Multimodal intraoperative monitoring during surgery of spinal deformities in 217 patients

A prospective study was performed on 217 patients who received MIOM during corrective surgery of spinal deformities between March 2000 and December 2005. Aim is to determine the sensitivity and specificity of MIOM techniques used to monitor spinal cord and nerve root function during corrective spine surgery. MIOM is becoming an increasingly used method of monitoring function during corrective spine surgery. The combination of monitoring of ascending and descending pathways may provide more sensitive and specific results giving immediate feedback information regarding any neurological deficits during the operation. Intraoperative somatosensory spinal and cerebral evoked potentials combined with continuous EMG and motor evoked potentials of the spinal cord and muscles were evaluated and compared with postoperative clinical neurological changes. A total of 217 consecutive patients with spinal deformities of different aetiologies were monitored by means of MIOM during the surgical procedure. Out of which 201 patients presented true negative findings while one patient presented false negative and three patients presented false positive findings. Twelve patients presented true positive findings where neurological deficit after the operation was predicted. All neurological deficits in those 12 patients recovered completely. The sensitivity of MIOM applied during surgery of spinal deformities has been calculated of 92.3% and the specificity 98.5%. Based upon the results of this study MIOM is an effective method of monitoring the spinal cord and nerve root function during corrective surgery of spinal deformities and consequently improves postoperative results. The Wake-up test for surgical procedure of spinal deformities became obsolete in our institution.

     

Multimodal intraoperative monitoring (MIOM) during cervical spine surgical procedures in 246 patients

A prospective study of 246 patients who received multimodal intraoperative monitoring during cervical spine surgery between March 2000 and December 2005. To determine the sensitivity and specificity of MIOM techniques used to monitor spinal cord and nerve root function during cervical spine surgery. It is appreciated that complication rate of cervical spine surgery is low, however, there is a significant risk of neurological injury. The combination of monitoring of ascending and descending pathways may provide more sensitive and specific results giving immediate feedback information and/or alert regarding any neurological changes during the operation to the surgeon. Intraoperative somatosensory spinal and cerebral evoked potentials combined with continuous EMG and motor-evoked potentials of the spinal cord and muscles were evaluated and compared with postoperative clinical neurological changes. A total of 246 consecutive patients with cervical pathologies, majority spinal stenosis due to degenerative changes of cervical spine were monitored by means of MIOM during the surgical procedure. About 232 patients presented true negative while 2 patients false negative responses. About ten patients presented true positive responses where neurological deficit after the operation was predicted and two patients presented false positive findings. The sensitivity of MIOM applied during cervical spine procedure (anterior and/or posterior) was 83.3% and specificity of 99.2%. MIOM is an effective method of monitoring the spinal cord functional integrity during cervical spine surgery and can help to reduce the risk of neurological deficit by alerting the surgeon when monitoring changes are observed.

     

The diagnostic value of multimodal intraoperative monitoring (MIOM) during spine surgery: a prospective study of 1,017 patients

A prospective study of 1,017 patients who received MIOM during spine surgery procedures between March 2000 and December 2005. To determine the sensitivity and specificity of MIOM techniques used to monitor spinal cord and nerve roots function during spine surgery. MIOM has become a widely used method of monitoring neural function during spine surgery. Several techniques only monitor either ascending or descending pathways and thus may not provide sensitive or specific results. MIOM aims to monitor both ascending and descending pathways therefore giving immediate feedback information regarding any neurological deficits during the operation. Intraoperative sensory spinal and cortical evoked potentials, combined with monitoring of EMG and motor evoked potentials recorded from the spinal cord and muscles elicited by electrical motor cortex, spinal cord, cauda equina and nerve root stimulation, was evaluated and compared with post-operative clinical neurological changes. One thousand and seventeen consecutive patients underwent a total of 4,731 h of MIOM to evaluate any neural deficits that may have occurred during spine surgery. Of these, 935 were true negative cases, 8 were false negative cases, 66 were true positive cases and 8 were false positive cases, resulting in a sensitivity of 89% and a specificity of 99%. Based on the results of this study, MIOM is an effective method of monitoring the spinal cord functional integrity during spine surgery and therefore can lead to reduction of neurological deficit and consequently improve postoperative results.

