The Journal of Bone & Joint Surgery

The Journal of Bone & Joint Surgery, Volume 86, Issue 10

Scientific Articles | October 01, 2004

Indications for Magnetic Resonance Imaging in Presumed Adolescent Idiopathic Scoliosis

Jon R. Davids, MD¹; Eric Chamberlin, MD²; Dawn W. Blackhurst, PhD³

¹ Motion Analysis Laboratory, Shriners Hospital for Children, 950 West Faris Road, Greenville, SC 29605. E-mail address: jdavids@shrinenet.org
² Pittsburgh Bone and Joint Surgeons, 1321 5th Avenue, McKeesport, PA 15132
³ Department of Biomedical Research, Greenville Hospital System, 701 Grove Road, Greenville, SC 29605

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The authors did not receive grants or outside funding in support of their research or preparation of this manuscript. They did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the authors are affiliated or associated.

Investigation performed at the Shriners Hospital for Children, Greenville, South Carolina

The Journal of Bone and Joint Surgery, Incorporated

J Bone Joint Surg Am, 2004 Oct 01;86(10):2187-2195

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Abstract

Background: The use of magnetic resonance imaging has led to the diagnosis of abnormalities of the central nervous system associated with apparent idiopathic scoliosis. The indications for magnetic resonance imaging for presumed adolescent idiopathic scoliosis have not been established.

Methods: One thousand, two hundred and eighty children with presumed adolescent idiopathic scoliosis were evaluated over a ten-year period. Magnetic resonance imaging of the central nervous system (brainstem and spinal cord) was performed for specific patients, on the basis of the presence of selected indicators determined from the clinical history, physical examination, and plain radiographic examination of the spine. The medical records were reviewed to determine the specific indicators, the results of the imaging studies, and the subsequent treatment.

Results: Magnetic resonance imaging was ordered for 274 (21%) of the 1280 children who were evaluated. Abnormal findings were seen in twenty-seven (10%) of the 274 patients who underwent imaging, or 2% of the entire cohort. The most valuable single indicator of an abnormal finding on magnetic resonance imaging was absence of thoracic apical segment lordosis: eight of thirty-nine patients with that indicator had an abnormal finding on magnetic resonance imaging. The optimal diagnostic yield for a single category of indicators occurred when an atypical curve pattern was the only indicator: six of fifty-eight patients in whom this was the case had an abnormal finding on magnetic resonance imaging. None of the twenty children in whom pain was the only indicator category had an abnormal imaging study. The optimal diagnostic yield occurred when both an atypical curve pattern and neurological indicators were present: thirteen (25%) of fifty-three patients in whom this was the case had an abnormal finding on magnetic resonance imaging. Thirteen of the twenty-seven patients received surgical treatment for the abnormality of the central nervous system revealed by the imaging.

Conclusions: The correct use of diagnostic tests is an important component of effective medical practice. An abnormality of the central nervous system is present in approximately 10% of patients with presumed adolescent idiopathic scoliosis in whom only subtle abnormalities are identified on the basis of the clinical history, physical examination, or radiographic examination. Knowledge of the diagnostic value of the specific clinical indicators, considered individually and in combination, can help the clinician to determine more effectively when advanced imaging of the central nervous system should be performed.

Level of Evidence: Diagnostic study, Level III-1 (study of nonconsecutive patients [no consistently applied reference "gold" standard]). See Instructions to Authors for a complete description of levels of evidence.

Figures in this Article

The relationship between scoliosis and lesions of the central nervous system—most commonly hydrosyringomyelia but also including Arnold-Chiari malformation, tethered spinal cord, tumor, and diastematomyelia—has been appreciated for at least sixty years^1-3. In the early literature, most cases were described as presenting with obvious symptoms as recorded in the clinical history, abnormal neurological findings on physical examination, and/or atypical curve patterns as seen radiographically^4-6. Improved imaging of the central nervous system (brain, brainstem, and spinal cord) with magnetic resonance imaging has led to the diagnosis of subclinical hydrosyringomyelia (and other lesions) associated with scoliosis^7-12. These patients may have a normal clinical history, subtle or no abnormal findings on neurological examination, and apparently typical coronal plane curve pattern radiographically. The relevance of these lesions with respect to the natural history of scoliosis and the risk of treatment with spinal arthrodesis in the face of unappreciated or subclinical abnormality of the central nervous system have not been clearly established^13-18. As a result, there is substantial controversy regarding the indications for imaging of the central nervous system in patients being evaluated for presumed adolescent idiopathic scoliosis.

For the last twelve years at our institution, the pediatric orthopaedic attending staff has agreed on common indications for magnetic resonance imaging of patients with presumed adolescent idiopathic scoliosis. This protocol was the result of explicit verbal discussion and agreement based on review of the literature and personal experience. These indications can be organized into three categories: pain, as determined by the clinical history; abnormal neurological findings, as determined by the physical examination; and atypical curve patterns, as determined radiographically (Table I). The goal of the current study was to establish which of these indicators best predicts the finding of clinically relevant abnormality of the central nervous system in patients with presumed adolescent idiopathic scoliosis.

