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.

Double major curvature treated with vertebral body tethering of both curves: how do outcomes compare to posterior spinal fusion?

PURPOSE: Vertebral body tethering (VBT) is a non-fusion alternative to posterior spinal fusion (PSF). There have been few reports on VBT of two curvatures. We aim to compare the radiographic outcomes between VBT and PSF in patients with double curvatures in which both curves were instrumented. METHODS: 29 AIS patients matched by Lenke, age (± 2 years), triradiate cartilage closure status, major Cobb angle (± 8°), and T5-T12 kyphosis (± 10°). Variables were compared using Wilcoxon rank-sum tests, Student's t tests, and chi-Square. Clinical success was defined as major curve < 35°. RESULTS: Group baseline demographics were similar. Major thoracic (T) curve types had significantly better major (VBT 51.5 ± 7.9° to 31.6 ± 12.0° [40%] vs. PSF 54.3 ± 7.4° to 17.4 ± 6.5° [68%]; p = 0.0002) and secondary curve correction in the PSF group. 71% of major T VBT patients were clinically successful versus 100% of PSF. Major thoracolumbar (TL) curve types experienced comparable major (VBT 52.3 ± 7.0° to 18.3 ± 11.4° (65%) vs. PSF 53.0 ± 5.2° to 23.8 ± 10.9° (56%); p = 0.2397) and secondary curve correction. 92% of major TL VBT patients were clinically successful versus 75% in the PSF group. There was no difference in T5-12 kyphosis or lumbar lordosis between groups for any curve type. There were 4 patients (13.8%) with major complications in the VBT group compared to 0 (0%) in the PSF. CONCLUSION: Patients with double major AIS who underwent VBT with major T curve types had less correction than PSF; however, those with major TL curves experienced similar radiographic outcomes regardless of procedure. Complications were greater for VBT.

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.

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.

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.

The Reliability of the AO Spine Upper Cervical Classification System in Children: Results of a Multi-Center Study.

BACKGROUND: There is no uniform classification system for traumatic upper cervical spine injuries in children. This study assesses the reliability and reproducibility of the AO Upper Cervical Spine Classification System (UCCS), which was developed and validated in adults, to children. METHODS: Twenty-six patients under 18 years old with operative and nonoperative upper cervical injuries, defined as from the occipital condyle to the C2-C3 joint, were identified from 2000 to 2018. Inclusion criteria included the availability of computed tomography and magnetic resonance imaging at the time of injury. Patients with significant comorbidities were excluded. Each case was reviewed by a single senior surgeon to determine eligibility. Educational videos, schematics describing the UCCS, and imaging from 26 cases were sent to 9 pediatric orthopaedic surgeons. The surgeons classified each case into 3 categories: A, B, and C. Inter-rater reliability was assessed for the initial reading across all 9 raters by Fleiss's kappa coefficient (kF) along with 95% confidence intervals. One month later, the surgeons repeated the classification, and intra-rater reliability was calculated. All images were de-identified and randomized for each read independently. Intra-rater reproducibility across both reads was assessed using Fleiss's kappa. Interpretations for reliability estimates were based on Landis and Koch (1977): 0 to 0.2, slight; 0.2 to 0.4, fair; 0.4 to 0.6, moderate; 0.6 to 0.8, substantial; and >0.8, almost perfect agreement. RESULTS: Twenty-six cases were read by 9 raters twice. Sub-classification agreement was moderate to substantial with α κ estimates from 0.55 for the first read and 0.70 for the second read. Inter-rater agreement was moderate (kF 0.56 to 0.58) with respect to fracture location and fair (kF 0.24 to 0.3) with respect to primary classification (A, B, and C). Krippendorff's alpha for intra-rater reliability overall sub-classifications ranged from 0.41 to 0.88, with 0.75 overall raters. CONCLUSION: Traumatic upper cervical injuries are rare in the pediatric population. A uniform classification system can be vital to guide diagnosis and treatment. This study is the first to evaluate the use of the UCCS in the pediatric population. While moderate to substantial agreement was found, limitations to applying the UCCS to the pediatric population exist, and thus the UCCS can be considered a starting point for developing a pediatric classification. LEVEL OF EVIDENCE: Level III.

