Evaluation of shoulder balance in early onset scoliosis after definitive fusion and comparison with adolescent idiopathic scoliosis shoulder balance.

STUDY DESIGN: The Children Spine Study Group registry was queried for early onset scoliosis (EOS) patients who had final definitive spinal fusion after their scoliosis was managed with either growing rods or VEPTR. The Harms Study Group registry was queried for adolescent idiopathic scoliosis (AIS) patients who had definitive fusion OBJECTIVE: The goal is to assess shoulder alignment in EOS patients after a definitive fusion and how these radiographic outcomes relate to the more familiar situation of post-definitive fusions shoulder alignment in AIS patients. BACKGROUND: EOS is a challenging pathology to manage. Numerous components are important in the success of spinal surgery for this population. Shoulder balance is a one of the components that is easily seen by the patient. Recently, the importance of its relationship to patient satisfaction has received greater attention. METHODS: Sample size: n = 145 (EOS (n = 34) and AIS (n = 111)). Shoulder balance parameters (SBP) of clavicular angle (CA), coracoid height difference (CHD), clavicular tilt angle difference (CTAD), and clavicle-rib cage intersection difference (CRID) measurements were measured from the reviewed radiographs and documented pre-definitive, post-definitive and 2-year follow-up measures. Shoulder balance parameters were compared between EOS and AIS cohorts at documented intervals. RESULTS: EOS mean pre-definitive fusion SBPs (CA, CTAD, CRID, CHD) were significantly higher compared to AIS, p = 0.004, 0.003, < 0.001, < 0.001, respectively. Significant post-definitive fusion corrections were noticed for CTAD (0.01), CHD (0.01), nearly significant CA (0.07), non-significant CRID in EOS patients. In AIS patients, no significant corrections were noticed for CA, CTAD, CHD and but significant for CRID (0.02). At post-definitive and 2-year follow-up, CA, CRID, CHD were not significant between cohorts, but CTAD (< 0.01) was significantly higher in EOS cohort at final follow-up. CONCLUSION: Post-definitive and 2-year follow-up shoulder balance for EOS patients was not significantly different from AIS patients. LEVEL OF EVIDENCE: III.

Assessing clinical trunk change with surface topography: anterior scoliosis correction as a model to evaluate curve progression.

PURPOSE: Previous work has suggested that surface topography can be used for repeated measurements of deformity during curve monitoring following an initial radiograph. Changes in deformity during natural curve progression may be subtle. An important preemptive question to answer is whether topography can follow a large change in spine deformity, as in scoliosis correction. We assess the ability of surface topography to track the evolution of spine deformity during anterior scoliosis correction relative to traditional radiographs. Anterior scoliosis correction was chosen for this analysis because it changes the shape of the trunk without leaving a surgical scar and muscle atrophy along the posterior spine. METHODS: Following IRB approval, 18 patients aged 14.6 ± 2.0 years at surgery were enrolled in a retrospective review of coronal radiographs and topographic scans acquired before and after scoliosis correction. Radiographic and topographic measures for the coronal curve angle before and after surgery were compared. RESULTS: Surface topography estimates correlate with radiographic measures of the pre- (r = 0.7890, CI = [0.4989 0.9201], p < 0.00001), postsurgical (r = 0.7485, CI = [0.4329 0.9006], p = 0.0004), and the change in the coronal curve angle (r = 0.6744, CI = [0.3028 0.8680], p = 0.0021) due to surgery. CONCLUSIONS: We provide evidence open for further extension that topography can follow changes in the coronal curve angle comparably to radiographs. LEVEL OF EVIDENCE: Level IV.

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.

Vertebral growth modulation by posterior dynamic deformity correction device in skeletally immature patients with moderate adolescent idiopathic scoliosis.