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TABLE I Indications for Magnetic Resonance Imaging

Pain	Neurological Findings	Atypical Curve Pattern
Back	Clonus	Left thoracic
Neck	Abnormal abdominal reflexes	Short segment (4 to 6 levels)
Radicular	Weakness	Decreased vertebral rotation
Headache	Urinary dysfunction (urinary tract infection)	Absence of thoracic apical segment lordosis
	Hyperreflexia	Rapid progression
	Asymmetric deep tendon reflexes
	Paresthesias
	Diminished rectal tone
	Cavus foot deformity
	Skin lesions

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TABLE I Indications for Magnetic Resonance Imaging

Pain	Neurological Findings	Atypical Curve Pattern
Back	Clonus	Left thoracic
Neck	Abnormal abdominal reflexes	Short segment (4 to 6 levels)
Radicular	Weakness	Decreased vertebral rotation
Headache	Urinary dysfunction (urinary tract infection)	Absence of thoracic apical segment lordosis
	Hyperreflexia	Rapid progression
	Asymmetric deep tendon reflexes
	Paresthesias
	Diminished rectal tone
	Cavus foot deformity
	Skin lesions

Materials and Methods

Materials and Methods | Results | Discussion | Appendix | References

The study was approved by our institution's medical executive research review committee. The medical records of all children referred to our institution for evaluation of idiopathic scoliosis between January 1991 and June 2001 were reviewed. Children ten years of age or less at the time of our initial evaluation (those with juvenile idiopathic scoliosis), those with failure of formation or segmentation of the spine on plain radiographs (congenital scoliosis), those with magnetic resonance imaging prior to referral or prior brain or spine surgery, and those with associated conditions or syndromes were excluded from further evaluation. Of the initial 1853 children referred to our institution during this period, 1280 met the criteria for inclusion into the study.

Each patient was evaluated by a team consisting of an orthopaedic resident and one of five pediatric orthopaedic attending staff. The medical records of all patients for whom magnetic resonance imaging had been ordered were reviewed to determine the child's age at presentation, gender, age at the time of the magnetic resonance imaging, age at menarche, menarchal status at the time of imaging, indications for additional imaging of the spine, results of the magnetic resonance imaging, and any additional orthopaedic or neurosurgical treatment following the imaging.

Plain radiographs of the spine made within one year before (as available) and immediately prior to the magnetic resonance imaging were analyzed. All plain radiographs of the spine were made at our institution with use of the same protocol. Anteroposterior and lateral radiographs were made with the patient standing, from a distance of 183 cm in each plane, with the radiographic beam centered on the tenth thoracic vertebra. For the lateral radiograph, the subject was instructed to cross his or her arms over his or her chest. Graduated filters were used to improve imaging of the cervical and thoracic levels. The radiograph measured 36 by 91 cm, and the image had to include the first cervical vertebra superiorly and the hip joints inferiorly to be accepted by the technician for use in the clinic. Curve magnitudes in the coronal plane were measured with the Cobb method, with use of the same goniometer and marking pencil¹⁹. Coronal plane curve patterns were classified as thoracic, thoracolumbar, lumbar, or double curves on the basis of the location of the apices and the magnitudes of the curves²⁰.

Clinical analysis of the radiographs of the spine during the study period, particularly for curve progression, thoracic alignment in the sagittal plane, and vertebral rotation, was frequently qualitative. Quantitative analysis of two of these parameters on the radiographs of the spine was performed at the time of the review in an effort to clarify the clinical decision-making process. Curve progression in the coronal plane was described as the number of degrees per month, determined from two radiographs, over at least a five-month period prior to the magnetic resonance imaging. Rapid curve progression was defined as =1° per month. This value was selected following discussion with four pediatric orthopaedic spine surgeons. Although this value has been utilized in clinical training and practice, it has never been objectively documented in the literature, to our knowledge. Sagittal plane alignment of the thoracic spine was also determined with the Cobb method, with measurement from T1 to T12. Normal sagittal plane alignment of the thoracic spine was considered to be between 20° and 50° of kyphosis^21-23. We did not attempt to quantify vertebral rotation because of the poor consensus regarding the optimal measurement technique among the attending staff physicians. In most cases, during the time-period reviewed in the study, vertebral rotation was assessed qualitatively by comparing the contours of the pedicles and the location of the spinous processes between vertebral levels.

Statistical Analysis

The clinical and radiographic characteristics of the patients with abnormal findings on magnetic resonance imaging were compared with those of the patients with normal findings on the imaging. The Student t test for independent groups was used to compare means between the two groups, and the Fisher exact test was used to compare proportions. P values of <0.05 were considered to indicate significance. The percentage of abnormal findings on magnetic resonance imaging (indicator yield) for each indicator and for clinically relevant combinations of indicators was also calculated.

Results

Materials and Methods | Results | Discussion | Appendix | References

Magnetic resonance imaging was ordered for 274 (21%) of the 1280 patients who were evaluated for presumed adolescent idiopathic scoliosis. Abnormal findings were observed in twenty-seven (10%) of the 274 patients who underwent imaging, or 2% of the entire cohort. There were thirteen cases of hydrosyringomyelia, ten cases of Arnold-Chiari malformation (two of those ten patients also had hydrosyringomyelia), four cases of tethered spinal cord, one tumor, and one case of diastematomyelia. Twenty-six of the twenty-seven patients with an abnormal finding on magnetic resonance imaging were referred to a neurosurgeon for evaluation. The one patient who was not evaluated by a neurosurgeon was a sixteen-year-old girl who had undergone the magnetic resonance imaging of the central nervous system because of an atypical curve pattern and symmetric bilateral clonus at the ankle. The magnetic resonance imaging was performed on the day before a posterior spinal fusion was done from T3 to L3 to correct a 66° right thoracic curve. The magnetic resonance imaging revealed a small hydrosyringomyelia at the C5 level, and the orthopaedic surgeon elected to proceed with the scheduled surgery because the lesion was small and located outside of the proposed fusion levels. After 2.5 years of follow-up, the thoracic curve was stable at 25°, and the clinical history and findings on physical examination remained unchanged relative to the preoperative status. Because there was no change in any of these parameters, the patient was not referred to a neurosurgeon.

