Incidence of Intraspinal and Extraspinal MRI Abnormalities in Patients With Adolescent Idiopathic Scoliosis

The value of magnetic resonance imaging and computed tomography in the study of spinal disorders

Computed tomography (CT) and magnetic resonance imaging (MRI) have replaced conventional radiography in the study of many spinal conditions, it is essential to know when these techniques are indicated instead of or as complementary tests to radiography, which findings can be expected in different clinical settings, and their significance in the diagnosis of different spinal conditions. Proper use of CT and MRI in spinal disorders may facilitate diagnosis and management of spinal conditions. An adequate clinical approach, a good understanding of the pathological manifestations demonstrated by these imaging techniques and a comprehensive report based on a universally accepted nomenclature represent the indispensable tools to improve the diagnostic approach and the decision-making process in patients with spinal pain. Several guidelines are available to assist clinicians in ordering appropriate imaging techniques to achieve an accurate diagnosis and to ensure appropriate medical care that meets the efficacy and safety needs of patients. This article reviews the clinical indications of CT and MRI in different pathologic conditions affecting the spine, including congenital, traumatic, degenerative, inflammatory, infectious and tumor disorders, as well as their main imaging features. It is intended to be a pictorial guide to clinicians involved in the diagnosis and treatment of spinal disorders.

Incidence of radiographic scoliosis in asymptomatic young Pakistani adults

Background:

Adolescent idiopathic scoliosis (AIS) is the most common scoliotic deformity of young adults. Screening of AIS is performed as part of the routine preemployment examination for physically demanding positions. We attempted to establish the incidence of clinically overt scoliosis in an adolescent (16 years old) and young adult (21 years old) population.

Methods:

We clinically and radiographically (X-rays) evaluated 85 applicants for physically demanding jobs in two age groups: those 16 versus those 21 years of age. Cobb’s angles and kyphosis angles were measured for each group. These data were then categorized into three grades based on radiographically documented scoliotic curvatures.

Results:

Most 16 years old demonstrated normal Cobb’s angles (90.56%), but kyphosis angles of 20–30° (40.27%). For the 21 years old, most participants had normal Cobb’s angles (93.75%), but exhibited higher than normal kyphosis angles (50%).

Conclusion:

Most young adults ages 16–21 years applying for physically demanding work were “fit.” However, the incidence of kyphosis was higher among the 21 years old population. Such screening for idiopathic scoliosis should be more stringently performed in younger patients applying for physically demanding work.

Entire-spine Magnetic Resonance Imaging Findings and Costs in Children With Presumed Adolescent Idiopathic Scoliosis

BACKGROUND

Patients with adolescent idiopathic scoliosis (AIS) are commonly monitored for curve progression with spinal radiographs; however, the utility of magnetic resonance imaging (MRI) screening is unclear. The purpose of this study was to assess the findings of screening MRI for patients with a nonsurgical curve size ordered during routine clinical care and compare them with MRI ordered for patients with large curves as part of preoperative screening.

METHODS

All consecutive patients with presumed AIS who underwent entire-spine MRI with a presumed diagnosis of idiopathic scoliosis at a single institution between 2017 and 2019 were retrospectively reviewed. Patients were stratified based on MRI indication into the following groups: preoperative evaluation, pain, neurological symptoms, abnormal radiographic curve appearance, rapidly progressive curve, and other. Neural axis abnormalities recorded included concern for tethered spinal cord, syringomyelia, and Chiari malformation. The MRI findings of preoperative patients with large curves were compared with all other patients. The number needed to diagnose (NND) a neurological finding was calculated in patients whose MRIs were ordered during routine clinical care. The amount charged for each patient undergoing entire-spine MRI was determined by review of our institution's Financial Decision Support system.

RESULTS

There were 344 patients included in this study with 214 (62%) MRIs performed for preoperative evaluation. Although MRI abnormalities were found in 49% of patients, only 7.0% (24/344) demonstrated neural axis abnormalities with no difference between preoperative and other indications (P=0.37). For patients with nonsurgical curves undergoing MRI due to a complaint of back pain (n=28), there were no neural axis abnormalities, and a lower rate of disk herniation/degenerative changes detected compared with preoperative MRI (3.6% vs. 18%, P=0.06). Among the 15 patients undergoing MRI for a neurological concern, 1 had a neural axis abnormality that required surgical detethering. The NND for MRI to detect a neural axis abnormality that potentially required neurosurgical intervention in nonpreoperative patients with a neurological concern was 34.4. The average cost for MRI was $17,816 (range: $2601 to $22,411) with a total cost of $2,368,439 for nonsurgical curves.

