Population Covered By The Guidance
This pathway provides guidance on imaging an adolescent with scoliosis.
Lead Researcher: Arjun Shivananda
Experts & Contributors: Ravinder Dhillon, Michael Ditchfield, Peter Shipman
Date reviewed: July 2017
Date Published: December 2017
- Scoliosis can arise from a variety of causes and is defined as a >10° abnormal lateral curvature of the spine in the coronal plane as defined by the Cobb angle
- The most common cause of scoliosis in children is idiopathic
- The primary imaging modality for evaluating adolescent scoliosis is a single PA erect film of the entire spine and including the iliac crests. A lateral film may also be performed
- The PA view is standard as it reduces the radiation dose to thyroid and breast
- Judicious use of radiation reduction techniques (e.g. contoured filter, air gap technique) and attention to imaging frequency are needed to minimise the radiation burden as patients with scoliosis are monitored with serial radiographs
- MRI is indicated for detection of spinal cord abnormalities when one or more “red flag” features are present
- The role of MRI for imaging all patients prior to surgical correction remains controversial. Recent studies indicate MRI is not required in preoperative patients with a negative history, normal physical examination and a typical curve pattern
- Prior to surgery, passive lateral bending plain films in the frontal plane enables the surgeon to measure the degree of correction and determine the levels included in the operation
Date of literature search: June 2017
References are graded from Level I to V according to the Oxford Centre for Evidence-Based Medicine, Levels of Evidence. Download the document
- Van Goethem J, Van Campenhout A, van den Hauwe L, Parizel PM. Scoliosis. Neuroimaging Clin N Am. 2007;17(1):105-15. (Review article). View the reference
- Reamy BV, Slakey JB. Adolescent idiopathic scoliosis: review and current concepts. Am Fam Physician. 2001;64(1):111-6. (Review article). View the reference
- Cassar-Pullicino VN, Eisenstein SM. Imaging in scoliosis: what, why and how? Clin Radiol. 2002;57(7):543-62. (Review article). View the reference
- El-Hawary R, Chukwunyerenwa C. Update on evaluation and treatment of scoliosis. Pediatr Clin North Am. 2014;61(6):1223-41. (Review article). View the reference
- Trobisch P, Suess O, Schwab F. Idiopathic scoliosis. Dtsch Arztebl Int. 2010;107(49):875-83. (Review article). View the reference
- Jaramillo D, Poussaint TY, Grottkau BE. Scoliosis: evidence-based diagnostic evaluation. Neuroimaging Clin N Am. 2003;13(2):335-41. (Review article). View the reference
- Cote P, Kreitz BG, Cassidy JD, Dzus AK, Martel J. A study of the diagnostic accuracy and reliability of the Scoliometer and Adam's forward bend test. Spine (Phila Pa 1976). 1998;23(7):796-802. (Level III evidence). View the reference
- Thomsen M, Abel R. Imaging in scoliosis from the orthopaedic surgeon's point of view. European Journal of Radiology. 2006;58(1):41-7. (Review article). View the reference
- Davids JR, Chamberlin E, Blackhurst DW. Indications for magnetic resonance imaging in presumed adolescent idiopathic scoliosis. J Bone Joint Surg Am. 2004;86-a(10):2187-95. (Level III evidence). View the reference
- Lee CS, Hwang CJ, Kim NH, Noh HM, Lee MY, Yoon SJ, et al. Preoperative Magnetic Resonance Imaging Evaluation in Patients with Adolescent Idiopathic Scoliosis. Asian Spine J. 2017;11(1):37-43. (Level IV evidence). View the reference
- Schulze A, Schrading S, Betsch M, Quack V, Tingart M. [Adolescent scoliosis : From deformity to treatment]. Orthopade. 2015;44(11):836-44. (Review article). View the reference
- Inoue M, Minami S, Nakata Y, Otsuka Y, Takaso M, Kitahara H, et al. Preoperative MRI analysis of patients with idiopathic scoliosis: a prospective study. Spine (Phila Pa 1976). 2005;30(1):108-14. (Level III evidence). View the reference
- Diab M, Landman Z, Lubicky J, Dormans J, Erickson M, Richards BS. Use and outcome of MRI in the surgical treatment of adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 2011;36(8):667-71. (Level III evidence). View the reference
- Malfair D, Flemming AK, Dvorak MF, Munk PL, Vertinsky AT, Heran MK, et al. Radiographic evaluation of scoliosis: review. AJR Am J Roentgenol. 2010;194(3 Suppl):S8-22. (Review article). View the reference
- Cardoso M, Keating RF. Neurosurgical management of spinal dysraphism and neurogenic scoliosis. Spine (Phila Pa 1976). 2009;34(17):1775-82. (Review article). View the reference
- Ozturk C, Karadereler S, Ornek I, Enercan M, Ganiyusufoglu K, Hamzaoglu A. The role of routine magnetic resonance imaging in the preoperative evaluation of adolescent idiopathic scoliosis. International Orthopaedics. 2010;34(4):543-6. (Level II evidence). View the reference
Pathway User Guide
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The relative radiation level (RRL) of each imaging investigation is displayed in the pop up box.
