Critical analysis of extensive cervical laminectomy

Conventional extensive laminectomy has been widely performed to reduce spinal cord compression, and is greatly facilitated by the use of an air drill. Laminectomy is recognized, however, as the occasional cause of problems after surgery, such as spinal instability or deformity, acceleration of spondylotic change, constriction of the dura mater caused by extradural scar formation, and lack of posterior bony protection for the spinal cord. In an effort to eliminate these negative aspects of conventional laminectomy, a surgical technique called suspension laminotomy has been used. Fifty-five patients treated with conventional extensive laminectomy and 55 others treated with suspension laminotomy were followed up clinically and compared. Flexibility and alignment of the cervical spine were assessed by plane radiographs, and dural configuration by computed tomographic scans. Neurologic improvement was also evaluated. Decrease of spinal movement after laminectomy was observed, notably during extension, probably as a result of functional insufficiency of paraspinal muscles. The incidence of postoperative spinal deformity was lower and the relief of dural constriction better in the patients treated with suspension laminotomy than in those treated with conventional laminectomy. Neurological recovery was significantly better in fully decompressed cases than in insufficiently decompressed cases.     

Treatment of syringomyelia after posttraumatic paraparesis or tetraparesis

This retrospective study of 12 patients with syringomyelia related to spinal cord trauma with paraplegia or tetraplegia and secondary progressive neurologic deficits was conducted to evaluate various surgical treatments. Judging by the results of postoperative neuroradiologic examinations, 75% had incomplete reduction of the spinal fracture at the time of initial surgery. The secondary neurologic deterioration occurred within a delay of 146 +/- 16 months and included ascending sensory deficits in 92%, deafferentation pain in 83%, and increased motor weakness in 33%. There was a positive correlation between the severity of symptoms, incomplete reduction of spinal fracture, and the degree of arachnoid scarring in preoperative neuroradiologic examinations. Syringoperitoneal shunting was performed in 83% of patients, and laminectomy with arachnoid lysis and dural grafting were performed in 17%. Pain was improved in 75%, sensory deficits in 25%, and motor weakness in 8%. During the follow-up period of 44 +/- 25 months, 30% of patients with syringoperitoneal shunting required repeated operation for obstruction or infection, whereas the syringomyelia remained collapsed in the two patients with laminectomy with arachnoid lysis and dural grafting, but this did not require additional surgery. In conclusion, laminectomy with arachnoid lysis and dural grafting seems to be a promising alternative treatment for patients with secondary neurologic deterioration after traumatic paraplegia or tetraplegia. Syringoperitoneal shunting may be reserved for patients without severe arachnoid scarring.     

早期前后联合入路治疗下颈椎骨折脱位并脊髓损伤

目的观察前后路一期减压、植骨、内固定治疗脊髓前后方均受压的下颈椎损伤的疗效。方法对本组自2004年1月至2005年12月5例下颈椎骨折脱位并脊髓损伤接受手术治疗的患者,进行回顾性分析。其中后路椎板切除、前路椎间盘切除、植骨颈椎前路钢板内固定术2例;后路椎板切除、前路病椎次全切除、钛网植骨融合钢板内固定术1例;后路椎板切除小关节复位、小关节间植骨侧块钢板内固定术、前路椎间盘切除、植骨术内固定2例。结果脱位均获完全复位,脊髓获得有效减压,椎间植骨6个月后均获骨性融合。4例脊髓功能有不同程度恢复,术中无重要神经、血管、气管及食道损伤,未发生术后消化道应激性溃疡。结论早期前后联合入路治疗下颈椎骨折脱位并脊髓损伤安全、有效。     

Staged spinal cord decompression through posterior approach for thoracic myelopathy caused by ossification of posterior longitudinal ligament.