     

Multimodal intraoperative monitoring (MIOM) during surgical decompression of thoracic spinal stenosis in 36 patients

A prospective study of 36 patients who received multimodal intraoperative monitoring (MIOM) during decompression of thoracic spinal stenosis between March 2000 and December 2005 was chosen as the study design. The objective was to determine the sensitivity and specificity of MIOM techniques used for monitoring spinal cord during surgical thoracic decompression. The background data revealed that the surgical decompression for thoracic spinal stenosis is less frequent than in other regions of the spine. However, due to the relative narrow spinal canal, neurological complications could be severe. The combination of monitoring ascending and descending pathways may provide an early alert to the surgeon in order to alter the surgical procedure, and avoid neurological complications. The methods involved evaluation of intraoperative somatosensory spinal and cerebral evoked potentials and motor evoked potentials of the spinal cord and muscles that were compared with post operative clinical neurological changes. 36 consecutive patients with thoracic spinal stenosis of different aetiologies were monitored by the means of MIOM during the surgical procedure. 31 patients had true negative while one patient had false positive findings. Three patients had true positive and one patient had false negative findings. This indicates a sensitivity of 75% and a specificity of 97%. The one case of false negative findings recovered completely within 3 months. In conclusion, the MIOM is an effective method of monitoring the spinal cord during surgical decompression of the thoracic spine.

     

Multimodal intraoperative monitoring (MIOM) during 409 lumbosacral surgical procedures in 409 patients

A prospective study on 409 patients who received multimodel intraoperative monitoring (MIOM) during lumbosacral surgical procedures between March 2000 and December 2005 was carried out. The objective of this study was to determine the sensitivity and specificity of MIOM techniques used to monitor conus medullaris, cauda equina and nerve root function during lumbosacral decompression surgery. MIOM has increasingly become important to monitor ascending and descending pathways, giving immediate feedback information regarding any neurological deficit during the decompression and stabilisation procedure in the lumbosacral region. Intraoperative spinal- and cortical-evoked potentials, combined with continuous EMG- and motor-evoked potentials of the muscles, were evaluated and compared with postoperative clinical neurological changes. A total of 409 consecutive patients with lumbosacral spinal stenosis with or without instability were monitored by MIOM during the entire surgical procedure. A total of 388 patients presented true-negative findings while two patients presented false negative and 1 patient false-positive findings. Eighteen patients presented true-positive findings where neurological deficit after the operation was intraoperatively predicted. Of the 18 true-positive findings, 12 patients recovered completely; however, 6 patients recovered only partially. The sensitivity of MIOM applied during decompression and fusion surgery of the lumbosacral region was calculated as 90%, and the specificity was calculated as 99.7%. On the basis of the results of this study, MIOM is an effective method of monitoring the conus medullaris, cauda equina and nerve root function during surgery at the lumbosacral junctions and might reduce postoperative surgical-related complications and therefore improve the long-term results.

     

Spinal cord and nerve root monitoring during surgical treatment of lumbar stenosis

The author describes application of intraoperative neurophysiologic monitoring to surgical treatment of lumbar stenosis. Benefits of somatosensory and motor evoked potential studies during surgical correction of spinal deformity are well known and documented. Free-running and evoked electromyographic studies during pedicle screw implantation is an accepted practice at many institutions. However, the functional integrity of spinal cord, cauda equina, and nerve roots should be monitored throughout every stage of surgery including exposure and decompression. Somatosensory evoked potentials monitor overall spinal cord function. Intraoperative electromyography provides continuous assessment of motor root function in response to direct and indirect surgical manipulation. Electromyographic activities observed during exposure and decompression of the lumbosacral spine included complex patterns of bursting and neurotonic discharge. In addition, electromyographic activities at distal musculature were elicited by impacting a surgical instrument or graft plug against bony elements of the spine. All electromyographic events provided direct feedback to the surgical team and were regarded as a cause for concern. Simultaneously monitored evoked potential and electromyographic studies protect spinal cord and nerve roots during seemingly low-risk phases of a surgical procedure when neurologic injury may occur and the patient is placed at risk for postoperative myelopathy or radiculopathy.     

