Intraspinal neural axis abnormalities in severe spinal deformity: a 10-year MRI review

Role of Posterior Longitudinal Ligament Complex in Spinal Deformity Secondary to Surgical Resection of the Intradural Tumor

OBJECTIVE

In most cases, complete resection of the intradural tumor is accompanied by long-term neurological complications. Postoperative spinal deformity is the most common complication after surgical resection of intradural tumors, and posterior longitudinal ligament complex (PLC) plays an important role in postoperative spinal deformity. In this study, we investigated the role of PLC in spinal deformity after the surgical treatment of intradural tumors.

METHODS

We analyzed the data of 218 consecutive patients who underwent intradural tumor resection from 2000 to 2018 in this retrospective study. Before 2010, patients underwent laminoplasty without maintaining the integrity of PLC (laminoplasty group, n = 155). After 2010, patients performed single-port laminoplasty to maintain the integrity of PLC (laminoplasty retain posterior ligament complex group, n = 63). The score of quality of life, painful cortex, spinal cord movement, progressive kyphosis or scoliosis, perioperative morbidity, and neurological results were analyzed in the laminoplasty group and laminoplasty retain posterior ligament complex group. The distributed variable was shown as mean ± standard deviation and an independent t-test or one-way analysis of variance was calculated.

RESULTS

There are 155 patients (71.1%) included in the laminoplasty group, and 63 patients (28.9%) in the laminoplasty retain posterior ligament complex group. The average age of patients was 42 ± 2.3 years, and the average modified McCormick score was 2. There were 158 (72.4%) patients with intramedullary tumors and 115 (52.7%) patients with extramedullary tumors. The length of hospital stays (8 days vs. 6 days; p = 0.023) and discharge to inpatient rehabilitation (48.4% vs. 26.9%; p = 0.012) were significantly lower in the laminoplasty retain posterior ligament complex group than the laminoplasty group. There was no significant difference in the risk of progressive deformity between the two groups at 18 months after surgery (relative risk 0.12; 95% confidence interval [CI] 0.43-1.25; p = 0.258) and at 20 months after surgery (relative risk 0.24; 95% CI 0.21-2.1).

CONCLUSION

Laminoplasty retains posterior ligament complex showed no impact on the spinal deformities compared with laminoplasty, but significantly improved the postoperative spinal activity, alleviated pain symptoms, and reduced hospital recovery time.

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.

Intra-Operative Neurophysiological Monitoring in Patients with Intraspinal Abnormalities Undergoing Posterior Spinal Fusion

OBJECTIVE

To analyze the intraoperative neurophysiological monitoring (IONM) data of patients with intraspinal abnormalities undergoing posterior spinal fusion and to determine how intraspinal abnormalities influence IONM results.

METHODS

Patients with severe kyphoscoliosis and intraspinal abnormalities who underwent posterior spinal correction and fusion between September 2015 and January 2019 were retrospectively reviewed. Candidate intraspinal abnormalities included Chiari malformation, syringomyelia, split cord malformation, and tethered cord syndrome. Total intravenous anesthesia was administered, and no muscle relaxant or inhalation anesthesia was used for maintenance. IONM data, including somatosensory evoked potentials (SSEP) and motor evoked potentials (MEP), were recorded. The P37 and N50 latencies and amplitude were recorded for SSEP, whereas only the amplitude was recorded for MEP. The possible high-risk factors for abnormal IONM results were analyzed.

RESULTS

The current study included 87 patients (40 men, 47 women) with an average age of 20.2 ± 10.4 years. The etiologies were neuromuscular in 45 patients, idiopathic in four, and congenital in 38. A total of 136 intraspinal abnormalities were detected, including Chiari malformation in 33 patients, syringomyelia in 55, split-cord malformation in 25, and tethered cord syndrome in 23. Forty patients had one intraspinal abnormality, whereas 47 patients had two or three intraspinal abnormalities. The monitorabilities were 87.4% and 97.7% for the SSEP and MEP, respectively. SSEP alerts were reported in five patients and MEP alerts in four patients, and new neurological deficits were observed in three patients postoperatively. The sensitivity and specificity were 100% and 97.3% for SSEP, and 100% and 98.8% for MEP, respectively. A significant difference in MEP amplitude between the concave and convex sides was observed, while significantly higher SSEP latency was observed on the concave side in patients with preoperative neurological deficits. There were 52 (59.8%) patients with abnormal IONM data. Preoperative neurological deficits (χ²  = 7.715, p = 0.005) and more than one intraspinal abnormality (χ²  = 9.186, p = 0.004) indicated a higher risk of abnormal IONM data.