STUDY DESIGN: Prospective clinical study of the effect of staged elimination of anatomic factors inhibiting posterior shift of the thoracic spinal cord on the degree of posterior shift of the thoracic spinal cord and its significance in augmenting the safety of ossification of posterior longitudinal ligament (OPLL) manipulation in thoracic OPLL myelopathy. OBJECTIVES: To develop a comprehensive method that enables safe and sufficient decompression of the spinal cord for thoracic OPLL myelopathy. SUMMARY OF BACKGROUND DATA: Decompression of the spinal cord by direct manipulations of thoracic OPLLs, via either anterior or posterior approach, caused some iatrogenic catastrophic spinal cord injuries, and methods to prevent such injuries during surgery have not yet been developed. METHODS: Procedures of elimination of anatomic factors inhibiting posterior shift of the thoracic spinal cord were performed in stages at intervals of between 1 month and 11 years depending on patients' neurologic status. The first stage operation consisted of extensive cervicothoracic laminoplastic decompression with or without posterior longitudinal durotomy, and if the decompression were insufficient, measures for OPLL-spinal cord separation with or without OPLL manipulation were added. RESULTS: All 17 patients with thoracic OPLL myelopathy showed improvements of neurology comparable with those with successful anterior approaches after decompression. The mean follow-up period was 42 months (range 6-101 months). Neurologic improvements persisted for the entire follow-up period in all patients except one patient who developed arachnoid cyst compressing the dorsum of the once-decompressed spinal cord 30 months after surgery. CONCLUSIONS: Staged posterior decompression to eliminate anatomic factors inhibiting posterior shift of the thoracic spinal cord is the safest and the most reliable method of spinal cord decompression to treat thoracic OPLL myelopathy, so far. However, long-term results are required before the methods can be established.     

颅颈区减压及后颅窝重建术治疗Chiari畸形合并脊髓空洞症

目的 探讨颅颈区减压及后颅窝扩大重建术治疗小脑扁桃体下疝畸形（ｃｈｉａｒｉ ｍａｌｆｏｍａｔｉｏｎ,ＣＭ）－脊髓空洞（ＳＭ）复合征的疗效。方法 对１９９４年至１９９９年收治的３７例ＣＭ－ＳＭ复合征患者,采取颅颈区减压、显微硬膜下探查松解、后颅窝扩大重建术,而不行空洞切开引流。结果 ３７例随访６个月至４．５年,症状改善３１例（８３．８％）;不变５例（１３．５％）,加重１例（２．７％）,无死亡;ＭＢＩ     

Spontaneous thoracic spinal cord herniation--case report.

A 54-year-old female presented with spontaneous thoracic spinal cord herniation manifesting as chronic progressive motor weakness in both legs. Spastic paraparesis (4/5) and pathological reflexes such as ankle clonus were noted. She also had mild bladder dysfunction but no bowel dysfunction. She had no sensory disturbance, including tactile and pinprick sense. Magnetic resonance (MR) imaging revealed that the atrophic spinal cord was displaced into the ventral extradural space at the T4-5 intervertebral level with markedly dilated dorsal subarachnoid space. Computed tomography obtained after myelography showed no evidence of intradural spinal arachnoid cyst. She underwent surgical repair of the spinal cord herniation via laminectomy, and spinal cord herniation through the ventral dural defect was confirmed. Postoperative MR imaging revealed improvement of the spinal cord herniation, but her symptoms were not improved. Spontaneous spinal cord herniation is a rare cause of chronic myelopathy, occurring in the upper and mid-thoracic levels, and the spinal cord is usually herniated into the ventral extradural space. Early differential diagnosis from intradural spinal arachnoid cysts is important for a satisfactory outcome.     

Experimental study on pedicle fat grafts after laminectomy: comparison of pedicle fat and free fat grafts

Scar formation adherent to the dura and nerve roots causes recurrent symptoms following laminectomy. Free and pedicle fat grafts have been performed in low-back surgery as a preventive measure. An experimental study in rats was designed to compare pedicle fat grafts and free fat grafts after wide laminectomy, for efficacy in preventing scar formation and for effects on the spinal cord. The following results were obtained. 1) Dense scar formation over the dura and degeneration of the cord were seen at control laminectomy sites. 2) Free fat grafts, examined at 2 and 4 weeks postoperatively, showed death of portions of the graft, whereas pedicle fat grafts always demonstrated the presence of living fat. 3) At 4 months postoperatively, pedicle fat grafts were statistically superior to free fat grafts, which showed scarring over the dura and degeneration of the cord. In conclusion, pedicle fat grafts were more effective in preventing dural scar formation and protecting the cord than free fat grafts.     

