Timing of intraoperative neurophysiological monitoring (IONM) recovery and clinical recovery after termination of pediatric spinal deformity surgery due to loss of IONM signals.

BACKGROUND CONTEXT: Intraoperative neurophysiological monitoring (IONM) is used to reduce the risk of spinal cord injury during pediatric spinal deformity surgery. Significant reduction and/or loss of IONM signals without immediate recovery may lead the surgeon to acutely abort the case. The timing of when monitorable signals return remains largely unknown. PURPOSE: The goal of this study was to investigate the correlation between IONM signal loss, clinical examination, and subsequent normalization of IONM signals after aborted pediatric spinal deformity surgery to help determine when it is safe to return to the operating room. STUDY DESIGN/SETTING: This is a multicenter, multidisciplinary, retrospective study of pediatric patients (<18 years old) undergoing spinal deformity surgery whose surgery was aborted due to a significant reduction or loss of IONM potentials. PATIENT SAMPLE: Sixty-six patients less than 18 years old who underwent spinal deformity surgery that was aborted due to IONM signal loss were enrolled into the study. OUTCOME MEASURES: IONM data, operative reports, and clinical examinations were investigated to determine the relationship between IONM loss, clinical examination, recovery of IONM signals, and clinical outcome. METHODS: Information regarding patient demographics, deformity type, clinical history, neurologic and ambulation status, operative details, IONM information (eg, quality of loss [SSEPs, MEPs], laterality, any recovery of signals, etc.), intraoperative wake-up test, postoperative neurologic exam, postoperative imaging, and time to return to the operating were all collected. All factors were analyzed and compared with univariate and multivariate analysis using appropriate statistical analysis. RESULTS: Sixty-six patients were enrolled with a median age of 13 years [IQR 11-14], and the most common sex was female (42/66, 63.6%). Most patients had idiopathic scoliosis (33/66, 50%). The most common causes of IONM loss were screw placement (27/66, 40.9%) followed by rod correction (19/66, 28.8%). All patients had either complete bilateral (39/66, 59.0%), partial bilateral (10/66, 15.2%) or unilateral (17/66, 25.8%) MEP loss leading to termination of the case. Overall, when patients were returned to the operating room 2 weeks postoperatively, nearly 75% (40/55) had monitorable IONM signals. Univariate analysis demonstrated that bilateral SSEP loss (p=.019), bilateral SSEP and MEP loss (p=.022) and delayed clinical neurologic recovery (p=.008) were significantly associated with having unmonitorable IONM signals at repeat surgery. Multivariate regression analysis demonstrated that delayed clinical neurologic recovery (> 72 hours) was significantly associated with unmonitorable IONM signals when returned to the operating room (p=.006). All patients ultimately made a full neurologic recovery. CONCLUSIONS: In children whose spinal deformity surgery was aborted due to intraoperative IONM loss, there was a strong correlation between combined intraoperative SSEP/MEP loss, the magnitude of IONM loss, the timing of clinical recovery, and the time of electrophysiological IONM recovery. The highest likelihood of having a prolonged postoperative neurological deficit and undetectable IONM signals upon return to the OR occurs with bilateral complete loss of SSEPs and MEPs.

Clinical Relevance of Painful Congenital Early-onset Scoliosis: A Magnetic Resonance Image-based Study.

BACKGROUND: Back pain, as a clinical marker in scoliosis, has been associated with underlying pathology for many years, warranting further magnetic resonance imaging (MRI). Failures of segmentation, mixed defects, female gender, rib anomalies, congenital thoracic anomalies, and neurocutaneous markers are known risk factors for abnormal MRI pathology findings in patients with congenital early-onset scoliosis (Congenital-EOS). Yet, back pain has not been evaluated as a risk factor for underlying MRI pathology in patients with Congenital-EOS. This study aimed to assess back pain as a risk factor for underlying pathology in Congenital-EOS using MRI as a diagnostic tool. METHODS: A retrospective database review from the Pediatric Spine Study Group (PSSG) of all patients with Congenital-EOS who reported a back pain complaint, and underwent a spinal MRI study before surgical intervention was performed. Patients were divided into those with an underlying MRI pathology and those without. Demographics were compared between groups. RESULTS: From a total of 2355 patients with Congenital-EOS registered in PSSG, 107 patients reported a back pain complaint, with only 42 patients fulfilling the inclusion criteria (being evaluated with an MRI study). Overall group mean age was 8.1±4.5 years, with 25 of the 42 patients (60%) being females. Twenty-four of 42 patients (57%) had a comorbidity reported such as cardiac problems, musculoskeletal complaints, neurological deficits/myelopathy, gastrointestinal symptoms, developmental delay, respiratory problems, craniofacial abnormalities, and chromosomal conditions. An underlying MRI pathology was found in 21 of 42 patients with Congenital-EOS (50%) with back pain. The underlying MRI pathologies found were tethered spinal cord, spinal canal stenosis, syringomyelia, Arnold-Chiari malformation, and arachnoid cyst. CONCLUSIONS: Abnormal MRI findings are common in patients with Congenital-EOS who report back pain. Gender, age, major coronal curve angle, thoracic or lumbar predominance deformity, and comorbidities type or amount were not associated with abnormal MRI findings. LEVEL OF EVIDENCE: Level II-Prognostic study.