STUDY DESIGN: Retrospective, comparative, multicenter. INTRODUCTION: Growth modulating spinal implants are used in the management of scoliosis such as anterior vertebral body tethering. A motion-sparing posterior device (PDDC) was recently approved for the treatment of moderate AIS. The purpose of this study was to determine if the PDDC can modulate growth in skeletally immature patients with AIS. METHODS: From a database of patients treated with the PDDC over 4 years, we identified those who had a minimum of 2 years follow-up. Pre-operative and post-operative Cobb angles and coronal plane wedging of the apical vertebra were evaluated on standing full length radiographs. Independent sample t test and one-way ANOVA with post-hoc Tukey HSD analysis was used to compare three groups in varying skeletal maturity: Risser 0-1, Risser 2-3, and Risser 4-5. RESULTS: 45 patients (14.2-years old, 11-17) were evaluated with a mean pre-op curve of 46° (35°-66°). The average preoperative major curve magnitude, of either Lenke 1 or 5 curve type, was similar among the three groups 47.6°, 46° and 41.5°. Deformity correction was similar in the three groups, with reduction to 26.4°, 20.4° and 26.2°, respectively, at final follow-up [p < 0.05]. Pre-op wedging 7.4° (3.8°-15°) was reduced after surgery to 5.7° (1°-15°) (p < 0.05). Of those patients, Risser 0-1 (n = 16) had preoperative wedging of 9.5° (6°-14.5°) that was reduced to 5.4° (1°-8°) postoperatively (p < 0.05); Risser 2-3 (n = 15) had pre-op 7.7° (4°-15°) vs. post-op 7.0° (3°-15°); Risser 4-5 (n = 14) had pre-op 4.8° (3.8°-6.5°) vs. post-op 4.7° (3.7°-6.5°). Delta Wedging in Risser 0-1 stage was significantly different than for Risser 2-3 and for Risser 4-5. CONCLUSION: The posterior dynamic deformity correction device was able to modulate vertebral body wedging in skeletally immature patients with AIS. This was most evident in patients who were Risser 0-1. In contrast, curve correction was similar among the three groups. This finding lends support to the device's ability to modulate growth.

Surgical management of moderate adolescent idiopathic scoliosis with a fusionless posterior dynamic deformity correction device: interim results with bridging 5-6 disc levels at 2 or more years of follow-up.

OBJECTIVE: A posterior dynamic deformity correction (PDDC) system was used to correct adolescent idiopathic scoliosis (AIS) without fusion. The preliminary outcomes of bridging only 3-4 discs in patients with variable curve severity have previously been reported. This paper examines a subgroup of patients with the authors' proposed current indications for this device who were also treated with a longer construct. METHODS: Inclusion criteria included a single AIS structural curve between 40° and 60°, curve flexibility ≤ 30°, PDDC spanning 5-6 levels, and minimum 2-year follow-up. A retrospective review was conducted and demographic and radiographic data were recorded. A successful outcome was defined as a curve magnitude of ≤ 30° at final follow-up. Any serious adverse events and reoperations were recorded. RESULTS: Twenty-two patients who met the inclusion criteria were operated on with the PDDC in 5 medical centers. There were 19 girls and 3 boys, aged 13-17 years, with Risser grades ≥ 2. Thirteen had Lenke type 1 curves and 9 had type 5 curves. The mean preoperative curve was 47° (range 40°-55°). At a minimum of 2 years' follow-up, the mean major curve measured 25° (46% correction, p < 0.05). In 18 (82%) of 22 patients, the mean final Cobb angle measured ≤ 30° (range 15°-30°). Trunk shift was corrected by 1.5 cm (range 0.4-4.3 cm). The mean minor curve was reduced from 27° to 17° at final follow-up (35% correction, p < 0.05). For Lenke type 1 patterns, the mean 2D thoracic kyphosis was 24° preoperatively versus 27° at final follow-up (p < 0.05), and for Lenke type 5 curves, mean lumbar lordosis was 47° preoperatively versus 42° at final follow-up (p < 0.05). The mean preoperative Scoliosis Research Society-22 questionnaire score improved from 2.74 ± 0.3 at baseline to 4.31 ± 0.4 at 2 years after surgery (p < 0.0001). The mean preoperative self-image score and satisfaction scores improved from preoperative values, while other domain scores did not change significantly. Four patients (18%) underwent revision surgery because of nut loosening (n = 2), pedicle screw backup (n = 1), and ratchet malfunction (n = 1). CONCLUSIONS: In AIS patients with a single flexible major curve up to 60°, the fusionless PDDC device achieved a satisfactory result as 82% had residual curves ≤ 30°. These findings suggest that the PDDC device may serve as an alternative to spinal fusion in select patients.

