Impact of Spinal Deformity and Surgery on Health-Related Quality of Life in Cerebral Palsy: A Multicenter Prospective Controlled Trial.

BACKGROUND: Spinal fusion for scoliosis associated with cerebral palsy (CP) is challenging to study because specialized outcome measures are needed. Therefore, evidence in favor of the benefits of surgery has not been firmly established. This study aimed to determine if corrective spinal fusion improves health-related quality of life (HRQoL) in children with CP scoliosis at 2 years. METHODS: Children with CP and scoliosis who met the criteria for posterior spinal fusion were offered enrollment at 16 US and Canada centers. Participants' families selected either operative intervention (OP) or nonoperative treatment (NON) in discussion with their surgeon with no influence by the decision to participate in the research study. Demographic, clinical data (function level, magnitude of deformity, comorbidities), and HRQoL (CPCHILD Questionnaire) were collected at baseline and 2 years. Change (from baseline) in total CPCHIL scores was the primary outcome. RESULTS: Three hundred one OP and 34 NON subjects had complete baseline and 2-year data. At baseline, both groups were comparable in function level, comorbid status, and CPCHILD scores (52.1 ±15.3 vs. 53.4 ±14.5; P=0.66). The OP group had a larger spinal deformity magnitude (84.5˚ ± 21.8˚ vs. 66.3˚ ± 18.1˚) (P=0.001). The total CPCHILD score improved in the OP group by 6.6 points (P<0.001). NON scores were unchanged (+1.2; P=0.65) during follow-up. There were also significant score increases in the OP group for 5 of 6 CPCHILD domains. The change in CPCHILD scores from enrollment to 2 years was more significant in the OP group (P=0.05). CONCLUSION: For children with CP who undergo spinal fusion, HRQoL improved over preoperative levels and an unchanged nonoperative control group. LEVEL OF EVIDENCE: Level II.

Representation and Race in Adolescent Idiopathic Scoliosis Research: Disparities in Curve Magnitude and Follow-Up.

STUDY DESIGN: Prospective Cohort Study. OBJECTIVE: The present study aims to determine if the racial representation of patients enrolled in a large prospective scoliosis registry is reflective of the general United States population. Further, we studied whether there was an association between race, pre-operative parameters, outcomes and loss to follow-up. METHODS: Prospectively collected data for patients who underwent spinal fusion for adolescent idiopathic scoliosis (AIS) was reviewed, including self-reported race/ethnicity. The U.S. pediatric population and U.S. patients enrolled in the prospective registry were compared. The data obtained was analyzed for variations between races, for pre-operative variables and follow-up. RESULTS: Of the 2210 included patients in the registry 66% of patients reported as White, while 52% of the 2018 U.S. pediatric population reported as White. 15% of the registry reported as Hispanic/Latino compared to 22% of the U.S. pediatric population, 13% Black compared to 14% of the U.S. pediatric population, and 4% Asian compared to 5% of the U.S. pediatric population. Asian and White patients had statistically significant higher 2-year follow-up in all but one of six enrollment sites (P < 0.001). Native American, Other, and Hispanic/Latino patients had the highest BMIs. Native American and Black patients had the highest pre-op thoracic Cobb angles. Pre-op ages of Black, Hispanic, and Native American patients were statistically lower (P < 0.01). CONCLUSION: This study demonstrates the association between race and patient follow-up and pre-operative factors in patients who underwent surgery for AIS. Black, Native American, and Hispanic populations were underrepresented both at pre-op and follow-up when compared to their relative proportion in the U.S. pediatric population.

Association between structural rib autograft and the rate of arthrodesis in children undergoing occiput-C2 instrumentation and fusion.