Who gets staged surgery in severe pediatric and adolescent spine deformity?

BACKGROUND: There is significant debate regarding the indications of staged surgery for severe adolescent spinal deformity, and the factors associated with the decision to perform staged compared to same-day surgery have not been previously investigated. Thus, the purpose of this study was to determine which factors were most strongly associated with this decision. METHODS: A prospective multicenter registry of adolescent patients with severe spinal deformity was reviewed. Two cohorts were identified: those who underwent a planned staged surgical procedure for deformity correction and those who underwent a same-day procedure. Patients who underwent an unplanned staged procedure secondary to complications during the initial procedure were excluded. Comparisons were made between these cohorts with respect to preoperative patient and radiographic variables to determine which factors were associated with the decision to perform a staged procedure. Surgical data was also compared to evaluate for differences in the intraoperative management of staged versus same-day patients. RESULTS: Two hundred and twenty-nine patients with severe spinal deformities were identified. Forty patients (17%) underwent a planned staged procedure and 189 patients (80%) underwent a same-day procedure. On univariate analysis of preoperative variables, patients who underwent staged surgery had a significantly younger age at surgery, greater major curve magnitude, greater major curve AVT to CSVL, lesser thoracic spine height, greater radiographic trunk shift, and a greater proportion of patients undergoing revision surgery (as opposed to primary correction) compared to those who underwent a planned single-stage procedure. Multivariate logistic regression of pre-operative variables showed that age < 16 years, maximum cobb angle ≥ 120 degrees, major curve AVT to CSVL of ≥ 3.5 cm, and revision surgery were independently associated with the decision to perform a staged procedure. Intraoperatively, patients in the staged cohort more frequently underwent combined anterior and posterior procedures, grade 4 or higher Schwab osteotomies, and had a greater number of levels fused. CONCLUSION: There is substantial variability with respect to the decision to perform surgery for severe adolescent spine deformities in a staged versus same-day fashion. This large analysis of prospectively collected data is the first to describe the factors most strongly associated with the decision to perform a staged procedure and may help guide the surgical decision-making for these patients.

The Effect of Implant Density on Adolescent Idiopathic Scoliosis Fusion: Results of the Minimize Implants Maximize Outcomes Randomized Clinical Trial.

BACKGROUND: Severe adolescent idiopathic scoliosis (AIS) can be treated with instrumented fusion, but the number of anchors needed for optimal correction is controversial. METHODS: We conducted a multicenter, randomized study that included patients undergoing spinal fusion for single thoracic curves between 45° and 65°, the most common form of operatively treated AIS. Of the 211 patients randomized, 108 were assigned to a high-density screw pattern and 103, to a low-density screw pattern. Surgeons were instructed to use ≥1.8 implants per spinal level fused for patients in the high-implant-density group or ≤1.4 implants per spinal level fused for patients in the low-implant-density group. The primary outcome measure was the percent correction of the coronal curve at the 2-year follow-up. The power analysis for this trial required 174 patients to show equivalence, defined as a 95% confidence interval (CI) within a ±10% correction margin with a probability of 90%. RESULTS: In the intention-to-treat analysis, the mean percent correction of the coronal curve was equivalent between the high-density and low-density groups at the 2-year follow-up (67.6% versus 65.7%; difference, -1.9% [95% CI: -6.1%, 2.2%]). In the per-protocol cohorts, the mean percent correction of the coronal curve was also equivalent between the 2 groups at the 2-year follow-up (65.0% versus 66.1%; difference, 1.1% [95% CI: -3.0%, 5.2%]). A total of 6 patients in the low-density group and 5 patients in the high-density group required reoperation (p = 1.0). CONCLUSIONS: In the setting of spinal fusion for primary thoracic AIS curves between 45° and 65°, the percent coronal curve correction obtained with use of a low-implant-density construct and that obtained with use of a high-implant-density construct were equivalent. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Return to play following spine surgery.

