前路减压融合术与后路单开门椎管扩大成形术治疗多节段脊髓型颈椎病的中期随访研究

Comparison of the middle-term follow-up results between anterior decompression with fusion and posterior open-door laminoplasty for treatment of multi-level cervical spondylotic myelopathy

目的观察颈椎前路减压融合术(anterior decompression with fusion,ADF)和后路单开门椎管扩大成形术(posterior open-door laminoplasty,LAMP)治疗多节段脊髓型颈椎病的中期疗效。方法回顾性收集2011年10月至2016年2月手术治疗多节段脊髓型颈椎病121例患者的病历资料。按手术方式不同分为ADF组和LAMP组。ADF组57例,男39例,女18例;年龄35~77岁,平均(58.8±10.1)岁;LAMP组64例,男48例,女16例;年龄28~82岁,平均(60.6±12.2)岁。主要观察指标为手术时间,术中出血量,术前、术后1、3、6、12和24个月及末次随访时日本骨科协会评分(Japanese Orthopaedic Association Scores,JOA)及改善率,疼痛视觉模拟评分(visual analogue scale, VAS),颈椎曲度,颈椎活动度(range of motion,ROM)以及LAMP术后脊髓前方残余压迫情况。记录轴性症状、C5神经根麻痹等并发症发生率。结果 ADF组平均随访(25.6±3.8)个月,LAMP组(27.3±4.1)个月。ADF组JOA评分术前平均(8.25±2.33)分,末次随访时(14.62±3.15)分,改善率为72.81%±11.32%;LAMP组JOA评分术前平均(8.84±3.65)分,末次随访时(12.97±4.32)分,改善率为66.54%±14.75%,两组末次随访时JOA评分(t=2.458,P=0.015)及改善率(t=3.172,P=0.002)的差异有统计学意义。术后1个月两组患者VAS评分均明显降低,ADF组为(1.92±0.75)分,LAMP组为(2.78±0.68)分,差异有统计学意义(t=2.364,P=0.021);至术后3个月两组间VAS评分的差异无统计学意义。ADF组术前颈椎曲度平均15.3°±7.6°,末次随访时19.2°±5.7°;LAMP组术前颈椎曲度平均16.8°±8.3°,末次随访时13.6°±4.3°,两组末次随访时颈椎曲度的差异有统计学意义(t=2.841,P=0.005)。两种术式均导致术后颈椎ROM下降,ADF组末次随访时15.2°±3.6°,LAMP组18.1°±4.1°,两组的差异有统计学意义(t=3.392,P=0.000),ADF组颈椎ROM丢失角度更多。术后并发症发生率ADF组为35.1%,LAMP组为20.3%,差异无统计学意义。LAMP组根据术后MRI有无脊髓前方残余压迫分为两个亚组,11例患者术后出现脊髓前方残余压迫。末次随访时有脊髓前方残余压迫组JOA评分平均(10.85±5.46)分,改善率40.52%±9.76%;无脊髓前方残余压迫组JOA评分平均(14.18±4.52)分,改善率70.38%±10.52%,两亚组比较差异有统计学意义。末次随访时颈椎曲度、颈椎ROM和ROM丢失角度,有脊髓前方残余压迫组分别是10.2°±7.3°、15.6°±6.7°、11.8°±8.3°;无脊髓前方残余压迫组分别是15.8°±6.5°、20.4°±10.2°、8.8°±6.8°,两亚组比较差异有统计学意义。结论多节段脊髓型颈椎病前路手术直接去除压迫,并有效维持颈椎曲度,神经功能恢复良好;LAMP术后出现颈椎曲度变小和颈椎活动度下降,可能会造成脊髓前方压迫,影响手术疗效。

Objective To compare the medium-term clinical and radiologic outcomes between anterior decompression with fusion (ADF) and posterior open-door laminoplasty (LAMP) in the treatment of multi-level cervical spondylotic myelopathy (MCSM). Methods Data of 121 patients meeting to inclusion criteria from October 2011 to February 2016 were retrospectively analyzed. All the patients were treated with ADF (ADF group, n=57) or LAMP (LAMP group, n=64) for MCSM. There were 39 males and 18 females in ADF group, aged from 35 to 77 years, with an average age of 58.8±10.1 years. And there were 64 cases in LAMP group, including 48 males and 16 females, aged from 28 to 82 years, with an average of 60.6±12.2 years. The operation time and blood loss were recorded. The clinical efficacy was evaluated by Japanese Orthopaedic Association Scores (JOA), improvement rate and visual analogue scale (VAS) before operation, 1, 3, 6, 12 and 24 months after operation and at the latest follow-up. At the same time, sagittal alignment of the C2-C7 lordotic angle and range of motion (ROM) in flexion and extension on plain X-rays was measured. Residual anterior compression to the spinal cord (ACS) in LAMP group on MRI was investigated. The incidence of complications such as axial symptoms and C5 nerve root paralysis were recorded. Results The average follow-up period was 25.6±3.8 months in ADF group and 27.3±4.1 months in LAMP group. Demographics were similar between the two groups. The mean JOA scores in ADF group increased from preoperative 8.25±2.33 to 14.62±3.15 at the latest follow-up, with an average recovery rate of 72.81%±11.32%. The mean JOA scores in LAMP group increased from preoperative 8.84±3.65 to 12.97±4.32 at the latest follow-up, with an average recovery rate of 66.54%±14.75%. The difference between two groups was statistically significant. Both of the VAS scores in the two groups decreased significantly at 1 month after the surgery, but the difference between the ADF group (1.92±0.75) and the LAMP group (2.78±0.68) was statistically significant (t=2.364, P=0.021). There was no significant difference in VAS score between the two groups at 3 months after operation. Cervical lordosis of ADF group increased from 15.3°±7.6° to 19.2°±5.7°, while that of LAMP group decreased from 16.8°±8.3° to 13.6°±4.3°. There was significant difference in cervical curvature between the two groups at the latest follow-up. Both two groups exhibited decreased cervical ROM, 15.2°±3.6° and 18.1°±4.1°, respectively, and the difference between two groups was statistically significant (t=3.392, P=0.000). At the latest follow-up, the incidence of complication was 35.1% in ADF group and 20.3% in LAMP group, and the difference between two groups has no statistically significant. The LAMP group was divided into two subgroups:(1) ACS(+)(n=11) comprising patients who had ACS after surgery, and (2) ACS(-)(n=53) comprising patients without ACS. At the latest follow-up, the average JOA score of patients with anterior residual compression of spinal cord was 10.85±5.46, while the average JOA score of patients without anterior residual compression of spinal cord was 14.18±4.52. The recovery rate differed significantly between the ACS(+) and ACS(-) groups, 40.52%±9.76% and 70.38%±10.52%, respectively. Also at the latest follow-up, the cervical curvature, ROM and ROM loss angle were 10.2°±7.3°, 15.6°±6.7° and 11.8°±8.3° in the group with anterior residual compression of spinal cord, respectively. The groups without anterior residual compression of spinal cord were 15.8°±6.5°, 20.4°±10.2° and 8.8°±6.8°, respectively. Conclusion Both ADF and LAMP groups provided good outcomes at 2-year time-point whereas ADF could achieve more satisfactory outcomes and better sagittal alignment at the middle-term. ADF can remove the compression directly, maintain the curvature of cervical vertebra effectively and restore the nerve function well. The clinical outcomes after LAMP could be influenced by ACS, due to the reduction of cervical curvature and the decrease of cervical range of motion.