Spinal posterior movement after posterior cervical decompression surgery: clinical findings and factors affecting postoperative functional recovery

This study investigated the posterior movement of the spinal cord after posterior decompression surgery and evaluated factors affecting postoperative functional recovery in patients with cervical spondylotic myelopathy (CSM). Thirty-two patients with CSM underwent posterior decompression from C3 to C7 through laminectomy (n=12) and single, open-door laminoplasty (n=20). There were no significant differences between laminectomy and laminoplasty in degree of spinal posterior movement, recovery rate, and curvature index. Japanese Orthopedic Association (JOA) scores improved from preoperative (10.63±1.77; range, 7-14) to 3-months postoperative (13.57±1.50; range, 11-16) (n=32, P<.05) and from preoperative (10.24±1.87; range, 7-14) to 6-months postoperative (14.16±1.54; range, 12-16) (n=21) (P<.05). C5 palsy was observed in 1 (3.1%) patient. The vertebral body-to-spinal cord distances significantly increased after operations, with the greatest posterior movement at C5 and the least posterior movement at C3 and C7. However, the difference in the degree of the spinal movement of C3 to C7 was not statistically significant (P>.05). Furthermore, no correlation was found between the magnitude of spinal posterior movement and the curvature index. In addition, the magnitude of posterior movement and age were not correlated with the postoperative JOA improvement, but the preoperative JOA scores were. Our study shows that both laminectomy and laminoplasty can produce a similar degree of posterior movement of the spinal cord. Cervical lordosis is not associated with the posterior movement of the cord. The preoperative JOA scores, but not posterior movement of the cord and age, are important determinants for postoperative outcome.     

Posttraumatic atlanto-axial subluxation and myelopathy. Efficacy of anterior decompression

Compression of the neuraxis may occur after displaced fractures of the dens. Nonunion or malunion increases the risk of developing neurologic complications because of the resulting atlanto-axial instability. Posterior decompression has generally been the surgical solution to myelopathy at this level. Two patients with cervical myelopathy due to displaced ununited dens fractures were treated with posterior fossa decompression and high cervical laminectomy. Both patients deteriorated after the surgery. Most of their neurologic deficits finally resolved after microsurgical transoral decompression (by resection of the dens). In those patients in whom atlanto-axial instability causes primarily anterior compression of the neuraxis, especially by a bony lesion, decompression posteriorly may not achieve the desired effect, and, instead, may cause a deterioration in the patient's condition. Anterior atlanto-axial subluxation effectively lengthens the bony spinal canal, which results in stretching of the relatively inelastic spinal cord over the bony deformity. If indirect methods of reduction fail to relieve the condition, then anterior transoral decompression is recommended.     

不同时间点减压对环扎法所致损伤脊髓Bcl-2、Bax蛋白的表达及意义

目的:探讨不同时间点减压环扎法所致损伤脊髓中神经细胞凋亡及Bax、Bcl-2的表达及其意义。方法:成年SD大鼠84只,随机分为4组:A组,仅行椎板减压及硬脊膜囊周长测量;采用环扎法建立大鼠脊髓损伤模型,B组于环扎术后8h行脊髓减压;C组于环扎术后72h行脊髓减压;D组环扎术后不行脊髓减压。各组分别于术后1d、7d、14d、21d取材,所得脊髓标本行HE染色、Tunel染色及免疫组化法检测Bax、Bcl-2阳性细胞数等情况,并采用BBB评分评价大鼠后肢神经功能变化。结果:Bax染色:B组和C组术后1d开始阳性细胞数增加,7d时达高峰,14d时仍较明显,21d降低;D组术后阳性细胞数持续升高。Bcl-2染色:B组和C组术后阳性细胞数持续升高;D组术后1d阳性细胞数最多,之后持续降低。Tunel染色:B、C及D组术后1d开始出现凋亡细胞,7d时达高峰,以后逐渐减少,21d时仍可见。Bcl-2/Bax值与Tunel阳性细胞数关系:B组和C组二者存在负相关;D组二者呈正相关。BBB评分:A组术后1周后肢运动功能恢复正常;B组和C组术后逐渐升高(P<0.05);D组术后1天开始逐渐降低,7天时最低,然后逐渐升高。结论:环扎法可以建立稳定的大鼠脊髓损伤模型;早期减压能减少继发性脊髓损伤细胞凋亡,有利于神经功能恢复。     

Pediatric spinal epidural metastases.