Intraoperative neurophysiologicalmonitoring during cervical spine surgery

Intraoperative neurophysiological monitoring (IONM) of spinal cord function has become commonplace during surgical correction for scoliosis. Less common, albeit no less important, is its use during cervical spine surgery. This report reviews the application of three IONM techniques during cervical spine surgery; namely, somatosensory evoked potentials (SSEP), dermatomal evoked potentials (DEP), and triggered electromyography (trEMG). Each section presents a brief discussion of technical and anesthetic considerations followed by a series of augmentive exemplary case studies to provide better understanding of how best to use IONM during anterior and posterior cervical spine surgery. Particular attention is given to identifying surgical maneuvers that pose particular risk either to the spinal cord or nerve roots as well as how IONM can reduce the incidence of postoperative neurological deficit when performed and interpreted properly. The initial section on SSEPs provides both a technical and surgical overview with particular emphasis on monitoring the "high-risk" patient with cervical spondylitic myelopathy or one with an unstable cervical spine. Those using DEPs and trEMGs represent recent advanced concepts and applications for monitoring cervical nerve root function during decompression (DEP) and placement of posterior lateral mass screws (trEMG), respectively.     

Neurophysiological monitoring of spinal cord function during instrumented anterior cervical fusion.

BACKGROUND CONTEXT: Somatosensory evoked potentials (SSEPs) monitor global spinal cord function, and the interpretation of motor loss is based on inferred rather than direct measurements. Therefore, SSEPs may not be useful for identifying motor function deficits caused by anterior spinal column injury or nerve root injury during decompression or placement of instrumentation. For these reasons, adjunctive methods for monitoring may be especially useful during cervical spine surgery. PURPOSE: To evaluate the effectiveness of SSEP and transcranial electrical motor evoked potential (tceMEP) monitoring of spinal cord function during anterior fusion of the cervical spine. STUDY DESIGN/SETTING: Retrospective review. PATIENT SAMPLE: Consecutive instrumented, anterior cervical spine surgeries performed by the same surgeon at a single institution for 119 patients. OUTCOME MEASURES: Record of neurophysiological alerts during surgery and record of postoperative neurological deficits not present before surgery. METHODS: Spinal cord function was monitored intraoperatively with recordings of ulnar and posterior tibial nerve SSEPs and tceMEPs. RESULTS: Six neurophysiologic alerts occurred that prompted surgeon and/or anesthesiologist intervention. Three patients developed new motor weakness after surgery. One patient had temporary right-leg weakness that was predicted accurately by the disappearance of the right lower extremity tceMEPs. One patient had additional temporary postoperative compromise of the right C5-C6 spinal nerve roots that could not be detected intraoperatively because of absent baseline tceMEPs from the affected muscles. For one patient who developed quadriparesis postoperatively, tceMEP monitoring was precluded by the excessive use of neuromuscular blockade during the procedure. CONCLUSIONS: The results illustrate the potential utility of intraoperative SSEPs and the tceMEPs for detection of changes in spinal cord function related to patient positioning and hemodynamic effects during anterior cervical fusion.     

Intraoperative spinal somatosensory evoked potential monitoring

The relationship of intraoperative monitoring of spinal cord somatosensory evoked potentials and postoperative deficit in 220 cases (121 with scoliosis, 41 with neoplasms, and 58 others) is reported. Bilateral posterior tibial nerve stimulation was used in 181 cases and unilateral median nerve stimulation in 39. Spinal cord (interspinous ligament needles), subcortical (neck surface), and cortical (scalp surface) SEP's were monitored. Seven patients had worsening of neurological function after surgery, three of whom demonstrated significant changes in SEP's monitored. In an additional four cases, there was more than a 50% decrease in amplitude of subcortical/cortical SEP's during monitoring, but no change in neurological status postoperatively. Combined monitoring of spinal cord, subcortical, and cortical SEP's enhanced the certainty of detecting spinal cord dysfunction even though there was a significant number of false-negative and false-positive results. A marked change in the SEP's indicated a high chance of developing a neurological deficit (three or 43% of seven cases), and if there was no change the chance of any neurological postoperative deficit was extremely low (four or 1.87% of 213 cases). These data justify the use of intraoperative SEP monitoring.     

