Incidence of spinal deformity after resection of intramedullary spinal cord tumors in children who underwent laminectomy compared with laminoplasty

Laminectomy Versus Laminoplasty in the Surgical Management of Long-Segment Intradural Spinal Tumors: Any Difference in Neurological Outcomes?

Background:

Previous comparative studies have shown that apart from lack of any significant difference in neurologic outcomes between laminoplasty and laminectomy following resection of intradural spinal tumours, spinal column issues such as postoperative deformities, malalignment, and adjacent level disease have also been clearly demonstrated to be quite similar for both techniques. However, there is no study yet that describes any difference in neurologic outcomes for long-segment intradural lesions as a rare subset of these lesions (in terms of number of spinal segments involved) following surgical management between these two techniques.

Materials and Methods:

This is a retrospective review of surgical treatment with either laminectomy or laminoplasty done for patients with long-segment intradural tumors at a tertiary health-care institution in India.

Results:

Out of over 167 patients surgically treated for intradural tumors during the study period, a total of 60 patients were included in the evaluation. The long-segment tumors were intramedullary in 22 (36.7%) patients and intradural-extramedullary in the remaining 38 (63.3%) patients. No patient in both cohorts had any revisional surgery after initial resection or any serious complications. The incidence of neurologic function remaining unchanged at the end of follow-up was similar between laminoplasty and laminectomy (12.5% vs. 11.1%). There was no significant correlation between the preoperative McCormick score and postoperative McCormick score (P > 0.05 at 95% degree of confidence; Spearman's rho = 0.028), suggesting that functional outcomes were not dependent on the initial neurologic status. Multivariate logistic regression analysis showed that : the two independent variables (Extent of surgery and Choice of procedure) were not significant predictors of the dependent variable (Functional outcome following surgery) (odds ratio = 3.836; p = 0.071).

Conclusion:

This retrospective evaluation demonstrates laminoplasty not to be more or less likely to have any better functional outcome or need for revision compared to laminectomy in the resection of long-segment intradural lesions. A quality randomized controlled study on a much larger scale will be required to validate this finding.

Risk factor analysis of kyphotic malalignment after cervical intramedullary tumor resection in adults

OBJECTIVE

A number of studies have reported that surgery for cervical intramedullary tumors via the posterior approach can result in postoperative sagittal malalignment of the cervical spine; however, the risk factors remain unclear. The purpose of this study was to investigate the changes in cervical spinal alignment after surgery for cervical intramedullary tumors in adults and to elucidate the risk factors for cervical spinal sagittal misalignment.

METHODS

Data for the period from April 2001 to December 2011 for all adults who had undergone surgery for cervical intramedullary spinal cord tumors at a single institution were retrospectively analyzed to determine the postoperative changes in cervical spine alignment. Patients younger than 20 years of age and those who required postoperative radiotherapy were excluded from the study. Patients were divided into 2 groups according to tumor location: upper tumor (U) group, in which the central region of the tumor was above the C-5 level; and lower tumor (L) group, in which the central region of the tumor was at or below the C-5 level. Changes in alignment of the cervical spine were measured on plain lateral radiographs. Data on atrophy of the deep extensor muscles (DEMs), tumor location, detachment of the DEMs from the C-2 spinous process, the C2–7 angle before surgery, patient age at surgery, tumor histology, patient sex, tumor size, and number of laminae affected were reviewed for each patient, and the correlation of each of these factors with cervical spinal malalignment was evaluated using statistical analysis.

RESULTS

The 54 adults eligible for analysis had a mean age of 49.1 years. Ependymoma was the most common cervical intramedullary tumor (63.0%) in this series. In the tumor location U group, the kyphotic angle of the C2–7 spinal segments increased after surgery (−5.8° ± 2.8°). In contrast, in the L group, the C2–7 lordotic angle increased after surgery (6.4° ± 2.6°). In the univariate analysis, atrophy of the DEMs, detachment of the DEMs from the C-2 spinous process, and an upper cervical location of the tumor were identified as factors significantly correlated with the development of cervical spinal kyphosis after surgery. Multiple linear regression analysis revealed the following as risk factors for kyphotic change of the cervical spine after surgery: 1) atrophy of the DEMs after surgery (β = −0.54, p < 0.01), and 2) detachment of the DEMs from the C-2 spinous process (β = −0.37, p < 0.01).

CONCLUSIONS

Atrophy of the DEMs after surgery and detachment of the DEMs from the C-2 spinous process are directly related to the risk of cervical spinal kyphosis after surgery for cervical intramedullary tumors in adults. Therefore, preservation of the DEMs, especially those attached to the C-2 spinous process, is important for the prevention of kyphotic malalignment of the cervical spine after surgery for intramedullary tumors.

Spinal cord tumors in children: A review of 21 cases treated at the same institution

INTRODUCTION

Spinal cord tumors in children (SCTC) are rare with a frequent diagnostic delay. Its management is multidisciplinary and challenging due to functional implications. The position of surgery is now better established but the role and timing of chemotherapy (CT) and radiotherapy (RT) still remains under debate. Adverse effects of treatments are important to be taken into account, in the follow-up of these children. The aim of this paper was to present a series of 21 cases of SCTC treated at the same institution, to briefly present clinical features, treatments and outcome, with a special focus on spinal deformities in children with this condition.

MATERIAL AND METHODS

Twenty-one consecutive SCTC were referred to our institution from 1990 to 2014. Data regarding age, sex, diagnostic delay, clinical examination, MRI, surgery, pathology, other treatment (CT and RT), orthopedic issues and follow-up of these children were retrospectively recorded.

RESULTS

Mean age was 8years (standard deviation: 5.2years) (range: 4 months-17years). Mean diagnosis delay was 5.5 months (standard deviation: 6.5 months) (range: 0 days-18 months). All children (10 girls, 11 boys) were operated on (10 partial removals, 7 subtotal and 4 gross total removals) as first-line treatment. Pathological results showed 12 juvenile pilocytic astrocytomas, 1 grade III astrocytoma, 1 grade IV astrocytoma, 3 oligodendrogliomas, 2 ependymomas, 1 glioblastoma and 1 rhabdoid tumor. Fourteen children (66.7%) received additional treatment: 12 CT and 7 RT. Ten children had postoperative spinal deformities. Mean follow-up (FU) was 71 months (5 months-180 months), with a median FU at 60 months, where 8 tumor progressions and 4 deaths were observed. Overall, survival (at 5years) was 81% and progression free survival (at 5years) was 67%.