| SYMBOL | RRL | EFFECTIVE DOSE RANGE |
|---|---|---|
| None | 0 | |
| Minimal | < 1 millisieverts | |
| Low | 1-5 mSv | |
| Medium | 5-10 mSv | |
| High | >10 mSv |
Disclaimer
Status Of Recommendations Each pathway is designed to assist clinicians in situations when faced with a large array of possible diagnostic tests and examinations. However, it is recognised that diagnostic practice may differ from a particular pathway depending on local availability of equipment and expertise, as well as the experience of individual clinicians. Therefore each pathway is neither a rigid set of rules, nor a substitute for clinical assessment, and individual patient circumstances should always be considered.
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Adolescent Scoliosis
Adolescent Scoliosis
Scoliosis is defined as >10o abnormal lateral curvature of the spine in the coronal plane, often associated with axial rotation
- Scoliosis is defined as >10° abnormal lateral curvature of the spine in the coronal plane, often associated with axial rotation
- Scoliosis can be classified as structural or non-structural (functional). Functional scoliosis can be postural or compensatory. It is non-progressive and correctable by ipsilateral bending
- Structural scoliosis can be classified into 5 aetiological causes: idiopathic (80%), congenital (10%), or associated with neuromuscular, developmental and other miscellaneous diseases
- Idiopathic scoliosis is a diagnosis of exclusion and can be subdivided based on age of onset: infantile (from birth to 3 years – <1% of cases), juvenile (4 to 10 years - 12-21%) and adolescent (>10 years and before skeletal maturity - 2-4%)
- Adolescent idiopathic scoliosis has a prevalence of 0.5-3% and is the most common form of the disease. Females are predominantly affected (female : male ratio 5-10:1) and are more likely to have more progressive disease and severe curves
- Adam's test was 92% sensitive and 60% specific for detecting thoracic curves >20° and 73% sensitive and 68% specific for lumbar curves >20°, when compared with Cobb’s angle as the gold standard
Plain Radiography
Plain Radiography
A single posteroanterior erect film of the entire spine and including the iliac crest is the primary imaging modality for evaluating adolescent scoliosis
- The primary imaging modality for evaluating adolescent scoliosis should include a posteroanterior erect film of the entire spine and including the iliac crests
- The PA view is standard as it reduces the radiation dose to thyroid and breast tissue despite delivering increased radiation absorption to bone marrow. Bone marrow is only one-sixth as sensitive to radiation as breast tissue
- Authors are also increasingly recommending a lateral film as part of the initial radiographic investigation
- The lateral view is necessary to determine the absence of apical segment lordosis of the thoracic spine (i.e. the presence of normal thoracic kyphosis or hyperkyphosis) which is considered an atypical curve pattern and found to be associated with increased incidence of neuroaxis abnormalities
- The scoliosis curve is described as “right” or “left” depending on their convexity and named by the location of the apex vertebrae
- The Cobb method is used to quantify the degree of scoliosis. A line parallel to the superior end plate of the most cephalic tilted vertebra and a line parallel to the inferior end plate of the most tilted caudal vertebra are drawn. Perpendicular lines to these are drawn and the Cobb angle is measured where the lines intersect
- Factors which reduce the reproducibility include patient position, radiographic technique and diurnal variation (5%deg; reported in one study)
- Hence, in the monitoring of scoliosis a 10° difference of the Cobb angle between radiographs taken at different times is necessary in order to be 95% confident that a true change in scoliosis has occurred