Role of motor-evoked potential monitoring in conjunction with temporary clipping of spinal nerve roots in posterior thoracic spine tumor surgery

Background contextThe vascular supply of the thoracic spinal cord depends on the thoracolumbar segmental arteries. Because of the small size and ventral course of these arteries in relation to the dorsal root ganglion and ventral root, they cannot be reliably identified during surgery by anatomic or morphologic criteria. Sacrificing them will most likely result in paraplegia.PurposeThe goal of this study was to evaluate a novel method of intraoperative testing of a nerve root's contribution to the blood supply of the thoracic spinal cord.Study design/settingThis is a clinical retrospective study of 49 patients diagnosed with thoracic spine tumors. Temporary nerve root clipping combined with motor-evoked potential (MEP) and somatosensory-evoked potential (SSEP) monitoring was performed; additionally, postoperative clinical evaluation was done and reported in all cases.MethodsAll cases were monitored by SSEP and MEPs. The nerve root to be sacrificed was temporarily clipped using standard aneurysm clips, and SSEP/MEP were assessed before and after clipping. Four nerve roots were sacrificed in four cases, three nerve roots in eight cases, and two nerve roots in 22 cases. Nerve roots were sacrificed bilaterally in 12 cases.ResultsMost patients (47/49) had no changes in MEP/SSEP and had no neurological deficit postoperatively. One case of a spinal sarcoma demonstrated changes in MEP after temporary clipping of the left T11 nerve root. The nerve was not sacrificed, and the patient was neurologically intact after surgery. In another case of a sarcoma, MEPs changed in the lower limbs after ligation of left T9 nerve root. It was felt that it was a global event because of anesthesia. Postoperatively, the patient had complete paraplegia but recovered almost completely after 6 months.ConclusionsTemporary nerve root clipping combined with MEP and SSEP monitoring may enhance the impact of neuromonitoring in the intraoperative management of patients with thoracic spine tumors and favorably influence neurological outcome.     

Continuous EMG recordings and intraoperative electrical stimulation for identification and protection of cervical nerve roots during foraminal tumor surgery

OBJECTIVE: Spinal cord function is now routinely monitored with somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) during surgery for intraspinal cervical dumbbell and foraminal tumors. However, upper extremity nerve roots are also at risk during these procedures. Anatomic relations are frequently difficult to interpret because the nerve roots may be displaced by the tumor. We used electrical stimulation with compound muscle action potential (CMAP) recordings at multiple sites to identify the location and course of the involved nerve root and to provide real-time information regarding the functional status of the roots to predict postoperative outcome. METHODS: Ten patients were monitored during surgery for cervical dumbbell or foraminal tumors. SEPs and MEPs were monitored as a routine procedure. CMAPs were recorded from needle electrodes placed in the deltoid, biceps, triceps, and flexor carpi ulnaris muscles. Spontaneous electromyography (EMG) muscle activity was also continuously monitored. A handheld monopolar stimulation electrode was used to elicit evoked EMG responses to identify and trace the course of nerves in relation to the tumor. In four patients, the stimulation threshold was tested before and after tumor resection to predict postoperative nerve root function. RESULTS: Electrical stimulation with CMAP recording was successful in localizing nerve roots during tumor resection in all 10 patients. Monitoring predicted postoperative nerve root preservation after tumor removal in each case. It was possible to identify either by using low-level stimulation (<2.0 V) or by observing changes in spontaneous EMG amplitude if activation was present during surgical dissection. The monitoring of spontaneous muscle activity in response to direct or indirect surgical manipulation during tumor resection also provided continuous assessment of nerve root function and identified any physiologic disturbance induced by surgical manipulation. CONCLUSIONS: Electrical stimulation in the operating field and recording of CMAPs facilitated nerve root identification and predicted postoperative function during dissection and separation from ligamentous or neoplastic tissue in 10 patients. Electrical stimulation might also be useful to predict postoperative preservation of function when nerve root sacrifice is necessary and no motor response is detected intraoperatively.     