CONCLUSION

Surgery is the goal standard for SCTC and the only appropriate treatment in cases of a low-grade lesion with stable disease on MR follow-up. Additional treatment must be reserved for high-grade lesions or tumor progression not attainable by a second look surgery. Spinal deformities are a frequent complication. Overall, survival and event free survival primarily depends on the pathology. Studies involving more centers are obligatory with the aim of collecting more cases and drawing more definitive conclusions regarding the management of these tumors.

Treatment and outcome of neuroblastoma with intraspinal extension: A systematic review

We performed a systematic review to define the long-term health problems and optimal treatment strategy for patients with neuroblastoma with intraspinal extension. Of 685 identified studies, 28 were included in this review. The burden of long-term health problems is high; a median of 50% of patients suffered from neurological motor deficit, 34% from sphincter dysfunction, and 30% from spinal deformity. The currently available literature remains suboptimal as a guide for treatment of NBL with intraspinal extension. More well-designed, prospective studies are needed to determine the optimal treatment strategy.

Surgery for spinal intramedullary tumors: technique, outcome and factors affecting resectability

Intramedullary spinal cord tumors (IMSCTs) are relatively infrequent lesions with ependymomas and astrocytomas representing the most common types. Microsurgical resection is established as the treatment of choice for these challenging lesions. We reviewed the surgical outcome of 29 cases operated for IMSCTs by the same surgeon between 2009 and 2015. The median follow-up period was 31 months, and all patients were followed up at least for 1 year. Among these 29 cases, 5 patients were previously operated for partial resection elsewhere. Age ranged from 9 to 62 years with a median of 39 years. All patients were symptomatic before surgery. The most common pathology was ependymoma (16 cases), and the most common tumor location was the cervical spine (18 cases). Gross total resection was achieved in 20 out of 29 cases (68.9%). Tumors were totally excised in all cases of ependymoma except in two patients; one was previously operated and irradiated and the second had an extensive anaplastic ependymoma. Sixteen cases experienced immediate post-operative worsening which was temporary in all but one case. At 1-year follow up, 23 patients (79.3%) maintained their pre-operative McCormick grade, 5 patients (17.2%) had a better grade, and 1 patient (3.5%) deteriorated. Surgery still represents the mainstay in the management of IMSCT. Gross total resection can be achieved safely in many cases especially in the presence of an identifiable plane of cleavage between the tumor and the normal spinal cord.

Posterior-only vertebral column resection for revision surgery in post-laminectomy rotokyphoscoliosis associated with late-onset paraplegia: A case report and literature review

RATIONALE

Severe post-laminectomy spinal deformity associated with late-onset paraplegia is a complex and rare disorder. Little is known about revision surgery in post-laminectomy rotokyphoscoliosis associated with late-onset paraplegia treated by the single stage posterior-only vertebral column resection (VCR) procedure.

PATIENT CONCERNS AND DIAGNOSES

The patient was a 14-year-old male diagnosed as post-laminectomy rotokyphoscoliosis associated with late-onset paraplegia. He underwent posterior total laminectomy through the thoracic spine for intramedullary spinal cord tumors at the age of 3 years in another hospital. He then developed kyphosis deformity 1 year after laminectomy, and underwent posterior spinal fusion without instrumentation at 9 years of age. However, the deformity gradually progressed over the years. Seven months before admission to our hospital, he developed a significant progression of neurological deficits, including weakness of strength and sensation in lower extremities bilaterally, with no bladder or bowel dysfunction. There was no improvement of spinal cord function with conservative measures, and he required a wheelchair for movement.

INTERVENTIONS

The patient underwent posterior-only VCR by single stage with the purposes of spinal cord decompression and spinal deformity correction.

OUTCOMES

Postoperatively, he was transferred to the intensive care unit (ICU) and required positive pressure ventilation support to improve his respiratory condition. The child experienced cerebrospinal fluid leak (CSF) which resulted in an unplanned return to the operating room. The neurological function improved from preoperative Frankel C to Frankel D within 12 months of surgery, and recovered completely to Frankel E by 18 months. At the 24 month follow-up, the good neurological function was maintained; pulmonary function tests (PFTs) revealed improved forced vital capacity (FVC) and forced expiratory volume for 1 second (FEV1). The patient's coronal major curve and sagittal kyphosis were corrected from 70° to 21°, and 170° to 75°, respectively.

LESSONS

These findings demonstrated that single-stage posterior-only VCR is efficacious but challenging for revision surgery in post-laminectomy rotokyphoscoliosis associated with late-onset paraplegia.

Outcomes following Aggressive Surgical Resection of Intra-Medullary Spinal Cord Tumours with Intra-Operative Neuro-Monitoring

Introduction:

Intra-medullary spinal cord tumours (IMCST) are relatively uncommon tumours of the central nervous system which can result in severe neurological disorder if untreated. Histologically, IMCSTs are often either biopsied or excised subtotal, but this may lead to early tumour recurrence and progressive neurological impairment. In an attempt to improve outcomes, the recent trend is to perform more radical tumour resection guided by intra-operative monitoring (IOM). However, there are no controlled studies comparing the resection of IMCSTs with or without IOM. In this single surgeon series, we analyse outcomes following optimal resection of IMCSTs in conjunction with IOM.

Methods:

In this retrospective single surgeon series, case notes and history of patients who underwent surgery between 2006–2012 at the Singapore General Hospital's Neurosurgery Department, were studied. IOM with somatosensory evoked potential (SSEP) and motor evoked potential (MEP) were utilised to facilitate optimal tumour resection. Neurological status were compared pre- and post-operatively with long-term follow-up on outcomes. Magnetic resonance imaging was used pre- and post-operatively to assess the degree of tumour resection.

Results:

Thirteen consecutive patients with IMCSTs (five males, mean age 36 years, range 12–60) underwent surgical treatment and were included in this study. Radical surgical resection was performed for 11 patients, while the remaining two had biopsies and partial debulking as frozen section showed high grade astrocytomas. Histology revealed six cases of ependymoma, five cases of astrocytoma, and one of hemangioblastoma and neuroenteric cyst. There was one case of wound infection which was treated successfully. There were no cases of cerebrospinal fluid leakage. Two patients had pre-existing spinal deformity, and underwent posterior instrumented fusion concomitantly. The neurological state improved or remained stable in 11 (85%) patients, and two patients had immediate post-operative neurological deterioration which improved subsequently with physiotherapy over one to two months. Favourable functional outcomes were observed in the majority of patients during follow-up. The patients with high grade tumours were treated with adjuvant radiotherapy post-operatively, however, they showed a poorer long-term outcome. The mean follow-up was 3.2 years from operation.