A total of 2259 children with solid malignant tumors were treated at St. Jude Children's Research Hospital between the years 1962 and 1987. Of these, 112 (5%) developed spinal epidural metastasis with spinal cord compression during the course of their disease process. Metastatic epidural spinal cord compression was caused most commonly by Ewing's sarcoma and neuroblastoma, followed by osteogenic sarcoma, rhabdomyosarcoma, Hodgkin's disease, soft-tissue sarcoma, germ-cell tumor, Wilm's tumor, and (rarely) hepatoma. There was no significant difference in outcome between patients with small-cell tumors (neuroblastoma, Hodgkin's disease, and germ-cell tumors) who received only chemotherapy and/or radiation therapy and the patients with similar lesions who received a decompressive laminectomy alone or prior to chemotherapy and/or radiation therapy. Patients with spinal cord compression from metastatic sarcoma (Ewing's sarcoma, soft-tissue sarcoma, osteogenic sarcoma, and rhabdomyosarcoma) showed a significant improvement with decompressive laminectomy alone or before medical therapy, compared to those who received radiation therapy and/or chemotherapy without posterior decompression. Pediatric tumors invade the spinal canal via the neural foramen, compressing the spinal cord in a circumferential manner, allowing decompressive laminectomy (posterior approach) to be an effective surgical approach. Sixty-six percent of children who had no evidence of motor or sensory function below the level of the compression became ambulatory after surgical decompression and medical treatment, regardless of tumor type.     

Disturbances of cerebrospinal fluid flow attributable to arachnoid scarring cause interstitial edema of the cat spinal cord

OBJECTIVE: Spinal arachnoid scarring may be caused by trauma, inflammation, surgery, spinal instability, degenerative diseases, or malformations and may lead to progressive neurological deficits and syringomyelia. We wanted to investigate the effects of focal arachnoid scarring in the cervical spinal canal of cats on pressures in the subarachnoid space and spinal cord tissue, as well as on spinal cord histological features. METHODS: Twenty-nine adult cats were used for this study. Nine animals served as control animals, whereas 20 animals received a focal arachnoid scar at C1-C2, which was produced by placement of a kaolin-soaked fibrin sponge on the posterior surface of the spinal cord. After 4 months, pressure recordings above and below the scar, in the subarachnoid space and spinal cord, were performed. Elasticity measurements were performed with small bolus injections. Morphometric analyses of brain and ventricle volumes, sizes of the central canal, and sizes of the perivascular spaces in gray and white matter were also performed. RESULTS: No animal developed clinical or neurophysiological evidence of neurological symptoms at any time. In the kaolin-treated group, pressure recordings revealed a significant increase in the subarachnoid pressure at C1, because of the cerebrospinal fluid flow obstruction. Pressure gradients tended to increase at all measuring points. A significant difference was detected between the spinal cord and subarachnoid space at C2, where the intramedullary pressure exceeded the subarachnoid pressure. Elasticity was significantly increased in the spinal cord at C2. Intracranially, no evidence of hydrocephalus was observed. In the spinal cord, perivascular spaces were significantly enlarged in the posterior white matter above the arachnoid scar and in the central gray matter below the area of scarring in the cervical cord. CONCLUSION: Arachnoid scarring at C1-C2 produces an interstitial type of edema in the central gray matter below the area of scarring in the cat cervical cord, because of altered cerebrospinal fluid and extracellular fluid flow dynamics. These changes may be interpreted as the initial stage in the development of syringomyelic cavities.     

Postoperative cerebrospinal-fluid fistula associated with erosion of the dura. Findings after anterior resection of ossification of the posterior longitudinal ligament in the cervical spine.

Of twenty-two patients who had had anterior decompression of the spinal canal for ossification of the posterior longitudinal ligament and cervical myelopathy, seven had absence of the dura adjacent to the ossified part of the ligament. The spinal cord and nerve-roots were visible through this defect. Although the arachnoid membrane appeared to be intact and watertight in most patients, a cerebrospinal-fluid fistula developed postoperatively in five, and three had a second operation to repair the defect in the dura. On the basis of this experience, we recommend use of autogenous muscle or fascial dural patches, immediate lumbar subarachnoid shunting, and modification of the usual postoperative regimen, such as limitation of mechanical pulmonary ventilation to the shortest time that is safely possible and use of anti-emetic and antitussive medications to protect the remaining coverings of the spinal cord when the dura is found to be absent adjacent to an ossified portion of the posterior longitudinal ligament in the cervical spine.     