CONCLUSIONS

Entire-spine MRI for nonpreoperative indications including pain, abnormal radiographic curve appearance, and rapid curve progression has minimal utility for patients with AIS. For patients with neurological complaints, the NND a potentially treatment-altering finding with MRI is 34.4.

LEVEL OF EVIDENCE

Level II-diagnostic.

Expert consensus on surgical treatment for adolescent idiopathic scoliosis in Japan

BACKGROUND

Surgical treatment for adolescent idiopathic scoliosis (AIS) has changed significantly with the advent of new medical devices and surgical procedures. Today, pre- and postoperative management differs widely between institutions. The purpose of this study is to establish consensus regarding the surgical management of AIS in Japan through the use of a questionnaire survey of experienced spine deformity surgeons.

METHODS

From February to March 2020, experienced spine deformity surgeons who perform more than 25 cases of AIS surgery annually were asked to respond to a questionnaire request regarding AIS surgical management formulated by the International Affairs Committee of the Japanese Scoliosis Society. For each of the questions, consensus was achieved upon a 70% agreement among respondents.

RESULTS

Responses were received from 25 of the 32 (78%) experienced spine deformity surgeons. The average age of the responding surgeons was 52 years with an average practice experience of 28 year. Consensus was achieved on 74 (76%) of the 97 aspects of care presented in the questionnaire and is broken down as follows: 12 of 17 items for preoperative management, all 5 items for perioperative management, 11 of 14 items for surgical technique, 9 of 15 items for implant selection, 6 of 8 items for bone grafting, 7 of 10 items for blood conservation, 5 of 7 items for postoperative management, all 17 items for postoperative evaluation, and 2 of 4 items for aftercare.

CONCLUSIONS

Expert consensus was achieved on 74 aspects of the surgical management of AIS in Japan. In implant selection and aftercare, consensus was obtained in less than 70% of the aspects, revealing differences in AIS management between institutions. These findings on AIS surgery in Japan, informed by expert opinion, will conceivably help spine deformity surgeons determine appropriate surgical management of AIS.

Increased cautiousness in adolescent idiopathic scoliosis patients concordant with syringomyelia fails to improve overall patient outcomes

Background:

Adolescent idiopathic scoliosis (AIS) is a common cause of spinal deformity in adolescents. AIS can be associated with certain intraspinal anomalies such as syringomyelia (SM). This study assessed the rate o f SM in AIS patients and compared trends in surgical approach and postoperative outcomes in AIS patients with and without SM.

Methods:

The database was queried using ICD-9 codes for AIS patients from 2003–2012 (737.1–3, 737.39, 737.8, 737.85, and 756.1) and SM (336.0). The patients were separated into two groups: AIS-SM and AIS-N. Groups were compared using t-tests and Chi-squared tests for categorical and discrete variables, respectively.

Results:

Totally 77,183 AIS patients were included in the study (15.2 years, 64% F): 821 (1.2%) – AIS-SM (13.7 years, 58% F) and 76,362 – AIS-N (15.2 years, 64% F). The incidence of SM increased from 2003–2012 (0.9 to 1.2%, P = 0.036). AIS-SM had higher comorbidity rates (79 vs. 56%, P < 0.001). Comorbidities were assessed between AIS-SM and AIS-N, demonstrating significantly more neurological and pulmonary in AIS-SM patients. 41.2% of the patients were operative, 48% of AIS-SM, compared to 41.6% AIS-N. AIS-SM had fewer surgeries with fusion (anterior or posterior) and interbody device placement. AIS-SM patients had lower invasiveness scores (2.72 vs. 3.02, P = 0.049) and less LOS (5.0 vs. 6.1 days, P = 0.001). AIS-SM patients underwent more routine discharges (92.7 vs. 90.9%). AIS-SM had more nervous system complications, including hemiplegia and paraplegia, brain compression, hydrocephalous and cerebrovascular complications, all P < 0.001. After controlling for respiratory, renal, cardiovascular, and musculoskeletal comorbidities, invasiveness score remained lower for AIS-SM patients (P < 0.001).