Conclusion:

Radical resection of intra-medullary tumours with IOM leads to a favourable functional outcome in selected groups of patients.

Management of cervical spine deformity after intradural tumor resection

Management of intradural spinal tumors requires posterior decompressive techniques. Cervical spine deformity secondary to sagittal and/or coronal imbalance after a laminectomy may result in significant cervical pain and functional deterioration, as well as neurological deficits in the most severe cases. In this paper, the authors discuss the management of cervical spine deformity after intradural tumor resection, with emphasis on the surgical strategies required to reestablish acceptable cervical spine alignment and to correct postoperative deformity. In general, after an oncological evaluation, assessing the alignment, extent, and flexibility of the deformity is mandatory before surgical planning. Rigid deformities require an osteotomy and, most often, combined approaches to restore cervical alignment. Flexible deformities can often be treated with a single approach, although a circumferential approach has its advantages.

Occipito-cervical fusion following gross total resection for the treatment of spinal extramedullary tumors in craniocervical junction: a retrospective case series

Background

Previous studies found that the facet joint of the C1 vertebra were removed (C1 facetectomy) before extirpation from the extramedullary tumor in craniocervical junction, leading to postoperative upper cervical instability or deformity. Occipito-cervical fusion (OCF) is a demanding and morbid surgical procedure, which can be used in such patients. This study is to analyze the clinical manifestation and surgical outcome of patients with craniocervical extramedullary tumor undergoing an extirpation of spinal tumors and OCF by one-stage posterior approach.

Methods

The surgical and clinical databases were searched for operative procedures that had been performed for patients with spinal extramedullary tumors in craniocervical junction at a single institution from January 2008 to July 2011. The following inclusion criteria were applied: (1) initial surgery for craniocervical extramedullary tumor, (2) gross total resection and occipito-cervical fusion had been performed, (3) minimum 2-year follow-up, and (4) no previous cervical spine surgery. Medical records included demographic characteristics, clinical assessment, and radiographic studies. Clinical outcomes before and after the surgery were assessed using Frankel grade and the Japanese Orthopaedic Association (JOA) score. Cervical sagittal alignment was evaluated by C0-2 angle and C2-7 angle based on X-ray.

Results

Nine patients were included in the study. Five patients had schwannoma, three patients had meningioma, and only one patient had neurofibroma. All cases were followed up for 24–42 months (average, 34.2 months). At the last follow-up, three patients improved from Frankel grade C to grade D, two patients from Frankel grade C to grade E, and one patient from Frankel grade D to grade E, while two patients remained stationary at the Frankel grade D. The JOA score of the eight patients were 9.0 (range, 6–17) before surgery and were 14.6 (range, 12–17) at the most recent follow-up (p < 0.05). The mean C0-2 angle and the mean C2-7 angle before surgery were 26.2 ± 5.3° and 17.4 ± 13.1°, respectively. At the end of follow-up, the mean C0-2 angle was 25.6 ± 4.8°, and the mean C2-7 angle decreased to 12.7 ± 10.9°. However, this trend did not reach statistical significance (p < 0.05). Two patients suffered from cerebrospinal fluid leaks postoperatively. All patients had a satisfactory fusion and did not exhibit a tumor recurrence during the follow-up period.

Conclusions

OCF following gross total resection appears to be a useful surgical procedure for the craniocervical extramedullary tumors requiring C1 facetectomy and does not cause postoperative kyphosis of the upper cervical spine.

Spinal tumors in children: long-term retrospective evaluation of a series of 134 cases treated in a single unit of pediatric neurosurgery

BACKGROUND CONTEXT

Spinal tumors in childhood are rare and heterogeneous, and their treatment is very demanding. It is necessary to both manage the disease and preserve the spinal stability so that the spine can grow normally. As a consequence, results in terms of both mortality and morbidity are often suboptimal.

PURPOSE

The results of a single pediatric neurosurgery institution are reported to highlight the peculiarities and pitfalls of the management of this disease. Tumors are analyzed from the point of view of their localization, histology, and outcome in terms of mortality and morbidity, with a special focus on postoperative spinal deformity.

STUDY DESIGN

The study design was retrospective.

PATIENT SAMPLE

Between 1995 and 2011, 134 children (75 males and 59 females) were admitted for spinal tumors, accounting for 7.7% of all the patients admitted for central nervous system malignancies. The mean age was 8.5 years (14 days-26 years), and the mean follow-up was 28 months (3 months-13 years).

OUTCOME MEASURES

Clinical and radiological outcomes were evaluated to assess mortality, morbidity, and surgical outcomes. A special interest was directed toward morbidity related to spinal deformity and neurologic deficits.

METHODS

Patients were divided into four groups: intramedullary (46 patients), intradural extramedullary (25 patients), extradural (53 patients), and paravertebral tumors (10 patients). Data were obtained retrospectively from medical records and radiological archives.

RESULTS

Low-grade glioma was the most common histology (14.1%). One hundred seventeen patients were surgically treated, with a total of 138 surgical procedures. A posterior approach was chosen in 111 cases, with osteoplastic laminotomy in 80. Radiotherapy was administered to 22 patients and chemotherapy to 26. At the last follow-up, 16 patients (11.9%) had died. A good control of the tumor with clinical improvement was reported in 100 patients (74.6%). Five patients developed a spinal instability (3.7%).

CONCLUSIONS

The goals of surgery should be histology, spine and nerve root decompression, and preservation of spinal stability. In our experience, osteoplastic laminotomy was a good surgical approach to perform the resection of the tumor with a low risk of secondary spinal instability.

Intradural Extramedullary Ependymoma with Leptomeningeal Dissemination: The First Case Report in a Child and Literature Review

BACKGROUND

Primary intradural extramedullary ependymomas are very rare tumors and have never been described in children.

CASE DESCRIPTION

We report on an 11-year-old girl presenting with a 1-month history of neck pain, left arm weakness, paresthesia in the fingers of the left hand and gait disturbances. Magnetic resonance imaging on admission revealed an intradural extramedullary cystic lesion at the cervical level with craniospinal leptomeningeal nodules causing mild hydrocephalus. The multicystic lesion was surgically removed and neuropathologic examination revealed a World Health Organization grade II ependymoma. The patient underwent adjuvant radiotherapy with progressive reduction of the metastatic nodules. At her 2-year follow-up, the patient was symptom free with no evidence of recurrence on magnetic resonance imaging.

