Improvement in axial rotation with bracing reduces the risk of curve progression in patients with adolescent idiopathic scoliosis.

PURPOSE: New evidence highlights the significance of 3D in-brace correction for Adolescent Idiopathic Scoliosis (AIS) patients. This study explores how axial parameters relate to treatment failure in braced AIS patients. METHODS: AIS patients (Sanders 1-5) undergoing Rigo-Chêneau bracing at a single institution were included. Axial vertebral rotation (AVR) was determined by utilizing pre-brace and in-brace 3D reconstructions from EOS® radiographs. The primary outcome was treatment failure: surgery or coronal curve progression > 5°. Minimum follow-up was two years. RESULTS: 75 patients (81% female) were included. Mean age at bracing initiation was 12.8 ± 1.3 years and patients had a pre-brace major curve of 31.0° ± 6.5°. 25 patients (76% female) experienced curve progression > 5°, and 18/25 required surgical intervention. The treatment failure group had larger in-brace AVR than the success group (5.8° ± 4.1° vs. 9.9° ± 7.6°, p = 0.003), but also larger initial coronal curve measures. In-brace AVR did not appear to be associated with treatment failure after adjusting for the pre-brace major curve (Hazard Ratio (HR):0.99, 95% Confidence Interval (CI):0.94-1.05, p = 0.833). Adjusting for pre-brace major curve, patients with AVR improvement with bracing had an 85% risk reduction in treatment failure versus those without (HR:0.15, 95% CI:0.02-1.13, p = 0.066). At the final follow-up, 42/50 (84%) patients without progression had Sanders ≥ 7. CONCLUSIONS: While in-brace rotation was not an independent predictor of curve progression (due to its correlation with curve magnitude), improved AVR with bracing was a significant predictor of curve progression. This study is the first step toward investigating the interplay between 3D parameters, skeletal maturity, compliance, and brace efficacy, allowing a future prospective multicenter study. LEVEL OF EVIDENCE: Retrospective study; Level III.

Utilizing a comprehensive machine learning approach to identify patients at high risk for extended length of stay following spinal deformity surgery in pediatric patients with early onset scoliosis.

PURPOSE: Early onset scoliosis (EOS) patient diversity makes outcome prediction challenging. Machine learning offers an innovative approach to analyze patient data and predict results, including LOS in pediatric spinal deformity surgery. METHODS: Children under 10 with EOS were chosen from the American College of Surgeon's NSQIP database. Extended LOS, defined as over 5 days, was predicted using feature selection and machine learning in Python. The best model, determined by the area under the curve (AUC), was optimized and used to create a risk calculator for prolonged LOS. RESULTS: The study included 1587 patients, mostly young (average age: 6.94 ± 2.58 years), with 33.1% experiencing prolonged LOS (n = 526). Most patients were female (59.2%, n = 940), with an average BMI of 17.0 ± 8.7. Factors influencing LOS were operative time, age, BMI, ASA class, levels operated on, etiology, nutritional support, pulmonary and neurologic comorbidities. The gradient boosting model performed best with a test accuracy of 0.723, AUC of 0.630, and a Brier score of 0.189, leading to a patient-specific risk calculator for prolonged LOS. CONCLUSIONS: Machine learning algorithms accurately predict extended LOS across a national patient cohort and characterize key preoperative drivers of increased LOS after PSIF in pediatric patients with EOS.

Preoperative Echocardiogram Does Not Contribute to Surgical Risk Assessment in Patients With Large Curve Scoliosis and No Cardiac Risk Factors.

OBJECTIVE: Severe scoliosis can affect thoracic organs, potentially leading to cardiovascular abnormalities. Thus, echocardiograms have been suggested for use in preoperative screening in patients with significant scoliosis. However, the utility of preoperative heart screenings in patients without known or suspected heart problems is not well understood. This study aims to find the incidence of cardiac findings in patients with severe scoliosis ≥90° without cardiac history. METHODS: A single-institution retrospective chart review was performed. Inclusion criteria were scoliosis patients with curves ≥90 degrees and a screening echocardiogram performed within 6 months of spine surgery. Patients with a previous cardiac history, diagnosis associated with cardiac comorbidities (eg, connective tissue disease), or major coronal curves <90 degrees were excluded. Echocardiogram reports and perioperative clinical notes from involved services (including orthopaedics, cardiology, and anesthesia) were reviewed. Any postoperative use of vasopressors and reasons for their use were recorded. RESULTS: Overall, 50 patients met the inclusion criteria. The mean age at surgery was 14.0 ± 4.9 years old (range: 2 to 33). The mean major curve was 108 ± 19 degrees (range: 90 to 160 degrees). A normal echocardiogram was seen in 38 (76%), whereas 6 patients (12%) had mild dilation of the aortic sinus or root, 4 (8%) had mild valvular regurgitation, 1 patient had a small atrial septal defect, and 1 had a trace pericardial effusion. No patient had any changes made to their perioperative plan and one patient was advised to see a cardiologist postoperatively. Postoperatively, 8 patients (16%) received vasopressors to raise blood pressure to meet preset goal MAP, but only one of these 8 had a positive echocardiogram (mild valvular insufficiency), which was not seen as a contributing factor to the use of pressors. CONCLUSIONS: This study suggests that screening echocardiograms for patients without a cardiac history or related symptoms does not contribute to the evaluation of perioperative risk or anesthetic management. Creating clear, evidence-based guidelines for the utilization of perioperative testing, like echocardiograms, can reduce the social, time, and financial burdens on families. Such guidelines are vital for appropriate risk assessment and proper utilization of health care resources. LEVEL OF EVIDENCE: Level III.