OBJECTIVE: The purpose of this study was to identify factors associated with fusion success among pediatric patients undergoing occiput-C2 rigid instrumentation and fusion. METHODS: The Pediatric Spine Study Group registry was queried to identify patients ≤ 21 years of age who underwent occiput-C2 posterior spinal rigid instrumentation and fusion and had a 2-year minimum clinical and radiographic (postoperative lateral cervical radiograph or CT scan) follow-up. Fusion failure was defined clinically if a patient underwent hardware revision surgery > 30 days after the index procedure or radiographically by the presence of hardware failure or screw haloing on the most recent follow-up imaging study. Univariate comparisons and multivariable logistic regression analyses were subsequently performed. RESULTS: Seventy-six patients met inclusion criteria. The median age at surgery was 9 years (range 1.5-17.2 years), and 51% of the cohort was male. Overall, 75% of patients had syndromic (n = 41) or congenital (n = 15) etiologies, with the most frequent diagnoses of Down syndrome (28%), Chiari malformation (13%), and Klippel-Feil syndrome (12%). Data were available to determine if there was a fusion failure in 97% (74/76) of patients. Overall, 38% (28/74) of patients had fusion failure (95% CI 27%-50%). Univariate analysis demonstrated that use of a rigid cervical collar postoperatively (p = 0.04) and structural rib autograft (p = 0.02) were associated with successful fusion. Multivariable logistic regression analysis determined that patients who had rib autograft used in surgery had a 73% decrease in the odds of fusion failure (OR 0.27, 95% CI 0.09-0.82; p = 0.02). Age, etiology including Down syndrome, instrumentation type, unilateral instrumentation, use of recombinant human bone morphogenetic protein, and other variables did not influence the risk for fusion failure. CONCLUSIONS: In this multicenter, multidisciplinary, international registry of children undergoing occiput-C2 instrumentation and fusion, fusion failure was seen in 38% of patients, a higher rate than previously reported in the literature. The authors' data suggest that postoperative immobilization in a rigid cervical collar may be beneficial, and the use of structural rib autograft should be considered, as rib autograft was associated with a 75% higher chance of successful fusion.

Results of posterior spinal fusion after failed anterior vertebral body tethering.

PURPOSE: In patients with adolescent idiopathic scoliosis (AIS) undergoing anterior vertebral tethering (AVBT), some will subsequently require posterior spinal fusion (PSF). Limited data exist on clinical and radiographic outcomes of fusion after tether failure. METHODS: 490 patients who underwent AVBT were retrospectively analyzed. Twenty patients (4.1%) subsequently underwent conversion to PSF. A control group of patients with primary PSF (no previous AVBT) was matched for comparison. Data were compared using paired t-tests and Fisher Exact Tests. RESULTS: There was a significant increase in estimated blood loss (EBL) (p = 0.002), percent estimated blood volume (%EBV) (p = 0.013), operative time (p = 0.002), and increased amount of fluoroscopy (mGy) (p = 0.04) as well as number of levels fused (p = 0.02) in the AVBT conversion group compared to primary fusion. However, no difference was found in implant density (p = 0.37), blood transfusions (p = 0.11), or intraoperative neuromonitoring events (p > 0.99). Both groups attained similar thoracic and lumbar percent correction (major coronal curve angle) from pre-op to the latest follow-up (thoracic p = 0.507, lumbar p = 0.952). CONCLUSION: A subset of patients with AVBT will require conversion to PSF. Although technically more challenging, revision surgery can be safely performed with similar clinical and radiographic outcomes to primary PSF.

Pain After Anterior Vertebral Body Tethering: Incidence, Risk Factors, and Timing.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To examine the incidence and risk factors for postoperative pain following anterior vertebral body tethering (AVBT) for adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Up to 78% of patients with AIS report preoperative pain; it is the greatest patient concern surrounding surgery. Pain significantly decreases following posterior spinal fusion, but pain following AVBT is poorly understood. MATERIALS AND METHODS: We retrospectively reviewed 279 patients with a two-year follow-up after AVBT for AIS. We collected demographic, radiographic, and clinical data pertinent to postoperative pain at each time interval of preoperative and postoperative visits (6 wk, 6 mo, 1 y, and annually thereafter). RESULTS: Within our cohort, 68.1% of patients reported preoperative pain. Older age ( P =0.014) and greater proximal thoracic ( P =0.013) and main thoracic ( P =0.002) coronal curve magnitudes were associated with preoperative pain. Pain at any time point > 6 weeks postoperatively was reported in 41.6% of patients; it was associated with the female sex ( P =0.032), need for revision surgery ( P =0.019), and greater lateral displacement of the apical lumbar vertebrae ( P =0.028). The association between preoperative and postoperative pain trended toward significance ( P =0.07). At 6 months postoperatively, 91.8% had pain resolution; the same number remained pain-free at the time of last follow-up. The presence of a postoperative complication was associated with new-onset postoperative pain that resolved ( P =0.009). Only 8.2% had persistent pain, although no risk factors were found to be associated with persistent pain. CONCLUSION: In our cohort of 279 patients with a minimum 2-year follow-up after AVBT, 68.1% reported preoperative pain. Nearly 42% reported postoperative pain at any time point, but only 8.2% had persistent pain. Postoperative pain after AVBT was associated with female sex, revision surgery, and Lenke lumbar modifier. AVBT is associated with a significant reduction in pain, and few patients report long-term postoperative pain.

