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

Idiopathic scoliosis in subjects with eye diseases: A systematic review with meta-analysis

Our aim was to find the best evidence on the prevalence of idiopathic scoliosis (IS) in subjects with eye diseases (EDs) and to determine the most common visual alterations that are present. Following the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), a bibliographic search up to June 2023 in the PubMed, PsycINFO, SCOPUS, and CINAHL Complete databases was performed. Observational studies were selected and the results were analyzed with prevalence odds ratio (OR). A total of six studies, including 18,396 subjects, were selected. The group of subjects with EDs was made up of 6048 individuals, of whom 655 (10.83%) had IS. The group of subjects without EDs was made up of 12,348 individuals of whom 444 (3.60%) presented with IS with an OR = 2.91, CI (95%) = [1.75, 4.83]. Blindness was assessed in a single study with an OR = 7.83, CI (95%) = [1.66, 36.90]; all three studies in the refractive error subgroup yielded an OR = 2.24, CI (95%) = [1.10, 4.58]; and the two studies that included subjects with strabismus showed an OR = 3.09, CI (95%) = [1.38, 7.00]. EDs were associated with an almost three times greater odds of having IS. We recommend the inclusion of vision testing in children with IS.

7.7% Prevalence of neural axis abnormalities on routine magnetic resonance imaging in patients with presumed adolescent idiopathic scoliosis scheduled for spine surgery: a consecutive single surgeon retrospective cohort of 182 patients

PURPOSE

The purpose of this study was to use a Delphi analysis to identify a clinically relevant threshold for the prevalence of neural axis abnormalities (NAAs) that would warrant routine preoperative screening.

METHODS

A panel of experienced physicians specializing in pediatric spine surgery, pediatric neurosurgery, and pediatric neuroradiology was formed to establish consensus using a Delphi process to identify a minimum prevalence of NAAs that would initiate the implementation of preoperative MRIs as standard of care. Following the Delphi analysis, patients scheduled for PSF (Posterior Spinal Fusion) from 2010 to 2018 were retrospectively identified. Patients were included based on the following criteria: (1) 10-18 years old at time of MRI (inclusive), (2) AIS diagnosis prior to preoperative MRI (no concerning curve pattern, rate of progression, or neurologic signs/symptoms to suggest alternative diagnosis to AIS), and (3) standard preoperative MRI of the cervical, thoracic, and lumbar spine undergone. The prevalence of NAAs on preoperative MRI was recorded for all patients.

RESULTS

There were 182 eligible patients. 14 had NAAs on MRI. The prevalence of NAAs was 7.7% [95% CI 4.27-12.57%]. This prevalence was significantly [p < 0.0001] higher than the clinically relevant threshold of 1.3% established by the Delphi panel. Of the 14 patients with NAAs noted on preoperative MRI, neurosurgical intervention was recommended for 4 patients, 2.2% [95% CI 0.6-5.5%] of the total cohort.

CONCLUSIONS

Delphi panelists reported a low tolerance for NAAs among patients undergoing PSF for presumed AIS. Group consensus recommended routine screening should be implemented if the prevalence of NAAs is greater than 1.3%. The prevalence of NAAs in our cohort as well as related studies was significantly higher than this threshold.

LEVEL OF EVIDENCE

Diagnostic-level III.

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.

Overview of Methods to Quantify Invasiveness of Surgical Approaches in Orthopedic Surgery—A Scoping Review

Background

There is a trend toward minimally invasive and more automated procedures in orthopedic surgery. An important aspect in the further development of these techniques is the quantitative assessment of the surgical approach. The aim of this scoping review is to deliver a structured overview on the currently used methods for quantitative analysis of a surgical approaches' invasiveness in orthopedic procedures. The compiled metrics presented in the herein study can serve as the basis for digitization of surgery and advanced computational methods that focus on optimizing surgical procedures.

Methods

We performed a blinded literature search in November 2020. In-vivo and ex-vivo studies that quantitatively assess the invasiveness of the surgical approach were included with a special focus on radiological methods. We excluded studies using exclusively one or multiple of the following parameters: risk of reoperation, risk of dislocation, risk of infection, risk of patient-reported nerve injury, rate of thromboembolic event, function, length of stay, blood loss, pain, operation time.