Avoiding PICU admission following PSF for neuromuscular scoliosis in non-ambulatory cerebral palsy managed with ERAS protocol.

PURPOSE: Children with neuromuscular scoliosis (NMS) undergoing posterior spinal fusion (PSF) have historically been managed post-operatively in the pediatric intensive care unit (PICU) due to institutional tendencies. This study sought to define risk factors for PICU admission when using an enhanced recovery after surgery (ERAS) pathway. METHODS: A retrospective review of children with non-ambulatory (GMFCS 4 or 5) cerebral palsy undergoing PSF for NMS performed at two institutions by 5 surgeons. Both institutions have a pre-existing ERAS pathway for NMS patients consisting of post-surgical transfer to the hospital floor with early reinstitution of feeding and mobilization. PICU admission is used at the discretion of the surgeon and anesthesiologist rather than by institutional decree. Patient and surgical factors were assessed for risk factors of PICU admission. RESULTS: A total of 103 children were included (84% GMFCS 5, mean 14.52 years (± 3.4 years)). Forty children (38.8%) required postoperative PICU admission. PICU admission was associated with seizure disorder (P = 0.09), pre-existing feeding tube (P = 0.003), tracheostomy (P = 0.03), and modified GMFCS-5 subclassification (P = 0.003). Independent predictors of PICU admission include pre-existing feeding (Odd's ratio = 2.9, P = 0.02) and length of surgery (Odd's ratio = 2.6, P < 0.001), with surgery lasting ≥ 5.0 h having an 82.5% sensitivity and 63.5% specificity (AUC 0.8, P < 0.001) for post-operative PICU admission. CONCLUSION: The majority of children with non-ambulatory cerebral palsy can be successfully managed on the hospital floor following PSF. The extent of central neuromotor impairment is significantly associated with PICU admission along with surgery lasting longer than 5 h.

Post-operative steroids in patients with patients with severe cerebral palsy undergoing posterior spinal fusion.

INTRODUCTION: Posterior spinal fusion (PSF) represents a large physiologic challenge for children with neuromuscular scoliosis (NMS). Perioperative complications are numerous with many occurring in the post-operative period due to pain and relative immobilization. This study assessed the impact of steroids on patients undergoing PSF for NMS. METHODS: A retrospective review of consecutive patients managed at a single center with PSF for NMS was reviewed. Clinical and radiographic analysis was used to evaluate baseline demographics, curve characteristics, and post-operative course. RESULTS: Eighty-nine patients who underwent PSF for NMS were included. Fifty-seven of these patients did not receive post-operative steroids (NS) while 32 patients were treated with post-operative steroids (dexamethasone, WS) for a median of 3 doses (median 6.0 mg/dose every 8 h after surgery). The demographic variables of the cohorts were similar with no difference in curve magnitude, number of vertebrae fused, number of osteotomies, or EBL between groups. A 70% decrease in the median post-operative morphine equivalents was observed in the steroid cohort (0.50 mg/kg WS vs 1.65 mg/kg NS, p value < 0.001). There was an association between post-operative morphine equivalents and length of stay (Spearman's rho = 0.22, p value = 0.04). There was no difference in wound healing, infection, and pulmonary or gastrointestinal complications between groups. No difference was found in pain at discharge, 30-day ED returns, or 30-day OR returns between groups. CONCLUSIONS: Post-operative dexamethasone resulted in a 70% decrease in morphine equivalent use after PSF for NMS without any increase in perioperative wound infections. LEVEL OF EVIDENCE: Level 3: case-control series.

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.

Outcomes of Posterior Spinal Fusion in Pediatric Patients with Down Syndrome.