CONCLUSIONS

Although a rare entity, intradural extramedullary ependymomas should be included in the differential diagnosis of intradural extramedullary lesions in children. Surgical treatment seems to play a pivotal role in the prognosis of these rare tumors, with a possible role for adjunctive radiotherapy in the case of recurrence, anaplastic transformation, and metastasis.

Laminoplasty preserving the deep extensor musculature for a pediatric cervicothoracic epidural hematoma case of hemophilia A

Postoperative malalignment after either a laminectomy or a laminoplasty in pediatric cases is a well-known complication. A 5-year-old boy with a history of hemophilia A presented with severe paresis. MRI showed an extensive epidural hematoma extending from C2 to T1. We performed decompression of the spinal cord using laminoplasty, preserving the insertion of the deep extensors. The patient completely recovered from the paresis. Even 7 years after the surgery we could not find any kyphotic deformities. The use of laminoplasty preserving the deep extensor musculature may be crucial for maintaining the postoperative cervical alignment in pediatric patients.

Bone fusion rate in the thoracic and lumbar spine after laminoplasty with laminar screws

STUDY DESIGN

Retrospective clinical study.

OBJECTIVE

The purpose of this study was to determine the bone fusion rate after laminoplasty with laminar screws.

SUMMARY OF BACKGROUND DATA

There are many procedures, mostly with miniplates and screws, to repair an opened lamina after surgery for intraspinal pathology. Laminoplasty with laminar screws is an alternative procedure; however, the surgical outcome of this procedure has not been reported before.

METHODS

Laminoplasty with laminar screws was performed in 40 consecutive patients (male to female ratio=18:22; age, 47.4±13.6 yr) after surgery for intradural pathology. The lamina flap, which was opened with a high-speed drill or Kerrison punch, was reattached to the host bone with bilateral laminar screws. The bony fusion was assessed with computed tomographic scans that were taken 14.1±6.4 months postoperatively. If the gap between the host bone and the grafted lamina was filled up with a bony bridge, it was regarded as "fused." The fusion rate was assessed in terms of the hemilamina, the operated level, and the patient. The operated level was considered fused when at least 1 side of the hemilamina was completely fused to the host bone. Fusion success for a patient was defined as "all operated levels were fused." The follow-up period was 40.7±13.8 months.

RESULTS

Screw fixation was successfully achieved in 97.7% (150/154 hemilaminae, 77 levels) of the hemilaminae. Solid bony fusion was achieved in 56.7% (85/150) of the hemilaminae, 75.3% (58/77) of the operated levels, and 67.5% (27/40) of the patients. Screw breakage or displacement of the grafted laminae was not observed during the follow-up period.

CONCLUSION

Laminoplasty with laminar screws had a 67.5% fusion rate, and migration of the grafted laminae was not observed in any of the patients probably due to additional fibrous unions.

LEVEL OF EVIDENCE

4.

Pediatric iatrogenic thoracic kyphosis and tension myelopathy treated with a thoracic pedicle subtraction osteotomy: a case report and review of the literature

PURPOSE

Pediatric kyphotic deformity is an uncommon clinical entity that can occur following posterior spinal operations and has significant complexity in its treatment. Tension myelopathy in a pediatric patient with a thoracic kyphotic deformity has not been reported in the literature.

CASE REPORT

We present a 17-year-old boy with a progressive thoracic kyphosis and tension myelopathy 4 years after he underwent a thoracic laminoplasty at an outside institution for the treatment of a dorsal spinal arachnoid cyst. At our institution, he was treated with a pedicle subtraction osteotomy as well as thoracic Ponte osteotomies for sagittal plane correction to relieve the tension myelopathy.

CONCLUSIONS

Both clinical and radiographic improvements were observed after surgery. We review the literature on pediatric thoracic kyphosis and tension myelopathy and the treatment of these pathologies.

Results of cervical recapping laminoplasty: gross anatomical changes, biomechanical evaluation at different time points and degrees of level involvement

Background

Recapping laminoplasty has become the frequently-used approach to the spinal canal when bone decompression of the vertebral canal is not the goal. However, what changes will occur after surgery, and whether recapping laminoplasty can actually reduce the risk of delayed deformities remains unknown.

Methodology

We designed an animal experiment using a caprine model, and partitioned the animals into in vitro and in vivo surgical groups. We performed recapping laminoplasty on one group and laminectomy on another group. These animals were sacrificed six months after operating, cervical spines removed, biomechanically tested, and these data were compared to determine whether the recapping laminoplasty technique leads to subsequent differences in range of motion. Image data were also obtained before the surgery and when the animals were killed. Besides, we investigated the initial differences in kinetics between recapping laminoplasty and laminectomy. We did this by comparing data obtained from biomechanical testing of in vitro-performed recapping laminoplasty and laminectomy. Finally, we investigated the effect that longitudinal distance has on cervical mechanics. This was determined by performing a two-level recapping laminoplasty, and then extending the laminoplasty to the next level and repeating the mechanical testing at each step.

Principal Findings

There were three mainly morphological changes at the six months after laminoplasty: volume reduction and bone nonunion of the recapping laminae, irregular fibrosis formation around the facet joints and re-implanted lamina-ligamentous complex. In the biomechanical test, comparing with laminectomy, recapping laminoplasty didn’t show significant differences in the immediate postoperative comparison, while recapping laminoplasty demonstrated significantly decreased motion in flexion/extension six months later. Inclusion of additional levels in the laminotomy procedure didn’t lead to changes in immediate biomechanics.

Conclusions

Recapping laminoplasty can’t fully restore the posterior structure, but still reduced the risk of delayed cervical instability in a caprine model.

Long-term incidence and risk factors for development of spinal deformity following resection of pediatric intramedullary spinal cord tumors

OBJECT

Spinal deformity in pediatric patients with intramedullary spinal cord tumors (IMSCTs) may be either due to neurogenic disability or due to secondary effects of spinal decompression. It is associated with functional decline and impairment in health-related quality-of-life measures. The authors sought to identify the long-term incidence of spinal deformity in individuals who had undergone surgery for IMSCTs as pediatric patients and the risk factors and overall outcomes in this population.