Return to physical activity is a primary concern for adolescents with idiopathic scoliosis who are indicated for spinal fusion surgery. Preoperative counseling often addresses questions regarding ability to return to sport, postoperative restrictions, time away from play, and the safety of returning to activities. Previous works have shown that flexibility can noticeably decrease after surgery, and that the ability to return to the same level of play may be impacted by the levels of the spine included in the fusion. Equipoise remains on when patients should be allowed to return to non-contact, contact, and collision play; however, there is a trend toward earlier release to activities over the last few decades. Sources agree, though, that returning to play is safe, with rare instances of complications reported for patients with spinal fusion. Here, we review the literature on the function of spinal fusion levels on flexibility and biomechanics, address factors that may influence one's recovery of sports performance, and discuss safety considerations regarding return play following spine surgery.

Perioperative Complications and Health-related Quality of Life Outcomes in Severe Pediatric Spinal Deformity.

STUDY DESIGN: Prospective multicenter cohort study. OBJECTIVE: To evaluate perioperative complications and mid-term outcomes for severe pediatric spinal deformity. SUMMARY OF BACKGROUND DATA: Few studies have evaluated the impact of complications on health-related quality of life (HRQoL) outcomes in severe pediatric spinal deformity. METHODS: Patients from a prospective, multicenter database with severe pediatric spinal deformity (minimum of 100 degree curve in any plane or planned vertebral column resection (VCR)) with a minimum of 2-years follow-up were evaluated (n=231). SRS-22r scores were collected preoperatively and at 2-years postoperatively. Complications were categorized as intraoperative, early postoperative (within 90-days of surgery), major, or minor. Perioperative complication rate was evaluated between patients with and without VCR. Additionally, SRS-22r scores were compared between patients with and without complications. RESULTS: Perioperative complications occurred in 135 (58%) patients, and major complications occurred in 53 (23%) patients. Patients that underwent VCR had a higher incidence of early postoperative complications than patients without VCR (28.9% vs. 16.2%, P =0.02). Complications resolved in 126/135 (93.3%) patients with a mean time to resolution of 91.63 days. Unresolved major complications included motor deficit (n=4), spinal cord deficit (n=1), nerve root deficit (n=1), compartment syndrome (n=1), and motor weakness due to recurrent intradural tumor (n=1). Patients with complications, major complications, or multiple complications had equivalent postoperative SRS-22r scores. Patients with motor deficits had lower postoperative satisfaction subscore (4.32 vs. 4.51, P =0.03), but patients with resolved motor deficits had equivalent postoperative scores in all domains. Patients with unresolved complications had lower postoperative satisfaction subscore (3.94 vs. 4.47, P =0.03) and less postoperative improvement in self-image subscore (0.64 vs. 1.42, P =0.03) as compared to patients with resolved complications. CONCLUSION: Most perioperative complications for severe pediatric spinal deformity resolve within 2-years postoperatively and do not result in adverse HRQoL outcomes. However, patients with unresolved complications have decreased HRQoL outcomes.

Myelopathic Patients Undergoing Severe Pediatric Spinal Deformity Surgery Can Improve Neurologic Function to That of Non-Myelopathic Patients by 1-Year Postoperative.

STUDY DESIGN: Multi-center, prospective, observational cohort. OBJECTIVE: To compare myelopathic vs. non-myelopathic ambulatory patients in short- and long-term neurologic function, operative treatment, and patient-reported outcomes. METHODS: Pediatric deformity patients from 16 centers were enrolled with the following inclusion criteria: aged 10-21 years-old, a Cobb angle ≥100° in either the coronal or sagittal plane or any sized deformity with a planned 3-column osteotomy, and community ambulators. Patients were dichotomized into 2 groups: myelopathic (abnormal preoperative neurologic exam with signs/symptoms of myelopathy) and non-myelopathic (no clinical signs/symptoms of myelopathy). RESULTS: Of 311 patients with an average age of 14.7 ± 2.8 years, 29 (9.3%) were myelopathic and 282 (90.7%) were non-myelopathic. There was no difference in age (P = 0.18), gender (P = 0.09), and Risser Stage (P = 0.06), while more patients in the non-myelopathic group had previous surgery (16.1% vs. 3.9%; P = 0.03). Mean lower extremity motor score (LEMS) in myelopathic patients increased significantly compared to baseline at every postoperative visit: Baseline: 40.7 ± 9.9; Immediate postop: 46.0 ± 7.1, P = 0.02; 1-year: 48.2 ± 3.7, P < 0.001; 2-year: 48.2 ± 7.7, P < 0.001). The non-myelopathic group had significantly higher LEMS immediately postoperative (P = 0.0007), but by 1-year postoperative, there was no difference in LEMS between groups (non-myelopathic: 49.3 ± 3.6, myelopathic: 48.2 ± 3.7, P = 0.10) and was maintained at 2-years postoperative (non-myelopathic: 49.2 ± 3.3, myelopathic: 48.2 ± 5.7, P = 0.09). Both groups improved significantly in all SRS domains compared to preoperative, with no difference in scores in the domains for pain (P = 0.12), self-image (P = 0.08), and satisfaction (P = 0.83) at latest follow-up. CONCLUSION: In severe spinal deformity pediatric patients presenting with preoperative myelopathy undergoing spinal reconstructive surgery, myelopathic patients can expect significant improvement in neurologic function postoperatively. At 1-year and 2-year postoperative, neurologic function was no different between groups. While non-myelopathic patients had significantly higher postoperative outcomes in SRS mental-health, function, and total-score, both groups had significantly improved outcomes in every SRS domain compared to preoperative.