Spontaneous reduction of a floated ossification of the ligamentum flavum after posterior thoracic decompression (floating method); report of a case (abridged translation of a primary publication)

Background contextAlthough complete resection is the preferred surgical treatment for ossification of the ligamentum flavum (OLF), it sometimes results in the floating method because of adhesion to, or ossification of, the dura mater. It is difficult to anticipate the degree of floating, and if the floated ossification is large, decompression of the spinal cord may not be sufficient.PurposeTo describe a case of spontaneous reduction of a floated OLF after posterior decompression.Study designCase report and review of the literature.MethodsA 70-year-old woman with OLF of the thoracic spine presented with gait disturbance. A computed tomographic myelogram showed a large ossification and severe spinal canal stenosis at T10–T11. It also showed slight spinal cord compression by ossification at T9–T10.ResultsWe performed a laminectomy with floating ossification at T9–T11 and posterior fusion with a pedicle screw system at T10–T11. After the operation, the patient's neurologic improvement was excellent. Five weeks after the operation, a computed tomogram showed reduction of the floated ossification. Improvement progressed up to 3 months after the operation, bringing a sufficient decompression of the spinal cord, whereas it was insufficient immediately after the operation.ConclusionsOur present study is the first report that showed OLF was reduced after the floating method. Reduction of the floated ossification was observed 5 weeks after the operation.     

The results of treatment of acute injuries of the upper thoracic spine with paralysis

We studied the cases of 218 patients who had had trauma to the upper region of the thoracic spine (first to tenth thoracic vertebra) that resulted in paralysis. Of these, 184 patients had a complete and thirty-four had an incomplete lesion of the spinal cord. Of the 184 patients who had a complete lesion of the spinal cord, none of the 149 patients who were followed for two to fifteen years recovered any significant neurological function, regardless of the type of operative or non-operative treatment. Thirty of the patients with an incomplete lesion of the spinal cord were followed for two to twenty years. Three others were lost to follow-up, and one died with ascending necrosis of the spinal cord and pulmonary failure three months after the laminectomy. Of the remaining thirty patients, twenty-three had an anterior cord syndrome, four had a central cord syndrome, and three had a Brown-Séquard syndrome. Five patients with an incomplete lesion were treated without surgery. Three of these patients recovered the ability to walk while two recovered some function but were still not able to walk. Seventeen patients with an incomplete lesion of the spinal cord were treated by laminectomy. Of these patients, two also had cord-cooling, two had a posterior fusion, and one had cord-cooling, spine fusion, and posterior instrumentation with Harrington rods. Five patients recovered partial ability to walk with braces, four did not, and eight lost neurological function or became completely paraplegic after surgery and did not recover. Eight patients with an incomplete lesion of the spinal cord were treated with anterior transthoracic decompression and fusion, three of whom had had a previous laminectomy that had not improved their status. Five patients recovered the ability to walk without aids, two walked with braces, and one recovered some motor function but was not able to walk. From this study, we concluded that laminectomy is contraindicated for incomplete lesions of the upper region of the thoracic spinal cord and that anterior transthoracic decompression and fusion offers the best chance of recovery of neurological function.     

手术治疗急性无骨折脱位型颈髓损伤的回顾性分析

[目的]分析前路和后路内固定治疗急性无骨折脱位型颈髓损伤的临床治疗效果。[方法]对56例急性无骨折脱位型颈髓损伤的患者进行颈椎前路减压、植骨及颈椎前路带锁钢板内固定术或后路减压侧块钢板螺钉内固定术。术后定期X线片观察损伤节段的稳定性和融合情况以及有无内置物并发症,以JOA评分判定脊髓功能恢复情况。[结果]56例获得随访,时间13～48个月。平均26个月。56例患者均损伤节段稳定,植骨愈合良好,无内置物并发症,脊髓功能JOA评分平均提高5.78分,取得满意疗效;前路术式与后路术式在改善脊髓功能方面无明显差异(P>0.05)。[结论]颈椎前路和后路术式治疗无骨折脱位型颈髓损伤,能使损伤节段获得即刻、坚强的稳定,解除颈髓压迫,为颈髓功能的恢复提供了有利条件。     