BACKGROUND: Trisomy 21 or Down syndrome is associated with multiple orthopaedic manifestations. Although cervical instability is the most common spinal condition associated with Down syndrome, the prevalence of scoliosis has been estimated at 4.8% to 8.7%. Very few prior studies have documented the role of spinal fusion in this population, and all have included ≤10 patients. METHODS: An institutional review board-approved multicenter retrospective analysis of patients with Down syndrome treated with spinal fusion between January 2009 and December 2019 was performed by cross-referencing Current Procedural Terminology (CPT) and International Classification of Diseases, Ninth and Tenth Revisions (ICD-9 and ICD-10) codes. Patients were followed for ≥2 years, with a mean follow-up of 3.77 years. Clinical and radiographic outcomes were collected, and complications were documented using the Clavien-Dindo-Sink (CDS) classification. RESULTS: A total of 23 patients were included: 96% had ≥1 medical comorbidities, including 16 (70%) with congenital heart disease, of whom 88% had previous cardiac surgery, and 10 (44%) with thyroid disorders. All 23 patients underwent posterior spinal fusion. The mean estimated blood loss was 617 ± 459 mL, the mean length of the surgical procedure was 290 ± 92.7 minutes, and the mean length of hospital stay was 6.03 ± 2.91 days. The major Cobb angle measured 61.7° ± 17.6°, which corrected to 19.4° ± 14.8° (68.6% correction; p < 0.001), with well-maintained correction at 2 years of 22.0° ± 10.3° (64.3% correction; p = 0.158). Thirteen (57%) of 23 patients had a change in curve of >5°. There were no intraoperative complications; however, 12 patients (52%) sustained postoperative complications (e.g., need for reoperation, implant failure, and pulmonary complications), including 6 patients with CDS type 3 or 4 (e.g., wound dehiscence, late superficial abscess, pleural effusion, pseudarthrosis, and readmission for hypoxia). Four patients (17%) required a revision surgical procedure. One patient (4%) required an unplanned intensive care unit admission. CONCLUSIONS: Although instrumented spinal fusion can effectively correct spinal deformity in these patients, complications are more frequent than in children with adolescent idiopathic scoliosis, with over half of patients sustaining a complication. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

1- vs. 2-year follow-up after posterior spinal fusion for AIS: what additional information is gained?

PURPOSE: Traditionally, 2-year follow-up data have been the established standard for reporting clinical outcomes following spinal deformity surgery. However, previous studies indicate that 2-year follow-up does not represent long-term outcomes. Currently, there is no clear data that demonstrate a difference in outcomes between the 1 and 2 years postoperative time-periods following posterior spinal fusions (PSF) for adolescent idiopathic scoliosis (AIS). METHODS: A multi-center, prospective database was queried for AIS patients treated with PSF. Clinical outcome scores, assessed by SRS-22, coronal and sagittal radiographic parameters were assessed at time periods: 6 months, 1 year, and 2 years post operatively. Complications and reoperation rates were also assessed. Statistical analysis compared outcomes variables across time-points to assess for significant differences. RESULTS: 694 patients (82.6% female, mean age at surgery 14.9 ± 2.13 years) were identified. Between post-operative year 1 and 2, significant difference in SRS-22 domain scores were present for function domain (4.5 vs. 4.6; p < 0.001), mental health domain (4.3 vs. 4.2; p < 0.001), and total domain score (4.4 vs. 4.4; p = 0.03) but were below the minimal clinically important difference threshold. New complication development was significantly higher within the first year following surgery than the 1-2 year follow-up period (p < 0.001) with greater complication severity within the 0-1 year follow-up period (P = 0.03). CONCLUSION: There are no clinically important changes in SRS-22 domain scores between 1 and 2 years following PSF for AIS, with higher complications in the first year following PSF. Two-year follow-up data provide little added clinical information while under-estimating the cumulative complication and reoperation rates at long-term follow-up.

Ten-year follow-up of Lenke 5 curves treated with spinal fusion.

INTRODUCTION: Patients with surgically treated Lenke 5 curves require at least partial fusion of the lumbar spine. The implications of lumbar fusion remain unknown as long-term follow-up is sparse. METHODS: A retrospective review of a prospectively collected registry of patients with Lenke 5 curves treated with spinal fusion was performed. Clinical and radiographic outcomes as well as SRS-22 scores were collected at 2- and 10-year follow-up. RESULTS: 54 of 247 available patients met all inclusion criteria [26 treated with posterior spinal fusion (PSF) and 28 with anterior spinal fusion (ASF)]. Preoperative lumbar curve magnitude was 45.1 ± 8.4° and corrected to 14.0 ± 7.2° (p < 0.001). A 3.3 ± 7.3° increase in curve size was noted at final follow-up (p < 0.008) with 20.3% of patients having a loss of correction (LOC)of 10° or more. Thoracic curve correction and kyphosis were stable at 10-year follow-up. End vertebrae angulation improved from 11.2 ± 23.2° to 0.96 ± 6.4° (p = 0.004) and translation improved from 2.5 ± 2.9 to 0.92 ± 1.5 cm (p = 0.008) with no LOC. Disc wedging below the lower instrumented vertebrae increased from 0.3 ± 4.9° to 2.8 ± 4.4° (p < 0.001) with no change at 10 years. SRS-22 self-image and satisfaction improved from post-operative to final follow-up. No patient required a second operation. CONCLUSIONS: Both ASF and PSF showed durable results at 10-year follow-up with no obvious difference between approaches. 20% of patients had a LOC > 10°; this did not correlate with pain or need for revision surgery. Disc wedging was stable. Selection of LIV did not correlate with pain scores. LEVEL OF EVIDENCE: Level III.