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.

Posterior-only Resection of Single Hemivertebrae With 2-Level Versus >2-Level Fusion: Can We Improve Outcomes?

BACKGROUND: The outcomes of congenital scoliosis (CS) patients undergoing hemivertebra (HV) resection surgery with a 2-level fusion versus a >2-level fusion are unclear. We hypothesized that CS patients undergoing HV resection and a >2-level fusion have decreased curve progression and reoperation rates compared with 2-level fusions. METHODS: Retrospective review of prospectively collected data from a multicenter scoliosis database. Fifty-three CS patients (average age 4.5, range 1.2 to 10.9 y) at index surgery were included. Radiographic and surgical parameters, complications, as well as revision surgery rates were tracked at a minimum of 2-year follow-up. RESULTS: Twenty-six patients had a 2-level fusion while 27 patients had a >2-level fusion with similar age and body mass index between groups. The HV was located in the lumbar spine for 69% (18/26) 2-level fusions and 30% (8/27) >2-level fusions ( P =0.006). Segmental HV scoliosis curve was smaller in 2-level fusions compared to >2-level fusions preoperatively (38 vs. 50 degrees, P =0.016) and at follow-up (25 vs. 34 degrees, P =0.038). Preoperative T2-T12 (28 vs. 41 degrees, P =0.013) and segmental kyphosis (11 vs. 23 degrees, P =0.046) were smaller in 2-level fusions, but did not differ significantly at postoperative follow-up (32 vs. 39 degrees, P =0.22; 13 vs. 11 degrees, P =0.64, respectively). Furthermore, the 2 groups did not significantly differ in terms of surgical complications (27% vs. 22%, P =0.69; 2-level fusion vs. >2-level fusion, respectively), unplanned revision surgery rate (23% vs. 22%, 0.94), growing rod placement or extension of spinal fusion (15% vs. 15%, P =0.95), or health-related quality of life per the EOS-Questionnaire 24 (EOSQ-24). Comparison of patients with or without the need for growing rod placement or posterior spinal fusion revealed no significant differences in all parameters analyzed. CONCLUSIONS: Two-level and >2-level fusions can control congenital curves successfully. No differences existed in curve correction, proximal junctional kyphosis or complications between short and long-level fusion after HV resection. Both short and long level fusions are viable options and generate similar risk of revision. The decision should be individualized by patient and surgeon.

Navigation Options for Spinal Surgeons: State of the Art 2021.

The use of navigation in spinal surgery has been increasing over the past decade. There are three primary types of navigation in spinal surgery: three-dimensional image-based computer-assisted navigation, robot-assisted navigation, and three-dimensional printed patient-specific drill guides for navigation. All three have demonstrated increased accuracy in placement of spinal instrumentation versus freehand or fluoroscopic-assisted techniques. Each has unique preoperative and intraoperative technical considerations. All three typically rely on three-dimensional imaging and will have varied radiation exposure to the patient and surgical staff based on specific imaging settings used. Navigation options are continually improving and are expected to broaden efficiency, accuracy, and indications in the future.

Mortality in Early-Onset Scoliosis During the Growth-friendly Surgery Era.