Machine Learning for Benchmarking Adolescent Idiopathic Scoliosis Surgery Outcomes.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: The aim of this study was to design a risk-stratified benchmarking tool for adolescent idiopathic scoliosis (AIS) surgeries. SUMMARY OF BACKGROUND DATA: Machine learning (ML) is an emerging method for prediction modeling in orthopedic surgery. Benchmarking is an established method of process improvement and is an area of opportunity for ML methods. Current surgical benchmark tools often use ranks and no "gold standards" for comparisons exist. MATERIALS AND METHODS: Data from 6076 AIS surgeries were collected from a multicenter registry and divided into three datasets: encompassing surgeries performed (1) during the entire registry, (2) the past 10 years, and (3) during the last 5 years of the registry. We trained three ML regression models (baseline linear regression, gradient boosting, and eXtreme gradient boosted) on each data subset to predict each of the five outcome variables, length of stay (LOS), estimated blood loss (EBL), operative time, Scoliosis Research Society (SRS)-Pain and SRS-Self-Image. Performance was categorized as "below expected" if performing worse than one standard deviation of the mean, "as expected" if within 1 SD, and "better than expected" if better than 1 SD of the mean. RESULTS: Ensemble ML methods classified performance better than traditional regression techniques for LOS, EBL, and operative time. The best performing models for predicting LOS and EBL were trained on data collected in the last 5 years, while operative time used the entire 10-year dataset. No models were able to predict SRS-Pain or SRS-Self-Image in any useful manner. Point-precise estimates for continuous variables were subject to high average errors. CONCLUSIONS: Classification of benchmark outcomes is improved with ensemble ML techniques and may provide much needed case-adjustment for a surgeon performance program. Precise estimates of health-related quality of life scores and continuous variables were not possible, suggesting that performance classification is a better method of performance evaluation.

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.

What Happens After a Vertebral Body Tether Break? Incidence, Location, and Progression With Five-year Follow-up.

STUDY DESIGN: Retrospective review. OBJECTIVE: To study risk factors for anterior vertebral body tether (VBT) breakage. SUMMARY OF BACKGROUND DATA: VBT is used to treat adolescent idiopathic scoliosis in skeletally immature patients. However, tethers break in up to 48% of cases. MATERIALS AND METHODS: We reviewed 63 patients who underwent thoracic and/or lumbar VBT with a minimum five-year follow-up. We radiographically characterized suspected tether breaks as a change in interscrew angle >5°. Demographic, radiographic, and clinical risk factors for presumed VBT breaks were evaluated. RESULTS: In confirmed VBT breaks, the average interscrew angle change was 8.1°, and segmental coronal curve change was 13.6°, with a high correlation ( r =0.82). Our presumed VBT break cohort constituted 50 thoracic tethers, four lumbar tethers, and nine combined thoracic/lumbar tethers; the average age was 12.1±1.2 years and the mean follow-up was 73.1±11.7 months. Of 59 patients with thoracic VBTs, 12 patients (20.3%) had a total of 18 breaks. Eleven thoracic breaks (61.1%) occurred between two and five years postoperatively, and 15 (83.3%) occurred below the curve apex ( P <0.05). The timing of thoracic VBT breakage moderately correlated with more distal breaks ( r =0.35). Of 13 patients who underwent lumbar VBT, eight patients (61.5%) had a total of 12 presumed breaks. Six lumbar breaks (50%) occurred between one and two years postoperatively, and seven (58.3%) occurred at or distal to the apex. Age, sex, body mass index, Risser score, and curve flexibility were not associated with VBT breaks, but the association between percent curve correction and thoracic VBT breakage trended toward significance ( P =0.054). Lumbar VBTs were more likely to break than thoracic VBTs ( P =0.016). Seven of the patients with presumed VBT breaks (35%) underwent revision surgery. CONCLUSIONS: Lumbar VBTs broke with greater frequency than thoracic VBTs, and VBT breaks typically occurred at levels distal to the curve apex. Only 15% of all patients required revision. LEVEL OF EVIDENCE: 3.