Surviving Bad Meetings: Efficiencies to Thwart This Increasingly Common Administrative Time Vortex.

Meetings have become a near-constant presence in the practicing pediatric orthopaedist's day. While many meetings are productive and efficient, others may represent a time vortex that take precious hours away from other meaningful pursuits. Organizers and participants in meetings have an obligation to optimize these gatherings whenever possible. Selecting optimal times, ensuring that the minutes together are spent efficiently, creating an agenda and presenting ideas to be discussed in an effective manner, actively listening to other participants, and debriefing are all ways that meetings can be made more productive and enjoyable.

Continued Increase in Cost of Care Despite Decrease in Stay After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis.

INTRODUCTION: Previous studies have demonstrated decreased hospital length of stay (LOS) for children undergoing posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). METHODS: Hospitalization event data from the Kids Inpatient Database were queried for all PSF events for AIS performed in 2009, 2012, and 2016 using diagnosis and surgical codes. Data were subdivided into two groups: pre-enhanced recovery after surgery (ERAS) (2009 and 2012) and post-ERAS (2016). The primary outcome variables were LOS and total treatment charge (adjusted for 2020 inflation). Univariate and multivariate analysis were performed to identify differences in outcome variables. RESULTS: A total of 12,010 unique hospitalization events were identified, 74% female, mean 14.3 years. There was a decrease in LOS (pre-ERAS: 5.4 ± 4.0 versus 4.3 ± 3.2 days, P < 0.0001) with an increase in adjusted total treatment charge (pre-ERAS $193,544.4 ± $108,116.1 versus $200,469.1 ± $110,112.6; P = 0.0013). Pre-ERAS, male sex, smaller hospital, and non-Medicaid insurance were predictive of longer LOS, whereas pre-ERAS, older age, non-White race, male sex, hospital outside the Northeast, and non-Medicaid insurance were predictive of higher treatment costs. DISCUSSION: There continues to be a significant decrease in LOS for PSF hospitalization events for AIS; however, total treatment charges continue to rise. Future research should investigate potential factors influencing total treatment charges after PSF for AIS.

Complications following posterior spinal fusion for adolescent idiopathic scoliosis: a retrospective cohort study using the modified Clavien-Dindo-Sink system.

PURPOSE: Published complication rates after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) range from 1 to 22%. Complications are often minor and may be underestimated in registries. This study describes complications of PSF for AIS, classifies them according to a Clavien-Dindo-Sink (CDS) system, and investigates risk factors for occurrence of a complication. METHODS: This retrospective cohort study at two academic centers included all AIS patients aged 10-18 who underwent primary PSF 4/2014-12/2019. Data included demographics, comorbidities, curve magnitude, Lenke classification, levels osteotomized/fused, implant density, 90-day emergency department visits, readmissions, reoperations, and complications as defined by Harms Study Group. RESULTS: Among 424 patients, mean age was 14.7, mean BMI 22, 77% were female, and 57% had no comorbidities. There were 270 complications (0.64 per patient); 198 patients (47%) had ≥ 1 complication; and 63 patients (15%) had CDS grade ≥ II complications (deviation from standard postoperative course). Complications not related to persistent pain occurred in 103 patients (24%). Ninety-three percent of complications did not require readmission or reoperation (CDS I-II). Within 90 days, 8% presented to an ED, 2% required readmission, and 2% required reoperation. Common complications were back pain > 6 weeks postoperatively (26%), surgical site complications (7%), and ileus/prolonged constipation (3%). Risk factors for experiencing any complication were BMI ≥ 34 (OR 3.44) and Lenke 6 curve (OR 1.95). CONCLUSION: One in four AIS patients experiences a complication not related to persistent pain after primary PSF, higher than rates published from self-reported registries. Obesity and Lenke 6 curve may increase risk. While most do not require readmission or surgery, 15% of patients have their postoperative course altered by complications. LEVEL OF EVIDENCE: III-retrospective cohort study.