INTRODUCTION: Early-onset scoliosis (EOS) is a spinal deformity that occurs in patients 9 years of age or younger. Severe deformity may result in thoracic insufficiency, respiratory failure, and premature death. The purpose of this study is to describe the modern-day natural history of mortality in patients with EOS. METHODS: The multicenter Pediatric Spine Study Group database was queried for all patients with EOS who are deceased, without exclusion. Demographics, underlying diagnoses, EOS etiology, operative and nonoperative treatments or observation, complications, and date of death were retrieved. Descriptive statistics and survival analysis with Kaplan-Meier curves were performed. RESULTS: There were 130/8009 patients identified as deceased for a registry mortality rate of 16 per 1000 patients. The mean age at death was 10.6 years (range: 1.0 to 30.2 y) and the most common EOS etiology was neuromuscular (73/130, 56.2%; P<0.001). Deceased patients were more likely be treated operatively than nonoperatively or observed (P<0.001). The mean age of death for patients treated operatively (12.3 y) was older than those treated nonoperatively (7.0 y) or observed (6.3 y) (P<0.001) despite a larger deformity and similar index visit body mass index and ventilation requirements. Kaplan-Meier analysis confirmed an increased survival time in patients with a history of any spine operation compared with patients without a history of spine operation (P<0.0001). Operatively treated patients experienced a median of 3.0 complications from diagnosis to death. Overall, cardiopulmonary related complications were the most common (129/271, 47.6%; P<0.001), followed by implant-related (57/271, 21.0%) and wound-related (26/271, 9.6%). The primary cause of death was identified for 78/130 (60.0%) patients, of which 57/78 (73.1%) were cardiopulmonary related. CONCLUSIONS: This study represents the largest collection of EOS mortality to date, providing surgeons with a modern-day examination of the effects of surgical intervention to better council patients and families. Both fatal and nonfatal complications in children with EOS are most likely to involve the cardiopulmonary system. LEVEL OF EVIDENCE: Level IV-therapeutic.

Uncorrected Pelvic Obliquity Is Associated With Worse Health-related Quality of Life (HRQoL) in Children and Their Caregivers at the End of Surgical Treatment for Early Onset Scoliosis (EOS).

BACKGROUND: While largely of concern in nonambulatory patients, pelvic obliquity (PO) can be found in many patients with early onset scoliosis (EOS) and may remain following surgery. However, its association with health-related quality of life (HRQoL) in children and their caregivers at the end of treatment is not well understood. The purpose of this study was to investigate the association between residual PO and HRQoL in children and their caregivers at the end of surgical treatment in ambulatory patients with EOS. METHODS: In this retrospective cohort study, a multicenter EOS registry was queried to identify ambulatory patients who underwent definitive posterior spinal fusion (PSF) from 2012 to 2019. Patients with fusions extending to the pelvis were excluded. PO was measured at least 1 year following PSF. HRQoL, Parental Burden, Financial Burden, and Satisfaction were assessed through the 24-Item Early Onset Scoliosis Questionnaire (EOSQ-24) also at a minimum of 1 year following PSF. RESULTS: A total of 155 patients (12.5±2.1 y, 73.5% female) were included. Etiology distribution was 30.3% congenital, 12.9% neuromuscular, 21.3% syndromic, and 35.5% idiopathic. In congenital patients, those with residual PO >8 degrees had worse Satisfaction by 23.2 points compared with those with PO ≤8 degrees. In neuromuscular patients, those with residual PO >7 degrees had worse HRQoL by 16.1 points and Parental Burden by 22.3 points compared with their counterparts. In syndromic patients, those with residual PO >8 degrees had worse HRQoL by 14.8 points, Parental Burden by 16.4 points, and Satisfaction by 21.2 points compared with their counterparts. In idiopathic patients, those with >9 degrees of residual PO had worse HRQoL by 15.0 points and Financial Burden by 26.8 points compared with their counterparts. CONCLUSIONS: Remaining PO at the end of surgical treatment is associated with worse HRQoL in ambulatory children and their caregivers. These results suggest that correction of PO should remain a primary goal of treatment in patients with EOS undergoing surgery. LEVEL OF EVIDENCE: Level II-multicenter retrospective cohort study investigating prognosis.

0.4% incidence of return to OR due to screw malposition in a large prospective adolescent idiopathic scoliosis database.

PURPOSE: In contrast to infection and curve progression, return to OR for implant malposition is potentially within the surgeon's control. With increasing surgeon familiarity with freehand/fluoroscopic pedicle screw placement, rates of return to OR due to malposition may have decreased over time. We sought to document the incidence and risk factors for return to OR due to screw malposition in a large cohort of patients with idiopathic scoliosis. METHODS: AIS patients enrolled in a multicenter prospective registry with minimum 2-year follow-up undergoing PSF between 2003 and 2017 were included. Surgeries with the use of intraoperative CT-guided navigation were excluded. Return to OR due to screw malposition over time was tabulated. Lenke class, age at surgery, year of surgery, height, weight, surgeon and site were evaluated. RESULTS: 2435 patients underwent PSF with non-navigated open pedicle screw instrumentation. Mean age was 14.6 years, mean thoracic curve magnitude was 53°, and mean lumbar was 40°. Patients did not routinely undergo intraoperative or postoperative CT evaluation. There were 10 returns to OR for screw malposition at a mean of 0.83 years postoperatively (range 0.1-3.4 years), for an overall incidence of 0.4%. Of the 14 screws, 10 were thoracic, 7 were left-sided. No association was found between screw malposition and curve size, enrolling site, surgeon, BMI, Lenke class, or age. Five patients had radiculopathy which improved after screw revision. Return to OR for screw malposition changed from 2003 to 2017 (1-0.2%) but this did not reach statistical significance. CONCLUSION: Although the incidence of asymptomatic malpositioned screws is unknown, the rate of return to the OR for implant malposition overall in this registry was 1 in 250 patients. Recent data suggest the rate has decreased to 1 in 500 patients. Further work may determine whether enabling technologies can reduce the rate, ideally to a "never event".