SRS-22r Self-Image After Surgery for Adolescent Idiopathic Scoliosis at 10-year Follow-up.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To examine SRS-Self Image scores at up to 10 years after surgery for adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Self-image is complex with implications for surgical and patient-reported outcomes after AIS surgery. Surgically modifiable factors that impact self-image are inconsistently reported in the literature with few longer-term reports. We examined the rate and durability of self-image improvement. MATERIALS AND METHODS: An AIS registry was queried for patients with up to 10 years of follow-up after AIS surgery. A mixed effects model estimated change in SRS-22 Self Image from baseline to 6 weeks, 1 year, 2 years, 5 years, and 10 years. All enrolled patients contributed data to the mixed effects models. A sub-analysis of patients with 1-year and 10-year follow-up evaluated worsening/static/improved SRS-22 Self Image scores examined stability of scores over that timeline. Baseline demographic data and 1-year deformity magnitude data were compared between groups using parametric and nonparametric tests as appropriate. RESULTS: Data from 4608 patients contributed data to the longitudinal model; 162 had 1-year and 10-year data. Mean SRS-Self Image improvement at 10-year follow-up was 1.0 (95% CI: 0.9-1.1) point. No significant changes in Self-Image domain scores were estimated from 1-year to 10-year (all P >0.05) postoperative. Forty (25%) patients had SRS-Self Image worsening from 1 year to 10 years, 36 (22%) improved, and 86 (53%) were unchanged. Patients who worsened over 10 years had lower SRS-Self Image at baseline than those unchanged at enrollment (3.3 vs. 3.7, P =0.007). Neither radiographic parameters nor SRS-Mental Health were different at baseline for the enrolled patients. CONCLUSION: Ten years after surgery, 75% of patients reported similar or better SRS-Self Image scores than one year after surgery. Nearly 25% of patients reported worsening self-image at 10 years. Patients who worsened had lower baseline SRS-Self Image scores, without radiographic or mental health differences at baseline or follow-up.

Surgical Outcomes of Cerebral Palsy Patients With Scoliosis and Lumbar Hyperlordosis: A Comparative Analysis With 2-year Minimum Follow-up.

STUDY DESIGN: Retrospective review of a prospectively collected multicenter database. OBJECTIVE: To compare outcomes of patients with cerebral palsy (CP) who undergo surgery for scoliosis with normal lordosis (NL) versus hyperlordosis. SUMMARY OF BACKGROUND DATA: Surgical correction of scoliosis with lumbar hyperlordosis is challenging. Hyperlordosis may confer higher perioperative morbidity, but this is not well understood. MATERIALS AND METHODS: A multicenter database was queried for CP patients who underwent surgery from 2008 to 2017. The minimum follow-up was 2 years. Two groups were identified: lumbar lordosis <75° (NL) versus ≥ 75° hyperlordosis (HL). Perioperative, radiographic, and clinical outcomes were compared. RESULTS: Two hundred seventy-five patients were studied: 236 NL and 39 HL (-75 to -125°). The mean age was 14.1 years, and 52.4% were male. Patients with hyperlordosis had less cognitive impairment (76.9% vs. 94.0%, P =0.008) and higher CPCHILD scores (59.4 vs. 51.0, P =0.003). Other demographics were similar between the groups. Patients with hyperlordosis had greater lumbar lordosis (-90.5 vs. -31.5°, P <0.001) and smaller sagittal vertical axis (-4.0 vs. 2.6 cm, P <0.001). Patients with hyperlordosis had greater estimated blood loss (2222.0 vs. 1460.7 mL, P <0.001) but a similar perioperative complication rate (20.5% vs. 22.5%, P =0.787). Significant correction of all radiographic parameters was achieved in both groups. The HL group had postoperative lumbar lordosis of -68.2° and sagittal vertical axis of -1.0 cm. At a 2-year follow-up, patients with hyperlordosis continued to have higher CPCHILD scores and gained the greatest benefit in overall quality of life measures (20.0 vs. 6.1, P =0.008). The reoperation rate was 10.2%: implant failure (3.6%), pseudarthrosis (0.7%), and wound complications (7.3%). There were no differences in the reoperation rate between the groups. CONCLUSION: Surgical correction of scoliosis with hyperlordosis is associated with greater estimated blood loss but similar radiographic results, perioperative morbidity, and reoperation rate as normal lordosis. Patients with hyperlordosis gained greater overall health benefits. Correction of ≥25% of hyperlordosis seems satisfactory. LEVEL OF EVIDENCE: 3.