Sagittal spinopelvic alignment in ambulatory persons with cerebral palsy.

PURPOSE: This study aimed to describe the spinopelvic alignment of a cohort of young ambulatory individuals with cerebral palsy (CP) and compare it to published spinopelvic alignment data for the typically developing adolescents. METHODS: Thirty-seven adolescents (18 females) with CP at GMFCS I-III were included in this retrospective case series. Lumbar lordosis and pelvic incidence were measured, and their mismatch was calculated. A model that calculates predicted lumbar lordosis based on pelvic incidence in normative data was utilized to calculate a predicted lumbar lordosis in this cohort with cerebral palsy. RESULTS: At imaging, ages were mean and standard deviation 13.5 ± 3.0 years. Pelvic incidence was 46.2° ± 12.9°, pelvic tilt was 2.8° ± 9.4°, sacral slope was 43.6° ± 10.8°, and measured lumbar lordosis was 59.4° ± 11.6°. There were no differences in pelvic incidence or lumbar lordosis among the GMFCS levels; however, pelvic incidence was higher in females. Pelvic incidence-lumbar lordosis mismatch greater than 10° was found in 67% of the cohort. Mean predicted lumbar lordosis based on the model was 54.7° ± 8.5°, averaging 8° less than measured lordosis. CONCLUSION: PI-LL mismatch was identified in 67% of this cohort of ambulatory adolescents with CP, in part due to greater lordosis than predicted by a model based on data from adolescents without CP. The implications of this finding, such as the correlation between sagittal spinopelvic alignment and quality of life in this population, should be assessed further in ambulatory patients with cerebral palsy. LEVEL OF EVIDENCE: Level IV-retrospective cohort study and literature comparison.

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.

Evaluating compliance with the best practice guidelines for wrong-level surgery prevention in high-risk pediatric spine surgery.

PURPOSE: In 2018, Best Practice Guidelines (BPGs) were published for preventing wrong-level surgery in pediatric spinal deformity, but successful implementation has not been established. The purpose of this study was to evaluate BPG compliance 5 years after publication. We hypothesized higher compliance among BPG authors and among surgeons with more experience, higher caseload, and awareness of the BPGs. METHODS: We queried North American and European surgeons, authors and nonauthors, and members of pediatric spinal study groups on adherence to BPGs using an anonymous survey consisting of 18 Likert scale questions. Respondents provided years in practice, yearly caseload, and guideline awareness. Mean compliance scores (MCS) were developed by correlating Likert responses with MCS scores ("None of the time" = no compliance = MCS 0, "Sometimes" = weak to moderate = MCS 1, "Most of the time" = high = MCS 2, and "All the time" = perfect = MCS 3). RESULTS: Of the 134 respondents, 81.5% reported high or perfect compliance. Average MCS for all guidelines was 2.4 ± 0.4. North American and European surgeons showed no compliance differences (2.4 vs. 2.3, p = 0.07). Authors and nonauthors showed significantly different compliance scores (2.8 vs 2.4, p < 0.001), as did surgeons with and without knowledge of the BPGs (2.5 vs 2.2, p < 0.001). BPG awareness and compliance showed a moderate positive correlation (r = 0.48, p < 0.001), with non-significant associations between compliance and both years in practice (r = 0.41, p = 0.64) and yearly caseload (r = 0.02, p = 0.87). CONCLUSION: Surgeons reported high or perfect compliance 81.5% of the time with BPGs for preventing wrong-level surgery. Authorship and BPG awareness showed increased compliance. Location, study group membership, years in practice, and yearly caseload did not affect compliance. LEVEL OF EVIDENCE: Level V-expert opinion.