Ultrasonic Bone Scalpel (USBS) Does Not Reduce Blood Loss During Posterior Spinal Fusion (PSF) in Patients with Adolescent Idiopathic Scoliosis (AIS): Randomized Clinical Trial.

STUDY DESIGN: Randomized Clinical Trial. OBJECTIVE: The aim of this study was to compare the efficacy of USBS with standard-of-care surgical instruments during posterior spinal fusion (PSF) in patients with adolescent idiopathic scoliosis (AIS) by evaluating the difference in estimated blood loss per level fused (EBL/level). SUMMARY OF BACKGROUND DATA: PSF surgery for AIS is often associated with high blood loss. Use of an ultrasonic bone scalpel (USBS) has been proposed to reduce blood loss during scoliosis surgery. METHODS: This was a single-blinded (patient-blinded), randomized, controlled superiority trial. We randomized 66 patients with AIS undergoing PSF to the control group (osteotome) or the experimental group (USBS). The primary outcome was intraoperative EBL/level obtained from red blood cell salvage reports. One-year follow-up was available for 57 of 62 (92%) of patients. RESULTS: EBL/level averaged 35 and 39 mL/level in the experimental and control groups, respectively [adjusted mean difference USBS - osteotome -8 mL/level, 95% CI: -16.4 to 0.3 mL/level, P = 0.0575]. There was no difference in curve correction [adjusted mean difference: -1.7%, 95% CI: -7.0 to 3.6%, P = 0.5321] or operative time [adjusted mean difference: -3.55 minutes, 95% CI: -22.45 to 15.46 min, P = 0.7089] between groups. Complications requiring change in routine postoperative care were noted in eight patients: two occurred in patients assigned to the experimental group and six occurred in patients assigned to the control group. CONCLUSION: There was no clinically significant difference in total blood loss, EBL/level, or complications between the two groups. In contrast to reports from other centers, at our high-volume spine center, USBS did not lead to reduced blood loss during PSF for AIS. These results may not be generalizable to centers with longer baseline operative times or higher baseline average blood loss during PSF for AIS.Level of Evidence: 1.

When Should Instrumentation to the Pelvis be Considered in Minimally Ambulatory Adolescents With Neuromuscular Scoliosis?

INTRODUCTION: The goal of neuromuscular scoliosis (NMS) surgery is to improve sitting balance, facilitate daily care, and alleviate pain. In nonambulatory patients, where sitting balance is key, fusion to the pelvis is usually required. However, in minimally ambulatory patients, fusion to the pelvis remains controversial, and there is considerable practice variability in this patient population. The purpose of this study is to evaluate and summarize the available evidence regarding fusion constructs in minimally ambulatory patients with NMS and to provide expert opinion regarding when fusion to the pelvis should be considered. METHODS: A search of the English literature was performed using PubMed to identify papers pertaining to patients with NMS treated with instrumented posterior spinal fusion. Papers published before 2000, case reports, and level V evidence were excluded. RESULTS: The authors identified 8 studies for review. The majority included both nonambulatory and minimally ambulatory patients. Structured review of the literature demonstrated fusion to the pelvis may allow for greater curve and pelvic obliquity correction, but it is also associated with increased blood loss and operative time. There is no evidence that fusing to the pelvis decreases ambulatory status in minimally ambulatory patients. CONCLUSIONS: In minimally ambulatory patients with NMS, fusion short of the pelvis may be considered in patients with adequate head control without the presence of hip subluxation or dislocation and when pelvic obliquity is <15 degrees. Fusion to the pelvis is recommended in patients who do not meet these criteria.

Growth-friendly surgery results in more growth but a higher complication rate and unplanned returns to the operating room compared to single fusion in neuromuscular early-onset scoliosis: a multicenter retrospective cohort study.

