Diagnostic Accuracy of Neuromonitoring for Identification of New Neurologic Deficits in Pediatric Spinal Fusion Surgery.

BACKGROUND: Intraoperative neuromonitoring (IONM) modalities, transcranial motor-evoked potentials (TcMEPs), and somatosensory-evoked potentials (SSEPs) are accepted methods to identify impending spinal cord injury during spinal fusion surgery. Debate exists over sensitivity and specificity of these modalities. Our purpose was to measure the incidence of new neurologic deficits (NNDs) and estimate sensitivity and specificity of IONM modalities. METHODS: Institutional Ethics Board approval was obtained to review charts of patients younger than 22 years undergoing scoliosis surgery from 2007 to 2014 retrospectively. The definition of true-positive patients included two subgroups: (1) patients with an IONM alert, which did not resolve despite the interventions and had a NND postoperatively; or (2) patients with an IONM alert triggering interventions and the alert resolved with no NND postoperatively. Subgroup 2 of the definition is debatable; thus, we performed a multiple sensitivity analysis with three assumptions. Assumption 1: without interventions, all such patients would have experienced NNDs (assumption used in previous studies); Assumption 2: without intervention, half of these patients would have experienced NNDs; Assumption 3: without intervention, none of these of patients would have experienced NNDs. RESULTS: We included 296 patients. Patients with incomplete charts (n = 3), no IONM monitoring (n = 11), and inadequate baseline IONM (n = 7) were excluded. The incidence of NND was 3.7% (95% confidence interval, 2.1%-6.5%). Successful IONM in at least one modality was obtained in 275 patients (92.9%), of whom 268 (97.5%) and 259 (94.2%) had successful baseline TcMEP or SSEP signals, respectively. Fifty-one (17%) patients had IONM alerts, 41 were only TcMEP, 5 were only SSEP, and 5 were in both modalities. After interventions, 42 (82%) patients recovered, 41 had no NND (true-positive under Assumption (1), but one developed a NND (false-negative). Of the 9 patients with no alert recovery, 6 had a NND (true-positive) and 3 did not (false-positives). Of the remaining 224 patients with no alerts, 221 had no NND (true-negatives) and 3 did (false-negatives). Sensitivity was estimated to be 93.5%, 92.2%, and 46.7% for TcMEPs, combination (either TcMEPs or SSEPs), and SSEPs, respectively. Multiple sensitivity analysis demonstrated that sensitivity and specificity vary markedly with different assumptions. CONCLUSION: TcMEPs are more sensitive than SSEP at detecting an impending NND. IONM modalities are highly specific. Both sensitivity and specificity are impacted substantially by assumptions of the impact of interventions on alerts and NND. Properly designed, controlled, multicenter studies are required to establish diagnostic accuracy of IONM in scoliosis surgery.

Determining the factors associated with a prolonged length of stay for adolescent idiopathic scoliosis patients undergoing posterior spinal instrumentation and fusion in a single-payer health care system: are these factors different than those in the United States?

INTRODUCTION: Rapid recovery pathways (RRP) for adolescent idiopathic scoliosis patients undergoing posterior spinal instrumentation and fusion (PSIF) have been shown to be successful in reducing hospital length of stay (LOS). Although the majority of patients are discharged within 3 days, some patients require longer hospital admission. Previous studies in the United States have identified predictors of prolonged LOS for this patient population. The goal of this project was to determine if these predictors are the same for Canadian scoliosis patients and to identify those features which are different under this single-payer system. METHODS: A RRP for scoliosis surgery was implemented in March 2015 at a single, tertiary referral children's hospital in Canada. Previously identified features, along with numerous other patient factors, were collected. Spearman correlations were used to determine the factors most associated with hospital LOS and those factors were used in a multivariable regression model. RESULTS: A total of 161 patients were included in the analysis. Of the previously identified patient factors, only receiving a peri-operative transfusion was found to be significant (ρ = 0.24; p = 0.002). None of the other pre-identified variables were found to be significantly correlated with LOS. Variables not previously examined that were found to be significantly correlated with hospital LOS included ASA status (ρ = 0.19, p = 0.046), fusion involving both the thoracic and lumbar spine (ρ = 0.18, p = 0.025), and receiving celecoxib on post-operative day 1 (ρ = - 0.16; p = 0.038). The features that had the greatest association with LOS through multivariable regression was receiving a blood transfusion (B = 0.48; 95%CI 0.096-0.89; p = 0.017). CONCLUSIONS: In this study, we found that many of the features found to be significantly correlated with prolonged hospital LOS in the United States are not transferable to the Canadian healthcare system. This is important for the Canadian, and other surgeons in a single-payer system, in order to identify pre-operative or immediate post-operative factors that may extend patient LOS following PSIF and plan resources accordingly. LEVEL OF EVIDENCE: III; therapeutic.