Lowest instrumented vertebrae in early onset scoliosis: is there a role for a more selective approach?

PURPOSE: This purpose of this study was to assess the impact of patient and implant characteristics on LIV selection in ambulatory children with EOS and to assess the relationship between the touched vertebrae (TV), the last substantially touched vertebrae (LSTV), the stable vertebrae (SV), the sagittal stable vertebrae (SSV), and the LIV. METHODS: A multicenter pediatric spine database was queried for patients ages 2-10 years treated by growth friendly instrumentation with at least 2-year follow up. The relationship between the LIV and preoperative spinal height, curve magnitude, and implant type were assessed. The relationships between the TV, LSTV, SV, SSV, and the LIV were also evaluated. RESULTS: Overall, 281 patients met inclusion criteria. The LIV was at L3 or below in most patients with a lumbar LIV: L1 (9.2%), L2 (20.2%), L3 (40.9%), L4 (29.5%). Smaller T1 - T12 length was associated with more caudal LIV selection (p = 0.001). Larger curve magnitudes were similarly associated with more caudal LIV selection (p = < 0.0001). Implant type was not associated with LIV selection (p = 0.32) including MCGR actuator length (p = 0.829). The LIV was caudal to the TV in 78% of patients with a TV at L2 or above compared to only 17% of patients with a TV at L3 or below (p < 0.0001). CONCLUSIONS: Most EOS patients have an LIV of L3 or below and display TV-LIV and LSTV-LIV incongruence. These findings suggest that at the end of treatment, EOS patients rarely have the potential for selective thoracic fusion. Further work is necessary to assess the potential for a more selective approach to LIV selection in EOS. LEVEL OF EVIDENCE: III.

A New Look at Vertebral Body Tethering (VBT): Through the Modified Clavien-Dindo-Sink (mCDS) Classification.

INTRODUCTION: Anterior vertebral body tethering (AVBT) is increasingly popular as an option for surgical treatment of idiopathic scoliosis (IS). While the technology remains new, it is important for families and patients to be able to compare it to the current standard of care, posterior spinal fusion (PSF). The purpose of this study is to describe the complication rate of AVBT in IS using the mCDS and to compare it to the recently reported complication rate of PSF in IS. METHODS: A multicenter pediatric spine deformity database was queried for all idiopathic scoliosis patients who underwent vertebral body tethering. There were 171 patients with a minimum 9-month follow-up included in this study. Complications were retrospectively graded by 2 attending pediatric spine surgeons using the mCDS classification system. RESULTS: Data from 171 patients with idiopathic scoliosis was available for analysis, with 156/171 (91%) of patients being female and an average age of 12.2 years old at surgery. There were 156 thoracic tethers (1 with an LIV below L2), 5 lumbar tethers, 9 staged double tethers, and only 1 patient with same-day double tether. Fifty-five (55) (32%) patients experienced a total of 69 complications. The most common complication type for VBT by mCDS was Grade IIIb, encompassing 29/69 (42%) of complications. The second most frequent complication grade was Grade I at 23/69 (33%). Thirty-four (34) out of 69 (49%) of the VBT complications reported required either procedural/surgical intervention or admission to the ICU. CONCLUSIONS: This is the first study to directly compare the complication profile of VBT to PSF using the mCDS. Forty-nine percent (49%) of the VBT complications reported were at least Grade III, while only 7% of complications in the control PSF cohort from the literature were Grade III or higher. The mCDS complication classification brings light to the early learning experience of a new technique compared to the widely accepted standard of PSF for IS. LEVEL OF EVIDENCE: III - Retrospective comparative study.

Institutional Variability in Anesthesia Time for Mehta Casting in Early-Onset Scoliosis (EOS).

PURPOSE: Mehta casting is a potentially curative intervention for early-onset scoliosis (EOS) that typically requires multiple anesthetics. The Food and Drug Administration (FDA) reported that >3 hours of anesthesia under the age of 3 years old may alter brain development; however, no standard exists for the duration of anesthesia during casting. The purpose of this study is to quantify the variability in anesthesia during Mehta casting. We hypothesize that significant institutional variability exists and may be attributed to modifiable factors. METHODS: An EOS registry was used to identify patients who underwent at least one Mehta casting procedure. Anesthesia exposure was quantified, and site variability was assessed by patient characteristics, cast placement, procedure type, and equipment used. RESULTS: Our cohort consisted of 208 patients from 5 institutions (age 2.6±1.4 y). There were 1097 Mehta casting procedures, with 5.4±3.6 castings per patient. Of these patients, 106 (51%) were female, with an average age of 2.11±1.29 years old at the time casting was initiated. Patient etiologies included 154 idiopathic (74.0%), 22 syndromic (10.6%), 18 congenital (8.7%), 11 neuromuscular (5.3%), and 3 unknown (1.4%). Anesthesia time was 69±31 minutes and varied significantly between sites (59±14 to 117±46 min; P <0.001). Cumulative anesthesia time for patients under 3 years was 320±197 minutes with 120/161 (74.5%) patients exceeding 3 hours. Anesthesia time was lower after the FDA warning in 2016 compared with pre-2016 (71±30 vs. 66±32, P =0.008). CONCLUSIONS: Patients undergoing Mehta casting are at significant risk of exceeding 3 hours of anesthesia, which the FDA has stated may be harmful for children <3 years. Significant site variability indicates that standardization protocols should be developed to encourage best practices and minimize anesthetic times. LEVEL OF EVIDENCE: Prognostic Level II.