Surgeon and Caregiver Agreement on the Goals and Indications for Scoliosis Surgery in Children With Cerebral Palsy.

STUDY DESIGN: Prospective multicenter comparative study. OBJECTIVES: We aimed 1) to survey surgeons and caregivers to rank the surgical indications for spinal fusion of pediatric patients with neuromuscular scoliosis secondary to cerebral palsy in order of importance and 2) to characterize the agreement of surgeons and caregivers on major (top three) indications. SUMMARY OF BACKGROUND DATA: Surgery for spinal deformity in children with cerebral palsy is a multifaceted and individualized decision that may lead to miscommunication during informed consent. Little data exist on communication effectiveness between surgeon and caregiver during preoperative discussion. METHODS: This is a multicenter, prospective survey of Harms Study Group patient caregivers and their surgeons. Participants ranked their most important of 15 indications in descending level of importance, where the top 3 selections were considered major indications for surgery for the particular patient in question. Demographic and other perioperative factors were recorded. Surgeon-caregiver agreement on major indications was determined, taking into account preoperative factors and intersurgeon differences. RESULTS: 126 surgeon-caregiver pairs responded. The greatest percentage agreement that an indication was major was "to improve sitting" (69.0% major, 0.8% nonmajor), followed by "to prevent pulmonary compromise" (33.3% major, 24.6% nonmajor), "to improve pain" (31.7% major, 20.6% nonmajor), and "to improve head control/position" (20.7% major, 69.0% nonmajor). Preoperative pain showed an association with surgeon-caregiver agreement on pain as a major indication (p=.004), and intersurgeon differences in agreement on gastrointestinal and pain considerations existed (p=.002, p=.007, respectively). CONCLUSIONS: Surgeon-caregiver agreement is greater where literature support for a particular surgical indication is strong (ie, spinal fusion's known improvement of sitting posture in children with neuromuscular scoliosis). Stronger literature support may bolster surgeons' confidence in recommending a particular procedure, fostering greater communication, understanding, and agreement on surgical necessity between caregivers and surgeons. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Ponte Osteotomies Increase the Risk of Neuromonitoring Alerts in Adolescent Idiopathic Scoliosis Correction Surgery.

STUDY DESIGN: Observational cohort study of prospective database registry. OBJECTIVE: To determine the incidence of neurological complications in AIS patients undergoing surgical treatment with PO. SUMMARY OF BACKGROUND DATA: Despite the widespread use of Ponte Osteotomies (PO) in adolescent idiopathic scoliosis (AIS) correction, outcomes and complications in patients treated with this technique have not been well characterized. METHODS: A multicenter prospective registry of patients undergoing surgical correction of AIS was queried at 2-year follow-up for patient demographics, surgical data, deformity characteristics, and peri-operative complications. A neurological complication was defined as perioperative nerve root or spinal cord injury as identified by the surgeon. Patients were divided into those who underwent peri-apical PO and those without, and further stratified by Lenke curve classification into 3 groups (I-types 1 and 2, II-types 3, 4, 6, and III-type 5). Patients with- and without neurological complications were compared with respect to baseline demographics, surgical variables, curve types, fusion construct types (screws vs. hybrid), curve magnitude (coronal and sagittal Cobb), apical vertebral translation, and coronal-deformity angular ratios (C-DAR). RESULTS: Of 2210 patients included in the study, 1611 underwent PO. Peri-operative neurological complications occurred in 7 patients, with 6 in the PO group (0.37%) and 1 in non-PO group (0.17%) though this was not a statistically significant risk factor for peri-operative neurological injury (P = 0.45). Neuromonitoring alerts were recorded in 168 patients (7.6%: 9.3% PO group; 4.2% no-PO group (P < 0.001)). Multivariate logistic regression analysis found PO and curve magnitude to be independent risk factors for intraoperative neuromonitoring alerts (P < 0.01). CONCLUSION: PO and curve magnitude were independent risk factors for intraoperative neuromonitoring alerts in surgical AIS correction. The effect of Ponte osteotomy on neurological complications remains unknown due to the low incidence of these complications. LEVEL OF EVIDENCE: 3.