Conclusions:

These results indicate that patients concordant with AIS and SM may be treated more cautiously (lower invasiveness score and less fusions) than those without SM.

Incidence and significance of findings on spinal MRIs in a paediatric population with spinal column complaints

PURPOSE

We sought to identify correlations between working diagnosis, surgeon indication for obtaining spinal MRI and positive MRI findings in paediatric patients presenting with spinal disorders or complaints.

METHODS

Surgeons recorded their primary indication for ordering a spinal MRI in 385 consecutive patients. We compared radiologist-reported positive MRI findings with surgeon response, indication, working diagnosis and patient demographics.

RESULTS

The most common surgeon-stated indications were pain (70) and coronal curve characteristics (63). Radiologists reported 137 (36%) normal and 248 (64%) abnormal MRIs. In total, 58% of abnormal reports (145) did not elicit a therapeutic or investigative response, which we characterized as 'clinically inconsequential'. In all, 42 of 268 (16%) presumed idiopathic scoliosis patients had intradural pathology noted on MRI.Younger age (10.3 years versus 12.0 years) was the only significant demographic difference between patients with or without intradural pathology. Surgeon indication 'curve magnitude at presentation' was associated with intradural abnormality identification. However, average Cobb angles between patients with or without an intradural abnormality was not significantly different (39° versus 37°, respectively). Back pain without neurological signs or symptoms was a negative predictor of intradural pathology.

CONCLUSION

Radiologists reported a high frequency of abnormalities on MRI (64%), but 58% of those were deemed clinically inconsequential. Patients with MRI abnormalities were two years' younger than those with a normal or inconsequential MRI. 'Curve magnitude at presentation' in presumed idiopathic scoliosis patients was the only predictor of intrathecal pathology. 'Pain' was the only indication significantly associated with clinically inconsequential findings on MRI.

LEVEL OF EVIDENCE

III.

Magnetic resonance imaging effectiveness in adolescent idiopathic scoliosis

OBJECTIVE

To assess the effectiveness of preoperative magnetic resonance imaging (MRI) in adolescent idiopathic scoliosis (AIS) patients with unremarkable history and physical examination.

METHODS

The imaging data of consecutive patients with presumed AIS treated with a posterior spinal fusion between 2010 and 2016 were reviewed. The presence of traditional risk factors, atypical curve patterns, and its association with relevant abnormalities on MRI were investigated. The number needed to diagnose (NND) and the number needed to misdiagnose (NNM) were calculated to measure MRI effectiveness.

RESULTS

A total of 198 consecutive patients were identified and divided according to the presence of MRI findings. Both groups predominantly consisted of females, with a mean age of 15 years and right thoracic curvature. Neural axis abnormalities were detected in 25 patients, and the groups had a similar proportion of atypical findings, as curve magnitude, thoracic kyphosis, curve direction, and sex. The NND was 7.9 patients and NNM was 66 patients, meaning that the management was changed before the spine fusion in 12% of patients with neural axis abnormalities. None of the traditional risk factors could predict a higher incidence of neural axis abnormalities in asymptomatic AIS patients.

CONCLUSION

Traditional risk factors may not be predictive of patients with a higher risk of changes in MRI. Both NND and NNM are representations easily understood by clinicians. Using these indexes to define if a patient should be submitted for additional imaging tests may facilitate the decision of using MRI as a preoperative screening tool in AIS patients.

LEVEL OF EVIDENCE

Level II.

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.

Scoliosis in spinal muscular atrophy: is the preoperative magnetic resonance imaging necessary?

PURPOSE

To determine the prevalence of intraspinal alterations in scoliosis due to Spinal Muscular Atrophy (SMA).

METHODS

Cross-sectional, observational, descriptive study. Fifty-six patients with SMA diagnosis required surgical treatment due to scoliosis.