Failure to lengthen consensus for the magnetically controlled growing rod (MCGR).

INTRODUCTION: MCGR lengthening has become an important innovation in treating patients with EOS. An alternative to traditional growing instrumentation, a single surgical procedure is necessary for insertion of the construct, followed by non-invasive lengthening in the outpatient setting. With every new technology emanates a new complication to troubleshoot. Failure to lengthen in the MCGR is a significant cause of revision surgery. Currently, no consensus exists on how to define a MCGR lengthening failure, what steps are necessary after a failure to lengthen, and what factors determine these next steps. The primary goal of this study was to establish a consensus on how to define and navigate a MCGR that fails to lengthen. METHODS: A series of 3 surveys were distributed to 49 early onset scoliosis surgeons with 37 responses between December 2021 and April 2022. Consensus was defined as at least 70% agreement. RESULTS: 37 of 49 surgeons (75%) responded to the first survey, and all 37 surgeons responded to the following two surveys (100%). Consensus statements were reached on 25% of questions (3/12) from survey 1, 40% of questions (4/10) on survey 2, and 100% of questions (5/5) on survey 3. The questions that reached consensus are detailed in Table 1. Consensus steps to navigate a rod that fails to lengthen 1 mm (97%) in the office include retrying during the same visit (78%), changing technique in the office (88%), and not adjusting the interval between lengthening appointments (78%). Table 1 Items that reached consensus from each survey (12 total) Survey Question Response, Consensus Percentage 1 If a rod does not lengthen, do you try again in that office visit?​ Yes, 78% 1 All modes of XR are equivalent when determining failure to lengthen? Yes, 70% 1 If you are unsuccessful at lengthening, you should change the lengthening interval? No, 78% 2 Re-lengthening a rod following a failure to lengthen one should change their technique? Yes, 88% Reposition patient, 100% Alternate rods, 90% No traction in OR, 92.6% 2 Is a MCGR non-operational following 3 consecutive visits where the rod failed lengthening? Yes, 100% 2 Considerations when determining next steps with a non-operational rod? Skeletal Age, 100% Curve Progression, 97% Curve Stiffness, 93.8% Family Convenience, 83% Chronologic Age, 77% Time from Last Lengthening, 70% 2 Can an APP follow your protocol for a rod that has failed to lengthen? Yes, 81% 3 Are you comfortable using either clunk or stall to describe the phenomena of the internal clutch failing within the actuator when lengthening? Yes, 97.3% 3 Clunk/stall try again before an adjustment? Yes, 81% 3 Define failure to lengthen? Less than 1 mm length achieved, 97% 3 After two failure to lengthen events do you discuss next surgical steps?​ Yes, 97% 3 Once a rod had been classified as non-operational (no longer lengthening despite interventions) do you consider the underlying diagnosis when making next step decisions? Yes, 97% CONCLUSION: Best clinical practice guidelines using a Delphi method established a consensus on defining failure to lengthen in a MCGR (less than 1 mm), appropriate responses to failure to lengthen (re-attempt to lengthen and re-position patient) and a definition for a non-functional MCGR (failure to lengthen 3 consecutive times). This consensus will help standardize research on this important problem. LEVEL OF EVIDENCE: V-expert opinion.

Evaluating compliance with the 2013 best practice guidelines for preventing surgical site infection in high-risk pediatric spine surgery.