Slipped Capital Femoral Epiphysis Associated with Endocrinopathy: A Narrative Review.

¼: Slipped capital femoral epiphysis (SCFE) has a well-documented association with underlying endocrine conditions, including thyroid hormone aberrations and parathyroid dysfunction. ¼: Recombinant growth hormone therapy has also been identified as a risk factor for the development of SCFE. ¼: Presentation before their 10th birthday or after their 16th birthday along with height of <10th percentile are reliable risk factors for identifying children with an SCFE who are at a heightened risk for an underlying endocrinopathy and can been used to guide selective laboratory testing. ¼: Patients with unilateral SCFE presentations with an underlying endocrinopathy are at a heightened risk for contralateral slip development and should be treated with prophylactic fixation.

Risk factors for the development of DJK in AIS patients undergoing posterior spinal instrumentation and fusion.

PURPOSE: Typically, selection of lowest instrumented vertebra (LIV) in Adolescent Idiopathic Scoliosis (AIS) is based on the coronal radiograph; however, increasing evidence suggests that fusions proximal to the stable sagittal vertebrae (SSV) on the lateral radiograph can result in distal junctional kyphosis (DJK). The purpose of this study is to compare rates of DJK in patients with AIS that have a discordance between the Lowest Touched Vertebra (LTV) and the SSV and to identify risk factors for developing DJK. METHODS: Patients with AIS Lenke type 1, 2 and 3 curves treated with a posterior spinal fusion were separated into two groups. Group 1 had SSV that was proximal to the LTV whereas group 2 had SSV that was distal to the LTV. Comparisons were made for patients that were fused to the SSV(a), LTV(b) or between(c). Distal junctional angle (DJA) > 5° and increasing kyphosis at the end of the fusion construct were evaluated as risk factors for DJK. RESULTS: The rate of DJK was 0.0% in group 1a, 1b, and 1c compared to 4.3%, 18.5% and 10.0% in groups 2a, 2b and 2c, respectively(p < 0.001). The rate of DJK was 22.9% when the distal junctional angle(DJA) > 5° versus 1.4% when the DJA < 5°(p < 0.001). CONCLUSION: There was a low risk for progression of DJK when the SSV was proximal to the LTV, however, those with SSV distal to the LTV represent a high-risk group. Importantly, the development of DJK occurred almost exclusively in patients with LIV at the thoracolumbar junction which demonstrates that surgeons need to be cautious when ending fusions at T11, T12, and L1 in patients at high risk for DJK. Furthermore, having a distal junctional angle 5° or greater increased the risk of developing DJK by roughly 16-fold. At a minimum of 5-year follow-up, the development of DJK did not appear to adversely impact SRS outcomes or revision rates.

Modified Clavien-Dindo-sink classification system for adolescent idiopathic scoliosis.

PURPOSE: The Clavien-Dindosink (CDS) classification system provides more treatment-focused granularity than subjective methods of describing surgical complications; however, it has not been validated in posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). The purpose of this study was to modify the CDS system for application in patients with AIS undergoing PSF to assess its inter- and intra-rater reliability for describing complications faced by this population. METHODS: A review of all complications specific to patients with AIS captured in a large multicenter international database was performed. All complications were classified according to CDS, modified by addition of "prolonged initial hospital stay" as a criterion for Grade II. A survey of this complication list and an additional 20 clinical vignettes (sent out on two occasions) was sent to nine spinal deformity surgeons. Weighted kappa values were used to determine inter- and intra-rater reliability. RESULTS: The Fleiss κ value for interrater reliability among 5 respondents grading all AIS complications was 0.8 (very good). For each grade, interrater reliability was very good, with an overall range of 0.8-1. The overall kappa value for intrarater reliability among eight respondents grading 20 vignettes was between 0.6 (good) and 0.9 (very good). CONCLUSION: The modified CDS classification system has very good interrater and intrarater reliability in describing complications following PSF in patients with AIS. This system may be of greater utility for reporting outcomes than a "major" versus "minor" complication system and can serve as a valuable tool for improving surgical practices and patient outcomes in this population. LEVEL OF EVIDENCE: IV case series.