- The PA film compared to the AP view, reduces cumulative radiation dose to the thyroid gland and breast by 3 to 7 fold and would reduce the estimated risk of lifetime cancer by 3 to 4 fold
- A retrospective cohort study of 5573 female patients with scoliosis diagnosed before the age of 20 has shown that scoliosis patients are exposed to an average of 25 radiographs per patient with a mean estimated cumulative radiation dose to the breast of 10.8 cGy. The relative risk of dying from breast cancer was 1.7 (95% CI = 1.2-2.1) after an average of 40 years follow-up (77 observed breast cancer deaths vs 45 expected deaths in this population)
Preoperative Lateral Bending Views
Lateral Plain Film
Some authors also recommend a lateral film as part of the initial radiographic investigation
- Passive lateral bending view in the frontal plane enables the surgeon to measure the degree of correction and determine the levels included in the operation
- A chest radiograph is required to exclude any associated cardiopulmonary abnormalities
Magnetic Resonance Imaging (MRI)
Magnetic Resonance Imaging (MRI)
Modality of choice for assessment of the spinal cord and paraspinal soft tissues in patient with scoliosis
- MRI is the modality of choice for assessment of the spinal cord and paraspinal soft tissues in patients with scoliosis
- Spinal cord abnormalities are seen in 2-3% of patients with presumed adolescent idiopathic scoliosis
- Abnormalities detected by MRI include tethered spinal cord, Chiari malformations, hydromyelia, syringomyelia, intramedullary tumours, diastamatomyelia and intra-spinal lipomas
- Commonly accepted indications for MRI include
- Neurological findings including headache, neck pain, absence of abdominal reflex and asymmetric lower-extremity atrophy
- A typical curve pattern: examples are thoracic levoscoliosis, short segment curve (less than six segments), decreased vertebral rotation, rapid progression, and kyphosis near the apex of curve. Other features on scoliosis radiographs requiring MRI may be an underlying tumour or infection, widening of an intervertebral foramen or thickening of the paraspinal line. In one study, there was a 25% prevalence of neuroaxis abnormalities when both an atypical curve and neurological findings were present
- Age of onset 3
- The presence of abnormalities on MRI in those without any of the above features is variable depending on the series. Some studies report a 2-3% prevalence of which none required prior neurosurgical intervention or had postoperative neurological complications. (12) Others have reported prevalence up to 8% of which 15% required a neurosurgical procedure
- In view of this, many neurosurgeons advocate preoperative MRI to exclude spinal cord abnormality (e.g. tethering of the cord) that requires surgical intervention prior-to or in conjunction with scoliosis correction
Computed Tomography (CT)
Computed Tomography (CT)
CT better delineates any segmentation anomalies which may accompany a structural scoliosis as well as pars defects
- Thin section CT is the most accurate confirmatory test if there is concern regarding spondylolysis. Spondylolysis at L5 is common in patients with adolescent idiopathic scoliosis so CT can be limited to the lumbo-sacral junction. Spondylolysis is important to identify since the surgeons may choose to include this area while extending posterior fusion to pelvis
- CT ’s superior ability to display bony anatomy as well as its multiplanar and 3D capabilities make it useful in characterising spinal segmentation anomalies which may accompany a structural scoliosis, particularly for preoperative planning
Further Imaging may include Lateral Bending Views
Further Imaging may include Lateral Bending Views
Passive lateral bending view in the frontal plane enables the surgeon to measure the degree of correction and determine the level included in the operation