Age-Stratified Outcomes of Mehta Casting in Idiopathic Early-Onset Scoliosis: A Multicenter Review.

BACKGROUND: This study provides age-stratified outcomes of cast treatment for idiopathic early-onset scoliosis. METHODS: This is a multicenter, retrospective review of patients with idiopathic early-onset scoliosis treated with Mehta casting at 4 tertiary children's hospitals between 2001 and 2016. The inclusion criteria were idiopathic early-onset scoliosis and a minimum follow-up of 2 years after casting ended. The exclusion criteria were <2 casts, >3 casts at an outside facility, and a major curve of <20° pre-treatment. Subjects were grouped by age at first cast: <18 months, 18 to <24 months, 2 to <3 years, 3 to <4 years, and ≥4 years. RESULTS: There were 134 patients with a mean follow-up of 5.2 years (95% confidence interval [CI], 4.8 to 5.5 years) after casting. Prior to treatment, the major curve was not significantly different between the various age groups and was a mean of 50.4° (95% CI, 48.0° to 52.8° [range, 22° to 109°]). Of the <18-month group (n = 59), at the final follow-up at a mean of 7.4 years (95% CI, 6.8 to 8.1 years) of age, 75% had scoliosis of <15°, and 6.8% had undergone a surgical procedure or had a major curve of ≥50°. The results declined in the 18 to <24-month group (n = 30), with a major curve of <15° at the final follow-up at 8.5 years (95% CI, 7.3 to 9.7 years) of age in 33% (p < 0.001), and 17% having undergone a surgical procedure or had a major curve of ≥50°, with results nearly identical in the 2 to <3-year group (n = 21). The results continued to decline with increasing age; 23% of the 3 to <4-year group had a major curve of <15° at the final follow-up, and 31% had undergone a surgical procedure or had scoliosis of ≥50°. Of the ≥4-year group, just 9.1% had scoliosis of <15° (p < 0.0001 compared with the <18-month group), and 64% had undergone a surgical procedure or had scoliosis of ≥50°. CONCLUSIONS: Children who underwent casting prior to 18 months of age were more likely to have a major curve of <15° at a minimum 2-year follow-up after casting. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Risk factors for proximal junctional kyphosis after pediatric spinal deformity surgery with halo gravity traction.

PURPOSE: To determine risk factors for proximal junctional kyphosis (PJK) in pediatric patients with scoliosis undergoing halo gravity traction (HGT) prior to posterior spinal fusion (PSF). METHODS: Data from consecutive patients who underwent PSF after HGT with 2-year follow-up were retrospectively collected from a single center. Patients were divided into two groups: PJK vs. no PJK. RESULTS: Twenty-five patients (age 13.6 ± 3.1 years) underwent HGT for a mean of 42 ± 37 days. Eight patients (32%) developed radiographic PJK and 1 (4%) developed proximal junctional failure. PJK patients had greater loss of cervical lordosis (-17.4 ± 23.2 vs. 2.7 ± 16.2°, p < 0.05), greater increase in lumbar lordosis (9.3 ± 19.5 vs. -2.8 ± 12.8°; p = 0.034) during traction, and smaller overall major coronal curve angle correction (-16.8 ± 30.6 vs. -36.6 ± 16.4°; p = 0.026). From postoperative to last follow-up, PJK patients had a greater increase in upper end vertebrae (UEV) slope (3.3 ± 7.8 vs. -4.0 ± 7.7°; p = 0.004). Selection of UIV based on which vertebra was most level either pre-traction or in-traction was not associated with PJK development (p > 0.05). CONCLUSION: In-traction radiographic changes of decreased cervical lordosis, decreased major coronal curve, increased lumbar lordosis, and disruption of cervical sagittal balance at last follow-up may have implications for level selection and risk of PJK.

Trunk Range of Motion and Patient Outcomes After Anterior Vertebral Body Tethering Versus Posterior Spinal Fusion: Comparison Using Computerized 3D Motion Capture Technology.