Blood loss estimation during posterior spinal fusion for adolescent idiopathic scoliosis.

PURPOSE: Blood loss (BL) during posterior spinal fusion for adolescent idiopathic scoliosis (AIS) may be estimated using a variety of unproven techniques. Patient care and research on BL are likely impacted by a lack of standardization. A novel FDA-approved blood volume (BV) analysis system (BVA-100 Blood Volume Analyzer) allows rapid processing with > 97% accuracy. The purpose of this study was to investigate common methods for BL estimation. METHODS: BV assessment was performed with the BVA-100. After obtaining a baseline sample of 5 mL of blood, 1 mL of I-131-labeled albumin was injected intravenously over 1 min. Five milliliter blood samples were then collected at 12, 18, 24, 30, and 36 min post-injection. Intravenous fluid was minimized to maintain euvolemia. Salvaged blood was not administered during surgery. BL was estimated using several common techniques and compared to the BV measurements provided by the BVA-100 (BVABL). RESULTS: Thirty AIS patients were prospectively enrolled with major curves of 54° and underwent fusions of 10 levels. BL based on the BVA-100 (BVABL) was 519.2 [IQR 322.9, 886.2] mL. Previously published formulas all failed to approximate BVABL. Multiplying the cell saver volume return by 3 (CS3) approximates BVABL well with a Spearman correlation coefficient and ICC of 0.80 and 0.72, respectively. An extrapolated cell salvage-based estimator also showed high intraclass correlation coefficient (ICC) and Spearman coefficients with less bias than CS3. CONCLUSION: Published formulaic approaches do not approximate true blood loss. Multiplying the cell saver volume by 3 or using the cell salvage-based estimator had the highest correlation coefficient and ICC. LEVEL OF EVIDENCE: Prospective cohort Level 2.

Application of a Halo Fixator for the Treatment of Pediatric Spinal Deformity.

BACKGROUND: In spine surgery, the halo fixator was initially utilized to stabilize cervical fusions in patients with poliomyelitis. More recently, the indications for halo fixation have evolved to include stabilization and definitive treatment for upper cervical spine injuries (Jefferson fractures, atlanto-occipital dissociations, odontoid fractures, etc.), treatment of atlantoaxial rotatory subluxation, stabilization of long cervical fusions, and preoperative traction. In the realm of pediatric spinal deformity, halo fixation has proved to be a valuable resource for severe or neglected spinal deformities. In this video article, we demonstrate the application of a halo fixator in a pediatric patient with severe scoliosis. DESCRIPTION: The procedure includes appropriate pin placement in the safe zones of the skull performed under either general anesthesia or local anesthesia. Pins are secured to a halo frame that is sized to be 2 cm larger than the circumference of the skull and are tightened according to age-specific torque guidelines. ALTERNATIVES: Alternative treatments vary from cervical spine immobilization to definitive surgical treatment in the spine, or even spinal osteotomies, depending on the underlying spinal pathology. RATIONALE: The halo fixator works by limiting motion of the cervical spine in flexion, extension, and axial rotation. The halo is also able to control and correct translational injuries of the cervical spine. In the setting of spinal deformity, the halo fixator can also be utilized to overcome the effects of gravity and lengthen the spine. EXPECTED OUTCOMES: For spinal deformities, the halo fixator can be expected to lengthen the spine and increase deformity flexibility prior to definitive surgical treatment in the spine or growth-friendly spinal instrumentation. IMPORTANT TIPS: Correct identification of safe zones for pin placement is vital to correct pin placement.For pediatric patients, it is important to obtain fixation with a minimum of 6 to 8 pins.Pins should be tightened with use of a torque-limiting wrench, up to no more than 1 in/lb (55.9 mm/kg) per year of age, up to a maximum of 8 in/lb (447.9 mm/kg).Applied traction should be a maximum of 50% of the body weight of the patient.Neurovascular examination is vital following application of weight.