Disc Degeneration in Unfused Caudal Motion Segments Ten Years Following Surgery for Adolescent Idiopathic Scoliosis.

HYPOTHESIS: The frequency of disc degeneration (DD) in the distal mobile segments will increase over time following surgery for adolescent idiopathic scoliosis (AIS). DESIGN: Retrospective review of a prospective AIS registry. INTRODUCTION: Durability of surgical outcomes is essential for maintenance of quality of life as well as for family decision making and for assessment of the value of a healthcare intervention. We assessed DD, its risk factors, and association with health-related quality of life 10 years after AIS surgery. METHODS: Five radiographic indicators of DD, previously validated, were evaluated preoperatively and 1 month, 2, 5, and 10 years postoperatively by a radiologist in operative AIS patients. A composite radiographic score (CRS; range 0-10) was calculated using the sum of each of the DD indicators. The severity of CRS in relation to the time point after surgery and various risk factors were assessed using linear regression or Pearson χ2 test. CRS ≥3 was chosen to indicate significant DD. Association of CRS with SRS-22 outcome was evaluated by linear regression. RESULTS: 193 consecutive patients (mean age at surgery 14.4 years; 86% female) were assessed. Surgical approach included 102 posterior and 91 anterior fusions. Contributors to maximum CRS at 10 years were Schmorl's nodes (7.3% of patients), osteophytes (40.4%), sclerosis (29%), and irregular endplate (8.3%). CRS ≥3 occurred in 1.6%, 0.54%, 3.7%, 6.8%, and 7.3% of patients at the various time points (r2=0.83, p=.0313), respectively. More than 50% of DD occurred at the second (35.5%) and third (20%) disc caudal to the LIV. LIV of L4 compared with more cephalad LIV had the highest risk of developing significant DD (27.3%; p=.0267). It was found that disc wedging subjacent to the LIV (≥5°) and LIV translation (≥2 cm) lead to a sixfold increase in significant DD (odds ratio=6.71 and 6.13, respectively). Severity of DD was not associated with the number of levels fused (p=.2131), the surgical approach (p=.8245), or the construct type (p=.2922). No significant association was established between 10-year CRS and SRS-22 scores. CONCLUSION: In the first study of its kind, we found that only 7.3% of patients had significant DD 10 years after surgical correction of AIS. Rates of DD increased over time. Our data provide evidence to support recommendations to save as many caudal motion segments as possible, to avoid fusing to L4, and maintain the LIV tilt angle below 5° and LIV translation less than 2 cm.

A Detailed Comparative Analysis of Anterior Versus Posterior Approach to Lenke 5C Curves.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To prospectively compare radiographic, perioperative, and functional outcomes between anterior spinal instrumentation and fusion (ASIF) and posterior spinal instrumentation and fusion (PSIF) in Lenke 5C curves. SUMMARY OF BACKGROUND DATA: Historically, ASIF has been the treatment of choice for treatment of thoracolumbar adolescent idiopathic scoliosis. More recently, PSIF has gained popularity for its ease, versatility, and amount of correction achieved. Current literature lacks a prospective comparative analysis between these two approaches to better aid treating surgeons in decision making when treating Lenke 5C curves. METHODS: A prospective, longitudinal multicenter adolescent idiopathic scoliosis database was used to identify 161 consecutive patients with Lenke 5C curves treated by ASIF with a dual rod system, or PSIF with a pedicle screw-rod construct. Pre- and 2-year postoperative radiographic data, Scoliosis Research Society outcome scores, and perioperative comparisons were made between the two approaches. RESULTS: A total of 69 patients were treated with ASIF and 92 patients with PSIF. Curve extent, magnitude, stable, and end vertebrae distribution before surgery were similar between the two groups. At 2-year follow-up, there were no significant differences in percentage correction of the main curve (ASIF: 59.1%, PSIF: 59.6%), C7 decompensation (ASIF: -0.6 ±â€Š1.2, PSIF: -0.3 ±â€Š1.4 cm), length of hospital stay (ASIF: 5.6 days, PSIF: 5.7 days), postoperative day conversion to oral pain medication (ASIF: 3.2 days, PSIF: 3.2 days), and SRS outcome scores (P = 0.560) between the two groups. The number of levels fused was significantly lower in ASIF group (ASIF: 4.7, PSIF: 6.3; P < 0.001), but PSIF resulted in significantly less disc angulation below lowest instrumented vertebrae (ASIF: 3.4°, PSIF: 1.7°; P = 0.011), greater lumbar lordosis (P < 0.001), and greater % correction of lumbar prominence (P = 0.017). CONCLUSION: The amount of correction achieved was similar between ASIF and PSIF. ASIF resulted in shorter fusions (average 1.6 levels) compared with PSIF. This was at the expense of increased disc angulation below the lowest instrumented vertebrae, less lumbar lordosis, and a lower % correction of the lumbar prominence than PSIF. LEVEL OF EVIDENCE: 2.

