Routine use of magnetic resonance imaging in idiopathic scoliosis patients less than eleven years of age

Concurrent Presence of Thoracolumbar Scoliosis and Chiari Malformation: Is Operative Risk Magnified?

STUDY DESIGN

Retrospective review of Kids' Inpatient Database (KID).

PURPOSE

Identify the risks and complications associated with surgery in adolescents diagnosed with Chiari and scoliosis.

OVERVIEW OF LITERATURE

Scoliosis is frequently associated with Chiari malformation (CM). More specifically, reports have been made about this association with CM type I in the absence of syrinx status.

METHODS

The KID was used to identify all pediatric inpatients with CM and scoliosis. The patients were stratified into three groups: those with concomitant CM and scoliosis (CMS group), those with only CM (CM group), and those with only scoliosis (Sc group). Multivariate logistic regressions were used to assess association between surgical characteristics and diagnosis with complication rate.

RESULTS

A total of 90,707 spine patients were identified (61.8% Sc, 37% CM, 1.2% CMS). Sc patients were older, had a higher invasiveness score, and higher Charlson comorbidity index (all p<0.001). CMS patients had significantly higher rates of surgical decompression (36.7%). Sc patients had significantly higher rates of fusions (35.3%) and osteotomies (1.2%, all p<0.001). Controlling for age and invasiveness, postoperative complications were significantly associated with spine fusion surgery for Sc patients (odds ratio [OR], 1.8; p<0.05). Specifically, posterior spinal fusion in the thoracolumbar region had a greater risk of complications (OR, 4.9) than an anterior approach (OR, 3.6; all p<0.001). CM patients had a significant risk of complications when an osteotomy was performed as part of their surgery (OR, 2.9) and if a spinal fusion was concurrently performed (OR, 1.8; all p<0.05). Patients in the CMS cohort were significantly likely to develop postoperative complications if they underwent a spinal fusion from both anterior (OR, 2.5) and posterior approach (OR, 2.7; all p<0.001).

CONCLUSIONS

Having concurrent scoliosis and CM increases operative risk for fusion surgeries despite approach. Being independently inflicted with scoliosis or Chiari leads to increased complication rate when paired with thoracolumbar fusion and osteotomies; respectively.

Spontaneous Unilateral Chiari I Secondary to Acquired Tonsillar Hypertrophy/Pseudomass With Syringomyelia in a Juvenile With Progressive Scoliosis

Chiari type 1 malformation (CM-1) is a structural defect of the central nervous system in which part of the cerebellar tonsils descend below the level of the foramen magnum, sometimes with associated syringomyelia. Although Chiari malformations were traditionally believed to be congenital, several cases of acquired CM-1 with syringomyelia have been reported. Usually associated with repeat lumbar puncture, increased intracranial pressure, and craniocephalic disproportion, CM-1 in the absence of an underlying etiology is rare. We report a rare case of spontaneous idiopathic tonsillar hypertrophy causing unilateral CM-1 with syringomyelia associated with progressive scoliosis in a juvenile with a previously normal neonatal MRI brain and no known underlying pathology. A 9-year-old boy was found to have scoliosis at a routine well-child visit with progression indicated on radiographs 4 months later. Whole spine MRI was performed and showed a new CM-1 with globular, mass-like configuration of the descended right tonsil with otherwise normal tonsillar characteristics. Surgical decompression via suboccipital craniectomy and C1 laminectomy with duraplasty was performed with improvement illustrated on repeat MRI 3 months postoperatively. This rare case emphasizes the importance of routine MRI spine early in select patients with idiopathic scoliosis and illustrates the favorable outcomes noted after decompressive craniectomy.

The use of MRI in the study of patients with idiopathic scoliosis: a systematic review of the literature

Objective. To analyze the frequency of hidden neuraxial pathology in idiopathic scoliosis (IS), to substantiate the need for MRI in IS and to identify promising areas for the use of MRI in the examination of patients with IS.Material and Methods. The literature review was carried out using the PubMed and Google Scholar databases. Of the 780 papers on the research topic, 65 were selected after removing duplicates and checking for inclusion/exclusion criteria. As a result, 49 original studies were included in the analysis. Level of evidence – II.Results. According to modern literature, the main direction of using MRI in idiopathic scoliosis is the search for predictors of latent pathology of the spinal cord and craniovertebral junction. The frequency of neuraxial pathology in idiopathic scoliosis is 8 % for adolescent IS and 16 % for early IS. The main predictors of neuraxial pathology are male sex, early age of deformity onset, left-sided thoracic curve and thoracic hyperkyphosis. MRI in IS may be a useful addition to radiological diagnostic methods to identify risk factors and to study degenerative changes in the spine.Conclusion. MRI of the spine should be performed in the early stages of IS to detect latent spinal cord tethering. In type I Chiari anomalies, there is a possibility that early neurosurgery can prevent the development of scoliosis. The main signs of latent neuraxial pathology in IS are early progression of spinal deformity, left-sided thoracic curve, male gender and thoracic kyphosis over 40° according to Cobb.MRI can be used as an effective non-invasive tool in research aimed at identifying risk factors for IS, including helping to track early degeneration of intervertebral discs.

Minimum 5-year follow-up outcomes for one-stage posterior instrumentation without neurosurgery intervention for correction of scoliosis associated with Chiari I malformation and syringomyelia

INTRODUCTION

Traditionally, the common belief has been that, all patients with Chiari I malformation (CM-1) and syringomyelia (SM) undergoing a neurosurgical procedure even if they are neurologically asymptomatic. As the pathology of CM-1 and SM has become better understood, the traditional concepts have been challenged. The objective of this study was to investigate the minimum 5-year follow-up clinical outcomes of surgical treatment of patients with scoliosis associated with CM-1 and SM and to evaluate the necessity of neurosurgical intervention before corrective surgery.

METHODS

This retrospective study was performed from May 2009 to September 2014. We enrolled 35 patients with scoliosis associated with CM-1 and SM who were undergoing spinal correction surgery without neurosurgical intervention. During the surgery, spinal cord monitor and wake-up test were used. Preoperative, postoperative, and final follow-up major curve coronary Cobb angle, correction rate, apical vertebral rotation (AVR), apical vertebral translation (AVT), thoracic kyphosis angle (T5-T12), lumbar lordosis angle (L1-S1) were analyzed on radiographs.

RESULTS

The mean follow-up period was 82.5 months. The preoperative and postoperative mean curve coronary Cobb angle was from 55.7 ± 7.5° to 20.1 ± 5.8°, correction rate was 63.9%, AVR from 2.8 ± 0.6° to 1.3 ± 0.5°, AVT from 5.1 ± 1.4 to 1.7 ± 0.7 cm, thoracic kyphosis angle from 18.7 ± 4.0° to 32.2 ± 2.7°, lumbar lordosis angle from 36.3 ± 4.1° to 43.8 ± 3.2°. No neurological deficits occurred during the operation and follow-up.

CONCLUSIONS

Our minimum 5-year follow-up outcomes showed that in a distinct patient population of neurologically asymptomatic individuals with CM-1, SM and progressive scoliosis, posterior instrumented spinal deformity surgery can be safely done without neurosurgical interverventions with the help of preoperative flexibility evaluation and intraoperative neuromonitoring.

Chiari 1: Is decompression always necessary previous to scoliosis surgery?

The association between Chiari 1 malformation and scoliosis is well known in the literature. Prevalence has increased after the advent of magnetic resonance imaging. In children with this association, prophylactic suboccipital decompression prior to scoliosis correction is a common surgical procedure although the rationale for this surgical management and whether not performing it may lead to spinal cord injury has not been clearly elucidated. We conducted a systematic review of the literature with the aim to obtain strong data to support the hypothesis that it is safe to proceed with scoliosis correction without prior prophylactic suboccipital decompression for Chiari 1 in an asymptomatic population. Using the Prisma methodology, we analyzed 3250 studies published between 1972 and 2018. Only four studies met the inclusion criteria. None of the studies had a level of evidence high enough to recommend prophylactic decompression previous to correction of the spinal deformity.