METHODS

Treatment records for pediatric patients (age < 21 years) who underwent surgical treatment for histology-proven primary IMSCTs between 1975 and 2010 were reviewed. All patients were evaluated in consultation with the pediatric orthopedics service. Clinical records were reviewed for baseline and follow-up imaging studies, surgical fusion treatment, and long-term skeletal and disease outcomes.

RESULTS

The authors identified 55 patients (30 males and 25 females) who were treated for pediatric IMSCTs between January 1975 and January 2010. The mean duration of follow-up (± SEM) was 11.4 ± 1.3 years (median 9.3 years, range 0.2-37.2 years). Preoperative skeletal deformity was diagnosed in 11 (20%) of the 55 patients, and new-onset postoperative deformity was noted in 9 (16%). Conservative management with observation or external bracing was sufficient in 8 (40%) of these 20 cases. Surgical fusion was necessary in 11 (55%). Posterior surgical fusion was sufficient in 6 (55%) of these 11 cases, while combined anterior and posterior fusion was undertaken in 5 (45%). Univariate and multivariate analysis of clinical and surgical treatment variables indicated that preoperative kyphoscoliosis (p = 0.0032) and laminectomy/laminoplasty at more than 4 levels (p = 0.05) were independently associated with development of spinal deformity that necessitated surgical fusion. Functional scores and 10-year disease survival outcomes were similar between the 2 groups.

CONCLUSIONS

Long-term follow-up is essential to monitor for delayed development of spinal deformity, and regular surveillance imaging is recommended for patients with underlying deformity. The authors' extended follow-up highlights the risk factors associated with development of spinal deformity in patients treated for pediatric IMSCTs. Surgical fusion allows patients who develop progressive deformity to achieve long-term functional and survival outcomes comparable to those of patients who do not develop progressive deformity.

Quality of life after surgical treatment of primary intramedullary spinal cord tumors in children

OBJECT

Presently, the best available treatment for intramedullary spinal cord tumors (IMSCTs) in children is microsurgery with the objective of maximal tumor removal and minimal neurological morbidity. The latter has become manageable with the development and standard use of intraoperative neurophysiological monitoring. Traditionally, the perioperative neurological evaluation is based on surgical or spinal cord injury scores focusing on sensorimotor function. Little is known about the quality of life after such operations; therefore, this study was designed to investigate the impact of surgery for IMSCTs on the quality of life in children.

METHODS

Twelve consecutive pediatric patients treated for IMSCT were included in this retrospective fixed cohort study. A multidimensional questionnaire-based quality of life instrument, the Pediatric Quality of Life Questionnaire version 4 (PedsQL 4.0), was chosen to analyze follow-up data. This validated instrument particularly allows for a comparison between a patient cohort and a healthy pediatric sample population.

RESULTS

Of 11 mailed questionnaires (1 patient had died of progressive disease), 10 were returned, resulting in a response rate of 91%. There were 8 low-grade lesions (5 pilocytic astrocytomas, 1 ganglioglioma, 1 hemangioblastoma, and 1 cavernoma) and 4 high-grade lesions (2 anaplastic gangliogliomas, 1 glioblastoma, and 1 glioneuronal tumor). The mean age at diagnosis was 7.5 years, the mean follow-up was 4.2 years, and 83% of the patients were male. Total resection was achieved in 5 patients and subtotal resection in 7. Four patients had undergone 2 or more resections. The 4 patients with high-grade tumors and 2 with incompletely resected low-grade tumors underwent adjuvant treatment (2 chemotherapy and 4 both radiotherapy and chemotherapy). The mean modified McCormick Scale score at the time of diagnosis was 1.7; at the time of follow-up, 1.5. The mean PedsQL 4.0 total score in the low-grade group was 78.5; in the high-grade group, 82.6. There was no significant difference in PedsQL 4.0 scores between the patient cohort and the normal population.

CONCLUSIONS

In a small cohort of children who had undergone surgery for IMSCTs with a mean follow-up of 4.2 years, quality of life scores according to the PedsQL 4.0 instrument were not different from those in a normal sample population.

Symptomatic epidural compression in infants with neuroblastoma: a single-center experience with 5 cases

Infants affected by neuroblastoma with symptomatic epidural compression require early diagnosis and appropriate treatment to avoid severe late complications. However, no established guidelines are available regarding the optimal treatment of these patients. We describe 5 such infants. The interval between the onset of symptoms and tumor diagnosis was 3 to 8 days in 4/5 cases. None developed paraplegia before or after treatment. Treatment for epidural compression included first-line laminoplasty followed by chemotherapy in 3 patients, and chemotherapy first in the remaining 2. To date, all are alive and none have developed severe complications after a follow-up of 9 to 39 months (median, 20).

Intramedullary spinal cord cavernous malformations presenting with unexplained chest pain: case report and review of the literature

INTRODUCTION

Intramedullary spinal cord cavernous malformations are very uncommon in pediatric age, with only 26 cases reported within the available literature to date. The diagnosis of such lesions is often difficult and delayed because of their rarity and bizarre clinical presentation.

CASE REPORT

We report a case of intramedullary spinal cord cavernous malformation in a girl, in which sudden onset chest pain was the only presenting symptom, followed by appearance of neurological deficits after 5 days. We review the available literature discussing clinical features and principles of management of these lesions in children.

Central nervous system tumors

Central nervous system tumors are the most frequent malignant tumor in children and the main cause of death in this age group after traffic accidents. The current estimates are that one adult in 2500 is a survivor of a brain tumor that occurred during childhood. These tumors are particularly heterogeneous in terms of histology/biology, treatment, and outcome. They share, however, a high risk of neurological and cognitive morbidity due to the disease itself and the treatment modalities (radiotherapy, surgery, and chemotherapy). Diagnosis is frequently delayed because symptoms are usually nonspecific at the beginning of the evolution. Posterior fossa is the most frequent site and the tumors present most frequently with signs of intracranial hypertension. Supratentorial tumors are more frequent in infants and in adolescents; seizures are not uncommon, especially for benign tumors. When adjuvant treatment is needed, radiotherapy is usually the mainstay apart from some histologies where chemotherapy may be sufficient: low-grade gliomas, desmoplastic medulloblastomas, malignant glial tumors in infants. Multidisciplinary care is best performed in tertiary care centers and should include early rehabilitation programs soon after surgery.

Ultrasonic BoneScalpel for Osteoplastic Laminoplasty in the Resection of Intradural Spinal Pathology: Case Series and Technical Note

BACKGROUND:

Osteoplastic laminoplasty is a well-described technique that may decrease the incidence of progressive kyphosis when used in the setting of intradural spinal cord tumor resection.