PURPOSE: Compare radiographic outcomes, complications, and QoL in neuromuscular early-onset scoliosis (EOS) patients treated with single posterior spinal fusion (PSF) versus growth-friendly surgery and definitive fusion (GFDF). METHODS: In a retrospective cohort study, children with neuromuscular EOS, age 8-11 years at index surgery with PSF or GF devices, with minimum 2-year follow-up after final fusion were identified from a multicenter database. RESULTS: 16 PSF and 43 GFDF patients were analyzed. Demographics were similar except PSF patients were older at index surgery and had shorter follow-up. PSF patients had greater percentage major curve correction (62% vs 38%, p = 0.001) and smaller major curve at final follow-up (23° vs 40°, p = 0.005). The GFDF group underwent over five times more surgeries (8.7 vs 1.6, p = 0.0001). Four PSF patients (25%) experienced ten complications, resulting in five unplanned returns to the operating room (UPROR) in three patients (19%). 36 GFDF patients (84%) experienced 83 complications, resulting in 45 UPRORs in 24 patients (56%). Poisson regression adjusted for age showed that the GFDF group had more complications (p = 0.001) and UPRORs (p = 0.01). Although the GFDF patients had smaller preoperative T1-T12 and T1-S1 lengths, these were similar to the PSF patients at final follow-up, indicating that the GFDF patients had greater spinal growth. PSF patients had better postoperative EOSQ-24 Financial Impact and Family Burden scores. CONCLUSION: While there was a difference in age at index surgery, PSF may be more effective than GFDF at controlling neuromuscular EOS. GFDF patients achieved more spinal growth but eight times more complications and nine times more UPRORs.

Willingness to enroll in a surgical randomized controlled trial: patient and parent preferences regarding implant density for adolescent idiopathic scoliosis fusion.

STUDY DESIGN: Prospective survey of adolescent idiopathic scoliosis (AIS) patients/parents with surgical magnitude curves. OBJECTIVE: We hypothesized that patients and families considering fusion surgery would be willing to enroll in a randomized controlled trial (RCT) evaluating the effect of number of implants on curve correction. Surgical RCTs are infrequently performed, particularly in a pediatric population. Parental willingness to enroll affects both study design and trial feasibility. The Minimize Implants Maximize Outcomes (MIMO) Clinical Trial proposes to randomize patients to more versus fewer screws (high or low density) for Lenke 1A curve patterns, but it is unclear whether families and patients are willing to enroll in such a trial. METHODS: This study was undertaken at 4 of the 14 sites participating in the MIMO Clinical Trial. AIS patients with Cobb > 45° were included. Implant density is defined as screws per level fused. Patients and families reviewed the MIMO education module describing proposed advantages and disadvantages of high (> 1.8) vs. low (< 1.4) density screw constructs and completed a custom survey regarding their preferences about the trial. RESULTS: 159 individuals were surveyed (78 families), including 82 parents/guardians, and 77 patients. Of those surveyed, 95% mostly or completely understood the trial (range 47-78%), and 63% agreed to enroll. Parents and patients who completely understood the trial were significantly more likely to enroll. CONCLUSION: Randomization in the MIMO Trial was acceptable to the majority (63%) of patients and parents. Clear patient and parent education materials and access to the surgeon may facilitate enrollment in the trial. Parents afforded the child much autonomy when considering enrollment, although most families agree both child and parent should be in agreement before entering the trial. LEVEL OF EVIDENCE: II.

Awake serial body casting for the management of infantile idiopathic scoliosis: is general anesthesia necessary?

STUDY DESIGN: It is a retrospective cohort study. OBJECTIVES: To compare the radiographic and clinical outcomes of serial body casting for infantile idiopathic scoliosis (IIS) with versus without the use of general anesthesia (GA). Serial body casting for IIS has traditionally been performed under GA. However, reports of neurotoxic effects of anesthetics in young children have prompted physicians to consider instead performing these procedures while patients are awake and distracted by electronic devices. METHODS: Patients from a multicenter registry who underwent serial casting for IIS were included. The patients were divided into asleep (GA) and awake (no GA) cohorts. Comparisons were made between pre-casting, first in-cast, and post-casting radiographic measures in each cohort. The rates of successful casting (≥ 10° major CA improvement), curve progression, and incidence of casting abandonment for surgical intervention were also compared. RESULTS: One-hundred and twenty-one patients who underwent serial casting for IIS were included. Ninety-two (76%) patients were asleep during casting procedures, while 29 (24%) were awake. Patients in the awake cohort were older (p < 0.01), had a lower BMI (p = 0.03), and more severe curve magnitudes (p < 0.01) at baseline. Patients in the awake cohort experienced greater first-in-cast correction of the major curve (p = 0.01) and improvement in thoracic spine height (p < 0.01). The rate of casting success was higher in the awake cohort (72%) as compared to the asleep cohort (48%) (p = 0.02), although the rate of curve progression (worsening) was similar (p = 0.880). Lastly, there was a lower rate of conversion to surgery at 2 years post-initiation of casting, although this was not statistically significant (0% vs. 8%; p = 0.126). CONCLUSIONS: Patients who underwent awake serial casting had similar radiographic outcomes as compared to those who were under general anesthesia during the procedures. Thus, awake casting may provide a safe and effective alternative to the use of general anesthesia in patients with idiopathic infantile scoliosis. LEVEL OF EVIDENCE: III.