Surgical treatment of the abnormality of the central nervous system was performed in thirteen (48%) of the twenty-seven patients. A shunt was placed in two patients with hydrosyringomyelia. Decompression of the foramen magnum was performed in six patients with Arnold-Chiari malformation. All four cases of tethered spinal cord were released. The single case of diastematomyelia was treated with resection of the osseous segment. Subsequent surgical treatment of the scoliosis with spinal arthrodesis was performed in 156 (57%) of the 274 children referred for magnetic resonance imaging and in twenty (74%) of the twenty-seven patients with an abnormal finding on the magnetic resonance imaging. In no patient was neurological injury associated with the spinal arthrodesis.

The patients with abnormal findings on magnetic resonance imaging and those with normal findings were comparable with respect to age at presentation, gender, age at the magnetic resonance imaging, age at menarche, menarchal status at the time of the magnetic resonance imaging, curve pattern in the coronal plane, magnitude and direction of the upper curve, and magnitude and direction of the lower curve (see Appendix). Twenty-eight patients were referred for magnetic resonance imaging because of rapid curve progression. Radiographs were available for quantification of the curve progression in twenty of those patients, whereas, for the remaining eight, the radiographs made prior to referral to our institution that were used to make the determination of rapid progression either were not available for review or were not made in a standardized manner. The mean curve progression was 26° (range, 4° to 46°) and occurred at a mean rate of 2.1° per month (range, 0.4° to 8.7° per month), over a mean of 10.7 months (range, five to twenty-nine months). Nineteen of the twenty patients showed curve progression of =1° per month. Thirty-nine patients were referred for magnetic resonance imaging because of the absence of apical segment lordosis of the thoracic spine (i.e., the presence of normal thoracic kyphosis or hyperkyphosis) on the lateral plain radiograph. The mean thoracic kyphosis in these patients was 45° (range, 20° to 71°). Fourteen of the thirty-nine patients showed hyperkyphosis (thoracic kyphosis of >50°).

Pain (i.e., a clinical history of back, neck, or radicular pain or headache) was an indicator for magnetic resonance imaging for eighty-three patients. A neurological abnormality on the physical examination, such as clonus, abnormal reflexes, muscle weakness, or cavus foot deformity, was an indicator for magnetic resonance imaging for 181 patients. An atypical curve pattern was an indicator for magnetic resonance imaging for 135 patients. The number of patients referred for magnetic resonance imaging, and the number of studies that were abnormal, for each specific pain, neurological, or atypical curve measurement are presented in Table II. The most valuable specific indicators—i.e., those yielding the highest percentages of abnormal magnetic resonance images—were absence of thoracic apical segment lordosis (associated with an abnormal finding in eight [21%] of thirty-nine patients with that indicator), radicular pain (one [20%] of five patients), clonus (seven [17%] of forty-two patients), hyper-reflexia (three [17%] of eighteen patients), muscle weakness (seven [15%] of forty-six patients), and decreased vertebral rotation (three [15%] of twenty patients).

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TABLE II Indicators (Specific) for Magnetic Resonance Imaging

	No. (%) of Patients
Indicator	Total	Abnormal Findings on Magnetic Resonance Imaging
Pain
Back	70	2 (3)
Neck	2	0 (0)
Radicular	5	1 (20)
Headache	16	1 (6)
Neurological findings
Clonus	42	7 (17)
Abnormal abdominal reflexes	42	5 (12)
Weakness	46	7 (15)
Urinary symptoms	47	4 (9)
Urinary tract infection	13	1 (8)
Hyperreflexia	18	3 (17)
Asymmetric deep tendon reflexes	25	3 (12)
Paresthesias	21	3 (14)
Skin lesions	12	1 (8)
Cavus foot deformity	14	1 (7)
Atypical curve pattern
Left thoracic	30	3 (10)
Short segment scoliosis	9	1 (11)
Decreased vertebral rotation	20	3 (15)
Absent apical segment lordosis	39	8 (21)
Rapid progression	28	4 (14)
Other	38	8 (21)

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TABLE II Indicators (Specific) for Magnetic Resonance Imaging

	No. (%) of Patients
Indicator	Total	Abnormal Findings on Magnetic Resonance Imaging
Pain
Back	70	2 (3)
Neck	2	0 (0)
Radicular	5	1 (20)
Headache	16	1 (6)
Neurological findings
Clonus	42	7 (17)
Abnormal abdominal reflexes	42	5 (12)
Weakness	46	7 (15)
Urinary symptoms	47	4 (9)
Urinary tract infection	13	1 (8)
Hyperreflexia	18	3 (17)
Asymmetric deep tendon reflexes	25	3 (12)
Paresthesias	21	3 (14)
Skin lesions	12	1 (8)
Cavus foot deformity	14	1 (7)
Atypical curve pattern
Left thoracic	30	3 (10)
Short segment scoliosis	9	1 (11)
Decreased vertebral rotation	20	3 (15)
Absent apical segment lordosis	39	8 (21)
Rapid progression	28	4 (14)
Other	38	8 (21)