INCLUSION CRITERIA

scoliosis/kyphoscoliosis > 50 degrees in the coronal plane, clinical characteristics of Spinal Muscular Atrophy, accurate diagnosis by means of molecular or genetic study. Prior to the spinal surgery, and to find related intraspinal alterations, MRI of the spine and posterior cranial fossa was performed.

RESULTS

Forty females, 16 males, mean age 11 years (range 6-14 years). 94% of the patients had Spinal Muscular Atrophy type 2. The mean angle value was 81 degrees (range 53-122 degrees) in the coronal plane and 62 degrees (range 35-80 degrees) in the sagittal plane. The prevalence of intraspinal alterations was 1.78%. One patient with cervical hydromyelia and no neurological surgical procedure prior to the spinal deformity surgery was reported.

CONCLUSIONS

In the context of preoperative planning and strategy of patients with scoliosis due to Spinal Muscular Atrophy, MRI may have not to be requested.

Prevalence and clinical relevance of underlying pathological conditions in painful adolescent idiopathic scoliosis: a MRI-based study

STUDY DESIGN

Cross-sectional comparative study.

OBJECTIVES

Evaluate prevalence and clinical relevance of an underlying pathology in painful adolescent idiopathic scoliosis (AIS) patients after a non-diagnostic history, physical examination and spinal X-ray using Magnetic Resonance Image (MRI) as diagnostic tool. Discrepancies regarding indications of routine MRI screening in painful AIS patients are multifactorial. Few studies have investigated relationship and practical importance of painful AIS with an underlying pathology by MRI.

METHOD

A total of 152-consecutive AIS patients complaining of back pain during a 36-month period were enrolled. All patients underwent whole-spine MRI after a non-diagnostic history, physical examination and spinal X-ray. Underlying pathologies were reported as neural and non-neural axis abnormalities based on MRI reports. Variables such as sex, age, constant or intermittent pain, night pain, back pain location (thoracic or lumbar pain), Cobb-angle and follow-up were evaluated as clinical markers to predict presence of underlying MRI pathologies.

RESULTS

The presence of an underlying pathology was found by MRI in 54 painful AIS patients (35.5%). Isolated syringomyelia was the only neural axis abnormality found in 6 patients (3.9%). Non-neural axis abnormalities (31.6%) were composed by: 32 herniated nucleus pulposus, 5 vertebral disc desiccation, 4 ovarian cysts, 3 renal cysts, 2 sacral cysts, and 2 vertebral hemangiomas. There was no association with gender, age of presentation, initial coronal Cobb angle and follow up; with presence of an underlying pathology. Lumbar pain location was identified as an adequate clinical marker that correlated with presence of an underlying pathology (p = 0.01).

CONCLUSIONS

Prevalence of underlying pathologies diagnosed by MRI in painful AIS was found high (35.5%), but it's clinical relevance and implication are debatable. The use of MRI did not affect orthopedic management of painful AIS patients who showed an underlying pathology. A thorough evaluation must be performed by clinicians; and discussed with patients and family prior to undergo further imaging management.

LEVEL OF EVIDENCE

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.

Scoliosis in patients with Chiari malformation type I

The literature about the association between Chiari malformations (CMs) and scoliosis has been growing over the last three decades; yet, no consensus on the optimal management approach in this patient population has been reached. Spinal anomalies such as isolated syrinxes, isolated CM, and CM with a syrinx are relatively common among patients with presumed idiopathic scoliosis (IS), a rule that also applies to scoliosis among CM patients as well. In CM patients, scoliosis presents with atypical features such as early onset, left apical or kyphotic curvature, and neurological deficits. While spinal X-rays are essential to confirm the diagnosis of scoliosis among CM patients, a magnetic resonance imaging (MRI) is also recommended in IS patients with atypical presentations. Hypotheses attempting to explain the occurrence of scoliosis in CM patients include cerebellar tonsillar compression of the cervicomedullary junction and uneven expansion of a syrinx in the horizontal plane of the spinal cord. Early detection of scoliosis on routine spinal examination and close follow-up on curve stability and progression are essential initial steps in the management of scoliosis, especially in patients with CM, who may require full spine MRI to screen for associated neuro-axial anomalies; bracing and spinal fusion may be subsequently pursued in high-risk patients.