Intraoperative somatosensory evoked potential monitoring during anterior cervical discectomy and fusion in nonmyelopathic patients--a review of 1,039 cases.

BACKGROUND CONTEXT: Intraoperative somatosensory evoked potential (SSEP) monitoring has been shown to reduce the incidence of new postoperative neurological deficits in scoliosis surgery. However, its usefulness during cervical spine surgery remains a subject of debate. PURPOSE: To determine the utility of intraoperative SSEP monitoring in a specific patient population (those with cervical radiculopathy in the absence of myelopathy) who underwent anterior cervical discectomy and fusion (ACDF) surgery. STUDY DESIGN: Retrospective review. PATIENT SAMPLE: A total of 1,039 nonmyelopathic patients who underwent single or multilevel ACDF surgery. The control group (462 patients) did not have intraoperative SSEP monitoring, whereas the monitored group (577 patients) had continuous intraoperative SSEP monitoring performed. OUTCOME MEASURE: A new postoperative neurological deficit. METHODS: SSEP tracings were reviewed for all 577 patients in the monitored group and all significant signal changes were noted. Medical records were reviewed for all 1,039 patients to determine if any new neurological deficits developed in the immediate postoperative period. RESULTS: None of the patients in the control group had any new postoperative neurological deficits. In the monitored group there were six instances of transient SSEP changes (1 due to suspected carotid artery compression; 5 thought to be due to transient hypotension) which resolved with the appropriate intraoperative intervention (repositioning of retractors; raising the arterial blood pressure). Upon waking up from anesthesia, one patient in the monitored group had a new neurological deficit (partial central cord syndrome) despite normal intraoperative SSEP signals. CONCLUSIONS: ACDF appears to be a safe surgical procedure with a low incidence of iatrogenic neurological injury. Transient SSEP signal changes, which improved with intraoperative interventions, were not associated with new postoperative neurological deficits. An intraoperative neurological deficit is possible despite normal SSEP signals.     

SSEP analysis in surgery of idiopathic scoliosis: the influence of spine deformity and surgical approach

The study was conducted to assess the possible impact of spine deformity in patients with idiopathic scoliosis (IS) on tibial nerve somatosensory evoked potentials (t-SSEPs) and the influence of spine correction upon postoperative SSEP recordings. In 61 consecutive patients undergoing 64 spinal instrumentations, 129 pre- and postoperative SSEPs were analyzed. The degree of spine deformity was assessed by the pre-operative Cobb angle of the major scoliotic curve. In a control group, reference values of t-SSEP latencies were established with respect to body height. In a cohort study, IS patients were compared with healthy controls with respect to t-SSEP latency, amplitude, configuration and interside difference. The results of the analysis showed that preoperative-body-height-corrected t-SSEP latencies were prolonged in 61% of patients, with a pathological interside difference in 23.4% of them. The impairment of t-SSEPs was not related to the extent of spine deformity as assessed by the Cobb angle. Even without occurrence of postoperative neurological deficits, postoperative t-SSEPs showed significantly increased latencies without changes in t-SSEP configuration. The prolongation of t-SSEP latencies was related to the surgical procedure (combined ventro-dorsal approach), but not to the extent of spine correction, level of instrumentation, or number of fused segments.The analysis of preoperative t-SSEPs was of no predictive value for intra- or postoperative neurological complications. t-SSEPs are significantly affected in IS patients, although these patients show no obvious clinical neurological deficits. The extent of t-SSEP impairment is not related to the severity of scoliosis. Even in clinically uneventful surgery, the postoperative t-SSEPs can be deteriorated depending on the surgical approach. This indicates a subclinical impact of spine surgery upon spinal cord function.     