Spontaneous Reduction of Chiari Malformation and Syringomyelia After Posterior Spinal Fusion for Scoliosis: A Case Report

CASE

A 22-year-old skeletally mature man with scoliosis accompanied by syringomyelia associated with Chiari malformation type 1 was presented to our hospital. Because the maximal syrinx/cord ratio was small, and he had no neurological deficit, he underwent corrective surgery without the treatment of the syringomyelia.

CONCLUSION

The scoliosis was corrected without any neurological complications. Magnetic resonance imaging taken 8 days after the surgery showed the reduction of the size of the syringomyelia. The syringomyelia almost disappeared at the 8-year follow-up.

The Role of MRI in Children With Congenital Limb Deficiencies With Associated Scoliosis

BACKGROUND

The association of scoliosis and congenital limb deficiency has been well described. However, the incidence of neural axis abnormalities in this population is not known. The ability to assess the neural axis by physical examination may be limited in patients with a limb deficiency. Although mobility of the spine is important for all children, it can be especially so in children with a limb deficiency. As spinal fusion in children with limb deficiency potentially has more functional impact, detecting reversible forms of scoliosis seems particularly important.

METHODS

Retrospective review of children treated at 1 institution between 1990 and 2017 with both a diagnosis of a congenital limb deficiency, upper or lower, and scoliosis. Children were excluded if they had any neurological difference on history or physical examination, if they had sacral agenesis or spina bifida, or if their limb deficiency was related to trauma or early amniotic rupture sequence.

RESULTS

Twenty-four children were identified, 11 with lower extremity deficiency, 14 with upper extremity deficiency with 1 having both. Fifteen children demonstrated neural axis abnormalities, 6 (40%) required neurosurgery. Five (45%) of 11 lower extremity deficiency children had MRI findings, 3 of these needing neurosurgery. Of the 14 upper extremity deficiency children, 10 had MRI changes, and 3 required neurosurgery. Eight children with congenital scoliosis, 5 had MRI findings, with 4 children requiring neurosurgery. The other 16 children had scoliosis without vertebral abnormalities, 10 had MRI findings, and 2 required neurosurgery.

CONCLUSIONS

There is a high incidence of neural axis abnormalities (63%) in children with congenital limb deficiencies and scoliosis. A large portion of these require neurosurgical intervention. MRI should be considered soon after presentation in this population of children.

LEVEL OF EVIDENCE

Level IV.

DESIGN

Retrospective cohort.

MRI utilization and rates of abnormal pretreatment MRI findings in early-onset scoliosis: review of a global cohort

STUDY DESIGN

Retrospective review OBJECTIVES: To report the frequency of pretreatment magnetic resonance imaging (MRI) utilization and rates and types of intra-spinal abnormalities identified on MRI in patients with early-onset scoliosis (EOS). MRI can help identify spinal cord abnormalities in patients with EOS.

METHODS

We reviewed data from patients enrolled from 1993-2018 in an international EOS registry. Patients with incomplete/unverifiable data and those with spinal deformities secondary to infection or tumor were excluded, leaving 1343 patients for analysis. Demographic characteristics, pretreatment major curve magnitude, treatment type, and MRI findings were analyzed. Patients were categorized by EOS type (congenital, idiopathic, neuromuscular, syndromic), pretreatment MRI utilization, and presence of intra-spinal abnormality on MRI. Univariate testing and multivariate logistic regression were performed to identify demographic, radiographic, and clinical predictors of MRI utilization and abnormal MRI findings.

RESULTS

MRI was used in 836 patients (62%). Pretreatment MRI utilization rates ranged from 42% in neuromuscular EOS to 74% in congenital EOS. Prevalence of abnormal MRI findings was 24% overall, ranging from 13% in patients with idiopathic EOS to 39% in neuromuscular EOS. Compared with white/Caucasian patients, Asian/Asian-American patients had higher odds of MRI utilization and abnormal MRI findings. Treatment type, pretreatment major curve magnitude, age at MRI, and age at treatment were not associated with abnormal MRI findings. Overall, 249 abnormalities were identified in 197 patients. The most common findings were syrinx and tethered cord. Syrinx with Chiari malformation was the most frequent combination of abnormal findings.

CONCLUSION

In the two-thirds of patients who underwent MRI before EOS treatment, findings were abnormal in 24%. EOS type and race/ethnicity were associated with both MRI utilization and abnormal findings. The most frequent abnormalities were syrinx and tethered cord, and the type of abnormalities appeared to differ by EOS type.

LEVEL OF EVIDENCE

Prognostic, Level III.

The safety and efficacy of one-stage posterior surgery in the treatment of presumed adolescent idiopathic scoliosis associated with intraspinal abnormalities a minimum 3-year follow-up comparative study

PURPOSE

Adolescent idiopathic scoliosis (AIS) is a common type of idiopathic scoliosis. Previous studies reported that the incidence of intraspinal abnormalities among the presumed idiopathic scoliosis was 13-43%. Intraspinal abnormalities were also considered increasing the risks of progressing of scoliosis and neurological complications following scoliosis corrective surgery. The surgical strategy of presumed adolescent idiopathic scoliosis (PAIS) associated with intraspinal abnormalities remains controversial. The purpose of this study was to investigate whether one-stage posterior surgery safe and effective for the PAIS patients associated with intraspinal abnormalities.

MATERIALS AND METHODS

One hundred and thirteen consecutive patients who underwent one-stage posterior correction surgery were included. Thirty PAIS patients with intraspinal abnormalities without preoperative neurological symptoms were matched with eighty-three AIS patients for sex, age, blood loss, operating time, number of levels and location of instrumentation and curve magnitude. Radiographic and clinical parameters of the patients were evaluated before surgery, within 1 week after surgery, and more than 3 years at the last follow-up for complications and changes in main curve correction, global coronal balance, thoracic kyphosis, sagittal vertical axis, and ODI scores.

RESULTS

On average, the duration of follow-up was 51.5 months in the PAIS group compared to 52.5 months in the AIS group. The preoperative mean major coronal curve was 79.6° (ranged 56.2°-106.7°) and improved to 22.4° (ranged 6.4°-58.1°) at the last follow-up for a 71.9% of correction in the AIS group. The preoperative mean major coronal curve was 80.4° (ranged 63.4°-108.1°) and improved to 23.2° (ranged 4.8°-66.2°) at the last follow-up for a 71.1% of correction in PAIS group. The preoperative ODI score was 32.4 (10-42) in the PAIS group and improved to 11.4 (4-22) at last follow-up, 33.4 (12-42) in the AIS group and improved to 11.5 (5-22) at last follow-up. The global coronal balance, TK and SVA were all significantly improved after surgery and maintained to the last follow-up in the two groups. The neurological complications were observed in 3.3% of PAIS patients and 3.6% of AIS patients. No statistical difference in the parameters between the two groups was observed at the last follow-up.

CONCLUSION

One-stage posterior corrective surgery is safe and effective in PAIS patients associated with intraspinal abnormalities without preoperative neurological symptoms. Surgical guidelines of AIS are appropriate for the treatment of PAIS patients associated with intraspinal abnormalities.

Is the routine use of magnetic resonance imaging indicated in patients with scoliosis?

Background

To assess the reliability of the indicators for performing magnetic resonance imaging in patients with scoliosis and assess the incidence of neural axis anomalies in a population with scoliosis referred to a specialist centre.

Methods

A retrospective review of magnetic resonance imaging (MRI) reports of all patients under the age of 18 who underwent a pre-operative MRI for investigation of their scoliosis between 2009 and 2014 at a single institution was performed.

Results

There were 851 patients who underwent an MRI scan of their whole spine with a mean age of 14.08 years. There were 211 males and 640 females. One hundred and fourteen neural axis abnormalities (NAA) were identified. The presence of a left sided thoracic curve, a double thoracic curve, being male nor being diagnosed before the age of 10 were found to be statistically significant for the presence of a NAA. Furthermore, 2.34% of patients were also found to have an incidental finding (IF) of an extraspinal abnormality.