PURPOSE: Best Practice Guidelines (BPGs) were published one decade ago to decrease surgical site infection (SSI) in pediatric spinal deformity. Successful implementation has not been established. This study evaluated surgeon compliance with items on the BPG. We hypothesized that BPG authors and surgeons with more experience, higher caseload, and awareness of the BPG would have higher compliance. METHODS: We queried North American and European surgeons, authors and non-authors, and members of various spine study groups on adherence to BPGs using an anonymous survey. Mean compliance scores (MCSs) were developed by correlating Likert responses with MCSs ("None of the time" = no compliance = MCS 0, "Sometimes" = weak to moderate = MCS 1, "Most of the time" = high = MCS 2, "All the time" = perfect = MCS 3). RESULTS: Of the 142 respondents, 73.7% reported high or perfect compliance. Average compliance scores for all guidelines was 2.2 ± 0.4. There were significantly different compliance scores between North American and European surgeons (2.3 vs 1.8, p < 0.001), authors and non-authors (2.5 vs. 2.2, p = 0.023), and surgeons with and without knowledge of the BPGs (2.3 vs. 1.8, p < 0.001). There was a weak correlation between BPG awareness and compliance (r = 0.34, p < 0.001) and no correlation between years in practice (r = 0.0, p = 0.37) or yearly caseload (r = 0.2, p = 0.78) with compliance. CONCLUSIONS: Compliance among our cohort of surgeons surveyed was high. North American surgeons, authors of the BPGs and those aware of the guidelines had increased compliance. Participation in a spine study group, years in practice, and yearly caseload were not associated with compliance. LEVEL OF EVIDENCE: Level V-expert opinion.

Evaluating consensus and uncertainty among treatment options for early-onset scoliosis: new generation and international perspectives.

PURPOSE: It is currently unknown how treatment preferences differ between a senior group of U.S. spinal surgeons, a new generation of U.S. surgeons, and non-U.S. surgeons with regard to the treatment of early-onset scoliosis (EOS). The purpose of this study was to evaluate clinical consensus and uncertainty among treatment options for patients with EOS to understand how they compare between these three cohorts. METHODS: 11 senior pediatric spinal deformity surgeons in the U.S., 12 "junior" surgeons in the U.S., and 7 surgeons practicing in non-U.S. countries were invited to complete a survey of 315 idiopathic and neuromuscular EOS case scenarios. Treatment options included: conservative management, distraction-based methods, growth guidance/modulation, and arthrodesis. Consensus was defined as ≥ 70% agreement, and uncertainty was < 70%. Chi-squared and multiple regression analyses were performed to evaluate the associations between case characteristics and consensus for different treatments. RESULTS: Although all 3 cohorts of surgeons chose conservative management most frequently, the non-U.S. cohort of surgeons chose distraction-based methods more often, particularly for neuromuscular cases. In both U.S. surgeon cohorts, there was consensus for conservative management in idiopathic patients aged 3 or younger regardless of other factors, whereas non-U.S. surgeons selected distraction-based methods for some of these patients. CONCLUSION: Just as research studies are being conducted to find approaches to optimally manage the EOS population, future research efforts should focus on identifying the reasoning behind treatment preferences in different cohort of surgeons, as this will allow the interexchange of information which can ultimately improve EOS care. LEVEL OF EVIDENCE: V.

Operative choices matter: the role of UIV and sagittal balance in the development of proximal junctional kyphosis following posterior instrumentation for Scheuermann's kyphosis.

PURPOSE: This study sought to investigate associations between upper instrumented vertebra (UIV) location and the risk of proximal junctional kyphosis (PJK) at 2 years following posterior spinal fusion (PSF) for Scheuermann's kyphosis (SK). METHODS: In this retrospective cohort study, SK patients who underwent PSF and reached 2 years postop were identified in a multicenter international registry, excluding those with anterior release, prior spine surgery, neuromuscular comorbidity, post-traumatic kyphosis, or kyphosis apex below T11-T12. Location of UIV as well as the number of levels between UIV and preoperative kyphosis apex was determined. Additionally, the degree of kyphosis correction was evaluated. PJK was defined as a proximal junctional angle ≥ 10° that is ≥ 10° greater than the preoperative measurement. RESULTS: 90 patients (16.5 ± 1.9 yo, 65.6% male) were included. Preoperative and 2-year postoperative major kyphosis was 74.6 ± 11.6° and 45.9 ± 10.5°, respectively. Twenty-two (24.4%) patients developed PJK at 2 years. Patients with UIV below T2 had a 2.09 times increased risk of PJK when compared to those with UIV at or above T2, adjusting for distance between UIV and preoperative kyphosis apex [95% Confidence Interval (CI) 0.94; 4.63, p = 0.070]. Patients with UIV ≤ 4.5 vertebrae from the apex had a 1.57 times increased risk of PJK, adjusting for UIV relative to T2 [95% CI 0.64; 3.87, p = 0.326]. CONCLUSION: SK patients with UIV below T2 had an increased risk of developing PJK at 2 years following PSF. This association supports consideration of UIV location during preoperative planning. LEVEL OF EVIDENCE: Prognostic Level II.