The relationship between preoperative cervical alignment and postoperative spinal cord drift after decompressive laminectomy and arthrodesis for cervical spondylotic myelopathy

BackgroundCervical spondylotic myelopathy represents a debilitating disorder, often resulting in significant neurological impairment over time. Cervical laminectomy has enjoyed a successful track record in the surgical management of these patients. Little is understood regarding the significance of postdecompressive migration of the spinal cord in relation to patient outcome.MethodsPreoperative and postoperative cervical spine MRIs of 28 patients who underwent cervical laminectomy and fusion for the treatment of CSM were reviewed. Radiographic parameters including preoperative cervical alignment, LDI, space available at the level cepahlad/caudad to the decompression, percent spinal cord expansion at the radiographically most compressed level, and spinal cord drift to the midpoint of the spinal cord were measured and subsequently analyzed for statistical correlation. The recovery rate based on the mJOA score was calculated for each patient and analyzed for correlation with spinal cord drift.ResultsThe Cobb angle C2-7, cervical spinal angle, and CCI represented tightly correlated measures of cervical alignment. The preoperative cervical alignment did not statistically correlate with postoperative spinal cord drift. No statistical correlation was revealed between postdecompressive spinal cord drift and recovery rate.ConclusionsPreoperative cervical alignment does not statistically correlate with postoperative spinal cord drift in patients undergoing multisegmental decompressive laminectomy and fusion for CSM. The observation of significant posterior shifting of the spinal cord in the context of straight or kyphotic preoperative alignment suggests that posterior decompression and arthrodesis represent a viable option in the surgical management of patients with CSM with nonlordotic preoperative alignment.     

Spinal extradural meningeal cyst with spinal stenosis

STUDY DESIGN: Case report. OBJECTIVE: To present a rare pathology causing a common disease. SETTING: Spine unit of the orthopaedic surgery department of a university hospital in Berlin/Germany. CASE REPORT: A 39-year-old female with an intraspinal extradural arachnoid cyst of the lumbar spine presented with intermittent radiating lumbar pain. The magnetic resonance imaging (MRI) showed a dorsal spinal extradural arachnoid cyst at L3/4. After wide laminotomy L3, operative cyst resection and stabilisation at L3/4 by posterior lumbar interbody fusion (PLIF), major symptom relief occurred. CONCLUSION: Spinal extradural arachnoid cysts are a rare entity causing low back pain and intermittent radicular syndromes. They can be caused by arachnoid herniation through dural weak spots which are hereditary or occur after trauma. A ball-valve mechanism promotes growth. The main diagnostic tool for spinal extradural cysts is the MRI scan. Additionally, myelography is helpful to demonstrate fluid communication. Complete surgical removal of the cyst should be attempted to reduce risk of recurrence. If extensive decompression is needed for the surgical approach causing segmental instability, interbody fusion is recommended. The outcome depends on age, duration and degree of neurological damage.     

Idiopathic spinal cord herniation: case report and review of the literature

OBJECTIVE AND IMPORTANCE: Idiopathic spinal cord herniation (ISCH) is a rare condition, reported in only 25 patients thus far, in which the thoracic cord is prolapsed through an anterior dural defect. It typically presents in middle age as either Brown-Sequard syndrome or spastic paraparesis. CLINICAL PRESENTATION: A 55-year-old woman initially presented at the age of 41 years with Brown-Sequard syndrome at the T8 disc space level on the left side. Investigations, including primitive magnetic resonance imaging, were deemed negative at that time. After a stepwise deterioration over 14 years, she presented again with spastic paraparesis and double incontinence, in addition to her previous spinothalamic dysfunction. Magnetic resonance imaging at this stage suggested either ISCH or a dorsal arachnoid cyst. INTERVENTION: Through a T7-T8 laminectomy, a left-of-midline ISCH was identified and easily reduced by gentle cord traction. No dorsal arachnoid cyst was identified. The anterior dural defect was repaired with a XenoDerm patch (LifeCell Corp., Woodlands, TX). After surgery, there was improved motor and sphincter function. However, there was continued sensory disturbance. CONCLUSION: ISCH is rare cause of thoracic cord dysfunction. Despite prolonged diagnostic delay, significant clinical improvement may be obtained with ISCH reduction and anterior dural repair.