BACKGROUND: Anterior vertebral body tethering (AVBT) for adolescent idiopathic scoliosis (AIS) is postulated to preserve motion compared with traditional posterior spinal fusion (PSF), but few studies exist to date. We used a validated computerized 3D model to compare trunk motion between patients treated with PSF and AVBT, and analyzed trunk motion in relation to the lowest instrumented vertebra (LIV). METHODS: This was a single-center retrospective review of a consecutive series of skeletally immature patients with AIS who underwent motion analysis prior to PSF (n = 47) or AVBT (n = 65) and 2 years postoperatively. Patients were divided into 4 groups on the basis of the LIV (≤L1, L2, L3, L4). Computerized 3D kinematic evaluations included thoracic and lumbar flexion, extension, side-bending, and rotation. Patient outcomes were assessed using the Scoliosis Research Society (SRS)-22 questionnaire. RESULTS: The LIV was ≤L1 in 48 patients treated with AVBT and 23 treated with PSF, L2 in 4 AVBT and 8 PSF patients, L3 in 10 AVBT and 8 PSF patients, and L4 in 3 AVBT and 8 PSF patients. PSF patients had a significant loss of motion in all 4 directions at 2 years postoperatively (e.g., flexion loss was 11° for ≤L1 to 30° for L4; p < 0.001). This equated to a 7° loss of trunk flexion per additional LIV level included in the fusion. AVBT patients only demonstrated loss of flexion and side-bending at 2 years postoperatively (e.g., flexion loss of 11° for L1 to 17° for L4; p < 0.001). Preoperative curve size and flexibility did not have any significant impact on differences in trunk motion between AVBT and PSF. SRS-22 scores were predominantly similar for AVBT versus PSF preoperatively and at 2 years postoperatively. CONCLUSIONS: Patients treated with AVBT experienced predominantly less motion loss compared with PSF patients at 2 years postoperatively. Patients treated with PSF demonstrated loss of motion in all planes that increased with each additional LIV from ≤L1 to L4, with 7° loss of flexion per additional LIV. However, the differences in total trunk motions were relatively modest for PSF and AVBT with an LIV of ≤L1. Preoperative curve magnitude and flexibility had no significant impact on trunk motion in either group. SRS-22 scores were similar for both groups at 2 years postoperatively. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Inter- and intra-rater reliability and accuracy of Sanders Skeletal Maturity Staging System when used by surgeons performing vertebral body tethering.

PURPOSE: Pediatric orthopedic surgeons must accurately assess the skeletal stage of adolescent idiopathic scoliosis (AIS) patients for selection and timing of optimal treatment. Successful treatment using vertebral growth modulation is highly dependent on skeletal growth remaining. We sought to evaluate the current-state use of the Sanders Skeletal Maturity System (SSMS) in regard to precision and accuracy. We hypothesized that pediatric orthopedic surgeons currently use SSMS with moderate precision and accuracy. METHODS: Eight practicing pediatric orthopedic surgeons who perform vertebral body tethering surgery without specific training in SSMS were asked to assign the SSMS stage for 34 de-identified hand radiographs from AIS patients. Precision was evaluated as inter-rater reliability, using both Krippendorff's α and Weighted Cohen's kappa statistics, and as intra-rater reliability, using only Weighted Cohen's kappa statistics. Surgeon accuracy was evaluated using Weighted Cohen's kappa statistics with comparison of surveyed surgeons' responses to the gold standard rating. RESULTS: Inter-rater reliability across the surveyed surgeons indicated moderate to substantial agreement using both statistical methods (α = 0.766, κ = 0.627) with the majority of discord occurring when assigning SSMS stages 2 through 4. The surveyed surgeons displayed substantial accuracy when compared to the gold standard (κ = 0.627) with the majority of inaccuracy involving the identification of stage 3B. When re-surveyed, the surgeons showed substantial intra-rater reliability (κ = 0.71) with increased inconsistencies when deciding between SSMS stage 3A and stage 3B. CONCLUSION: The current-state use of SSMS across pediatric orthopedic surgeons for evaluation of AIS patients displays adequate but imperfect precision and accuracy with difficulties delineating SSMS stages 2 through 4, which correlate with adolescent growth periods germane to scoliosis growth modulation surgery. Centralized assessment of hand-bone age may help ensure standardized reporting for non-fusion scoliosis research.

Prospective Follow-up Report on Anterior Vertebral Body Tethering for Idiopathic Scoliosis: Interim Results from an FDA IDE Study.

