低T1-slope患者,2组间差异无统计学意义(P > 0.05,表 2)。

表 2 不同T1-slope亚组疗效对比 Table 2 Comparison of the curative effect of different T1-slope subgroups
3 讨论

近年来,颈椎矢状位平衡被作为颈椎手术疗效的重要考量指标引起了国内外学者的广泛关注。由于手术对颈椎曲度的重建以及对后方肌肉-韧带复合体的损伤,常可导致术后颈椎矢状位平衡丢失,从而引起颈椎曲度变直、后凸畸形等严重并发症,影响颈椎功能,降低患者生活质量[6-7]。T1-slope是近年备受关注的重要颈椎矢状位平衡评估指标。T1作为整个颈椎的底座,其倾斜度与颈椎前倾直接相关[8]。Knott等[9]指出T1-slope是与SVA相关性最高的矢状位平衡参数,可用于预测颈椎矢状位平衡状况。当颈椎前倾过多时,机体不得不通过颈椎过伸以代偿颈椎前倾,使视线保持水平[8, 10-11]。T1-slope较高的患者需要更多的颈椎前凸曲度和更大的肌肉负荷以维持颈椎矢状位平衡[11]。而当手术破坏颈椎后方肌肉-韧带复合体,使之难以承担头部重量时,则可出现矢状位平衡失代偿。T1-slope ≥ 25°的患者术后2年随访时颈椎后凸改变显著增加。Kim等[13]研究了术前的T1-slope程度对后路手术患者术后神经功能的影响,发现高T1-slope组术后JOA评分改善率显著低于低T1-slope组,提示术前较高的T1-slope可影响后路单开门术后神经功能恢复。林圣荣等[14]认为后路单开门椎管成形术术后颈椎矢状位平衡出现显著变化,而术前T1-slope较高的患者行后路单开门手术效果较差,需选择恰当的手术方式来降低其对手术疗效的不利影响[15-18]

本研究对比了术前T1-slope不同的患者在接受前路椎体次全切除术及后路椎管扩大椎板成形术术后颈椎矢状位平衡的变化,发现低T1-slope患者不论前路或后路手术均可获得良好疗效,而高T1-slope患者接受前路手术后JOA评分改善率明显优于接受后路手术者,其后凸畸形发生率亦明显低于后路者。笔者认为这是由于前路手术避免了损伤后方肌肉-韧带复合体,同时通过钛网和钢板塑形重建颈椎生理曲度和稳定性,进一步避免了颈椎矢状位平衡失代偿的发生。本研究为回顾性研究,在选择患者术式及分组中仍存在选择性偏倚。今后研究中有待行大样本前瞻性随机对照研究,以进一步明确颈椎矢状位平衡对手术方案选择的意义。

综上所述,前路椎体次全切除术对术后颈椎矢状位平衡的影响优于后路椎管扩大椎板成形术。术前高T1-slope患者行后路手术的效果较差,容易出现矢状位平衡失代偿。当患者术前T1-slope较高时,为减少术后矢状位平衡失代偿,经评估手术适应证后,可尽量选择前路手术。

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