Conclusions

From our series, the reported indications for performing an MRI scan in the presence of scoliosis are not reliable for the presence of an underlying NAA. We have demonstrated that there is a number of intra and extra dural anomalies found on MRI without clinical symptoms and signs. This acts as normative information for this group.

Keywords

Scoliosis; magnetic resonance imaging (MRI); neural axis abnormalities (NAA); adolescent idiopathic scoliosis (AIS).

Prevalence and risk factors for neural axis anomalies in idiopathic scoliosis: a systematic review

BACKGROUND

There is ongoing controversy about the routine use of magnetic resonance imaging (MRI) preoperatively in patients with presumed idiopathic scoliosis (IS). Routine MRI can help identify possible causes for the deformity and detect anomalies that could complicate deformity surgery. However, routine MRI increases health-care costs significantly and may reveal mild variations from normal findings without clinical relevance, which can still lead to anxiety and influence decision-making.

PURPOSE

Given the necessity to make evidence-based decisions both in the light of quality of care and cost control, the aim of this review is to report the prevalence of neural axis anomalies in IS and to identify risk factors associated with these anomalies.

STUDY DESIGN

A systematic review was carried out.

METHODS

An electronic search of PubMed, Embase, Cochrane, and Cinahl until May 2017 was performed. Studies were assessed by two reviewers independently according to predetermined inclusion (MRI in presumed IS) and exclusion criteria (diagnosis other than IS).

RESULTS

Fifty-one studies were included comprising 8,622 patients. In 981 patients, anomalies were found, resulting in an overall prevalence of 11.4%. The prevalence was 10.5%, 9.0%, and 14.2% when screening was performed of all IS patients, preoperative patients, or patients with presumed risk factors. The prevalence of a syrinx (3.7%), an Arnold-Chiari malformation (3.0%), or a combination of both (2.5%) was highest. Less frequent diagnoses included tethered cord (0.6%), an incidental malignancy (0.3%), and split cord malformations (0.2%). Risk factors for intraspinal anomalies included early-onset scoliosis, male gender, atypical curves, thoracic kyphosis, and abnormal neurologic findings such as reflexes and sensation.

CONCLUSIONS

This systematic review shows that a significant number of patients have intraspinal anomalies on preoperative MRI in (presumed) IS. The prevalence of finding spinal axis abnormalities increases in preselected patient groups with specific risk factors.

Should all paediatric patients with presumed idiopathic scoliosis undergo MRI screening for neuro-axial disease?

BACKGROUND

Idiopathic scoliosis is a relatively common childhood condition affecting 0.47-5.2% of the population. Traditional interventions focus on orthopaedic correction of the curve angle. There is a spectrum of patients with scoliosis who are found to have neuro-axial abnormality on full MRI of the spine, but not all surgeons request imaging in the absence of neurological symptoms. There is evidence to suggest that treatment of neuro-axial disease may improve scoliosis curve outcome. We therefore sought to estimate what proportion of patients with normal neurology and scoliosis are found to have neuro-axial abnormality on full MRI imaging of the spine, in particular Chiari malformation and syringomyelia.

RESULTS

Out of 11 identified studies consisting of 3372 paediatric patients (age < 18 years), mean weighted proportion demonstrates that 14.7% of patients with scoliosis (Cobb angle > 20°) and normal neurological examination will demonstrate a neuro-axial abnormality on full MRI imaging of the spine. Of patients, 8.3 and 8.4% were found to have Chiari malformation and syringomyelia, respectively.

CONCLUSIONS

Up to one in seven paediatric patients with scoliosis and normal neurological examination will demonstrate neuro-axial disease on MRI imaging of the spine. Given that younger age and earlier age of decompression is associated with improvement in curve angle, it seems important that MRI screening be considered in all patients regardless of neurological examination findings. There is a potentially long-term benefit in these patients. Multi-cross institutional prospective studies are encouraged to further investigate effect on curve angle.

Intraspinal anomalies in early-onset idiopathic scoliosis

Aims

In the United Kingdom, lower incidences of intraspinal abnormalities in patients with early onset idiopathic scoliosis have been observed than in studies in other countries. We aimed to determine the rates of these abnormalities in United Kingdom patients diagnosed with idiopathic scoliosis before the age of 11 years.

Patients and Methods

This retrospective study of patients attending an urban scoliosis clinic identified 71 patients satisfying a criteria of: clinical diagnosis of idiopathic scoliosis; age of onset ten years and 11 months or less; MRI screening for intraspinal abnormalities. United Kingdom census data combined with patient referral data was used to calculate incidence.

Results

Mean age at diagnosis was six years with 39 right-sided and 32 left-sided curves. Four patients (5.6%) were found to have intraspinal abnormalities on MRI. These consisted of: two combined Arnold-Chiari type 1 malformations with syrinx; one syrinx with a low lying conus; and one isolated syrinx. Overall annual incidence of early onset idiopathic scoliosis was one out of 182 000 (0.0006%).

Conclusion

This study reports the lowest rates to date of intraspinal anomalies in patients with early onset idiopathic scoliosis, adding to knowledge regarding current incidences of these abnormalities as well as any geographical variation in the nature of the disease. Cite this article: Bone Joint J 2017;99-B:829–33.

The prevalence of intraspinal anomalies in infantile and juvenile patients with "presumed idiopathic" scoliosis: a MRI-based analysis of 504 patients

Background

Though several studies have reported the incidence of intraspinal neural axis abnormalities in infantile and juvenile “presumed idiopathic” scoliosis, there has been a varying prevalence ranging from 11.1 to 26.0 % based on a limited sample size. Therefore, such inconclusive findings have resulted in some questions on the MRI-associated role in the management of these patients. We aimed to investigate the prevalence and distribution of intraspinal anomalies in the infantile and juvenile patients with “presumed idiopathic” scoliosis and to explore the radiographic and clinical indicators with large sample size.

Methods

A total of 504 infantile and juvenile patients diagnosed with “presumed idiopathic” scoliosis were examined for potentially-existing neural axis abnormalities by MRI. Patients were grouped into two cohorts according to the presence of neural axis abnormalities. Radiographic parameters including curve magnitude, curve pattern, location of apex, degree of thoracic kyphosis, and span of curve were recorded and compared between the two groups. The prevalence of the neural abnormalities between the infantile-age group and juvenile-age group was also compared. The student t test was used to evaluate the differences of continuous variables and the chi-square test was used to evaluate the difference of categorical variables. Fisher exact test was applied to detect the difference of the rate of intraspinal anomalies between the “infantile idiopathic scoliosis” and “juvenile idiopathic scoliosis” group.

Results

Involving the spinal cord, 94 patients (18.7 %) were found to have a neural abnormality: Arnold-Chiari malformation alone in 43 patients, Arnold-Chiari malformation combined with syringomyelia in 18 patients, isolated syringomyelia in 13 patients, diastematomyelia in six patients, tethered cord combined with diastematomyelia in six patients, tethered cord alone in four patients, and other uncommon intraspinal abnormalities in the remaining four patients. Totally Arnold-Chiari malformation with or without syringomyelia accounted for 64.8 % (61/94) among all these abnormalities. Male gender, left thoracic curve and right lumbar curve were found to be significantly associated with the presence of neural axis abnormalities on MRI.

Conclusions

The incidence of neural axis abnormalities in the presumed IIS and JIS was 18.7 %. Thus a routine MRI evaluation appears warranted for those “presumed idiopathic” scoliosis patients if aged less than 10 years, being male or having left thoracic or right lumbar curve.

The Role of Routine Preoperative Magnetic Resonance Imaging in Idiopathic Scoliosis: A Ten Years Review

Study Design

Prospective study.

Purpose

To determine the role of routine preoperative magnetic resonance imaging (MRI) to detect the incidence and risk factors for intraspinal anomalies in patients with idiopathic scoliosis.