OBJECTIVE:

The BoneScalpel by Aesculap (Central Valley, Pennsylvania) is an ultrasonic osteotome that precisely cuts bone while preserving the underlying soft tissues, potentially reducing the risk of dural laceration during laminoplasty. By producing osteotomies as narrow as 0.5 mm, the device may also facilitate postoperative osteointegration.

METHODS:

A retrospective analysis was conducted of 40 patients (mean age, 38.0 years; range, 4.0-79.7 years) who underwent osteoplastic laminoplasty using the BoneScalpel for the treatment of intradural spinal pathology at the Johns Hopkins Hospital between January 2009 and December 2011. After lesion resection, titanium plates were used to reconstruct the lamina in all cases. The technical results and procedure-related complications were subsequently noted.

RESULTS:

Successful laminoplasty was carried out in all 40 patients. Intraoperatively, 1 case of incidental durotomy was noted after use of the device, which was repaired primarily without neurological or clinical sequelae. During the follow-up period (mean, 195 days; median, 144 days), there were 2 complications (1 cerebrospinal fluid leak, 1 seroma) and no cases of immediate postoperative instability.

CONCLUSION:

The BoneScalpel is a safe and technically feasible device for performing osteoplastic laminoplasty.

Postoperative spinal deformity after treatment of intracanal spine lesions

BACKGROUND CONTEXT

Surgical treatment of intracanal (both intramedullary and extramedullary) spine lesions requires posterior decompressive techniques in nearly all instances. Postoperative spinal deformities, most notably sagittal and coronal decompensation, are of significant concern for both the patient and the spinal surgeon.

PURPOSE

To review and define principles and features of spinal deformities after posterior spinal decompression for intracanal spinal lesions, and to define patients who may benefit from the concomitant spinal fusion.

METHODS

A systematic review of MEDLINE was conducted, including articles published between 1980 and 2011. Articles related to spinal deformities after posterior decompression for the treatment of intracanal spine lesions were identified.

RESULTS

Ten articles met all inclusion and exclusion criteria. All were case series with limited evidence (Level IV). Many risk factors to deformity were implied but with limited evidence. Young age was the most commonly identified risk in these articles.

CONCLUSIONS

Spinal deformity after posterior decompression is a common complication, most notably in children and young adults, after the removal of intramedullary tumors. Many risk factors have been implied to increase the postoperative development of spinal deformity, including young age, laminectomy extension, preoperative deformity, and extensive facet resection, among others. However, there is a lack of high-quality evidence to propose an algorithm for treatment or preventive measures. New studies with larger series of patients and standardized clinical outcomes are necessary to establish optimal treatment protocols.

Intramedullary tumors in children

Intramedullary tumors of the spinal cord account for 35-40% of intraspinal tumors in children. The biological behavior of these tumors is of slow progression, and hence aggressive surgery has been advocated. Surgical adjuncts include use of intraoperative neurophysiological monitoring, preoperative ultrasound, microsurgical techniques and ultrasonic suction devices. Osteoplastic laminoplasty approaches avoid post-laminectomy deformities in younger children. Postoperative radiotherapy and more recently chemotherapy regimes have been proposed for incompletely resected tumors.

Complications associated with the treatment for spinal ependymomas

Spinal cord ependymomas are rare neoplasms, comprising approximately 5% of all CNS tumors and 15% of all spinal cord tumors. Although surgery was once reserved for diagnosis alone, the evolution of surgical practices has elevated resection to the treatment of choice for these lesions. While technological advances continue to improve the capacity for gross-total resections and thus decrease the risk of recurrence, ependymoma spinal surgery still contains a variety of potential complications. The presence of neurological deficits and deterioration are not uncommonly associated with spinal cord ependymoma surgery, including sensory loss, dorsal column dysfunction, dysesthetic syndrome, and bowel and bladder dysfunction, particularly in the immediate postoperative period. Surgical treatment may also lead to wound complications and CSF leaks, with increased risk when radiotherapy has been involved. Radiation therapy may also predispose patients to radiation myelopathy and ultimately result in neurological damage. Additionally, resections of spinal ependymomas have been associated with postoperative spinal instability and deformities, particularly in the pediatric population. Despite the advances in microsurgical techniques and intraoperative cord monitoring modalities, there remain a number of serious complications related to the treatment of spinal ependymoma tumors. Identification and acknowledgment of these potential problems may assist in their prevention, early detection, and increased quality of life for patients afflicted with this disease.

Late sequelae of symptomatic epidural compression in children with localized neuroblastoma

BACKGROUND

To describe late sequelae and their correlation with presenting clinical features and tumor treatment in children with symptomatic epidural compression (EC) secondary to localized neuroblastoma.

PROCEDURES

A total of 98 evaluable children diagnosed with neuroblastoma and EC, who survived a minimum of 2 years were identified in two Italian and French neuroblastoma series.

RESULTS

Symptoms of EC at diagnosis included motor deficit in 94 cases and sphincter deficits in 33. Initial treatment was chemotherapy in 66 cases, neurosurgical decompression in 29 and radiotherapy in 3. Chemotherapy was chosen more frequently for younger children and for those with stage 3 disease. Overall treatment consisted of chemotherapy alone in 44 cases, neurosurgery and chemotherapy in 38, radiotherapy and chemotherapy, with or without neurosurgery, in 16. After a median follow-up of 7.3 years, 57 children (58.2%) had one or more sequelae. Motor sequelae involved 50/57 of these children and correlated with age and severity of motor deficit at diagnosis and neurosurgical treatment. Spine deformities involved 27/57 children and were more frequent in those with severe motor deficit at diagnosis, or who were treated by neurosurgery or radiotherapy. Sphincter dysfunctions involved 31/57 children and were more frequent among children who presented with sphincter symptoms and severe motor deficit.

CONCLUSIONS

Fifty-eight percent of the children with localized neuroblastoma and symptomatic EC registered in this study developed late sequelae. The severity of motor deficit at diagnosis was the main risk factor.