Definition of Tweener: Consensus Among Experts in Treating Early-onset Scoliosis.

BACKGROUND: The term "Tweener" is colloquially used to refer to early-onset scoliosis (EOS) patients whose age and development make them candidates for multiple surgical options. The purpose of this study was to establish expert consensus on a definition to formally characterize the Tweener population. METHODS: A 3-round survey of surgeons in an international EOS study group was conducted. Surgeons were provided with various patient characteristics and asked if each was part of their definition for Tweener patients. Responses were analyzed for consensus (≥70%), near-consensus (60% to 69%), and no consensus (<60%). RESULTS: Consensus was reached (89% of respondents) for including chronological age in the Tweener definition; 8 to 10 years for females and 9 to 11 years for males. Surgeons agreed for inclusion of Sanders score, particularly Sanders 2 (86.0%). Patients who have reached Sanders 4, postmenarche, or have closed triradiate cartilage should not be considered Tweeners. Bone age range of 8 years and 10 months to 10 years and 10 months for females (12 y for males) could be part of the Tweener definition. CONCLUSIONS: This study suggests that the Tweener definition could be the following: patients with open triradiate cartilage who are not postmenarche and have not reached Sanders 4, and if they have one of the following: Sanders 2 or chronological age 8 to 10 years for females (9 to 11 y for males) or bone age 8 years and 10 months to 10 years and 10 months for females (12 y for males). This definition will allow for more focused and comparative research on this population. LEVEL OF EVIDENCE: Level V-expert opinion.

Reliability of Preoperative Supine Versus Bending Radiographs in Estimating the Structural Nature of Curves in EOS.

BACKGROUND: The study sought to evaluate the utility of a single supine radiograph in determining curve flexibility in early-onset scoliosis (EOS) patients. METHODS: EOS patients with upright (standing/seated), supine, and side-bending radiographs who underwent spinal deformity surgery were identified. Coronal parameters included: proximal thoracic (PT) curve, main thoracic (MT) curve, and thoracolumbar/lumbar (TL/L) curve. Each radiograph was measured twice by 2 different raters. Correlation coefficients were utilized to investigate associations between the different radiographs. Interrater Correlation Coefficient (ICC) assessed intrarater and interrater reliability. RESULTS: Thirty-seven EOS patients were identified (age at diagnosis: 7.0±2.9 y, preoperative age: 13.0±2.9 y; 73% female; etiologies: 54% idiopathic, 30% syndromic, and 16% neuromuscular). Supine PT and MT curve measurements were highly associated with corresponding side-bending measurements (PT: r=0.75, P<0.001; MT: r=0.80, P<0.001), and TL/L curves were very highly associated (TL/L: r=0.92, P<0.001). The mean absolute differences between supine and side-bending measurements were PT: 11.3±7.8 degrees, MT: 14.8±8.3 degrees, and TL/L: 16.2±7.6 degrees, where the side-bending was on average smaller than the supine measurement. The intrarater reliabilities were excellent, with an ICC ranging from 0.93 to 0.96 for side-bending films and 0.94 to 0.97 for supine films. The interrater reliability was excellent with ICC value of 0.88 for side-bending films and 0.93 for supine films. CONCLUSIONS: A single, preoperative supine radiograph was highly predictive of side-bending radiographs in patients with EOS. Supine curves measured an average of 15 degrees larger than bending curves in the MT and TL/L region. A single supine film may eliminate the need for effort-related, dual side-bending radiographs. LEVEL OF EVIDENCE: Level II-retrospective study.

Younger age at spinal cord detethering is potentially associated with a reduced risk of curve progression in children with early onset scoliosis.