The values of the indicators when considered as separate categories (pain, neurological, and atypical curve) and with the categories combined (for patients with one or more indicators in more than one category) are presented in Table III. One hundred and fifty-eight (58%) of the 274 patients were referred for magnetic resonance imaging because of a single category of indicators. Of the fifty-eight patients for whom an atypical curve pattern was the only indicator, six (10%) had abnormal findings on magnetic resonance imaging. Of the eighty patients for whom a neurological abnormality was the only indicator, five (6%) had abnormal findings on magnetic resonance imaging. Finally, none of the twenty patients for whom pain was the only indicator had abnormal findings on magnetic resonance imaging. Within each of the three categories of indicators, the yield of abnormal findings on magnetic resonance imaging was not significantly better, with the numbers available, for the patients with one indicator than it was for those with more than one indicator. Indicators from more than one category were present in 115 (42%) of the 274 patients referred for magnetic resonance imaging. The optimal diagnostic yield was obtained when both an atypical curve pattern and neurological indicators were present, with abnormalities on magnetic resonance imaging found in thirteen (25%) of fifty-three such cases.

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TABLE III Indicators (Categorical and Combination) for Magnetic Resonance Imaging

	No. (%) of Patients
Indicator	Total	Abnormal Findings on Magnetic Resonance Imaging	P Value
Pain			NS
Yes	83	3 (4)
1 finding	72	2 (3)
>1 finding	10	1 (10)
Neurological findings			NS
Yes	181	20 (11)
1 finding	102	10 (10)
>1 finding	79	10 (13)
Atypical curve pattern			NS
Yes	135	21 (16)
1 finding	111	17 (16)
>1 finding	24	4 (17)
Combination of findings			NA
Pain only	20	0 (0)
Atypical curve only	58	6 (10)
Neurological only	80	5 (6)
Pain + atypical curve	14	1 (7)
Pain + neurological	38	1 (3)
Atypical curve + neurological	53	13 (25)
Pain + neurological + atypical curve	10	1 (10)

*NS = no significant difference in diagnostic yield between one finding and more than one finding within a category. NA = not applicable.

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TABLE III Indicators (Categorical and Combination) for Magnetic Resonance Imaging

	No. (%) of Patients
Indicator	Total	Abnormal Findings on Magnetic Resonance Imaging	P Value
Pain			NS
Yes	83	3 (4)
1 finding	72	2 (3)
>1 finding	10	1 (10)
Neurological findings			NS
Yes	181	20 (11)
1 finding	102	10 (10)
>1 finding	79	10 (13)
Atypical curve pattern			NS
Yes	135	21 (16)
1 finding	111	17 (16)
>1 finding	24	4 (17)
Combination of findings			NA
Pain only	20	0 (0)
Atypical curve only	58	6 (10)
Neurological only	80	5 (6)
Pain + atypical curve	14	1 (7)
Pain + neurological	38	1 (3)
Atypical curve + neurological	53	13 (25)
Pain + neurological + atypical curve	10	1 (10)

*NS = no significant difference in diagnostic yield between one finding and more than one finding within a category. NA = not applicable.

Discussion

Materials and Methods | Results | Discussion | Appendix | References

We are aware of only three studies in the literature in which the results of magnetic resonance imaging were evaluated in a prospective, consecutive case series of patients with presumed adolescent idiopathic scoliosis who were ten years of age or older, had normal findings on physical examination, and had "typical" findings on coronal plane radiographs of the spine^8,9,12. Those studies established the prevalence of abnormalities of the central nervous system (primarily hydrosyringomyelia and Arnold-Chiari malformations) in presumed adolescent idiopathic scoliosis to be between 2% (seven of 327 patients)⁸ and 4% (two of forty-five patients)⁹. The larger the cohort studied, the lower the prevalence of central nervous system abnormalities appreciated on routine screening of patients with presumed adolescent idiopathic scoliosis^8,9,12. In two of the studies, the abnormalities of the central nervous system were thought to be subclinical, and standard surgical stabilization of the scoliosis with posterior arthrodesis was performed without complication^8,12. In all of these studies, the investigators concluded that routine screening with magnetic resonance imaging of individuals with presumed adolescent idiopathic scoliosis is not warranted.

Other studies have documented the results in retrospective, nonconsecutive case series of children with presumed adolescent idiopathic scoliosis who, as a result of abnormalities identified on the basis of the clinical history, physical examination, or plain radiographs of the spine, had magnetic resonance imaging, which revealed a central nervous system abnormality^{7,13-15,24-34}. The value of the clinical and radiographic indicators identified in those studies is suggested but cannot be established because of the retrospective, nonconsecutive nature of the investigations, which does not allow the prevalence of the central nervous system abnormalities in children with presumed adolescent idiopathic scoliosis to be determined. Furthermore, we are not aware of any study in which the prognostic relevance of the presence of more than one indicator, within either one or more categories, was considered.

Decision analysis, a form of probability theory, provides a framework in which to determine the optimal use of a diagnostic test by considering its diagnostic power and the utility value assigned to the possible outcomes of treatment^35,36. In the current study, the prevalence of abnormality of the central nervous system was approximately 10% in patients with presumed adolescent idiopathic scoliosis who presented with subtle abnormalities as identified on the basis of the clinical history, physical examination, or radiographic examination. The presumed prevalence of abnormalities of the central nervous system for the entire cohort was 2%, which is similar to that reported in smaller magnetic resonance imaging screening series, suggesting that few cases were missed by our selective screening protocol.