BACKGROUND: Anterior vertebral body tethering (aVBT) has emerged as a novel treatment option for patients with idiopathic scoliosis. We present the results from the first U.S. Food and Drug Administration (FDA) Investigational Device Exemption (IDE) study on aVBT. METHODS: In this prospective review of a retrospective data set, eligible patients underwent aVBT at a single center from August 2011 to July 2015. Inclusion criteria included skeletally immature patients with Lenke type-1A or 1B curves between 30° and 65°. Clinical and radiographic parameters were collected, with the latter measured by an independent reviewer. RESULTS: Fifty-seven patients (49 girls and 8 boys), with a mean age (and standard deviation) of 12.4 ± 1.3 years (range, 10.1 to 15.0 years), were enrolled in the study. The patients had a mean of 7.5 ± 0.6 levels tethered, the mean operative time was 223 ± 79 minutes, and the mean estimated blood loss was 106 ± 86 mL. The patients were followed for an average of 55.2 ± 12.5 months and had a mean Risser grade of 4.2 ± 0.9 at the time of the latest follow-up. The main thoracic Cobb angle was a mean of 40.4° ± 6.8° preoperatively and was corrected to 18.7° ± 13.4° at the most recent follow-up. In the sagittal plane, T5-T12 kyphosis measured 15.5° ± 10.0° preoperatively, 17.0° ± 10.1° postoperatively, and 19.6° ± 12.7° at the most recent follow-up. Eighty percent of patients had curves of <30° at the most recent follow-up. The most recent Scoliosis Research Society (SRS) scores averaged 4.5 ± 0.4, and scores on the self-image questionnaire averaged 4.4 ± 0.7. No major neurologic or pulmonary complications occurred. Seven (12.3%) of 57 patients had a revision: 5 were done for overcorrection and 2, for adding-on. CONCLUSIONS: Anterior VBT is a promising technique that has emerged as a treatment option for patients with immature idiopathic scoliosis. We present the results from the first FDA-approved IDE study on aVBT, which formed the basis for the eventual Humanitarian Device Exemption approval. The findings affirm the safety and efficacy of this technique and suggest opportunities for improvement, particularly with respect to reoperation rates. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Complete paraplegia 36 h after attempted posterior spinal fusion for severe adolescent idiopathic scoliosis: a case report.

INTRODUCTION: The incidence of neurologic complications with spinal surgery for adolescent idiopathic scoliosis (AIS) has been reported to be 0.69%. This rare complication typically occurs during surgery or immediately postoperatively. We report the occurrence of a delayed neurologic deficit that presented 36 h after the initial surgery of a staged posterior spinal fusion for severe AIS. CASE PRESENTATION: A 12-year-old girl with severe thoracolumbar AIS of 125° underwent attempted posterior spinal fusion from T2-L4. The case was complicated by a transient loss of transcutaneous motor evoked potentials (TcMEP) that resolved with an increase in the mean arterial pressure (MAP) and relaxation of curve correction with rod removal. The patient awoke with normal neurologic function. She had a transient decrease in MAP 36 h post-op and awoke on postoperative day #2 with nearly complete lower extremity paraplegia (American Spinal Injury Association [ASIA] Impairment Scale B). Emergent exploration and removal of the concave apical pedicles resulted in improvement of TcMEPs and return of function. DISCUSSION: Delayed postoperative neurologic deficit is a very rare phenomenon, with only a few case reports in the literature to date. The delayed neurologic decline of our patient was likely secondary to a transient episode of postoperative hypotension combined with spinal cord compression by the apical concave pedicles. Close monitoring and support of spinal cord perfusion as well as emergent decompression are imperative in the setting of a delayed neurologic deficit. Further multicenter study on this rare occurrence is underway to identify potential causes and improve treatment.

What happens to the unfused upper thoracic curve after posterior spinal fusion for adolescent idiopathic scoliosis?