Results

The final selection included 51 articles. In the included papers, approaches to 8 different anatomical structures were investigated, the majority of which examined procedures of the hip (57%) and the spine (29%). The different modalities to measure the invasiveness were categorized into three major groups “biological” (23 papers), “radiological” (25), “measured in-situ” (14) and their use “in-vivo” or “ex-vivo” was analyzed. Additionally, we explain the basic principles of each modality and match it to the anatomical structures it has been used on.

Discussion

An ideal metric used to quantify the invasiveness of a surgical approach should be accurate, cost-effective, non-invasive, comprehensive and integratable into the clinical workflow. We find that the radiological methods best meet such criteria. However, radiological metrics can be more prone to confounders such as coexisting pathologies than in-situ measurements but are non-invasive and possible to perform in-vivo. Additionally, radiological metrics require substantial expertise and are not cost-effective. Owed to their high accuracy and low invasiveness, radiological methods are, in our opinion, the best suited for computational applications optimizing surgical procedures. The key to quantify a surgical approach's invasiveness lies in the integration of multiple metrics.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

An analysis of clinical risk factors for adolescent scoliosis caused by spinal cord abnormalities in China: proposal for a selective whole-spine MRI examination scheme

BACKGROUND

Approximately 80% of adolescent scoliosis cases are idiopathic, and some non-idiopathic scoliosis cases caused by spinal cord abnormalities are misdiagnosed as idiopathic scoliosis. This study examined the risk factors for non-idiopathic scoliosis with intramedullary abnormalities, explored the feasibility of whole-spine MRI, and provided a theoretical basis for the routine diagnosis and treatment of adolescent idiopathic scoliosis.

METHOD

The clinical data of adolescent scoliosis patients who were admitted to Shanghai Tongren Hospital and Shanghai Changhai Hospital between July 1, 2013, and December 31, 2018, were reviewed. According to the whole-spine MRI results, the patients were divided into either the idiopathic group or the intramedullary abnormality group. Sex, age, main curvature angle, main curvature direction, kyphosis angle, scoliosis type, coronal plane balance, sagittal plane balance, abdominal wall reflex, sensory abnormality, ankle clonus and tendon reflexes were compared between the two groups. Student's t test was used to evaluate the differences in the continuous variables, and the chi-square test was used to evaluate the differences in the categorical variables. Fisher's exact test was applied to detect the difference in the rate of intraspinal anomalies between the groups. Logistic regression was used to evaluate the correlation between the multivariate risk factors and intramedullary abnormalities.

RESULT

A total of 714 adolescent scoliosis patients with a mean age of 13.5 (10-18 years) were included in the study, and intramedullary abnormalities were found in 68 (9.5%) patients. There were statistically significant differences in the incidence rates of intramedullary abnormalities between males and females, left and right thoracic curvatures, angular scoliosis and smooth scoliosis, and abnormal abdominal wall reflex and ankle clonus (P < 0.01). Logistic regression showed that the ratios for sex, scoliosis direction, scoliosis type, abdominal wall reflex and ankle clonus were 2.987, 3.493, 4.823, 3.94 and 8.083, respectively. The ROC curve showed a sensitivity of 66.18% and a specificity of 89.01%, and the Youden index corresponding to the optimal critical point was 0.5519.

CONCLUSION

Risk factors associated with adolescent scoliosis caused by abnormal intramedullary abnormalities included male sex, thoracic scoliosis on the left side, sharp curvature of the spine, abnormal abdominal wall reflex and ankle clonus. In adolescent scoliosis patients, the incidence of scoliosis caused by intramedullary abnormalities was approximately 9.5%. These clinical indicators suggest that there is a high-risk adolescent scoliosis population who should undergo whole-spinal MRI preoperatively to rule out intramedullary abnormalities.

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

BACKGROUND

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

PURPOSE

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

STUDY DESIGN

A systematic review was carried out.

METHODS

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

RESULTS

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

CONCLUSIONS

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

Incidence of Neuraxial Abnormalities Is Approximately 8% Among Patients With Adolescent Idiopathic Scoliosis: A Meta-analysis

BACKGROUND

Several studies have sought to address the role of routine preoperative MRI in patients with adolescent idiopathic scoliosis (AIS) undergoing deformity correction. Despite similar results regarding the prevalence of neuraxial anomalies detected on MRI, published conclusions conflict and give opposing recommendations. Lack of consensus has led to important variations in use of MRI before spinal surgery for patients with AIS.