Evolution of Surgery for Adolescent Idiopathic Scoliosis Over 20 Years: Have Outcomes Improved?

STUDY DESIGN: Retrospective review of a prospective adolescent idiopathic scoliosis (AIS) registry. OBJECTIVE: To study the evolution of the operative approach, outcomes, and complication rates in AIS surgery over the past 20 years. SUMMARY OF BACKGROUND DATA: Surgical techniques in AIS surgery have evolved considerably over the past 20 years. We study the trends in the operative management of AIS over this period and their impact on perioperative outcomes. METHODS: A total of 1819 AIS patients (1995-2013) with 2-year F/U were studied. Operative approach, perioperative parameters, major complication rates, and SRS outcomes were assessed. Linear regression was used to assess the trend of changes over 5-year quartiles. RESULTS: Mean age at surgery was 14.6 ±â€Š2.1 years, 80.2% were females, and this remained consistent throughout. Operative time, EBL/level, and LOS decreased over the 20 years (P < 0.0001). The use of antifibrinolytic (AF) increased from 6.7% to 68.8% in the past 10 years (P < 0.0001). Number of levels fused increased and LIV was more distal (in relation to stable vertebrae) over time in Lenke 1 and 2 curves (levels fused 7.97-9.94, P < 0.0001 and 9.8-11.0, P=0.0134, respectively). Anterior spinal fusion (ASF) in Lenke 1 curves decreased from 81% in the first quartile to 0% in the last (P = 0.0429). ASF for Lenke 5 curves evolved from 78% in the second quartile to 0 in the last. Thoracoplasty performance decreased from 76% to 20.3% (P = 0.1632). All screw constructs in PSF cases increased from 0% to 98.4% (P = 0.0095). Two-year major complication rates decreased over time (18.7%-5.1%; P = 0.0173). Increased improvement in SRS scores were observed in pain, image, function, and total domains. CONCLUSION: Evolution of surgical technique in AIS over the past 20 years has resulted in a cessation of anterior only surgery, increasing use of all screw constructs, less blood loss, greater use of AF, shorter operative times and LOS, lower major complications rates, and greater improvements in SRS scores. LEVEL OF EVIDENCE: 2.

Anesthetic considerations for a novel anterior surgical approach to pediatric scoliosis correction.

BACKGROUND: Idiopathic scoliosis is a condition that may require surgical correction. Limitations of previous surgical modalities, however, created the need for novel methods of repair. One such technique, a newer form of anterolateral scoliosis correction, has shown considerable promise, which our center has had substantial experience performing. AIM: In this article, we present the case details of our first 105 patients for the purposes of describing the evolution and details of the anesthetic management and considerations for this procedure. METHODS: A retrospective review of medical records for 105 patients undergoing anterolateral instrumentation procedure for idiopathic scoliosis correction done at a single institution from May 2014 to June 2016 was performed. The details of perioperative management as well as surgical technique were reported for all patients. RESULTS: The mean age for patients was 14.8 years (range 10-18); the mean weight was 49.9 kg (range 25-82). Unilateral procedures were performed on 46.7%, with bilateral and hybrid procedures performed on 50.5% and 4.7%, respectively. The median number of levels corrected was 8 (interquartile range [IQR] 7-9) for unilateral, right 7 (IQR 6-7) and left 5 (IQR 4-5) for bilateral, and 4 (IQR 4-4.5) for hybrids. The average estimated blood loss (EBL) was 310 mL±138, with cell salvaged blood transfused in 61% of patients, and allogenic blood transfusion required in only two patients. CONCLUSIONS: The described anesthetic and analgesic management provides a framework for delivering perioperative care for this challenging procedure, which is gaining popularity as a modality for scoliosis correction.