CONCLUSIONS

IONM can be effectively used in patients with intraspinal abnormalities who undergo posterior spinal fusion. Patients with preoperative neurological deficits and more than one intraspinal abnormality have a higher risk of abnormal IONM monitoring.

Whole-Spine Magnetic Resonance Imaging: A Review of Suggested Indications

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The spinal column has a propensity for lesions to manifest in a multifocal manner, and identification of the lesions can be difficult.

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When used to image the spine, magnetic resonance imaging (MRI) most accurately identifies the presence and location of lesions, guiding the treatment plan and preventing potentially devastating complications that are known to be associated with unidentified lesions.

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Certain conditions clearly warrant evaluation with whole-spine MRI, whereas the use of whole-spine MRI with other conditions is more controversial.

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We suggest whole-spine MRI when evaluating and treating any spinal infection, lumbar stenosis with upper motor neuron signs, ankylosing disorders of the spine with concern for fracture, congenital scoliosis undergoing surgical correction, and metastatic spinal tumors.

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Use of whole-spine MRI in patients with idiopathic scoliosis and acute spinal trauma remains controversial.

Spinal-Shortening Process Positively Improves Associated Syringomyelia in Patients with Scoliosis After Single-Stage Spinal Correction

OBJECTIVE

Single-stage spinal correction without previous neurosurgical intervention has been attempted in patients with scoliosis associated with syringomyelia (SM). However, evidence to demonstrate its potential influence on associated SM from direct spinal correction is still lacking. The aim of the present study was to explore the role of spinal shortening in the prognosis of SM-associated scoliosis after single-stage spinal correction without previous neurosurgical intervention.

METHODS

Patients with SM-associated scoliosis without previous neurological intervention, who had undergone posterior direct instrumental correction (PDIC) without osteotomy and posterior vertebral column resection (PVCR) at a single center, were selected for comparative analysis. The basic demographic and pre- and postoperative imaging data of the spinal deformity and SM at the final follow-up were compared separately for the 2 different spinal correction procedures.

RESULTS

A total of 23 patients were included in the final analysis: 13 had undergone PDIC and 10 had undergone PVCR. The mean follow-up period was 6.2 years (range, 5-9 years). At the final follow-up, the mean corrective rate of scoliosis and kyphosis was 65.7% and 48.4%, respectively. Obvious SM reduction was achieved in 11 patients (47.8%), with an average reduction of 37.3%. No patient experienced neurologic deterioration or had required further neurosurgical intervention for SM during follow-up. The patients who had undergone PVCR had had much more severe scoliosis (98.8° vs. 60.5°; P = 0.000) and kyphosis (74.8° vs. 43.6°; P = 0.032). Moreover, 80.0% of the patients who had undergone PVCR had experienced obvious SM improvement compared with 23.1% of those who had undergone PDIC (P = 0.007).

CONCLUSIONS

The reduction of spinal cord tension is an important factor influencing SM improvement. As the most powerful spinal-shortening osteotomy, PVCR can effectively correct severe spinal deformities and improve associated SM. Single-stage posterior spinal correction can be a potential choice for selected patients with scoliosis and untreated SM using strict inclusion criteria, which will not only achieve safe spinal correction but could also steadily improve and stabilize SM.

Analysis of the corrective contribution of strong halo-femoral traction in the treatment of severe rigid nonidiopathic scoliosis

Introduction

Strong halo-femoral traction has been widely used in the field of severe rigid scoliosis correction. The objective of this study was to analyze the corrective contribution of strong halo-femoral traction in the treatment of severe rigid nonidiopathic scoliosis and discuss its meaning.

Material and methods

A retrospective review was performed for patients with severe rigid nonidiopathic scoliosis who were treated with halo-femoral traction in our center from December 2008 to December 2015. All cases underwent halo-femoral traction for 2 to 4 weeks before a one-stage posterior operation, and the absolute and relative contribution rates of each orthopedic factor (bending, fulcrum, traction, surgery) were analyzed.