Overview of Literature

The incidence and risk factors for intraspinal anomalies in patients with idiopathic scoliosis are controversial, and the indications for preoperative MRI in these patients vary among centers.

Methods

Information on patients with idiopathic scoliosis who were surgical candidates over 10 years (age at presentation, sex, magnitude and apex of major curve, intraspinal anomalies detected by MRI, and neurological examination results) were recorded, the patients were grouped according to the intraspinal anomaly, and the data were analyzed.

Results

Of the 271 patients with idiopathic scoliosis, 27 had neuroaxial abnormalities (9.9%). Of these 27 patients, 14 (52%) underwent a neurosurgical procedure. Significant differences were observed in the frequency of early disease onset and male sex (p<0.05) between the group of patients with neuroaxial abnormalities on preoperative MRI and those who did not have a cord anomaly. No difference was detected in the magnitude or direction of the curve.

Conclusions

Neuroaxial abnormalities in patients with idiopathic scoliosis and a normal neurological examination were highly frequent (9.9%). Missing these abnormalities before surgery could inflict catastrophic postoperative complications. The incidence of neuroaxial abnormalities was higher in male patients and in those with early onset disease. Thus, MRI is essential for all patients with idiopathic scoliosis who require medical intervention.

Intrathecal Anomalies in Presumed Infantile Idiopathic Scoliosis: When Is MRI Necessary?

STUDY DESIGN

Retrospective review.

OBJECTIVE

To determine the rate of abnormal magnetic resonance imaging (MRI) findings in patients with presumed infantile idiopathic scoliosis (IIS) and the rate of neurosurgical intervention in those patients, and to develop a guideline concerning when to obtain an MRI.

SUMMARY OF BACKGROUND DATA

The reported rate of intrathecal anomalies associated with presumed IIS varies in the literature (12% to 50%). Conclusions have led to conflicting recommendations concerning when an MRI is indicated.

METHODS

After appropriate internal review board approval, the authors retrospectively reviewed the medical records of patients from a single institution meeting the inclusion criteria: presumed idiopathic curve with a magnitude of ≥20°, age <36 months at diagnosis, normal neurologic examination, and presentation between 2002 and 2010. The authors reviewed the MRI findings, whether neurosurgical intervention took place, and the orthopedic treatment course (observation, brace, cast, or surgery).

RESULTS

A total of 56 patients were identified and reviewed; 43 had had an MRI. Seven of 43 patients were found to have an anomaly (16.2%). A fatty filum was identified in 2 patients, a syrinx in 3, Chiari I malformation in 2, and a tethered cord in 1 (this patient also had a syrinx). Two of the 7 patients required neurosurgical intervention (28%). Patients who did not have an MRI were statistically younger, had smaller Cobb angles, and required less orthopedic treatment.

CONCLUSIONS

The incidence of intrathecal anomalies (16.2%) at the authors' institution was similar to previously published reports; however, the need for neurosurgical intervention was significantly lower in this study (28%). For younger patients with small curves (<30°) who do not require orthopedic treatment, MRI under sedation can be delayed or avoided. Clinical judgment should be the determinant for whether to use MRI when evaluating patients with presumed IIS.

Evaluation of coronal shift as an indicator of neuroaxial abnormalities in adolescent idiopathic scoliosis: a prospective study

Background

In previous studies, many indicator factors have been proposed to select patients who need an MRI screening of the spinal canal. In current study, the clinical and radiologic factors including coronal parameters of the curve were evaluated to find out which indicator is more important.

Methods

A prospective study included 143 consecutive patients with the diagnosis of adolescent idiopathic scoliosis who were treated between 2010 and 2013 at our spinal clinics. Only patients with normal or subtle neurologic findings were included. All patients were evaluated by a total spine MRI protocol for examination of neuroaxial abnormalities. Known indicators and also coronal shift were analysed in all patients with or without abnormal MRI.

Results

The incidence of neuroaxial abnormalities was 11.9% (17 of 143); only 5 patients (3.5%) were operated to treat their neuroaxial problem. The significant indicators of the abnormalities in our patients were: younger age at onset, asymmetric superficial abdominal reflex and, coronal shift more than 15 mm (P = 0.03). Some previously known indicators like atypical curves, male gender, double curves and absence of thoracic lordosis were not different between two groups of the patients.

Conclusions

A total spine MRI is recommended at presentation in patients with younger age, abnormal neurologic findings and severe coronal shift.

Scoliosis-Associated Cervical Spine Pathologies

STUDY DESIGN

A total of 126 scoliosis patients admitted to the hospital were screened for concomitant cervical pathologies.

OBJECTIVES

To investigate the prevalence of cervical spine pathologies and the clinical relevance of magnetic resonance imaging (MRI) in the evaluation of patients with neuromuscular, congenital, syndromic, and idiopathic scoliosis.

BACKGROUND SUMMARY

With the development of MRI, upper neural axis abnormalities such as syringomyelia and Chiari malformation are increasingly being found in patients with scoliosis, but no report in the literature describes other pathologies in the cervical area seen concomitant with different scoliosis types.

METHODS

A total of 126 consecutive patients who were classified as having neuromuscular, congenital, syndromic, and idiopathic scoliosis were retrospectively evaluated. Data regarding cervical neural axis abnormalities obtained from the MRI studies were analyzed and classified into each type of scoliosis group.

RESULTS

A total of 126 patients with scoliosis were evaluated for hindbrain and cervical spine anomalies. Patients were divided into 4 groups regarding the type of scoliosis. The cervical spine of all patients was evaluated with MRI and other radiologic methods when needed. The most frequently seen pathology was syringomyelia. Other pathologies found included congenital vertebral anomalies, Chiari malformation, arachnoid cyst, atlanto-axial dissociation, split cord, posterior vertebral fusion, vertebral hypoplasia, neurenteric cyst, myelomalacia, dermoid cyst, and decrease in craniovertebral angle. Cervical pathologies were most frequently seen in neuromuscular scoliosis, followed by congenital and syndromic groups.

CONCLUSIONS

Cervical spinal pathologies vary according to the type of scoliosis. The number of cervical spinal pathologies diagnosed in idiopathic scoliosis patients was least compared with neuromuscular and syndromic groups. The most common pathology was syringomyelia, followed by congenital vertebral anomalies and cerebral tonsillar hernia. Preoperative MRI scan provides vital information regarding cervical spinal pathologies encountered in scoliosis patients.

Are intraspinal anomalies in early onset idiopathic scoliosis as common as once thought? A two centre United Kingdom study

PURPOSE

Rates of neural axis abnormalities in infantile and juvenile idiopathic scoliosis may be as high as 50 %. We aimed to determine the rates of neural axis abnormalities in early onset idiopathic scoliosis patients in a British population.

METHODS

This retrospective study at two British spinal deformity clinics identified 72 patients satisfying the inclusion criteria of: (1) age at diagnosis of 7 years and younger, (2) idiopathic scoliosis and (3) magnetic resonance imaging of the neuraxis.

RESULTS

The mean age at diagnosis was 3.6 years and the mean Cobb angle was 47° with a near equal distribution of left (32) and right (36) sided curves. Eight (11.1 %) neural axis abnormalities consisting of two syrinxes, one Arnold-chiari Type I malformation and five combined (Arnold-chiari malformation Type I and syrinx) anomalies were identified.

CONCLUSIONS

This multi-centre study on the largest number of British subjects to date helps to establish the rates of neural axis abnormalities.

Indication for preoperative MRI of neural axis abnormalities in patients with presumed thoracolumbar/lumbar idiopathic scoliosis

PURPOSE

The purpose of this study was to investigate the incidence of neural axis abnormalities in patients with presumed "idiopathic" thoracolumbar or lumbar scoliosis by magnetic resonance imaging (MRI) and try to determine which clinical and radiographic characteristics correlate with neural axis abnormalities on MRI in these patients.