PURPOSE: In children with early onset scoliosis (EOS) who have tethered spinal cord (TSC), spinal cord detethering is commonly performed prior to spinal deformity correction (SDC). The purpose of this study was to investigate whether age or curve magnitude at the time of detethering is associated with curve progression at a follow-up of at least 2 years. It was hypothesized that patients who undergo detethering at a younger age, or those with a smaller curve magnitude, would experience a reduced rate of curve progression when compared with those who are older or with larger curves. METHODS: Patients with EOS who underwent detethering at least 2 years prior to SDC were identified in a multicenter international registry. Radiographs were assessed just prior to the detethering procedure (pre-detether) and at the most recent visit prior to SDC (most recent post-detether). The rate of curve progression > 10° was examined. Owing to unequal follow-up in individual patients, Cox regression was used to investigate associations between primary variables (age and magnitude of major coronal curve) and rate of curve progression. RESULTS: 37 patients met inclusion criteria and 18 (mean age: 3.7 ± 2.9 years, 66.7% female, mean follow-up: 3.4 ± 1.3 years) had radiographic data available for analysis. Pre-detether and most recent post-detether major coronal curves were 44.8° ± 18.5° and 47.6° ± 23.9°, respectively. 5 (27.8%) patients had curve progression > 10° at a follow-up of 3.2 ± 1.2 years. Patients with progression > 10° were older at the time of detethering when compared with those without (5.6 ± 2.8 vs. 3 ± 2.7 years, p = 0.084). Regression analysis demonstrated that as age at detethering increased by 1 year, the rate of curve progression > 10° increased by 28.6% [95% confidence interval (CI) 0.899; 1.839, p = 0.169]. There was no evidence of an association between pre-detethering curve magnitude and rate of curve progression > 10° [HR: 1.027, 95% CI 0.977; 1.079, p = 0.297]. CONCLUSION: In a small multicenter cohort of EOS patients with TSC, younger age, but not curve size, at the time of detethering was associated with a lower rate of scoliosis progression. Although these results indicate a potential role for early spinal cord detethering in the EOS population, they require further prospective investigation with a larger number of patients. LEVEL OF EVIDENCE: Level II.

Modified Clavien-Dindo-Sink system is reliable for classifying complications following surgical treatment of early-onset scoliosis.

PURPOSE: Appropriately measuring and classifying surgical complications is a critical component of research in vulnerable populations, including children with early-onset scoliosis (EOS). The purpose of this study was to assess the inter- and intra-rater reliability of a modified Clavien-Dindo-Sink system (CDS) classification system for EOS patients among a group of pediatric spinal deformity surgeons. METHODS: Thirty case scenarios were developed and presented to experienced surgeons in an international spine study group. For each case, surgeons were asked to select a level of severity based on the modified CDS system to assess inter-rater reliability. The survey was administered on two occasions to allow for assessment of intra-rater reliability. Weighted Kappa values were calculated, with 0.61 to 0.80 considered substantial agreement and 0.81 to 1.00 considered nearly perfect agreement. RESULTS: 11/12 (91.7%) surgeons completed the first-round survey and 8/12 (66.7%) completed the second. Inter-observer weighted kappa values for the first and second survey were 0.75 [95% CI 0.56-0.94], indicating substantial agreement, and 0.84 [95% CI 0.70-0.98], indicating nearly perfect agreement, respectively. Intra-observer reliability was 0.86 (range 0.74-0.95) between the first and second surveys, indicating nearly perfect agreement . CONCLUSION: The modified CDS classification system demonstrated substantial to nearly perfect agreement between and within observers for the evaluation of complications following the surgical treatment of EOS patients. Adoption of this reliable classification system as a standard for reporting complications in EOS patients can be a valuable tool for future research endeavors, as we seek to ultimately improve surgical practices and patient outcomes. LEVEL OF EVIDENCE: Level V.

Strategies reducing risk of surgical-site infection following pediatric spinal deformity surgery.

BACKGROUND: Identifying beneficial preventive strategies for surgical-site infection (SSI) in individual patients with different clinical and surgical characteristics is challenging. The purpose of this study was to investigate the association between preventive strategies and patient risk of SSI taking into consideration baseline risks and estimating the reduction of SSI probability in individual patients attributed to these strategies. METHODS: Pediatric patients who underwent primary, revision, or final fusion for their spinal deformity at 7 institutions between 2004 and 2018 were included. Preventive strategies included the use of topical vancomycin, bone graft, povidone-iodine (PI) irrigations, multilayered closure, impermeable dressing, enrollment in quality improvement (QI) programs, and adherence to antibiotic prophylaxis. The CDC definition of SSI as occurring within 90 days postoperatively was used. Multiple regression modeling was performed following multiple imputation and multicollinearity testing to investigate the effect of preventive strategies on SSI in individual patients adjusted for patient and surgical characteristics. RESULTS: Univariable regressions demonstrated that enrollment in QI programs and PI irrigation were significantly associated, and topical vancomycin, multilayered closure, and correct intraoperative dosing of antibiotics trended toward association with reduction of SSI. In the final prediction model using multiple regression, enrollment in QI programs remained significant and PI irrigation had an effect in decreasing risks of SSI by average of 49% and 18%, respectively, at the individual patient level. CONCLUSION: Considering baseline patient characteristics and predetermined surgical and hospital factors, enrollment in QI programs and PI irrigation reduce the risk of SSI in individual patients. Multidisciplinary efforts should be made to implement these practices to increase patient safety. LEVEL OF EVIDENCE: Prognostic level III study.

Contraindications to magnetically controlled growing rods: consensus among experts in treating early onset scoliosis.