Results

A total of 38 patients were included (15 males and 23 females), with a mean age of 16.4 ± 3.73 years (10–22 years) and follow-up of 55.05 ± 6.63 months (range 40–68 months). The etiology was congenital in 17 patients, neuromuscular in 14 patients, neurofibromatosis-1 in 3 patients, and Marfan syndrome in 2 patients. Congenital high scapular disease with scoliosis was found in 2 patients. The mean coronal Cobb angle of the major curve was 97.99° ± 11.47° (range 78°–124°), with a mean flexibility of 15.68% ± 6.65%. The absolute contribution rate (ACR) of bending was 27.26% ± 10.16%, the ACR of the fulcrum was 10.91% ± 2.50%, the ACR of traction was 32.32% ± 11.41%, and the ACR of surgery was 29.50% ± 9.70%. A significant difference in correction was noted between the ACRs of traction and the fulcrum (P < 0.05).

Discussion

Strong halo-femoral traction plays a relatively significant role in the treatment of severe rigid nonidiopathic scoliosis while decreasing the risk of operation, and it is a safe and effective method for the treatment of severe rigid nonidiopathic scoliosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-020-02093-8.

The rate of intraspinal problems and clinical evaluation of scoliosis: A cross-sectional, descriptive study

Objectives

This study aims to define the chronological, angular, and topographic classes in presumed idiopathic scoliosis and to investigate the frequency of generalized joint hypermobility, pain, neurological deficit, ankle deformity, Risser grade, and magnetic resonance imaging (MRI) findings in these patients.

Patients and methods

This cross-sectional, descriptive study included a total of 36 patients (11 males, 25 females; mean age 13.4±4.6 years; range, 6 to 24 years) with idiopathic scoliosis between January 2015 and January 2019. Data including age, sex, complaint of pain, generalized joint hypermobility (based on Beighton score), neurological deficit, ankle deformity, and definition of scoliosis were recorded. Chronological, angular, and topographic classification were carried out. The Risser grade and MRI findings were noted.

Results

Of all patients, 30 (83.3%) were idiopathic, five (13.9%) were neuromuscular, and one (2.8%) was congenital scoliosis based on MRI findings. Of 13 (36.1%) spine MRI scans, six (46.2%) were intraspinal anomalies, four were syringomyelia (30.8%), one was Chiari type 1 malformation (7.7%), and one was hemivertebrae with diastematomyelia (7.7%). The highest rates of classes according to chronological, angular, and topographical classifications of idiopathic scoliosis were adolescent (17/30, 56.7%), low angular (24/30, 80.0%), and lumbar scoliosis (15/30, 50.0%), respectively. Ten patients (33.3%) complained of pain, while 23 patients (76.7%) had no neurological deficit and seven (23.3%) had hypoesthesia. Seventeen patients (56.7%) had generalized joint hypermobility.

Conclusion

Idiopathic scoliosis with non-severe spinal deformity may present with intraspinal neural axis abnormalities, even when it is neurologically intact. Based on our study results, it seems to be useful to consider whole spine MRI for the evaluation of thoracic and lumbar scoliosis.

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.

Cervical Abnormalities in Severe Spinal Deformity: A 10-year MRI Review

Objective

To investigate the incidence of cervical anomalies (CA), including cervical intraspinal neural axis abnormalities (CIINAA) and/or cervical osseous abnormalities (COA), and the clinical relevance in severe spinal deformities (SSD) at a single center.

Methods

A retrospective study of SSD admitted for spinal surgery from January 2003 to January 2015 was conducted at a single center. Inclusion criteria: patients who present with coronal Cobb over 90° (and/or sagittal cobb ≥90°); and patients with complete imaging and clinical data preoperatively. Exclusion criteria: ankylosing spondylitis, adult onset scoliosis, scoliosis secondary to bone destruction. There were 108 SSD patients who fulfilled the criteria in this research (41 males and 67 females). The mean age of the patients was 18.1 ± 2.7 years (range, 10–45 years). The clinical and radiological data of these patients were reviewed to identify CA and to analyze the relationship between clinical and radiographic characteristics in the population of SSD.