The most valuable single indicator of abnormality of the central nervous system as determined with magnetic resonance imaging in the study group was absence of thoracic apical segment lordosis on the lateral plain radiograph of the spine. Thoracic apical segment lordosis (sagittal plane alignment of the thoracic segment of the spine involved in the primary curve) has been identified as a central feature of the pathophysiology and pathomechanics of the progressive deformity associated with adolescent idiopathic scoliosis^37-43 (Figs. 1-A and 1-B). In the majority of reports addressing the relationship between adolescent idiopathic scoliosis and abnormalities of the central nervous system, analysis of spinal curve patterns has been restricted to the coronal plane^7,8,10-13,31. The few investigators who have analyzed the relationship between sagittal plane alignment in children with scoliosis and central nervous system abnormalities have consistently found an absence of thoracic apical segment lordosis^{9,14,25,27,30,33,44,45}. Appreciation of thoracic apical segment lordosis may be difficult because of a failure to image the spinal deformity in the true sagittal plane. The alignment of the spinal segment in the sagittal plane may also be obscured by the overlap of the thoracic cage, which may lead to the appearance of kyphosis. Although the determination of the absence of thoracic apical segment lordosis (i.e., the presence of normal thoracic sagittal kyphosis or hyperkyphosis) as an indicator for additional imaging was qualitative in the current study, all of the cases referred for magnetic resonance imaging on the basis of this indicator had sagittal thoracic alignment in at least 20° of kyphosis (Figs. 2-A, 2-B, and 2-C). Although failure to image the spinal deformity in the true sagittal plane may confound the accuracy of radiographic measurements, the current study suggests that patients with presumed adolescent idiopathic scoliosis may have a lesion of the central nervous system when the sagittal thoracic alignment is in =20° of kyphosis. The absence of thoracic apical segment lordosis is a radiographic indicator of an atypical curve pattern in patients with presumed adolescent idiopathic scoliosis. Careful analysis of sagittal plane alignment in children with presumed adolescent idiopathic scoliosis is essential. An inability to visualize the alignment because of poor radiographic technique should not be accepted.

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Figs. 1-A and 1-B: Spinal radiographs of a twelve-year-old girl with adolescent idiopathic scoliosis. The anteroposterior radiograph (Fig. 1-A) shows a right thoracic curve that measures 34° according to the Cobb method. The lateral radiograph (Fig. 1-B) shows the typical sagittal profile for true adolescent idiopathic scoliosis (i.e., thoracic apical segment lordosis and overall thoracic kyphosis of <20° or lordosis), with thoracic lordosis measuring —10° according to the Cobb method. This patient had no pain and had no abnormalities on physical examination. The curve pattern was determined to be typical, and magnetic resonance imaging of the central nervous system was not indicated in the current study.

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Figs. 2-A, 2-B, and 2-C: Spinal radiographs of a fourteen-year-old girl with presumed adolescent idiopathic scoliosis. The anteroposterior radiograph (Fig. 2-A) shows a right thoracic curve that measures 44° according to the Cobb method. The lateral radiograph (Fig. 2-B) shows the absence of the expected sagittal profile for adolescent idiopathic scoliosis (i.e., absence of thoracic apical segment lordosis, and overall thoracic kyphosis of >20°), with the thoracic kyphosis measuring 40° according to the Cobb method. The curve pattern was judged to be atypical on the basis of the abnormal sagittal thoracic profile, which was an indicator for magnetic resonance imaging of the central nervous system in the current study. The physical examination revealed clonus at the left ankle, which was also an indicator for magnetic resonance imaging of the central nervous system. The transverse section magnetic resonance image (Fig. 2-C) through the T5 vertebral body level revealed a hydrosyringomyelia, with the lesion appearing as a dark hole within the substance of the spinal cord (arrow). The patient was referred to a neurosurgeon, who judged the lesion to be too small to warrant surgical decompression and drainage. Subsequent orthopaedic management consisted of posterior spinal fusion from T4 to L2, with use of a titanium rod system to facilitate possible future imaging of the spinal canal. The curve magnitude at the time of surgery was 58°, and the surgery was performed without complication. The patient has remained asymptomatic, and the curve magnitude at the time of the most recent follow-up, two years after the spinal arthrodesis, was 32°.

The current study also showed that the presence of more than one indicator within the same category (clinical history of pain, neurological findings on physical examination, or an abnormal curve pattern on radiographic examination) did not increase the diagnostic yield with regard to abnormal finding on magnetic resonance imaging of the central nervous system. Pain as the only indicator had the worst diagnostic yield, with no cases of central nervous system abnormality appreciated on magnetic resonance imaging. The current study supports previous recommendations in the literature that generalized back pain in children with presumed adolescent idiopathic scoliosis and no other findings on the physical examination or plain radiographic imaging of the spine not be considered an indication for additional evaluation with advanced imaging⁴⁶. The optimal diagnostic yield in the current study was achieved when one or more indicators in more than one category were present. The combination of a neurological abnormality appreciated on clinical examination and an atypical curve pattern on plain radiographs of the spine was particularly valuable, resulting in the identification of abnormality of the central nervous system in 25% (thirteen) of fifty-three patients.