Somatosensory evoked potential monitoring of spinal cord ischemia during aortic operations

Somatosensory evoked potentials were monitored in 22 consecutive patients undergoing surgical correction of an aortic coarctation. Induction of spinal cord ischemia by cross clamping of the aorta elicited a change in the evoked potential in 9 patients (41%). These alterations occurred within 5 minutes of aortic clamping in 3 cases and after 18 to 21 minutes in the remaining 6 cases. Loss of the somatosensory evoked potential for more than 14 minutes was associated with postoperative neurological deficit. Alteration of the evoked potential within 5 minutes of aortic cross clamping was significantly related to poor collateral circulation shown on the preoperative aortogram. The pathophysiology of evoked potential changes in spinal ischemia is discussed in detail.     

Monitoring evoked potentials during spinal surgery in one institution

Purpose

To review the experience of one tertiary care institution with somatosensory evoked potential (SSEP) monitoring during spinal surgery in order to assess the ability to monitor and predict neurological outcome effectively.

Methods

Records of all patients undergoing spinal surgery during 18 mo were retrospectively reviewed. Information from the patient chart included preoperative neurological status, surgical procedure, anaesthetic management, and postoperative neurological outcome. Information regarding the techniques used and interpretation of all SSEP tracings were obtained from evoked potential data sheets completed for each patient. The incidences of clinically important SSEP changes and new postoperative neurological deficits were analysed.

Results

Somatosensory evoked potential monitoringof the lower and upper extremities with non invasive techniques was used in 309 patients undergoing surgery on the cervical (88), thoracic (52), and lumbar spine (169). Thirty seven patients (11%) did not have suitable tracings for interpretation and 17 (5.5%) had baseline tracings described as poor. An intraoperative SSEP change occurred in 16 patients (6%) with SSEP and seven (2.6%) had a new neurological deficit postoperatively. Three persistent deficits were predicted by permanent SSEP change, and one transient deficit by a transient SSEP change. False positive results occurred in 12 patients (4.4%) and false negative results occurred in three (1.1%), with a sensitivity of 57% and a specificity of 95%. The incidence of SSEP changes was greater in the thoracic (18%) than in the cervical (1.2%) or lumbar (5.4%) groups (P < 0.05).

Conclusion

Effective SSEP monitoring was possible despite the many factors which may have interfered with monitoring. More improvements in the techniques and conditions of monitoring are needed to decrease the incidence of false positive and negative results.     

Neurophysiological monitoring of lumbar spinal nerve roots: A case report of postoperative deficit and literature review

IntroductionIntraoperative neurophysiological monitoring (IONM) has proven to help reduce the probability of postoperative neurological deficit for spinal deformity correctional surgeries. However, in rare cases new deficits may still happen. We report a surgical case in which the patient had postoperative paralysis. We would like to call for more case reports with postoperative neurological deficits as they present difficult clinical cases.Presentation of caseA 61-year-old male patient with severe thoracolumbar kyphoscoliosis underwent posterior spinal correction and fusion with segmental T10-L5 pedicle screws and rods instrumentation with IONM. The only intraoperative event was a pedicle breach at left L3 which was detected by triggered electromyography (EMG) testing, and the pedicle screw was repositioned. Left lower extremity paralysis was observed upon patient awakening. He received rehabilitation treatment and had limited recovery of muscle strength. Partial lumbar nerve root injury was likely the cause of the paralysis.DiscussionThis is a case with new lumbar nerve root deficit, with positive EMG signal change, but negative somatosensory evoked potential (SSEP) and motor evoked potential (MEP) findings. We discuss the different neurophysiological modalities for monitoring lumbar spinal nerve root function. We review journal articles from the past two decades which reported lumbar root deficits, and list neuromonitoring events during the surgeries.ConclusionMultimodality monitoring with spontaneous and electrically triggered EMG combined with SSEP and MEP may provide the best chance to detect lumbar nerve root injuries.     

Nerve root entrapment with pseudomeningocele after percutaneous endoscopic lumbar discectomy: A case report

Context: Pseudomeningocele is a relatively uncommon postoperative complication of spine surgery. Although the condition tends to be asymptomatic and self-limiting, it may cause radicular pain and neurological defect due to herniation of the nerve root or the spinal cord. Its pathophysiology remains unclear. Only few cases with intraoperative photos have been reported.

