肌电图监测在极外侧入路椎间融合术联合经皮椎弓根螺钉内固定术中的应用

Application of electromyography monitoring in extreme lateral interbody fusion combined with percutaneous pedicle screw osteosynthesis

目的:探讨肌电图监测在极外侧入路椎间融合术(extreme lateral interbody fusion,XLIF)联合经皮椎弓根螺钉内固定术中应用的可行性和监测效果。方法:对46例行XLIF联合经皮椎弓根螺钉内固定术治疗的患者进行实时肌电图监测,其中男24例,女22例;年龄53.2±18.7岁。XLIF通道建立过程中采用自发肌电图监测神经根在术中是否受到牵拉、激惹等刺激,通过计算真阳性率和真阴性率得出监测的灵敏度和特异度。同时,利用诱发肌电图监测132枚椎弓根螺钉置入对神经电生理变化的影响。分析并推测手术中肌电监测的影响因素,尽量控制监测假阳性及假阴性的发生。为评价肌电监测的临床效果,记录肌电监测的阳性和阴性结果例数,并比较术前及术后1个月患者的JOA评分(Japanese Orthopaedic Association score)及Oswestry功能障碍指数(Oswestry disability index,ODI)评分。结果:46例患者共69个节段行椎间融合(L1/2 5例,L2/3 9例,L3/4 32例,L4/5 23例)。自发肌电监测有16例发现异常肌电波形,其中14例(真阳性)经调整手术操作后能恢复正常波形,2例(假阳性)经短暂观察后自行恢复至正常,14例患者中有3例术后出现神经根功能损伤症状。其余30例术中无异常肌电波形的患者中,有3例(假阴性)术后出现神经根功能损伤症状,27例(真阴性)术后无神经根功能损伤症状。通过上述数据计算得出术中自发肌电图监测灵敏度为82.35%,特异度为93.10%。后路经皮椎弓根螺钉固定术中采用诱发肌电监测132枚椎弓根螺钉置入(L1:8枚,L2:15枚,L3:27枚,L4:48枚,L5:34枚),其中118枚螺钉置入时肌电监测提示阴性,术后CT提示其中有5枚螺钉穿破椎弓根皮质。另外14枚螺钉攻丝后,刺激强度为10m A时出现肌电图反应,术后有13个椎弓根出现椎弓根内侧皮质骨折表现。患者术前JOA评分14.8±2.1分,术后为23.9±2.5分,较术前明显改善(P<0.05)。术前ODI评分为38.3±3.1分,术后为13.6±2.9分,改善率为65.7%,较术前明显改善(P<0.05)。结论:极外侧入路腰椎融合联合经皮椎弓根螺钉内固定术中应用肌电图监测具有较高的灵敏度和特异度,有一定的临床应用价值。

Objectives：To explore the feasibility and monitoring effect of the application of electromyography（EMG） monitoring in extreme lateral interbody fusion（XLIF） combined with percutaneous pedicle screw osteosynthesis.Methods：46 cases（24 males,22 famales） who were treated with XLIF combined with percutaneous pedicle screw osteosynthesis were given ECG monitoring,aging 53.2 ±18.7 years.During the establishment of XLIF channel,spontaneous EMG monitoring was applied to monitor whether the nerve root was extracted,irritated or stimulate.Evoked EMG monitoring was used to monitor the effects of physiological changes of nerve for the implantation of 132 pedicle screws at the same time.The influence factors of EMG monitoring were analyzed and speculated to control the occurrence of false positives and false negatives.The positive and negative results were recorded,and the patients′ preoperative and postoperative JOA and ODI scores were compared to evaluate the clinical effect of EMG monitoring.Results：69 segments were treated with interbody fusion in 46 cases（L1/2 in 5 cases,L2/3 in 9 cases,L3/4 in 32 cases,L4/5 in 23 cases）.A-mong them,16 cases were found abnormal EMG waveform,in which 14 cases（true positive） recovered from abnormal EMG reactions after adjustment of operation but the symptom of nerve root injury after operation appeared in 3 cases,the normal waveform after a brief observation appeared in 2 cases（false positive）.Among the 30 patients without abnormal waveform,the symptom of nerve root injury after operation appeared in 3cases（true negative）,27 cases were normal.The sensitivity and specificity of intraoperative spontaneous EMG monitoring was 82.35% and 93.10% in our data.The intraoperative evoked EMG monitoring was used to monitor the implantation of 132 pedicle screws（8 pieces in L1,15 pieces in L2,27 pieces in L3,48 pieces in L4,34 pieces in L5）.The EMG results of 118 pedicle screws were negative,in which 5 screws broke cortex of pedicle in CT examination.EMG response appeared in another 14 screws after tapping when the intensity was 10 m A.The pedicle interior cortex of 13 vertebrate was broken.The preoperative JOA score of monitoring group was 14.8 ±2.1,and postoperative JOA score was 23.9 ±2.5,which was obvious improved（P〈0.05）.The preoperative ODI score of monitoring group was 38.3±3.1,and postoperative ODI score was 13.6±2.9,and the improvement rate was 65.7%（P〈0.05）.Conclusions：The application of EMG monitoring in extreme lateral interbody fusion combined with percutaneous pedicle screw osteosynthesis showed high sensitivity and specificity,which has a preferable clinical value.