Appropriate orthopaedic and neurosurgical management of children with presumed adolescent idiopathic scoliosis and an abnormality of the central nervous system appreciated on magnetic resonance imaging is controversial. The mechanism by which hydrosyringomyelia or Arnold-Chiari malformation may cause scoliosis has not been determined. Possible causes include mechanical injury to the lower motor neurons by the expanding cavitary lesion characteristic of hydrosyringomyelia, resulting in paravertebral muscle imbalance and spinal deformity^16,47-49. Lesions of the brainstem may disrupt balance function, leading to spinal deformity⁵⁰. Treatment of hydrosyringomyelia and/or Arnold-Chiari malformation associated with scoliosis is also controversial. In patients with more obvious or severe cases, shunting or decompression of the central nervous system lesion has been reported to lead to improvement or stabilization of the spinal deformity^{1,17,34,51-59}. Injury to the spinal cord following standard spinal arthrodesis for scoliosis associated with hydrosyringomyelia has been reported^14,48,60,61. The single study, of which we are aware, in which radiographic outcomes were evaluated following spinal arthrodesis for scoliosis associated with hydrosyringomyelia demonstrated progression of >10° within and/or outside the fusion levels in either the coronal or the sagittal plane in all ten patients after a mean duration of follow-up of forty-six months (range, twenty-seven to sixty-three months)¹⁴. The abnormal finding on the magnetic resonance imaging study resulted in a change in clinical management—i.e., neurosurgical treatment of the central nervous system—in 48% (thirteen) of our twenty-seven patients with a lesion of the central nervous system. Aspects of the orthopaedic management of the spinal deformity (e.g., the desired magnitude of curve correction, implant selection, and selection of fusion levels) in children with presumed adolescent idiopathic scoliosis who have an abnormality of the central nervous system noted on magnetic resonance imaging should be influenced by a knowledge of the risk of neurological injury, the risk of curve progression following standard posterior arthrodesis, and the need for future imaging of the central nervous system.

Clinical decision-making may be guided by statistical analyses of the disease characteristics within the population being treated. The current study establishes the prevalence of abnormalities of the central nervous system in patients with presumed adolescent idiopathic scoliosis who had only subtle findings identified on the basis of the clinical history, physical examination, and radiographic examination of the spine. The diagnostic yield of the specific clinical indicators, considered individually and in combination, was also determined. The informational content of magnetic resonance imaging of the central nervous system is well established in the literature^24,28,57. The locations of the lesions found in the current study suggest that, when magnetic resonance imaging is selected for patients with presumed adolescent idiopathic scoliosis, it should be performed from the level of the brainstem to the sacrum. Although the prevalence of such abnormalities is low, the current study also suggests that the clinical management will be altered for almost 50% of subjects with presumed adolescent idiopathic scoliosis who have an abnormality of the central nervous system noted on magnetic resonance imaging.

Appendix

Materials and Methods | Results | Discussion | Appendix | References

A table presenting multiple comparisons of the children in the study with abnormal and normal magnetic resonance imaging studies is available with the electronic versions of this article, on our web site at (go to the article citation and click on "Supplementary Material") and on our quarterly CD-ROM (call our subscription department, at 781-449-9780, to order the CD-ROM).

References

Materials and Methods | Results | Discussion | Appendix | References

BakerAS, Dove J. Progressive scoliosis as the first presenting sign of syringomyelia. Report of a case. J Bone Joint Surg Br.1983;65: 472-3.65472 1983 [PubMed]

McIlroyWJ, Richardson JC. Syringomyelia: a clinical review of 75 cases. Can Med Assoc J.1965;93: 731-4.93731 1965 [PubMed]

WoodsWW, Pimenat AM. Intramedullary lesions of the spinal cord: study of sixty-eight consecutive cases. Arch Neurol Psych.1944;52: 383-99.52383 1944

BertrandSL, Drvaric DM, Roberts JM. Scoliosis in syringomyelia. Orthopedics.1989;12: 335-7.12335 1989 [PubMed]

WeberFA. The association of syringomyelia and scoliosis. In: Proceedings of the Canadian Orthopaedic Association. J Bone Joint Surg Br.1974;56: 589.56589 1974

WilliamsB. Orthopaedic features in the presentation of syringomyelia. J Bone Joint Surg Br.1979;61: 314-23.61314 1979

AraiS, Ohtsuka Y, Moriya H, Kitahara H, Minami S. Scoliosis associated with syringomyelia. Spine.1993;18: 1591-2.181591 1993 [PubMed][CrossRef]

DoT, Fras C, Burke S, Widmann RF, Rawlins B, Boachie-Adjei O. Clinical value of routine preoperative magnetic resonance imaging in adolescent idiopathic scoliosis. A prospective study of three hundred and twenty-seven patients. J Bone Joint Surg Am.2001;83: 577-9.83577 2001

MaioccoB, Deeney VF, Coulon R, Parks PF Jr. Adolescent idiopathic scoliosis and the presence of spinal cord abnormalities. Preoperative magnetic resonance imaging analysis. Spine.1997;22: 2537-41.222537 1997 [PubMed][CrossRef]

SamuelssonL, Lindell D, Kogler H. Spinal cord and brain stem anomalies in scoliosis. MR screening of 26 cases. Acta Orthop Scand.1991;62: 403-6.62403 1991 [PubMed][CrossRef]

ShenWJ, McDowell GS, Burke SW, Levine DB, Chutorian AM. Routine preoperative MRI and SEP studies in adolescent idiopathic scoliosis. J Pediatr Orthop.1996;16: 350-3.16350 1996 [CrossRef]

WinterRB, Lonstein JE, Heithoff KB, Kirkham JA. Magnetic resonance imaging evaluation of the adolescent patient with idiopathic scoliosis before spinal instrumentation and fusion. A prospective, double-blinded study of 140 patients. Spine.1997;22: 855-8.22855 1997 [PubMed][CrossRef]

EvansSC, Edgar MA, Hall-Craggs MA, Powell MP, Taylor BA, Noordeen HH. MRI of `idiopathic' juvenile scoliosis. A prospective study. J Bone Joint Surg Br.1996;78: 314-7.78314 1996