Finding: We present a case of pseudomeningocele with nerve root entrapment after percutaneous endoscopic lumbar discectomy (PELD). A 52-year-old man had undergone PELD for sciatic pain and showed good postoperative recovery. Unfortunately, he was readmitted for progressive right leg pain at six weeks after the surgery. After the failure of conservative therapy, he received PELD again to explore the surgical site. Intraoperatively, a pseudomeningocele-containing nerve root, herniating through a small defect in the dural sac, was identified. During the dissection process, the pseudomeningocele was broken, which led to entrapment of the nerve root. Thereafter, the microsurgical technique was adopted to relocate the nerve root into the thecae sac and to repair the dural tear by non-resorbable suture.

Conclusion: To our knowledge, this case report is the first documented instance of identification of a pseudomeningocele under an endoscope, and provides insights into the transformation of a pseudomeningocele into a cerebrospinal fluid fistula with nerve root entrapment. For neurological deficit caused by pseudomeningocele following PELD, operative revision by the microsurgery technique is the appropriate strategy.     

Neurological deficit in injuries of the thoracic and lumbar spine

Summary Seventy consecutive patients with injuries of the thoracic and lumbar spine accompanied by neurological deficit were prospectively studied and followed-up.In 40 of these patients with a burst fracture, the degree of involvement of the cross-sectional area of the spinal canal, as revealed on first CT after admission, was not correlated with the type and degree of initial neurological deficit.In patients with injuries of the lumbar spine, neurological deficit may be mild, although the sagittal diameter of the spinal canal may be reduced by as much as 90%.We cannot establish a difference in neurological recovery between those cases who were managed conservatively and those in whom a surgical decompression and stabilization procedure was performed.Surgical stabilizing procedures, however, result in immediate stabilization of the spine, they diminish pain, facilitate nursing care and allow more rapid mobilization and earlier active rehabilitation.If major extraspinal injuries form a relative contra-indication to surgical decompression of the cord and stabilization of the spine injury, the patient can quite well be treated conservatively without endangering neurological recovery.     

强直性脊柱炎后凸截骨矫形致神经损伤并发症分析

 目的 探讨截骨矫形治疗强直性脊柱炎后凸畸形神经系统并发症的原因及预防措施。方法 回顾性分析2006年1月至2012年1月行截骨矫形术治疗126例强直性脊柱炎后凸畸形患者资料,其中18例术后发生神经系统并发症,男15例,女3例;手术时年龄25～56岁,平均36.8岁;术前后凸Cobb角57°～96°,平均76.3°;患者术前ASIA分级均为E级。回顾术中操作情况,分析术后发生神经并发症的原因。结果 18例患者均获得随访,随访时间6～49个月,平均35个月;术后后凸Cobb角为19°～38°,平均27°;获得截骨角度31°～76°,平均49.3°,外观得到明显改善。3例(2.4%,3/126)发生脊髓损伤,其中1例在T12截骨处产生矢状面移位,术中经调整上下螺钉高度和预弯棒角度,重新恢复截骨处的矢状面排列后患者无异常;1例截骨闭合后椎管狭窄导致脊髓受压,重新减压后患者随访无异常;1例术中发生医原性颈椎骨折脱位造成脊髓损伤,复位固定后6个月随访时ASIA分级为B级。15例(11.9%,15/126)发生神经根损伤,其中2例为截骨闭合时L3神经根受到挤压,1例为L3椎弓根置钉失误所致,以上3例患者表现为股四头肌乏力;其余12例表现为相应神经根区域皮肤麻木,主要原因是截骨时神经根受到过度牵拉,截除椎弓根下壁时过度激惹神经根;经脱水、神经营养治疗后恢复正常。结论 神经损伤是截骨矫形术中灾难性并发症。认识强直性脊柱炎的病理特点,避免截骨端发生位移,截骨处充分减压,正确摆放患者手术体位,能够有效降低神经损伤的发生。