Results

The major curves of scoliosis and segmental kyphosis were 109.1° ± 24.7° and 91.2° ± 29.1°. Cervical abnormalities were detected in 56 patients (51.85%) with 9 different CA, including 28 patients (25.9%) with 6 different COA, 21 patients (19.4%) with 3 different CIINAA, and 7 patients (6.5%) with a combination of COA and cervical intraspinal neural axis abnormalities (CINAA). Basilar invagination and Klippel–Feil syndrome were the most frequent COA. Syringomyelia was the most frequent CINAA. SSD with COA in upper vertebral levels (UVL) had a higher incidence of CINAA than those in subaxial vertebral levels (SVL) (P = 0.024) and SSD with multiple COA (mCOA) in UVL had a higher incidence of CINAA than those with single COA (sCOA) (P = 0.029). In the present study, 83.9% of the SSD with CA were asymptomatic.

Conclusion

The incidence of CA in SSD was 51.85%, with most presenting with intact neurologic status. As the diversity of COA increased, we found a higher incidence of CINAA, especially in UVL.

Severe Kyphoscoliosis Associated with Multiple Giant Intraspinal Epidural Cysts: A Case Report and Literature Review

BACKGROUND

Severe kyphoscoliosis associated with multiple giant spinal epidural arachnoid cysts (SEACs) is an extremely rare condition and remains a challenge in clinical practice. This study aimed to present a case of severe spinal deformity associated with multiple giant SEACs and to discuss strategies for the preoperative diagnosis and treatment.

CASE DESCRIPTION

A 22-year-old man with severe thoracolumbar kyphoscoliosis associated with multiple giant SEACs presented with progressive scoliosis, spastic paralysis, numbness, and abnormal gait. X-ray and magnetic resonance imaging revealed severe rigid kyphoscoliosis, extensive diffuse cystic space-occupying lesions, and diffuse spinal cord compression. After multidisciplinary consultation and discussion, the patient underwent a cyst-peritoneal shunting surgery followed by posterior vertebral column resection (PVCR) correction. The postoperative course was uneventful. Both kyphosis and scoliosis were significantly corrected, and muscle weakness of the lower extremities and sensory disturbance partially improved. At the 2-year follow-up visit, the patient could freely walk without the aid of crutches, but there were some residual neurologic deficits in both legs. A plain radiograph showed that bony fusion was achieved, and the correction was well maintained.

CONCLUSIONS

Cyst-peritoneal shunting surgery followed by PVCR, as in our case, could be an alternative surgical strategy for multiple giant SEACs associated with severe rigid kyphoscoliosis.

Clinical manifestations and radiological characteristics in patients with idiopathic syringomyelia and scoliosis

PURPOSE

To clarify the clinical manifestation and radiological characteristics of idiopathic syringomyelia (IS) and to investigate the relationship between syrinx and scoliotic curves in IS-related scoliosis patients.

METHODS

Fifty-five patients with IS and scoliosis were identified and reviewed retrospectively from June 2009 to December 2016. Radiographic features of syrinx, scoliosis and clinical manifestations of neurological deficits were collected. The syrinx/cord (S/C) ratio was defined as the anteroposterior diameter of syrinx divided by the diameter of spinal cord at the same level. Patients were classified into two groups, the thoracic group (T group, apex vertebra located from T2 to intervertebral disk of T11-T12) and the thoracolumbar/lumbar group (TL/L group, apex vertebra located from T12 to L5).

RESULTS

There was no correlation between the radiological features of idiopathic syrinx and scoliotic curve parameters. The TL/L group had a lower level of most caudal extent (13.7 compared with 10.6, P = 0.029) and lower level of largest S/C ratio (12.0 compared with 8.7, P = 0.016) than that in T group. The deviated side of syrinx was not coincident with major curve convexity (27.2% concordance rate, P = 0.522) or dominant side of neurological deficit (16.3% concordance rate, P = 0.212).

CONCLUSIONS

Patients with major curves located on the thoracolumbar or lumbar spine had a much lower caudal extent and lower level of greatest S/C ratio compared to patients with major curves located on the thoracic spine. No significant relationships were detected between syrinx features, scoliotic curve parameters and neurological deficits. These slides can be retrieved under Electronic Supplementary Material.