FergusonRL, DeVine J, Stasikelis P, Caskey P, Allen BL Jr. Outcomes in surgical treatment of "idiopathic-like" scoliosis associated with syringomyelia. J Spinal Disord Tech.2002;15: 301-6.15301 2002 [PubMed][CrossRef]

HugusJJ, McGee-Collett M, Besser M, Gurr KR, Taylor TKF. Scoliosis in syringomyelia: a new view. In: Proceedings of the Australian Orthopaedic Association. J Bone Joint Surg Br.1990;72: 1098.721098 1990

MejiaEA, Hennrikus WL, Schwend RM, Emans JB. A prospective evaluation of idiopathic left thoracic scoliosis with magnetic resonance imaging. J Pediatr Orthop.1996;16: 354-8.16354 1996 [CrossRef]

PhillipsWA, Hensinger RN, Kling TF Jr. Management of scoliosis due to syringomyelia in childhood and adolescence. J Pediatr Orthop.1990;10: 351-4.10351 1990 [PubMed][CrossRef]

WilliamsB. Syringomyelia. Neurosurg Clin N Am.1990;1: 653-85.1653 1990 [PubMed]

MorrissyRT, Goldsmith GS, Hall EC, Kehl D, Cowie GH. Measurement of the Cobb angle on radiographs of patients who have scoliosis. Evaluation of intrinsic error. J Bone Joint Surg Am.1990;72: 320-7.72320 1990 [PubMed]

KingHA, Moe JH, Bradford DS, Winter RB. The selection of fusion levels in thoracic idiopathic scoliosis. J Bone Joint Surg Am.1983;65: 1302-13.651302 1983 [PubMed]

BernhardtM, Bridwell KH. Segmental analysis of the sagittal plane alignment of the normal thoracic and lumbar spines and thoracolumbar junction. Spine.1989;14: 717-21.14717 1989 [PubMed][CrossRef]

VedantamR, Lenke LG, Keeney JA, Bridwell KH. Comparison of standing sagittal spinal alignment in asymptomatic adolescents and adults. Spine.1998;23: 211-5.23211 1998 [PubMed][CrossRef]

VoutsinasSA, MacEwen GD. Sagittal profiles of the spine. Clin Orthop.1986;210: 235-42.210235 1986

BarnesPD, Brody JD, Jaramillo D, Akbar JU, Emans JB. Atypical idiopathic scoliosis: MR imaging evaluation. Radiology.1993;186: 247-53.186247 1993 [PubMed]

CharryO, Koop S, Winter R, Lonstein J, Denis F, Bailey W. Syringomyelia and scoliosis: a review of twenty-five pediatric patients. J Pediatr Orthop.1994;14: 309-17.14309 1994 [CrossRef]

EmeryE, Redondo A, Rey A. Syringomyelia and Arnold Chiari in scoliosis initially classified as idiopathic: experience with 25 patients. Eur Spine J.1997;6: 158-62.6158 1997 [CrossRef]

FarleyFA, Song KM, Birch JG, Browne R. Syringomyelia and scoliosis in children. J Pediatr Orthop.1995;15: 187-92.15187 1995 [PubMed]

GeisseleAE, Kransdorf MJ, Geyer CA, Jelinek JS, Van Dam BE. Magnetic resonance imaging of the brain stem in adolescent idiopathic scoliosis. Spine.1991;16: 761-3.16761 1991 [PubMed][CrossRef]

HaniehA, Sutherland A, Foster B, Cundy P. Syringomyelia in children with primary scoliosis. Childs Nerv Syst.2000;16: 200-2.16200 2000 [PubMed][CrossRef]

LoderRT, Stasikelis P, Farley FA. Sagittal profiles of the spine in scoliosis associated with an Arnold-Chiari malformation with or without syringomyelia. J Pediatr Orthop.2002;22: 483-91.22483 2002 [PubMed][CrossRef]

O'BrienMF, Lenke LG, Bridwell KH, Blanke K, Baldus C. Preoperative spinal canal investigation in adolescent idiopathic scoliosis curves > or = 70 degrees. Spine.1994;19: 1606-10.191606 1994 [PubMed][CrossRef]

OzerdemogluRA, Denis F, Transfeldt EE. Scoliosis associated with syringomyelia: clinical and radiologic correlation. Spine.2003;28: 1410-7.281410 2003 [PubMed]

SchwendRM, Hennrikus W, Hall JE, Emans JB. Childhood scoliosis: clinical indications for magnetic resonance imaging. J Bone Joint Surg Am.1995;77: 46-53.7746 1995 [PubMed]

TomlinsonRJ Jr, Wolfe MW, Nadall JM, Bennett JT, MacEwen GD. Syringomyelia and developmental scoliosis. J Pediatr Orthop.1994;14: 580-5.14580 1994 [PubMed][CrossRef]

BernsteinJ. Decision analysis. J Bone Joint Surg Am.1997;79: 1404-14.791404 1997

PaukerSG, Kassirer JP. The threshold approach to clinical decision making. N Engl J Med.1980;302: 1109-17.3021109 1980 [PubMed][CrossRef]

DeaconP, Flood BM, Dickson RA. Idiopathic scoliosis in three dimensions. A radiographic and morphometric analysis. J Bone Joint Surg Br.1984;66: 509-12.66509 1984 [PubMed]

DicksonRA, Lawton JO, Archer IA, Butt WP. The pathogenesis of idiopathic scoliosis. Biplanar spinal asymmetry. J Bone Joint Surg Br.1984;66: 8-15.668 1984 [PubMed]