Risk Factors of Proximal Junctional Kyphosis in Adolescent Idiopathic Scoliosis-The Pelvis and Other Considerations.

STUDY DESIGN: Prospective multicenter database study. OBJECTIVES: To assess the incidence of proximal junctional kyphosis (PJK) in operative adolescent idiopathic scoliosis (AIS) using contemporary surgical techniques and to identify risk factors for PJK. SUMMARY OF BACKGROUND DATA: The incidence of PJK has been reported as high as 46% in AIS. Factors associated with PJK have been incompletely explored. METHODS: Prospectively enrolled 851 AIS patients (2000-2011, 78.5% female, average 14.4 years) were evaluated 2 years postoperatively. Radiographic and sagittal spinopelvic parameters and rod contour angle (RCA), a new measure that reflects the proximal contouring of the rod, were independently evaluated for association with PJK based on Lenke type. Multivariate logistic regression with backward elimination was performed to identify risk factors for PJK. RESULTS: Overall PJK incidence was 7.05% and varies based on Lenke type (Lenke 1, 6.35%; Lenke 2 and 4, 4.39%; Lenke 3 and 6, 11.64%; and Lenke 5, 8.49%; p = .06). Among patients with Lenke 1 curves, risk factors for PJK were loss of kyphosis after surgery, and stopping caudal to the upper end vertebra (UEV). The risk of developing PJK increases by 7.1% with each lost degree of kyphosis compared with preoperation that occurs after the instrumentation is placed. For Lenke 2 and 4 curves, loss of kyphosis and more lordotic (negative) RCA were risk factors for PJK. For Lenke 3 and 6 curves, larger preoperative T5-T12 kyphosis was the only significant risk factor for PJK. Upper instrumented vertebra (UIV) at or cephalad to the UEV was associated with increased risk of PJK in Lenke 5 curves, which was contrary to the finding for Lenke 1 curves. No significant correlation was found between sagittal pelvic parameters and developing PJK. CONCLUSION: The incidence of PJK in patients after surgery for AIS is 7.05% and varies based on Lenke type. Loss of kyphosis, larger preoperative kyphosis, UIV caudal to the proximal UEV (Lenke 1), UIV at or cephalad to the UEV (Lenke 5), and decreased RCA were the major risk factors for PJK in AIS. LEVEL OF EVIDENCE: Level II.

MRI Screening in Operative Scheuermann Kyphosis: Is it Necessary?

STUDY DESIGN: Patients with preoperative spine magnetic resonance imaging (MRI) studies from a prospective multicenter study of operative adolescent Scheuermann kyphosis (SK). OBJECTIVES: To investigate the usefulness of MRI screening in operative planning for SK surgeries. SUMMARY OF BACKGROUND DATA: Neural axis abnormalities in operative SK have not been previously studied with MRI screening, despite its use. METHODS: One orthopedic surgeon and two radiologists evaluated all images retrospectively. Radiographs were evaluated for kyphosis apex and magnitude. MRIs were evaluated for spinal cord abnormalities, epidural lipomatosis, location and number of vertebral wedging, Schmorl nodes and posterior disc herniations, frequency of spondylolysis, etc. The relationship of these pathologies to the kyphosis apex was explored. This group was compared to a surgical SK group without preoperative MRIs. RESULTS: Eighty-six patients with MRIs, mean age 16.3 years, 64% male, and a mean preoperative kyphosis of 75.9° were evaluated. There were 17 spinal cord abnormalities. Low-lying conus was found in 2 patients, and syrinx in 15 (no Chiari malformations). Epidural lipomatosis was found in 49 patients, average of 5.7 levels. Anterior vertebral wedging occurred in all (mean 4.7 levels). Posterior disc herniations averaged 5.2 levels/patient and 1.8 levels caudad to the apex. Spondylolysis was reported in 8.1%. Four cases (4.7%) had the operative plan changed as a result of the preoperative MRI: two due to neural compression, one due to disc herniation and one due to a spinal cord draped over the apex. Thirty-one patients did not receive an MRI; there were no significant differences between the two groups. The rate of postoperative neurologic change was 3.5% in the MRI group and 3.2% in the no-MRI group. CONCLUSIONS: Based on 4.7% of cases requiring a change in the operative plan as a result of preoperative MRI, the authors recommend considering performing screening MRI in operative SK patients.