Laminotomy in adults: technique and results

The objective of this study was to describe step by step our surgical technique of laminotomy and analyze our series with regard to spinal deformities (risk and predisposing factors), postoperative pain and rate of postoperative contusions. Data regarding patients who underwent our technique of laminotomy (N = 40, mean follow-up: 52 ms) (N = 40) between 2002 and 2006 were retrospectively evaluated. The technique used is illustrated in depth. Chronic pain was present in 30% with a mean score of 3/10 cm (Graphic Rating Scale). Postoperative kyphoses occurred in three patients, all below 35 years of age and with laminotomies which involved C2 and/or C7. None of these deformities required further surgical treatment because they were self-limiting or asymptomatic at a mean follow-up of 52 months. Based on the results, our technique proved to be safe and effective in terms of late deformities, blood loss, early and chronic postoperative pain and protection from postoperative accidents over the surgical site.

Spinal epidural abscess with myelitis and meningitis caused by Streptococcus pneumoniae in a young child

BACKGROUND

Spinal epidural abscess (SEA) in children is a rare infectious emergency warranting prompt intervention. Predisposing factors include immunosuppression, spinal procedures, and local site infections such as vertebral osteomyelitis and paraspinal abscess. Staphylococcus aureus is the most common isolate.

DESIGN

Case report and literature review.

FINDINGS

A 2.5-year-old boy with tetraparesis was found to have an SEA in the posterior lumbar epidural space with evidence of meningitis and myelitis on MRI spine in the absence of any local or systemic predisposing factors or spinal procedures. Streptococcus pneumoniae was isolated from the evacuated pus.

CONCLUSIONS

Definitive treatment of SEA is a combination of surgical decompression and iv antibiotics. Timely management limits the extent of neurological deficit.

Symptomatic apoplexy in intramedullary ependymoma: a report of a pediatric patient

Spinal intramedullary ependymomas often harbor clinically asymptomatic intratumoral bleeds. Such tumors presenting with apoplectic events have not been described in the literature. The authors report on a 2-year-old female who presented with sudden loss of sensorimotor functions below the thoracic spine as a consequence of hemorrhage within an intramedullary ependymoma. The clinical, radiological, and surgical findings are described. Gross total resection provided near-normal spinal functions in the present case.

Infantile cervical intramedullary cavernous angioma manifesting as hematomyelia. Case report

A 2-month-old infant presented with a cervical intramedullary spinal cord cavernous angioma manifesting as left hemiparesis caused by hematomyelia. Osteoplastic laminotomy of the cervical spine was carried out with subsequent microsurgical excision of the intramedullary spinal cord cavernous angioma. Magnetic resonance imaging revealed no residual tumor. At 25 months after the surgery, she presented no neurological deficit without recurrence and cervical deformity. This case of infantile intramedullary spinal cord cavernous angioma presenting with cervical hematomyelia shows osteoplastic laminotomy of the cervical spine might be helpful to prevent consequent cervical deformity in pediatric cases.

Short-term progressive spinal deformity following laminoplasty versus laminectomy for resection of intradural spinal tumors: analysis of 238 patients

OBJECTIVE

Gross total resection of intradural spinal tumors can be achieved in the majority of cases with preservation of long-term neurological function. However, postoperative progressive spinal deformity complicates outcome in a subset of patients after surgery. We set out to determine whether the use of laminoplasty (LP) vs laminectomy (LM) has reduced the incidence of subsequent spinal deformity following intradural tumor resection at our institution.

METHODS

We retrospectively reviewed the records of 238 consecutive patients undergoing resection of intradural tumor at a single institution. The incidence of subsequent progressive kyphosis or scoliosis, perioperative morbidity, and neurological outcome were compared between the LP and LM cohorts.

RESULTS

One hundred eighty patients underwent LM and 58 underwent LP. Patients were 46 +/- 19 years old with median modified McCormick score of 2. Tumors were intramedullary in 102 (43%) and extramedullary in 102 (43%). All baseline clinical, radiographic, and operative variables were similar between the LP and LM cohorts. LP was associated with a decreased mean length of hospitalization (5 vs 7 days; P = .002) and trend of decreased incisional cerebrospinal fluid leak (3% vs 9%; P = .14). Following LP vs LM, 5 (9%) vs 21 (12%) patients developed progressive deformity (P = .728) a mean of 14 months after surgery. The incidence of progressive deformity was also similar between LP vs LM in pediatric patients < 18 years of age (43% vs 36%), with preoperative scoliosis or loss of cervical/lumbar lordosis (28% vs 22%), or with intramedullary tumors (11% vs 11%).

CONCLUSION

LP for the resection of intradural spinal tumors was not associated with a decreased incidence of short-term progressive spinal deformity or improved neurological function. However, LP may be associated with a reduction in incisional cerebrospinal fluid leak. Longer-term follow-up is warranted to definitively assess the long-term effect of LP and the risk of deformity over time.

Outcome of osteoplastic laminotomy for excision of spinal cord tumours

PURPOSE

To evaluate the outcome of osteoplastic laminotomy after excision of primary tumours of the thoracolumbar and lumbar spine.

METHODS

Records of 10 male and 11 female consecutive patients aged 15 to 57 (mean, 37) years who underwent osteoplastic laminotomy for excision of spinal cord tumours in the thoracolumbar (n=13) and lumbar (n=8) spine were reviewed. After tumour resection, the removed posterior elements were reattached to the superior and inferior processes using anchoring sutures. Pre- and post-operative functional status was retrospectively graded according to the modified McCormick scale. Spinal deformities were classified as sagittal and coronal malalignment, segmental instability, and spondylolisthesis.

RESULTS

The mean follow-up duration was 43 (range, 12-108) months. The mean number of laminae excised was 1.3 (range, 1-4). At the final follow-up, the modified McCormick scale score improved in 16 patients, remained unchanged in 4, and deteriorated in one. No patient developed any severe complication, recurrence, spondylolisthesis, or aseptic necrosis of grafted laminae. In 2 patients their spinal deformities became worse: one had segmental instability of 17 degrees at L3-4 secondary to non-union of the L3 lamina; the other (with type-I neurofibromatosis and dystrophic deformity) underwent fusion for severe low back pain and lumbar kyphosis and progressive rotational dislocation, despite union of the grafted L2 lamina.

CONCLUSIONS

Osteoplastic laminotomy preserves the structures that could be important for spinal stability and may reduce the risk of deformities. Anterior strut grafting and posterior fusion may be necessary in neurofibromatosis patients with dystrophic deformities.

Surgical considerations of spinal ependymomas in the pediatric population

OBJECTIVES

The objective of this manuscript is to discuss current management strategies regarding pediatric patients with intramedullary spinal cord ependymomas. Spinal ependymoma is the second most common spinal cord tumor in children. The clinical evaluation of these patients, operative techniques, postoperative management considerations, and long-term outcomes are discussed.