HowellFR, Dickson RA. The deformity of idiopathic scoliosis made visible by computer graphics. J Bone Joint Surg Br.1989;71: 399-403.71399 1989 [PubMed]

KojimaT, Kurokawa T. Quantitation of three-dimensional deformity of idiopathic scoliosis. Spine.1992;17(3 Suppl): S22-9.17S22 1992 [PubMed][CrossRef]

RasoVJ, Russell GG, Hill DL, Moreau M, McIvor J. Thoracic lordosis in idiopathic scoliosis. J Pediatr Orthop.1991;11: 599-602.11599 1991 [PubMed]

RoafR. The basic anatomy of scoliosis. J Bone Joint Surg Br.1966;48: 786-92.48786 1966 [PubMed]

SomervilleEW. Rotational lordosis; the development of single curve. J Bone Joint Surg Br.1952;34: 421-7.34421 1952 [PubMed]

OuelletJA, LaPlaza J, Erickson MA, Birch JG, Burke S, Browne R. Sagittal plane deformity in the thoracic spine: a clue to the presence of syringomyelia as a cause of scoliosis. Spine.2003;28: 2147-51.282147 2003 [PubMed][CrossRef]

WhitakerC, Schoenecker PL, Lenke LG. Hyperkyphosis as an indicator of syringomyelia in idiopathic scoliosis: a case report. Spine.2003;28: E16-20.28E16 2003 [PubMed][CrossRef]

RamirezN, Johnston CE, Browne RH. The prevalence of back pain in children who have idiopathic scoliosis. J Bone Joint Surg Am.1997;79: 364-8.79364 1997 [PubMed]

ChumaA, Kitahara H, Minami S, Goto S, Takaso M, Moriya H. Structural scoliosis model in dogs with experimentally induced syringomyelia. Spine.1997;22: 589-95.22589 1997 [PubMed][CrossRef]

HuebertHT, MacKinnon WB. Syringomyelia and scoliosis. J Bone Joint Surg Br.1969;51: 338-43.51338 1969

IsuT, Chono Y, Iwasaki Y, Koyanagi I, Akino M, Abe H, Abumi K, Kaneda K. Scoliosis associated with syringomyelia presenting in children. Childs Nerv Syst.1992;8: 97-100.897 1992 [CrossRef]

MuhonenMG, Menezes AH, Sawin PD, Weinstein SL. Scoliosis in pediatric chiari malformations without myelodysplasia. J Neurosurg.1992;77: 69-77.7769 1992 [PubMed][CrossRef]

FarleyFA, Puryear A, Hall JM, Muraszko K. Curve progression in scoliosis associated with Chiari I malformation following suboccipital decompression. JSpinal Disord Tech.2002;15: 410-4.15410 2002 [CrossRef]

HarounRI, Guarnieri M, Meadow JJ, Kraut M, Carson BS. Current opinions for the treatment of syringomyelia and chiari malformations: survey of the Pediatric Section of the American Association of Neurological Surgeons. Pediatr Neurosurg.2000;33: 311-7.33311 2000 [PubMed][CrossRef]

HidaK, Iwasaki Y, Koyanagi I, Abe H. Pediatric syringomyelia with chiari malformation: its clinical characteristics and surgical outcomes. Surg Neurol.1999;51: 383-91.51383 1999 [CrossRef]

IsuT, Iwasaki Y, Akino M, Abe H. Hydrosyringomyelia associated with a Chiari I malformation in children and adolescents. Neurosurgery.1990;26: 591-7.26591 1990 [PubMed][CrossRef]

KontioK, Davidson D, Letts M. Management of scoliosis and syringomyelia in children. J Pediatr Orthop.2002;22: 771-9.22771 2002 [PubMed][CrossRef]

MarianiC, Cislaghi MG, Barbieri S, Filizzolo F, Di Palma F, Farina E, D'Aliberti G, Scarlato G. The natural history and results of surgery in 50 cases of syringomyelia. J Neurol.1991;238: 433-8.238433 1991 [PubMed][CrossRef]

MilhoratTH, Chou MW, Trinidad EM, Kula RW, Mandell M, Wolpert C, Speer MC. Chiari I malformation redefined: clinical and radiographic findings for 364 symptomatic patients. Neurosurgery.1999;44: 1005-17.441005 1999 [PubMed][CrossRef]

OzerdemogluRA, Transfeldt EE, Denis F. Value of treating primary causes of syrinx in scoliosis associated with syringomyelia. Spine.2003;28: 806-14.28806 2003 [PubMed]

VaqueroJ, Martinez R, Arias A. Syringomyelia-Chiari complex: magnetic resonance imaging and clinical evaluation of surgical treatment. J Neurosurg.1990;73: 64-8.7364 1990 [CrossRef]

NoordeenMH, Taylor BA, Edgar MA. Syringomyelia. A potential risk factor in scoliosis surgery. Spine.1994;19: 1406-9.191406 1994 [PubMed][CrossRef]

NordwallA, Wikkelso C. A late neurologic complication of scoliosis surgery in connection with syringomyelia. Acta Orthop Scand.1979;50: 407-10.50407 1979 [PubMed][CrossRef]

Topics

central nervous system ; pain ; lordosis ; spine ; vibration ; adolescent idiopathic scoliosis

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Jon R. Davids, Eric Chamberlin, Dawn W. Blackhurst; Indications for Magnetic Resonance Imaging in Presumed Adolescent Idiopathic Scoliosis. The Journal of Bone & Joint Surgery. 2004 Oct;86(10):2187-2195.

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