Factors affecting the outcome in appearance of AIS surgery in terms of the minimal clinically important difference.

PURPOSE: The minimal clinically important difference (MCID) of the Appearance domain of the SRS-22 questionnaire is an increase ≥1.0 in surgically treated patients with adolescent idiopathic scoliosis (AIS). However, no study has sought to identify the factors associated with an SRS-22 Appearance score increase greater than the MCID at 2 years. METHODS: A retrospective analysis was performed on a prospectively collected multicenter database of 1020 surgically treated AIS patients with a minimum 2-year follow-up. Patients were divided into two cohorts: "I" = Improved after surgery (Δ Appearance ≥1.0) and "NI" = Not improved after surgery (Δ Appearance <1.0). Univariate regression was used to find a significant difference between the cohorts for individual measures. Multivariate logistic regression was used to find continuous predictors. RESULTS: 663 (65%) patients were improved greater than the MCID, and 357 were not improved (35%). The improved cohort trended toward a greater percentage of underweight patients (p = 0.074) with lower preoperative SRS Appearance scores (p < 0.001) and larger preoperative trunk shifts (p = 0.033). Postoperatively, those patients with greater percent correction of thoracic (p = 0.021) and lumbar (p = 0.003) Cobb angles, smaller apical lumbar translation (p = 0.006), and a greater correction in trunk shift (p = 0.003) were most likely to attain the MCID. CONCLUSION: Several factors influence which patients are most likely to attain the MCID following surgery for AIS. Factors such as preoperative appearance scores and body weight are patient specific; other factors such as percent correction of the thoracic and lumbar Cobb angles, trunk shift, and lumbar apical translation may be influenced by the surgeon. LEVEL OF EVIDENCE: II.

The Classification for Early-onset Scoliosis (C-EOS) Correlates With the Speed of Vertical Expandable Prosthetic Titanium Rib (VEPTR) Proximal Anchor Failure.

BACKGROUND: The Classification for Early-onset Scoliosis (C-EOS) was developed by a consortium of early-onset scoliosis (EOS) surgeons. This study aims to examine if the C-EOS classification correlates with the speed (failure/unit time) of proximal anchor failure in EOS surgery patients. METHODS: A total of 106 EOS patients were retrospectively queried from an EOS database. All patients were treated with vertical expandable prosthetic titanium rib and experienced proximal anchor failure. Patients were classified by the C-EOS, which includes a term for etiology [C: Congenital (54.2%), M: Neuromuscular (32.3%), S: Syndromic (8.3%), I: Idiopathic (5.2%)], major curve angle [1: ≤20 degrees (0%), 2: 21 to 50 degrees (15.6%), 3: 51 to 90 degrees (66.7%), 4: >90 degrees (17.7%)], and kyphosis ["-": ≤20 (13.5%), "N": 21 to 50 (42.7%), "+": >50 (43.8%)]. Outcome was measured by time and number of lengthenings to failure. RESULTS: Analyzing C-EOS classes with >3 subjects, survival analysis demonstrates that the C-EOS discriminates low, medium, and high speed of failure. The low speed of failure group consisted of congenital/51-90/hypokyphosis (C3-) class. The medium-speed group consisted of congenital/51-90/normal and hyperkyphosis (C3N, C3+), and neuromuscular/51-90/hyperkyphosis (M3+) classes. The high-speed group consisted of neuromuscular/51-90/normal kyphosis (M3N), and neuromuscular/>90/normal and hyperkyphosis (M4N, M4+) classes. Significant differences were found in time (P<0.05) and number of expansions (P<0.05) before failure between congenital and neuromuscular classes.As isolated variables, neuromuscular etiology experienced a significantly faster time to failure compared with patients with idiopathic (P<0.001) and congenital (P=0.026) etiology. Patients with a major curve angle >90 degrees demonstrated significantly faster speed of failure compared with patients with major curve angle 21 to 50 degrees (P=0.011). CONCLUSIONS: The ability of the C-EOS to discriminate the speeds of failure of the various classification subgroups supports its validity and demonstrates its potential use in guiding decision making. Further experience with the C-EOS may allow more tailored treatment, and perhaps better outcomes of patients with EOS. LEVEL OF EVIDENCE: Level III.