40% reoperation rate in adolescents with spondylolisthesis.

STUDY DESIGN: Multicenter retrospective. OBJECTIVE: To determine the long-term complication rate associated with surgical treatment of spondylolisthesis in adolescents. There is limited information on the complication rate associated with posterior spinal fusion (PSF) of spondylolisthesis in the pediatric and adolescent population. METHODS: Patients who underwent PSF for spondylolisthesis between 2004 and 2015 at four spine centers, < 21 years of age, were included. Exclusion criteria were < 2 years of follow-up or anterior approach. Charts and radiographs were reviewed. RESULTS: 50 patients had PSF for spondylolisthesis, 26 had PSF alone, while 24 had PSF with trans-foraminal lumbar interbody fusion (TLIF). Mean age was 13.9 years (range 9.6-18.4). Mean follow-up was 5.5 years (range 2-15). Mean preoperative slip was 61.2%. 20/50 patients (40%) experienced 23 complications requiring reoperation at a mean of 2.1 years (range 0-9.3) for the following: implant failure (12), persistent radiculopathy (3), infection (3), persistent back pain (2), extension of fusion (2), and hematoma (1). In addition, there were 22 cases of radiculopathy (44%) that were transient. Rate of implant failure was related to preoperative slip angle (p = 0.02). Reoperation rate and rates of implant failure were not associated with preoperative % slip (reoperation: p = 0.42, implant failure: p = 0.15), postoperative % slip (reoperation: p = 0.42, implant failure: p = 0.99), postoperative kyphosis of the lumbosacral angle (reoperation: p = 0.81, implant failure: p = 0.48), change in % slip (reoperation: p = 0.30, implant failure: p = 0.12), change in slip angle (reoperation: p = 0.42, implant failure: p = 0.40), graft used (reoperation: p = 0.22, implant failure: p = 0.81), or addition of a TLIF (reoperation: p = 0.55, implant failure: p = 0.76). CONCLUSION: PSF of spondylolisthesis in the adolescent population was associated with a 40% reoperation rate and high rate of post-operative radiculopathy. Addition of a TLIF did not impact reoperation rate or rate of radiculopathy.

Serial Casting in Neuromuscular and Syndromic Early-onset Scoliosis (EOS) Can Delay Surgery Over 2 Years.

BACKGROUND: The primary goal in managing early-onset scoliosis (EOS) is delaying/preventing surgical intervention while allowing improved spinal growth and chest wall and lung development to improve life expectancy. The effectiveness of serial casting for patients with neuromuscular and syndromic EOS is unclear. METHODS: Patients from 2 multicenter registries who underwent serial casting for nonidiopathic scoliosis (NIS) were reviewed retrospectively. Comparisons were made between precasting and postcasting major and compensatory curves and spine height. The need for surgical intervention and any treatment complications were documented. Risk factors for major curve progression from baseline to casting cessation were evaluated via univariate analysis. RESULTS: Forty-four patients (23 females; 21 males) with NIS (26 syndromic, 18 neuromuscular) and a mean age of 3.2 years at baseline were included. Mean follow-up and casting duration was 3.9 and 2.0 years, respectively. There were no statistically significant differences between mean precasting and postcasting major curve (55 vs. 60 degrees; P=0.348), minor curve (31 vs. 33 degrees; P=0.510), or rib-vertebra angle difference (18 vs. 29 degrees; P=0.840). However, thoracic height (15.5 vs. 16.8 cm; P=0.031) and lumbar height (8.9 vs. 9.8 cm; P=0.013) were significantly greater upon casting cessation. Currently, 13 patients (30%) have had successful casting (improvement of major curve ≥10 degrees) while 24 patients (55%) experienced major curve progression (worsening), and 19 patients (43%) required surgical intervention. Mean time from first casting to surgery was 34.5±15.1 months. There were no statistically significant predictors for major curve progression on univariate analysis. CONCLUSIONS: Spinal deformity progression despite casting and the subsequent need for surgical intervention for NIS were significantly higher compared with those reported for idiopathic EOS. However, serial casting did afford a substantial delay in surgical intervention. Ultimately, serial casting for neuromuscular or syndromic EOS is an effective strategy for delaying surgical intervention, despite suboptimal radiographic outcomes. LEVEL OF EVIDENCE: Level III.