OBJECTIVE: Spontaneous lumbar curve correction after selective thoracic fusion in surgery for adolescent idiopathic scoliosis (AIS) is well described. However, only a few articles have described the course of the uninstrumented upper thoracic (UT) curve after fusion, and the majority involve a hybrid construct. In this study, the authors sought to determine the outcomes and associated factors of uninstrumented UT curves in patients with AIS. METHODS: The authors retrospectively reviewed a prospectively collected multicenter AIS registry for all consecutive patients with Lenke type 1-4 curves with a 2-year minimum follow-up. UT curves were considered uninstrumented if the upper instrumented vertebra (UIV) did not extend above 1 level from the lower end vertebra of the UT curve. The authors defined progression as > 5°, and divided patients into two cohorts: those with improvement in the UT curve (IMP) and those without improvement in the UT curve (NO IMP). Radiographic, demographic, and Scoliosis Research Society (SRS)-22 survey outcome measures were compared using univariate analysis, and significant factors were compared using a multivariate regression model. RESULTS: The study included 450 patients (370 females and 80 males). The UT curve self-corrected in 86% of patients (n = 385), there was no change in 14% (n = 65), and no patients worsened. Preoperatively, patients were similar with respect to Lenke classification (p = 0.44), age (p = 0.31), sex (p = 0.85), and Risser score (p = 0.14). The UT curves in the IMP group self-corrected from 24.7° ± 6.5° to 12.6° ± 5.9°, whereas in the NO IMP group UT curves remained the same, from 20.3° ± 5.8° to 18.5° ± 5.7°. In a multivariate analysis, preoperative main thoracic (MT) curve size (p = 0.004) and MT curve correction (p = 0.001) remained significant predictors of UT curve improvement. Greater correction of the MT curve and larger initial MT curve size were associated with greater likelihood of UT curve improvement. CONCLUSIONS: Spontaneous UT curve correction occurred in the majority (86%) of unfused UT curves after MT curve correction in Lenke 1-4 curve types. The magnitude of preoperative MT curve size and postoperative MT curve correction were independent predictors of spontaneous UT curve correction.

Use of postoperative neurophysiological testing to help guide management in a case of delayed neurological injury.

Bimodal intraoperative neuromonitoring (IONM), combining transcranial motor-evoked potentials (tcMEP) and somatosensory-evoked potentials (SSEP), enables real-time detection and prevention of spinal cord injury during pediatric spinal deformity correction. Although rare, false-positive and false-negative signal alerts have been reported. However, no previously published accounts have described the use of postoperative neurophysiological testing to both identify new-onset neurological injury and guide reintervention. Here, we describe the case of an 18-year-old young man with achondroplasia, thoracolumbar kyphosis, and L2 wedge vertebra who underwent T12-L4 posterior spinal fusion with L2 vertebral column resection. Despite two intraoperative decreases in tcMEP amplitude, corrective measures on both occasions produced a return of IONM signal. Curiously, despite movement of the bilateral lower extremities upon waking, continued observation demonstrated minimal movement of the left lower extremity. Postoperative neurophysiological testing then identified limited muscle group activation below the left quadriceps, prompting operative reintervention. After cage removal and laminectomy lengthening, the patient recovered bilateral lower extremity function. He later returned to surgery for repeat cage placement at L2 via a retroperitoneal exposure, with no noted IONM changes and subsequent neurological improvement.

Crossing the cervicothoracic junction in complex pediatric deformity using anterior cervical discectomy and fusion: a case series.

PURPOSE: Proximal instrumentation failure is a challenge in posterior spinal fusions (PSFs) crossing the cervicothoracic junction. High rates of proximal junctional kyphosis (PJK) and loss of fixation have been reported. In this single-center retrospective cohort study, we evaluate the utility of anterior cervical discectomy and fusion (ACDF) in addition to traditional PSF crossing the cervicothoracic junction in order to mitigate implant-related complications. METHODS: All patients who underwent PSF across the cervicothoracic junction with ACDF with 2 years of follow-up data were reviewed. We analyzed clinical, surgical, and radiographic measures such as operative details, presence of PJK, complications, instrumentation migration, curve angles, and vertebral translation. Measurements were compared statistically using paired samples t-tests. RESULTS: Ten patients (6 girls, 4 boys) met inclusion criteria with a mean age at surgery of 12.8 ± 3.3 years and follow-up of 3.38 ± 0.9 years. All patients underwent ACDF (range 1-3 levels), and 8 (80%) underwent traction. The average number of levels fused posteriorly was 16.7 ± 4.7 and anteriorly was 2.4 ± 0.7. The major coronal curve averaged 48.8 ± 34.7° preoperatively and 23.3±13.3° postoperatively (p = 0.028). The average major sagittal curve was 83.5 ± 24.2° preoperatively, resolving to 53.9 ± 25.5° (p=0.001). One patient suffered rod breakage at T7, and another developed symptomatic PJK 19 months postoperatively. CONCLUSION: Our data suggest that ACDF procedures added to PSFs crossing the cervicothoracic junction offer promise for reducing risk for instrumentation-related complications. ACDF also significantly helps improve and maintain both coronal and sagittal correction over 2 years. LEVEL OF EVIDENCE: 4.