PURPOSE: The purpose of this study was to describe contraindications to the magnetically controlled growing rod (MCGR) in patients with early onset scoliosis (EOS) by establishing consensus amongst expert surgeons who treat these patients frequently. METHODS: Nine pediatric spine surgeons from an international EOS study group participated in semi-structured interviews via email to identify factors that influence decision making in the use of MCGR. A 39-question survey was then developed to specify these factors as contraindications for MCGR-these included patient age and size, etiology, medical comorbidities, coronal and sagittal curve profiles, and skin and soft tissue characteristics. Pediatric spine surgeons from the EOS international study group were invited to complete the survey. A second 29-item survey was created to determine details and clarify results from the first survey. Responses were analyzed for consensus (> 70%), near consensus (60-69%), and no consensus/variability (< 60%) for MCGR contraindication. RESULTS: 56 surgeons of 173 invited (32%) completed the first survey, and 64 (37%) completed the second survey. Responders had a mean of over 15 years in practice (range 1-45) with over 6 years of experience with using MCGR (range 2-12). 71.4% of respondents agreed that patient size characteristics should be considered as contraindications, including BMI (81.3%) and spinal height (84.4%), although a specific BMI range or a specific minimum spinal height were not agreed upon. Among surgeons who agreed that skin and soft tissue problems were contraindications (78.6%), insufficient soft tissue (98%) and skin (89%) to cover MCGR were specified. Among surgeons who reported curve stiffness as a contraindication (85.9%), there was agreement that this curve stiffness should be defined by clinical evaluation (78.2%) and by traction films (72.3%). Among surgeons who reported sagittal curve characteristics as contraindications, hyperkyphosis (95.3%) and sagittal curve apex above T3 (70%) were specified. Surgeons who indicated the need for repetitive MRI as a contraindication (79.7%) agreed that image quality (72.9%) and not patient safety (13.6%) was the concern. In the entire cohort, consensus was not achieved on the following factors: patient age (57.4%), medical comorbidities (46.4%), etiology (53.6%), and coronal curve characteristics (58.9%). CONCLUSION: Surgeon consensus suggests that MCGR should be avoided in patients who have insufficient spinal height to accommodate the MCGR, have potential skin and soft tissue inadequacy, have too stiff a spinal curve, have too much kyphosis, and require repetitive MRI, particularly of the spine. Future data-driven studies using this framework are warranted to generate more specific criteria (e.g. specific degrees of kyphosis) to facilitate clinical decision making for EOS patients. LEVEL OF EVIDENCE: Level V-expert opinion.

Degree of Postoperative Curve Correction Decreases Risks of Postoperative Pneumonia in Patients Undergoing Both Fusion and Growth-friendly Surgical Treatment of Neuromuscular Scoliosis.

INTRODUCTION: Due to a combination of poor respiratory muscle control and mechanical lung compression secondary to spine and chest wall deformities, patients with neuromuscular (NM) early-onset scoliosis (EOS) are at a high risk for pulmonary complications including pneumonia. The purpose of this study is to examine the effect of surgical intervention on the prevalence and risk of postoperative pneumonia in patients with NM EOS. METHODS: In this retrospective cohort study, pediatric (18 y old and below) patients with NM EOS undergoing index fusion or growth-friendly instrumentation from 2000 to 2018 were identified. Patients were then categorized into 2 groups: those with ≥50% curve correction and those with <50% curve correction of the coronal deformity at the first postoperative visit. The primary outcome of interest was postoperative pneumonia occurring between 3 weeks and 2 years postoperatively. Manual chart review was supplemented with phone call surveys to ensure all occurrences of preoperative/postoperative pneumonia (ie, in-institution and out-of-institution visits) were accounted for. RESULTS: A total of 35 patients (31% female, age at surgery: 10.3±4.3 y) with NM EOS met inclusion criteria. Twenty-three (66%) patients experienced at least 1 case of preoperative pneumonia. Twenty-six (74%) patients had ≥50% and 9 (26%) patients had <50% immediate postoperative curve correction. In total, 12 (34%) patients experienced at least 1 case of postoperative pneumonia (7 in-institution, 5 out-of-institution). Seven (27%) patients with ≥50% curve correction versus 5 (56%) with <50% curve correction experienced postoperative pneumonia. Relative risk regression demonstrated that patients with <50% curve correction had increased risk of postoperative pneumonia by 2.1 times compared with patients with ≥50% curve correction (95% confidence interval: 0.9; 4.9, P =0.099). CONCLUSION: The prevalence of preoperative and postoperative pneumonia is high in patients with NM EOS. This study presents preliminary evidence suggesting that percent curve correction is associated with the occurrence of postoperative pneumonia in patients with NM EOS undergoing surgical correction.