METHODS

The database of a single spinal deformity center was retrospectively reviewed to identify all patients with a primary diagnosis of idiopathic scoliosis (IS) between January 2003 and August 2011. A total of 446 patients with main thoracolumbar or lumbar curves were identified. Radiographic parameters including main curve Cobb angles, location of curve apex, span of main curve, thoracic kyphosis (T5-T12), thoracolumbar junction kyphosis (T10-L2), lumbar lordosis (L1-S1), and sagittal and coronal balance were measured.

RESULTS

Neural axis abnormalities were detected in 35 (7.8 %) patients. For patients with neural axis abnormalities, a higher proportion of male gender and long thoracolumbar curves were presented. In these patients, the mean age was smaller and the mean Cobb angle of main curve was larger. Greater thoracic kyphosis (≥ 30°) was more frequently found in those with neural axis abnormalities. The incidences of thoracolumbar junction hyperkyphosis were similar between two groups (P > 0.05). There was no difference between two groups as to lumbar lordosis and coronal and sagittal balance.

CONCLUSION

We recommend the routine use of MRI in the patients with one or more of the following characteristics: right curves, long curve span, apex at thoracolumbar spine and hyperthoracic kyphosis.

The use of routine preoperative magnetic resonance imaging in identifying intraspinal anomalies in patients with idiopathic scoliosis: a 10-year review

PURPOSE

This study sought to quantify the frequency of previously unidentified spinal cord anomalies identified by routine preoperative magnetic resonance imaging (MRI), in patients planned for surgical scoliosis correction.

METHODS

Our study group comprised 206 patients with idiopathic scoliosis who underwent deformity correction from 1998 to 2008. Clinical records of all the patients were retrospectively reviewed to ascertain the proportion having a neural abnormality on preoperative MRI scan.

RESULTS

Twenty of 206 patients (9.7 %) were diagnosed with an unexpected intraspinal anomaly on routine preoperative MRI. In all cases, a neurosurgical opinion was sought prior to further intervention. Of the 20 patients, 11 underwent a neurosurgical procedure (de-tethering of cord, decompression of Chiari, decompression of syrinx). There was no statistically significant difference between the group of patients who had intrinsic spinal cord anomalies on preoperative MRI and those did not have a cord abnormality with regard to age at presentation, gender, side of dominant curve and degree of curve (p < 0.05).

CONCLUSION

The high frequency of spinal cord abnormalities unidentified by preoperative neurological examination, and the frequent need for subsequent neurosurgical intervention, suggests that MRI assessment prior to deformity correction is important in the management of idiopathic scoliosis.

Different curve pattern and other radiographical characteristics in male and female patients with adolescent idiopathic scoliosis

STUDY DESIGN

Retrospective radiographical study.

OBJECTIVE

To compare the sex differences in curve patterns and radiographical characteristics in patients who have adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Sex differences in AIS have been documented in the incidence of curve progression, response to bracing, and outcomes of surgical treatment. However, limited information is available about the relation between sex and scoliosis curve patterns and radiographical presentations.

METHODS

A total of 359 male and 999 female patients with AIS with major curve of 20° or more were recruited. Standard posteroanterior and lateral radiographs of spine were reviewed to classify scoliosis curve patterns as typical or atypical and to measure curve severity and thoracic kyphosis. In 351 surgically treated patients, side-bending films were used to assess curve flexibility. Comparisons between male and female patients were made by subgrouping patients according to curve patterns and severity.

RESULTS

Atypical curves were more frequently observed in male (19.8%) than in female patients (8.9%) (P < 0.01). Sex differences were also found in the distribution of curve types. Main thoracic curve was the most common curve type in both sexes. Furthermore, significantly higher incidence of main thoracic curve in patients with severe AIS than in patients with moderate AIS was found in male (P < 0.001) but not in female patients. In patients with severe AIS who had typical curve patterns that included a major thoracic curve, male patients had larger magnitude of thoracic curve, more severe thoracic kyphosis, and more rigid thoracic and lumbar curves than female patients.

CONCLUSION

Atypical curve patterns were more predominant in male than in female patients with AIS. The thoracic curve in male patients with AIS might have higher incidence of progression than that in female patients. The higher rigidity of both thoracic and lumbar curves in male patients with AIS with severe curves might contribute to the lower curve correction rate and poor response to brace than in female cases.

Magnetic resonance imaging evaluation of patients with idiopathic scoliosis: a prospective study of four hundred seventy-two outpatients

STUDY DESIGN

A prospective study of magnetic resonance imaging findings in outpatients with idiopathic scoliosis.

OBJECTIVE

The purpose of this study was to determine the prevalence of neural axis abnormalities in outpatients with scoliosis and to analyze the characteristics of patients who had such abnormalities.

SUMMARY OF BACKGROUND DATA

In previous studies, neural axis abnormalities were found in 2.9% to 37% of patients with idiopathic scoliosis. The current guidelines for MRI screening in scoliosis are valuable, and the proposed indications for performing MRI in the literature include early onset, atypical curvature, double thoracic curve (King type-5), rapid progression, male gender, and abnormal neurologic findings.

METHODS

A total of 472 outpatients with a primary diagnosis of idiopathic scoliosis were examined for neural axis abnormalities by magnetic resonance imaging. Logistic regression was used to determine significant predictors of neural axis abnormalities on MRI.

RESULTS

The incidence of neural axis abnormalities on MRI was 3.8% (18 of 472 patients). Among the 18 patients, 6 had a Chiari I malformation alone, 10 had a Chiari I malformation combined with syringomyelia, and 2 had a syringomyelia without Chiari I malformation. Male gender, patients younger than 11 years old, and abnormal superficial abdominal reflexes were significantly associated with the detection of neural axis abnormalities on MRI.

CONCLUSION

We recommend routine use of MRI in male patients, younger than 11 years old, and abnormal superficial abdominal reflexes. Even if a patient has no specific indications for MRI, we recommend its routine use in preoperative planning.

Right thoracic curves in presumed adolescent idiopathic scoliosis: which clinical and radiographic findings correlate with a preoperative abnormal magnetic resonance image?

STUDY DESIGN

Prospective case control study.

OBJECTIVE

This study investigated preoperative presumed adolescent idiopathic scoliosis (AIS) patients with right thoracic curves to determine which clinical and radiographic findings correlate with neural axis abnormalities on magnetic resonance imaging (MRI).

SUMMARY OF BACKGROUND DATA

Neural axis abnormalities on MRI are not uncommon in patients with left thoracic curves, increased thoracic kyphosis, and in children less than 10 years old. For adolescents with right thoracic curves, less is known regarding which clinical and/or radiographic characteristics accompany neural axis abnormalities.

METHODS

A total of 529 presumed AIS patients with Lenke 1-4 right thoracic curve patterns had MRI evaluation before surgery. Thirty-six of these patients had abnormal MRIs (syrinx, Chiari malformation, and/or tethered cord). To differentiate between those with normal MRIs (n = 493) and those with abnormal MRIs (n = 36), the following preoperative clinical parameters were evaluated: age, gender, height, weight, asymmetric abdominal reflexes, thoracic rotation (scoliometer), coronal balance, trunk shift, shoulder elevation, and the Scoliosis Research Society (SRS)-30 questionnaire. Radiographically, thoracic curve magnitude, thoracic rotation (Nash-Moe), coronal balance, trunk shift, length of thoracic curve, location of curve apex, sagittal balance, thoracic kyphosis (T2-T12), and lumbar lordosis were evaluated.

RESULTS

Neural axis abnormalities were found in 6.8%. Those with abnormal MRI findings had significantly greater clinical thoracic rotation (mean difference, 2.4°) and significantly greater radiographic thoracic kyphosis (mean difference 5.9°). However, there were no significant differences in: age (14.9 vs. 14.7 years), height for age (when adjusted for gender), asymmetric abdominal reflexes (3.5% normal MRI group vs. 6.1% abnormal group), coronal balance (clinical or radiographic), trunk shift(clinical or radiographic), shoulder elevation, thoracic curve magnitude (61.4° normal MRI group vs. 63.6° abnormal group), length of thoracic curves (7.0 segments normal group vs. 7.2 segments abnormal group), location of curve apexes, radiographic sagittal balance, or any domains of the preoperative SRS-30 questionnaire.