INTRODUCTION

The gold standard for the treatment of spinal ependymoma continues to be gross total resection. Patients with residual tumor postoperatively may benefit from adjuvant radiation therapy. Intraoperative monitoring is critical to minimize permanent postoperative neurologic deficit.

CONCLUSION

Patients requiring multilevel laminectomy may benefit from concomitant laminoplasty or instrumented fusion to avoid progressive spinal column deformity.

SPONTANEOUS INTRAMEDULLARY HEMORRHAGE OF SPINAL HEMANGIOBLASTOMA

OBJECTIVE

Spontaneous hemorrhage of a spinal hemangioblastoma is a rare event. With limited reports in the literature, the risk of acute hemorrhage associated with these lesions is poorly understood.

METHODS

A 39-year-old man presented with paraplegia and bilateral upper-extremity weakness related to an acute intramedullary hemorrhage from a thoracic spinal hemangioblastoma. Magnetic resonance imaging revealed an intramedullary hemorrhage from T3 to T6 with prominent flow voids along the dorsal aspect of the spinal cord from T6 to T10. Magnetic resonance angiography of the thoracic spine indicated a prominent enhancing vessel along the dorsum of the thoracic cord.

RESULTS

An emergency T3 to T8 laminoplasty was performed for evacuation of the hematoma and gross total resection of the lesion. Pathological analysis of the tumor biopsy confirmed the diagnosis of hemangioblastoma.

CONCLUSION

The risk of spontaneous hemorrhage from a spinal hemangioblastoma is low. Spinal hemangioblastomas presenting with intramedullary hemorrhage tend to cause severe neurological deficits and have a poorer long-term prognosis compared with subarachnoid hemorrhage and nonhemorrhagic lesions.

Paediatric intramedullary spinal cord cavernous malformations: case report and review of the literature

Cavernous malformations are vascular lesions which can occur throughout the entire neuraxis. This term is synonymous to cavernous angioma, cavernous haemangioma, and cavernoma. They comprise of closely packed, capillary-like vascular channels, without intervening neural tissue. MR imaging is currently the study of choice for the diagnosis of cavernous malformations as they are considered angiographically occult lesions. Intramedullary location represents only 3-5% of all central nervous system cavernous malformations, with the majority of them being supratentorial. Only 10% of the intramedullary cavernous malformations present in the paediatric population. As the natural history of these lesions is not well known, the debate on the optimal management of them is still ongoing. Here we describe the case of a 14-year-old male with progression of symptoms over an 18 months period, which necessitated microsurgical removal of a T9 intramedullary cavernous malformation.

Case report: a case of persistent back pain and constipation in a 5-year-old boy

Pediatric intramedullary spinal cord tumors are rare and account for 3% to 6% of all central nervous system tumors. Astrocytomas are infiltrating neoplasms, and they predominate in the pediatric population. We report a case of an intramedullary spinal cord astrocytoma in a 5-year-old boy with nonspecific mid-back pain for 3 months. Physical examination revealed clonus, thoracolumbar tenderness, and pain with sitting straight leg raises. An urgent magnetic resonance imaging showed an intramedullary tumor in the mid-thoracic cord, confirmed by surgical excision. The physician should maintain a high index of suspicion when evaluating the pediatric patient who presents with unexplained and persistent back pain. Associated findings, including nocturnal pain and neurological symptoms may indicate a more serious underlying pathology such as a tumor. Early detection, prompt treatment, and proper post surgical management will often lead to improved outcomes in patients.

Paravertebral malignant tumors of childhood: analysis of 28 pediatric patients

PURPOSE

To evaluate the clinical features and treatment results of the primary paravertebral malignant tumors (PMTs) in our department.

METHODS

Medical records of 28 children with primary PMTs treated between 1988-2007 were analyzed retrospectively.

RESULTS

Primary PMTs constituted 4.8% of the cancer cases in our department. Tumor diagnoses were mostly neuroblastoma (46.4%) and soft tissue sarcomas (35.7%). These cases presented with pain (64.3%), motor dysfunction (42.8%), sphincter dysfunction (35.7%), palpable mass (32.1%), and sensory deficits (7.1%). All tumors were extradural. Physical examination revealed motor deficits (53.6%), deep tendon reflex alterations (53.6%), sphincter dysfunction (35.7%), pathologic reflexes (25%), abnormal cutaneous reflexes (25%), and sensory deficits (17.8%). Sixteen had cord compression (CC; 13 clinical, three radiological CC). Eleven of them presented with advanced disease. Seven were managed by surgical departments by primary surgery (three unresponsive). Others were managed by pediatric oncology: five with corticosteroids+/-chemotherapy (one unresponsive), one with radiotherapy (RT), and two with surgery for the clinical CC. Surgery was tumor excision in nine, laminectomy in nine, laminotomy in one, and delayed surgery after chemotherapy in two cases. In chemotherapy and surgery groups, there were neurologic sequela associated with the advanced disease at diagnosis in 38% and 37%, respectively. At 3-year median follow-up, nine patients died, 17 are alive (four with neurologic sequela), and two are lost of follow-up.

CONCLUSION

Majority of cases presented with advanced disease. Late referral is the major cause of morbidity and mortality. The CC caused by PMTs should be initially managed with corticosteroids +/- chemotherapy to avoid the adverse late effects of RT and surgery.

Cervical spine instability following cervical laminectomies for Chiari II malformation: a retrospective cohort study

OBJECTIVE

The treatment of symptomatic Chiari II malformations typically involves multilevel cervical laminectomies in very young children. These patients are at significant risk of cervical instability. The purpose of this study was to determine the incidence and significance of cervical instability after multilevel cervical laminectomies in a cohort of patients decompressed for Chiari II malformation.

METHODS

Postoperative dynamic lateral cervical spine radiographs were obtained on pediatric patients who had multilevel cervical laminectomies for symptomatic Chiari II malformations. Postoperative cervical spine instability was determined radiographically using published criteria. Clinical instability and need for cervical fusion were also assessed.

RESULTS

Nine patients met inclusion criteria for the study. Five of the nine patients (56%) showed evidence of radiographic instability of their cervical spines following surgery for their Chiari II malformations, according to the criteria used. No patient showed evidence of clinical instability or required cervical fusion.

CONCLUSION

Radiographic evidence of cervical spine instability following multilevel cervical laminectomies for Chiari II is common but may be of minimal clinical significance. The reason for the lack of clinical instability in what might be considered high-risk patients is not understood.