QUESTIONS/PURPOSES

This systematic review and meta-analysis of studies about patients with AIS evaluated (1) the overall proportion of neuraxial abnormalities; (2) the patient factors and curve characteristics that may be associated with abnormalities; and (3) the proportion of patients who underwent neurosurgical intervention before scoliosis surgery and the kinds of neuraxial lesions that were identified.

METHODS

We performed a search of four electronic databases (PubMed, EMBASE, CINAHL Plus, and SCOPUS) utilizing search terms related to routine MRI and AIS, yielding 206 articles. Studies included had at least 20 participants, patients with ages 11 to 21 years, and a Methodological Index for Non-Randomized Studies (MINORS) study quality score of 8 and 16 points for noncomparative and comparative studies, respectively. Non-English manuscripts, animal studies, and those that did not include patients with AIS solely were excluded. Eighteen articles with 4746 patients were included for analysis of the overall proportion of neuraxial abnormalities, 12 articles with 3028 patients for analysis by sex, eight articles with 1603 patients for right main thoracic curve, eight articles with 665 patients for a left main thoracic curve, and 13 articles with 3063 patients and 230 (7.5%) abnormalities for number of neurosurgical interventions before scoliosis correction. The mean MINORS score for studies included was 14 (range, 10-20). Each study was analyzed for the proportion of patients identified with neuraxial abnormalities and associations with specific demographics. We determined the proportion of patients who underwent surgical interventions before scoliosis surgery as well as the types of neuraxial lesions identified. The articles were assessed for heterogeneity and publication bias. Because all groups were determined to be heterogeneous, a random-effects model was used for each group in this meta-analysis; with this analysis, an overlap of 95% confidence intervals suggests no difference at the p < 0.05 level, but this analytic approach does not provide p values.

RESULTS

The pooled proportion of neuraxial abnormalities detected on MRI was 8% (95% confidence interval [CI], 6%-12%). With the numbers available, we found no difference in the proportion of male and female patients with neuraxial abnormalities (18% [95% CI, 11%-29%] versus 9% [95% CI, 6%-12%], respectively). Likewise, there was no difference in the proportion of pooled neuraxial abnormalities in right and left curves (9% [95% CI, 6%-14%] versus 15% [95% CI, 5%-35%], respectively). In the subset of abnormalities analyzed for number of neurosurgical interventions before scoliosis correction, the pooled proportion showed that 33% (95% CI, 24%-43%) underwent neurosurgical intervention before deformity correction. The most common abnormalities of the 367 found on MRI were syringomyelia in 127 patients (35%), Arnold-Chiari Type 1 malformation with syrinx in 103 patients (28%), and isolated Arnold-Chiari Type 1 malformation in 91 patients (25%).

CONCLUSIONS

The proportion of patients with AIS who have neuraxial abnormalities is high (8%) and a large number undergo surgical intervention before scoliosis reconstruction. We did not find any particular demographic variables that indicated an increased risk of abnormality. Clinicians should consider advanced imaging before surgical intervention in the treatment of a patient with an idiopathic diagnosis. Preventable variables need to be identified by future studies to establish a better working treatment protocol for these patients.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Simultaneous Surgical Treatment of Congenital Spinal Deformity Associated with Intraspinal Anomalies

Study Design

Prospective case series.

Purpose

To study the safety, efficacy, and long-term outcomes of single-stage surgical intervention for congenital spinal deformity and intraspinal anomalies.

Overview of literature

Congenital spinal deformities associated with intraspinal anomalies are usually treated sequentially, first by treating the intraspinal anomalies followed by deformity correction after a period of 3–6 months. Recently, a single-stage approach has been reported to show better postoperative results and reduced complication rates.

Methods

Thirty patients (23 females and seven males) were prospectively evaluated for the simultaneous surgical treatment of congenital spinal deformity with concurrent intraspinal anomalies from May 2006 to October 2016. The average age at presentation was 9.8±3.7 years, with the average follow-up duration being 49.06±8.6 months. Clinical records were evaluated for clinical, radiological, perioperative, and postoperative data.

Results

The average angle of deformity was 56.53°±25.22° preoperatively, 21.13°±14.34° postoperatively, and 23.93°±14.99° at the final follow-up. The average surgical time was 232.58±53.56 minutes (range, 100–330 minutes), with a mean blood loss of 1,587.09±439.09 mL (range, 100–2,300 mL).

Conclusions

Single stage surgical intervention for intraspinal anomalies with congenital spinal deformity correction, including adequate intra-operative wake-up test, is a viable option in appropriately selected patients and has minimum complication rates.