CONCLUSION

Of preoperative presumed AIS patients with right thoracic curves who underwent MRI evaluation of the neural axis, 6.8% were found to have neural axis abnormalities, with those having increased rotation and/or increased kyphosis at higher risk. Surgeons should use this information when deciding whether a preoperative MRI is indicated in those with right thoracic AIS curve patterns.

The utility of superficial abdominal reflex in the initial diagnosis of scoliosis: a retrospective review of clinical characteristics of scoliosis with syringomyelia

Background

With increasing use of magnetic resonance imaging (MRI), underlying syringomyelia is increasingly found in patients with presumed idiopathic scoliosis. To determine the indications for MRI in the differential diagnosis of scoliosis, several clinical characteristics of syringomyelia have been reported. Neurological signs, particularly abnormal superficial abdominal reflex (SAR), are important in establishing the initial diagnosis of scoliosis. However, the prevalence of abnormal SAR in patients with scoliosis and the sensitivity of this sign in predicting syringomyelia are not well known. We aimed to determine the diagnostic utility of SAR and other characteristics of syringomyelia in patients with scoliosis.

Methods

We reviewed the medical records of 93 patients with scoliosis, 90 of whom underwent corrective surgery. All patients underwent MRI to determine the presence of syringomyelia. Mean age at surgery was 12.5 years. Abnormal SAR was defined as unilateral or bilateral absence or hyporeflexia of SAR. We calculated indices of diagnostic utility of abnormal SAR for non-idiopathic scoliosis and for syringomyelia. Abnormal SAR, left thoracic curve pattern, gender, and curve flexibility were compared between scoliosis with syringomyelia and idiopathic scoliosis. Logistic regression analysis was performed with the existence of syringomyelia as the dependent variable and curve flexibility as the independent variable.

Results

Abnormal SAR was observed in 20 patients (prevalence 22%). All 6 patients with myopathic scoliosis displayed bilateral absence of SAR. The sensitivity of abnormal SAR for non-idiopathic scoliosis was 38%, with 96% specificity, 90% PPV (positive predictive value), and 60% NPV (negative predictive value). Syringomyelia was identified in 9 of the 93 patients (9.7%); 8 of these had abnormal SAR. The sensitivity of abnormal SAR for syringomyelia in presumed idiopathic scoliosis was 89%, with 95% specificity, 80% PPV, and 98% NPV. Gender, abnormal neurological findings, and curve flexibility differed significantly between patients with syringomyelia and those with idiopathic scoliosis (P < 0.05). In the logistic regression model, the area under the receiver operating characteristic (ROC) curve was 0.79 and the cut-off value of curve flexibility for syringomyelia was 50% (P = 0.08).

Conclusion

Abnormal SAR was a useful indicator not only for syringomyelia, but also for myogenic scoliosis.

Curve length, curve form, and location of lower-end vertebra as a means of identifying the type of scoliosis

PURPOSE

To determine if the curve length, curve form, and location of the lower-end vertebra can identify the type of scoliosis.

METHODS

Standing posteroanterior and lateral radiographs of 78 women and 27 men with scoliosis aged 8 to 32 years were retrospectively analysed. Parameters measured were (1) the curve length (the number of vertebrae in the main curve), (2) the curve form (C-form, inverted C-form, or S-form), (3) the curve apex (the vertebral body at the apex of each curve), (4) the site of the scoliosis (thoracic, thoracolumbar, or lumbar), and (5) the location of the lower-end vertebra.

RESULTS

Only 3 (4%) of 77 patients with idiopathic scoliosis had a curve length of >8 vertebrae, compared with 19 (90%) of 21 patients with neuromuscular/neuropathic scoliosis (p<0.001, Fisher's exact test). 14 (18%) of the patients with idiopathic scoliosis had an S-form curve, compared with none in those with neuromuscular/neuropathic or congenital/osteogenic scoliosis (p=0.035, Fisher's exact test). No patient with idiopathic scoliosis had the lower- end vertebra located at L5, compared with 8 (38%) patients with neuromuscular scoliosis (p<0.001, Fisher's exact test). The criteria for neuromuscular/neuropathic scoliosis (a curve length of >8 vertebrae, a C-form or inverted C-form curve, and a lower-end vertebra located at L4 or L5) had 81% specificity, 76% sensitivity, 100% positive and 93% negative predictive values.

CONCLUSION

These criteria may help identify patients with neuromuscular/neuropathic scoliosis for further investigation by magnetic resonance imaging or computed tomography before they undergo corrective surgery.

The left thoracic curve pattern: a strong predictor for neural axis abnormalities in patients with "idiopathic" scoliosis

STUDY DESIGN

A prospective trial of MRI study in patients with "idiopathic" left thoracic scoliosis.

OBJECTIVE

To investigate the prevalence of neural axis abnormalities in asymptomatic patients with "idiopathic" left thoracic scoliosis.

SUMMARY OF BACKGROUND DATA

Some patients with neural axis abnormalities have scoliosis as the only presenting sign, and they might be given a diagnosis of "idiopathic" scoliosis. These neural axis abnormalities are risk factors for neurologic injury during spine correction. With the development of MRI, neural axis abnormalities are increasingly being found in patients with "idiopathic" scoliosis. However, there are few reports on the prevalence of neural axis abnormalities in asymptomatic patients with "idiopathic" left thoracic scoliosis.

METHODS

A total of 68 patients with presumed "idiopathic" left thoracic scoliosis were examined for neural axis abnormalities, using MRI.

RESULTS

Neural axis abnormalities were detected in 37 (54%) patients, including Chiari 1 malformation in 15 patients, Chiari 1 malformation with syringomyelia in 10, Chiari 1 malformation with syringomyelia and tethered cord in 1, Chiari 1 malformation with syringomyelia and diastematomyelia in 1, syringomyelia in 8, syringomyelia with tethered cord in 1, and arachnoidal cyst in cerebellomedullary cistern in 1 patient. There were statistically significant differences between patients with and without neural axis abnormalities regarding gender and curve severity (P < 0.05).

CONCLUSION

When a left thoracic curve pattern is present in patients with "idiopathic" scoliosis, especially in male patients or patients with severe curve, strong consideration should be given to the possibility of the presence of neural axis abnormalities, and acquisition of an MRI scan considered.

Intraspinal anomalies in scoliosis: An MRI analysis of 177 consecutive scoliosis patients

BACKGROUND

The association of intraspinal neural anomalies with scoliosis is known for more than six decades. However, there are no studies documenting the incidence of association of intraspinal anomalies in scoliotic patients in the Indian population. The guide lines to obtain an magnetic resonance imaging (MRI) scan to rule out neuro-axial abnormalities in presumed adolescent idiopathic scoliosis are also not clear. We conducted a prospective study (a) to document and analyze the incidence and types of intraspinal anomalies in different types of scoliosis in Indian patients. (b) to identify clinico-radiological 'indicators' that best predict the findings of neuro-axial abnormalities in patients with presumed adolescent idiopathic scoliosis, which will alert the physician to the possible presence of intraspinal anomalies and optimize the use of MRI in this sub group of patients.

MATERIALS AND METHODS

The data from 177 consecutive scoliotic patients aged less than 21 years were analyzed. Patients were categorized into three groups; Group A - congenital scoliosis (n=60), group B -presumed idiopathic scoliosis (n=94) and group C - scoliosis secondary to neurofibromatosis, neuromuscular and connective tissue disorders (n=23). The presence and type of anomaly in the MRI was correlated to patient symptoms, clinical signs and curve characteristics.