Coronal deformity angular ratio as a predictive factor for in-brace curve correction and long-term outcome of brace treatment in adolescents with idiopathic scoliosis.

PURPOSE: To investigate the relationship between coronal deformity angular ratio (C-DAR) and in-brace correction (IBC) and their role in predicting the long-term bracing outcome in adolescents with idiopathic scoliosis (AIS). METHODS: In this retrospective multicenter study, the patient's sex, age, primary curve Cobb angle (at initiation of brace treatment, best in-brace, before spinal fusion, and final follow-up), curve pattern, duration of brace treatment, brace type, and C-DAR at initiation of bracing were recorded. The C-DAR values were classified as < 5, 5 ≤ to ≤ 6, and > 6. The IBC values were classified as ≥ 50%, 40% ≤ to ≤ 49%, and < 40%. We classified the patients into two groups of success and failure according to the Cobb angle at the final follow-up. RESULTS: A total of 164 patients (25 boys and 119 girls) were included. Bracing was successful in 60.4% of them. There was a significant association between C-DAR and bracing outcome (p < 0.0001). 63.9% of the patients with C-DAR < 5 had an IBC ≥ 50%. However, when C-DAR was 5 ≤ to ≤ 6 and > 6, 29.2% and 16.9% of the patients had an IBC of ≥ 50%, respectively. For patients with IBC ≥ 50%, the success rate of bracing was 89.2%. Results of logistic regression analysis revealed that the strongest predictor for brace treatment outcome was the C-DAR, with an odds ratio of 2.11. CONCLUSION: C-DAR may be used as a predictive factor for the long-term outcome of brace treatment in AIS. LEVEL OF EVIDENCE: IV.

Is it feasible to implement a rapid recovery pathway for adolescent idiopathic scoliosis patients undergoing posterior spinal instrumentation and fusion in a single-payer universal health care system?

PURPOSE: The purpose of this project was to determine if it is feasible to implement a rapid recovery pathway (RRP) for the surgical treatment of adolescent idiopathic scoliosis (AIS) within a single-payer universal healthcare system while simultaneously decreasing length of stay (LOS) without increasing post-operative complications. METHODS: A retrospective analysis was completed for all patients who underwent posterior spinal fusion for AIS at a tertiary children's hospital in Canada between March 2010 and February 2019, with date of implementation of the RRP being March 1st, 2015. Patient demographic information was collected along with a variety of outcome variables including: LOS, wound complication, infection, 30-day return to the OR, 30-day emergency department visit, and 30-day hospital readmission. An interrupted time series analysis was utilized to determine if any benefits were associated with the implementation of the RRP. RESULTS: A total of 244 patients were identified, with 113 patients in the conventional pathway and 131 in the RRP. No significant differences in demographic features or post-operative complications were found between the two cohorts (p > 0.05). Using a robust linear time series model, LOS was found to be significantly shorter in the RRP group, with the average LOS being 5.2 [95% IQR 4.3-6.1] days in the conventional group and 3.4 [95% IQR 3.3-3.5] days in the RRP group (p < 0.05). CONCLUSION: This study shows that it is possible to implement a RRP for the surgical treatment of AIS within a single-payer universal healthcare system. Use of the pathway can effectively reduce hospital LOS without increasing the risk of developing a post-operative complication. This has the upside potential to reduce healthcare and family costs. LEVEL OF EVIDENCE: Therapeutic III.

Responding to neuromonitoring changes in 3-column posterior spinal osteotomies for rigid pediatric spinal deformities.

STUDY DESIGN: Retrospective review of prospectively collected data on the neuromonitoring changes recorded during a consecutive series of cord level 3-column posterior spinal osteotomies for the correction of rigid pediatric spinal deformities in children between 2005 and 2012. OBJECTIVE: To review the neuromonitoring changes observed during the performance of these procedures, to highlight the high-risk steps, and to describe actions taken to avert major neurological injury. SUMMARY OF BACKGROUND DATA: Significant motor evoked potentials (MEP) changes are common during the performance of spinal osteotomies in children. The real-time intraoperative information provided by MEPs can provide the necessary information to direct key surgical decisions. METHODS: The neuromonitoring changes occurring during the performance of 37 3-column, cord level, posterior spinal osteotomies in 28 patients were recorded. The procedures were divided, for comparative purposes, into 2 groups based on the presence or absence of alerts. A decrease in somatosensory evoked potentials and transcranial MEPs greater than 50% of baseline was considered an alert. Alerts were classified chronologically as type I: prior to decompression, type II: occurring during decompression and bone resection, type III: occurring after osteotomy closure. RESULTS: Somatosensory evoked potential alerts occurred in 3 patients, all of whom had significant MEP alerts. There were 2 type I, 15 type II, and 6 type III MEP alerts. Increasing blood pressure improved MEPs in all with the exception of 8 type II and 4 type III. The unresponsive 8 type II alerts were treated with osteotomy closure with the expectation that spinal shortening would decompress the spinal cord and improve spinal cord perfusion. The unresponsive 4 type III alerts all responded to reopening, manipulation, and subsequent reclosure of the osteotomy either with a cage or less correction. There were 5 immediate postoperative motor deficits. No patient had a permanent deficit. CONCLUSION: Changes unresponsive to increasing blood pressure occurring during decompression and bone resection (type II) responded well to osteotomy closure. Unresponsive changes during osteotomy closure (type III) were treated successfully with opening the osteotomy, cage adjustment, and less correction.