RESULTS

The incidence of intraspinal anomalies in congenital scoliosis was 35% (21/60), with tethered cord due to filum terminale being the commonest anomaly (10/21). Patients with multiple vertebral anomalies had the highest incidence (48%) of neural anomalies and isolated hemi vertebrae had none. In presumed 'idiopathic' scoliosis patients the incidence was higher (16%) than previously reported. Arnold Chiari-I malformation (AC-I) with syringomyelia was the most common neural anomaly (9/15) and the incidence was higher in the presence of neurological findings (100%), apical kyphosis (66.6%) and early onset scoliosis. Isolated lumbar curves had no anomalies. In group-C, incidence was 22% and most of the anomalies were in curves with connective tissue disorders.

CONCLUSION

The high incidence of intraspinal anomalies in presumed idiopathic scoliosis in our study group emphasizes the need for detailed examination for subtle neurological signs that accompany neuro-axial anomalies. Preoperative MRI screening is recommended in patients with presumed 'idiopathic' scoliosis who present at young age, with neurological findings and in curves with apical thoracic kyphosis.

The role of routine magnetic resonance imaging in the preoperative evaluation of adolescent idiopathic scoliosis

The routine use of magnetic resonance imaging (MRI) in adolescent idiopathic scoliosis remains controversial, and current indications for MRI in idiopathic scoliosis vary from study to study. The purpose of this study was to demonstrate the prevalence of neural axis malformations and the clinical relevance of routine MRI studies in the evaluation of patients with adolescent idiopathic scoliosis undergoing surgical intervention without any neurological findings. A total of 249 patients with a diagnosis of idiopathic scoliosis were treated surgically between the years 2002 and 2007. A routine whole spine MRI analysis was performed in all patients. On the preoperative clinical examination, all patients were neurologically intact. There were 20 (8%) patients (3 males and 17 females) who had neural axis abnormalities on MRI. Three of those 20 patients needed additional neurosurgical procedures before corrective surgery; the remaining underwent corrective spinal surgery without any neurosurgical operations. Magnetic resonance imaging may be beneficial for patients with presumed idiopathic scoliosis even in the absence of neurological findings and it is ideally performed from the level of the brainstem to the sacrum.

Intraspinal anomalies in infantile idiopathic scoliosis: prevalence and role of magnetic resonance imaging

STUDY DESIGN

Retrospective case series of magnetic resonance imaging (MRI) findings in patients with presumed infantile idiopathic scoliosis (IIS).

OBJECTIVE

To identify the prevalence of intraspinal anomalies in patients with presumed IIS at a single, large volume institution and further define the role for a screening MRI.

SUMMARY OF BACKGROUND DATA

Idiopathic scoliosis in patients less than 10 years of age has been shown to carry a higher prevalence of concordant intraspinal anomalies, up to 20%, in juveniles, when compared to the adolescent age group. Few studies exist assessing the prevalence of intraspinal anomalies in the IIS patient population. Dobbs et al (2002) reported a 21.7% prevalence of neural axis abnormalities in 46 patients with presumed IIS across 3 combined spinal deformity clinics and recommended a screening MRI for all IIS patients with a curve >20 degrees.

METHODS

A retrospective review of the medical records of 54 patients at a single institution with a presumed diagnosis of IIS was performed. All patients satisfied the strict inclusion criteria of: curve > or =20 degrees, age <36 months at diagnosis, normal neurologic examination (i.e., normal tone, motor strength, reflexes, etc.), absence of any concomitant syndromes or congenital anomalies, and an MRI of the spine from skull to coccyx.

RESULTS

MRI revealed a neural axis abnormality in 7 (13%) of 54 patients who underwent an MRI. In this subset of 7 patients, 5 (71.4%) required neurosurgical intervention. Tethered cord requiring surgical release was identified in 3 patients, Chiari malformation requiring surgical decompression was found in 2 patients, and a small nonoperative syrinx was found in 2 patients.

CONCLUSION

This study represents the largest evaluation of intraspinal anomalies in IIS to date. Our patient population exhibited a smaller percentage (13%) of neural axis abnormalities than previously reported. On the basis of these findings, the close observation may be a reasonable alternative to an immediate screening MRI in patients presenting with presumed IIS and a curve >20 degrees.

MRI Findings in Spinal MRI of 306 Children with Scoliosis

The aim of this study was to analyze the MRI findings and assess the prevalence of different associated structural abnormalities in children with scoliosis and to determine if the age of onset is a possible indicator of intraspinal pathology. This is a retrospective analysis of 663 consecutive MR examinations (319 patients). Thirteen patients with known intraspinal tumors were excluded and a total of 306 patients aged 2–18 years with scoliosis were subjected for analysis. The scoliosis was regarded as idiopathic in 62% of patients. Among the remaining 38% the most commonly seen abnormality was syrinx and Chiari malformations. There was no statistically significant difference in the occurrence of syrinx only or syrinx associated with Chiari I malformation in patients younger than ten years and those older than ten years. MRI examination is an essential part of the work up of scoliosis in the pediatric population especially before any corrective surgery. This study and a review of the current literature suggest there is no clinical marker that would definitely serve as an indicator of the presence of intraspinal pathology in these patients.

DECISION MAKING IN PEDIATRIC SPINAL DEFORMITY

OBJECTIVE

To review the concepts involved in the decision-making process for management of pediatric patients with spinal deformity.

METHODS

The literature was reviewed in reference to pediatric deformity evaluation and management.

RESULTS

Pediatric spinal deformity includes a broad range of disorders with differing causes, natural histories, and treatments. Appropriate categorization of pediatric deformities is an important first step in the clinical decision-making process. An understanding of both nonoperative and operative treatment modalities and their indications is requisite to providing treatment for pediatric patients with spinal deformity. The primary nonoperative treatment modalities include bracing and casting, and the primary operative treatments include nonfusion instrumentation and fusion with or without instrumentation. In this article, we provide a review of pediatric spinal deformity classification and an overview of general treatment principles.

CONCLUSION

The decision-making process in pediatric deformity begins with appropriate diagnosis and classification of the deformity. Treatment decisions, both nonoperative and operative, are often predicated on the basis of the age of the patient and the natural history of the disorder.

Radiological presentations in relation to curve severity in scoliosis associated with syringomyelia

BACKGROUND

Few radiographic guidelines are available to assist clinicians in deciding when to order magnetic resonance imaging in patients with a normal history and physical examination. Most of the recent reports on the radiographic characteristics of scoliosis are limited by a small number of patients and a shortage of large curves. The association between radiological features and the severity of scoliosis has little been elaborated. The purpose of this study is to further explore the radiological presentations in relation to curve severity in scoliosis associated with Chiari malformation and syringomyelia.

METHODS

A total of 87 children and adolescents were divided into 3 groups: group 1 (10 degrees < or = Cobb angle < or = 30 degrees), group 2 (30 degrees < Cobb angle < or = 60 degrees), and group 3 (Cobb angle > 60 degrees). Curves were classified into typical and atypical patterns in the coronal plane, and the sagittal profile was measured. Cerebellar tonsillar descent or syrinx patterns in relation to curve severity and the frequency of atypical curves were also investigated.

RESULTS

The frequency of atypical curve patterns from groups 1 to 3 was 46.2%, 45.2%, and 40.7%, respectively. A total of 65.3% of patients with typical curve patterns had atypical features in all of the 3 groups. There was a significant difference of kyphotic angle among the 3 groups showing that the larger curves tended to have greater thoracic kyphosis. Both the degree of cerebellar tonsillar descent and syrinx patterns had no correlation with the curve severity or the frequency of atypical curves.

CONCLUSIONS

These results show that radiographic presentations including atypical curve patterns, atypical features in typical curve patterns, and a normal to hyperkyphotic thoracic spine may suggest the need for a preoperative magnetic resonance imaging. Kyphosis may be indicative of progressive scoliosis. There is no evidence to suggest that the degree of cerebellar tonsillar descent and syrinx patterns have an effect on the progress of scoliosis and the frequency of atypical curves.

Scoliosis: a review

Scoliosis, lateral curvature of the spine, has been studied since Hippocrates' time, but remains a disputed subject in orthopaedic surgery, because of its several varieties, unknown cause and unpredictable course. A review of 30 years' experience in a paediatric orthopaedic unit was undertaken to clarify the problem. Patient records, collected prospectively, were examined to demonstrate the incidence, prevalence, extent, course and outcome of the commonest variety, adolescent idiopathic scoliosis. Reference was made to the results of previously published studies. Records from a school screening programme showed that, while slight degrees of spinal curvature were widely prevalent in the community, these were of no clinical significance and major cosmetic deformity was rare: only 8 in 10,000 adolescent girls had Cobb angles of 40 degrees or more and only half of these underwent surgical correction. Evidence to support non-operative treatment could not be demonstrated and it did not reduce the incidence of surgical intervention. Because the course of scoliosis did not seem to correspond with much published work, or with current hypotheses of aetiology, a rethinking of the whole subject is advocated. An alternative model of pathogenesis deriving from developmental biology was proposed. While advances in surgical methods have been significant, the core problems of aetiology and natural history remain. Until they are resolved, all conclusions on management must be provisional. This is where innovative thinking needs to be directed.

The pediatric Chiari I malformation: a review

BACKGROUND

Both the diagnosis and treatment regimens for the Chiari I malformation (CIM) are varied and controversial. The present paper analyzes the literature regarding this form of hindbrain herniation in regard to definition, anatomy, pathobiology, symptoms, findings, treatment, and outcomes.

DISCUSSIONS

Appropriate literature germane to the CIM is reviewed and discussed. There is variation in the reported anatomy, outcome, and treatment for children with CIM. Based on the literature, most patients have preoperative symptoms or findings (e.g., syringomyelia) improve no matter what surgical technique is utilized. However, standardized treatment paradigms based on randomized controlled studies are still necessary to elucidate the optimal selection and treatment criteria.

The outcomes of scoliosis surgery in patients with syringomyelia

STUDY DESIGN

A retrospective review of a consecutive case series.

OBJECTIVE

To describe patient demographics, syrinx morphology, and deformity characteristics, as well as postsurgical correction, progression, and complications.

SUMMARY OF BACKGROUND DATA

Conflicting data are available on the natural and postsurgical history of patients with spinal deformity associated with syringomyelia. This is the largest series in the literature on the surgical outcomes of these patients.

METHODS

All patients treated for spinal deformity at our institution with an associated syrinx were reviewed. Demographics, deformity morphology, treatment methods, and postoperative outcomes were measured and recorded.

RESULTS

Thirteen patients met inclusion criteria. All were Lenke thoracic modifier normal or positive. Ten patients underwent neurosurgical decompression. All curves either progressed or remained unchanged following neurosurgical treatment. The average thoracic kyphosis measured 46 degrees (29 degrees-69 degrees). Thoracic kyphosis was significantly increased compared with a population of adolescent idiopathic patients (P = 0.00002). The average curve before scoliosis surgery was 71 degrees (31 degrees-119 degrees) in the coronal plane and 46 degrees (29 degrees-68 degrees) in the sagittal plane. The average correction from the initial scoliosis surgery was 48% (6%-83%). All patients had spinal cord monitoring or wake-up tests during surgery. There were no instances of spinal cord injury from surgery. Three patients progressed significantly following anterior fusion, 2 of whom required further corrective surgery. Following arthrodesis, 4 patients progressed >10 degrees during follow-up.

CONCLUSION

The lack of thoracic hypokyphosis seen in idiopathic-like curves is a strong indicator of a possible underlying syrinx. Neurosurgical treatment of the syrinx did not improve the scoliosis. Caution should be exercised when choosing fusion levels, and arthrodesis should be planned with the underlying pathology in mind. Scoliosis surgery has proven to be safe in patients with treated syrinx when spinal cord monitoring or wake-up tests are used.

Scoliosis associated with syringomyelia: analysis of MRI and curve progression

Little is known about the natural history of scoliosis found in patients with syringomyelia, including the factors affecting scoliosis curve progression and the effect of syrinx drainage treatment. Twenty patients having scoliosis with syringomyelia diagnosed by MRI were followed up for 6.6 (range 2.0-12.6) years on an average. Various factors potentially influencing curve pattern or progression in these patients were then retrospectively reviewed. The convex side of major curve of scoliosis tended to be on the same side as the syrinx and as the unilateral neurologic abnormality. No correlation was found between the location and the size of the syrinx and the location and size of the major curve of the scoliosis, or between the severity of neurologic deficit and the size of the major curve of the scoliosis. In patients under the age of ten at the time of diagnosis of scoliosis and with a flexible curve, decompression of the syrinx improved or stabilized scoliosis. In most patients over the age of ten, surgical treatment of the scoliosis was necessary because of the large initial size of the curve or progression of the curve even after syrinx drainage. Other factors including gender, location of the syrinx, type of the curve, and severity of neurologic deficits did not correlate with the progression of the curve. The results of this retrospective study suggest that early diagnosis and decompression of a syrinx in scoliosis patients especially under the age of ten is crucial and may decrease the curve size and limit scoliosis curve progression.

Scoliosis in a child with Chiari I malformation and the absence of syringomyelia: case report and a review of the literature

BACKGROUND

Scoliosis is a common finding in children with Chiari I malformation and syringomyelia. The development of scoliosis associated with a Chiari malformation typically has been ascribed to the presence of syringomyelia. Decompression of the hindbrain hernia will often alleviate the syringomyelia and, in many cases, stabilize or reverse the scoliosis.

CASE REPORT

We report a child with Chiari I malformation and scoliosis who presented with Valsalva-induced headache/neck pain. MRI revealed no syringomyelia or hydrocephalus. Radiographs revealed that her scoliotic curvature was approximately 13 degrees and was a single levoscoliotic curve. This patient underwent a posterior fossa decompression with duraplasty for her Valsalva-induced pain. Postoperatively, she had resolution of her pain and there has been no progression of her scoliosis at 3 years follow-up.

PROGNOSIS

Intriguingly, and scattered throughout the medical literature, many have noted cases of scoliosis in patients with only a Chiari I malformation and no syringomyelia. Moreover, experimental studies have induced scoliosis in animals after compression of the dorsal columns. After a review of the medical literature regarding a potential cause and effect of herniated hindbrain-induced scoliosis in the absence of syringomyelia, this association although rare, does seem plausible.

Pedicle rotation in scoliosis: a marker for occult intrathecal abnormalities

STUDY DESIGN

The Perdriolle method was used to assess retrospectively radiographic pedicle rotation for association with occult intrathecal abnormalities in patients with scoliosis.

OBJECTIVE

To determine if pedicle rotation can be predictive of underlying intrathecal abnormalities.

SUMMARY OF BACKGROUND DATA

Scoliosis associated with intrathecal abnormalities is thought to produce less rotation than true idiopathic scoliosis. No supporting evidence was found in the literature.

METHODS

A consecutive series of patients with a presenting diagnosis of idiopathic scoliosis were reviewed for anteroposterior radiographs and spinal magnetic resonance imaging (MRI). A blinded single examiner evaluated radiographic curve parameters. MRI reports were reviewed for the presence or absence of intrathecal abnormalities.

RESULTS

A total of 78 MRIs included 15 intrathecal abnormalities and 63 normals. The abnormal MRI group had more males and apex left curves. Primary curve in the intrathecal abnormality group had a mean of 9.6 degrees of apical vertebrae rotation compared to 17.7 degrees in idiopathic curves (average 37 degrees and 40 degrees Cobb angles, respectively). Of angulation, 1 degrees correlated with 0.21 degrees and 0.34 degrees of rotation in intrathecal abnormality versus no abnormality groups, respectively.

CONCLUSIONS

Curves with occult intrathecal pathology had significantly less rotation than those without. Pedicle rotation assessment is a useful adjuvant for identifying scoliosis with intrathecal abnormalities.