Congenital trigger thumb in children: electron microscopy and immunohistochemical analysis of the first annular pulley.

Although numerous studies have been performed on congenital trigger thumb (CTT), the pathogenesis is still unknown. Cytocontractile proteins and myofibroblasts are present during soft-tissue contraction, and they may have a role in CTT. The aim of the study is to clarify the immunohistochemical and the electron microscopy characteristics of the first annular (A-1) pulley in CTT. The specimens from the A-1 pulleys were collected from 22 children with CTT. Electron microscopy was used to study the last five specimens. Immunohistochemistry staining demonstrated that all specimens stained positively for vimentin and for α-smooth muscle actin, and stained negatively for desmin. Electron microscopy showed fibroblasts in collagenous matrix, which contain vimentin-like material and associated at the surface with elastin-like tubular matrix filaments and elastin fibers. In two specimens, a few cells showed markers of myofibroblastic differentiation. The presence of the cytocontractile proteins and myofibroblasts suggests proliferation of fibrous tissues during either the intrauterine or extrauterine phase of development and may account for the presence of congenital stenosis at the level of the A-1 pulley. We believe that CTT may be developmental; if the process started in the intrauterine phase it might present as a fixed flexion contracture and will show mature fibroblasts. If the process started in the extrauterine phase, it might present as triggering first and will show myofibroblastic changes, then with the maturation of the fibrous tissue, result in a fixed flexion contracture.

Treatment and outcome of vertebral Langerhans cell histiocytosis at the Children's Hospital of Eastern Ontario.

BACKGROUND: We wished to evaluate the treatment methods for vertebral Langerhans cell histiocytosis (LCH) (a rare reticuloendothelial disorder) at a tertiary care pediatric centre and compare treatment and outcomes with those reported in the recent literature. METHODS: A total of 55 charts were retrieved between 1980 and 2003 for children with LCH. Only those children who were under 18 years of age, had a diagnosis of LCH, histiocytosis X or eosinophilic granuloma and had documented vertebral involvement were included. The data collected were compared with data in the literature with respect to epidemiologic features, symptoms, investigations and procedures done, treatment, outcome and follow-up. RESULTS: Of the 8 children who met the inclusion criteria for vertebral LCH, the most common presenting complaint was back or neck pain. The thoracic vertebrae were most commonly affected followed equally by cervical and lumbar spines. Most children underwent a complete diagnostic work-up. A single solitary lesion was found in only 1 child. Biopsies were attempted in all cases with 6 positive results. Treatment varied depending on the severity of the presenting complaint; however, none of the tumours was completely resected. Follow-up averaged 3.4 years, and only 1 child has had a recurrence. CONCLUSION: A multidisciplinary investigation is recommended for children with suspected vertebral LCH. Treatment depends on the severity of the disease.

Cervical spine instability in children with Goldenhar's syndrome.

OBJECTIVE: To study the vertebral involvement of the cervical spine, in particular the stability of C1-C2, in children with proven Goldenhar's syndrome. DESIGN: A case review. SETTING: The Children's Hospital of Eastern Ontario, Ottawa. PATIENTS: Eight children who had a minimum of 2 out of 3 Goldenhar criteria plus other strong associations with the syndrome and for whom detailed radiographic spinal assessment, including flexion-extension views of the cervical spine and computed tomography of the congenital anomalies, were available. OUTCOME MEASURES: Radiographic findings. RESULTS: Seven children demonstrated cervical spine anomalies. Of particular concern was the high incidence of C1-C2 instability in 3 children, 2 of whom required occiput to C2 fusion. The presence of hemivertebrae and failures of segmentation were most common and resulted in thoracic scoliosis, leading to spinal fusion in 2 children. CONCLUSIONS: In patients with Goldenhar's syndrome the cervical spines must be monitored carefully for C1-C2 subluxation before any proposed surgery for other malformations associated with the syndrome, so that any instability can be identified to avoid cord impingement during a general anesthetic.