Reversible Intraoperative Neurophysiologic Monitoring Alerts in Patients Undergoing Arthrodesis for Adolescent Idiopathic Scoliosis: What Are the Outcomes of Surgery?

BACKGROUND: Confidence in intraoperative neurophysiologic monitoring (IONM) data can allow scoliosis surgeons to proceed with surgery even after a monitoring alert, assuming the recovery of signals. We sought to determine the outcomes of surgical treatment of adolescent idiopathic scoliosis (AIS) after a notable IONM alert. METHODS: We identified 676 patients who underwent arthrodesis with use of IONM for the treatment of AIS. The patients were divided into 2 cohorts: those who experienced a lower-extremity IONM alert and those who did not. An alert was defined as a notable change in IONM data, specifically, a ≥50% drop in somatosensory evoked potentials (SSEPs) and/or in transcranial motor evoked potentials (tcMEPs). RESULTS: Of the 676 patients, 36 (5.3%) experienced IONM alerts. Those patients had a larger preoperative major Cobb angle (mean of 61° ± 13° compared with 55° ± 12° for the no-alert group; p < 0.01), a greater number of levels fused (mean of 12 ± 2 compared with 11 ± 2; p < 0.01), a longer operative duration (mean of 357 ± 157 minutes compared with 298 ± 117 minutes; p < 0.01), a higher estimated blood loss (1,857 ± 1,323 mL compared with 999 ± 796 mL; p < 0.01), and a greater volume of autologous blood transfused (mean of 527 ± 525 mL compared with 268 ± 327 mL; p < 0.01). Among patients who experienced an alert and had a completed operation (34 of 36 patients), mean postoperative radiographic measurements were similar to those of the no-alert group in terms of the percentage of correction of the major Cobb angle (alert, 66% ± 13%; no alert, 64% ± 19%; p = 0.53) and of rib prominence (alert, 49% ± 36%; no alert, 47% ± 46%; p = 0.83) and measurement of thoracic kyphosis (alert, 23° ± 10°; no alert, 22° ± 2°; p = 0.58). The Scoliosis Research Society (SRS)-22 outcome scores were also similar between the 2 cohorts. CONCLUSIONS: Notable IONM changes occurred in 5.3% of the patients who underwent arthrodesis for AIS. Those patients had larger preoperative deformity, a longer operative duration, a greater number of levels fused, a higher estimated blood loss, and a greater volume of autologous blood transfused. Return of IONM data guided the surgeon to safely complete the procedure in 34 of 36 patients, with correction similar to that of patients who did not experience an alert. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

VEPTR Implantation After Age 3 is Associated With Similar Radiographic Outcomes With Fewer Complications.

BACKGROUND: The purpose of this study was to analyze the risks and benefits of early vertical expandable prosthetic titanium rib (VEPTR) implantation (below 3 y of age) compared with delayed intervention (3 to 6 y of age). Early intervention with milder deformity may make device implantation easier and may facilitate symmetric chest and pulmonary development. However, later intervention may decrease the number of lengthenings required, and implant anchor points and bone quality may be better in older patients. METHODS: A multicenter prospective database of patients treated with the VEPTR device was retrospectively reviewed. A total of 71 patients with minimum 5-year follow-up were included. Thirty-seven patients had VEPTR surgery below 3 years of age (group 1), and 34 patients had surgery between 3 and 6 years of age (group 2). Radiographs from the preoperative, immediate postoperative, and most recent follow-up visits were reviewed to determine coronal plane deformity and change in T1-T12 height over time. Complications were analyzed using a nonparametric mean cumulative function for the number of complications per subject over time. RESULTS: Patients in both groups had similar diagnoses, ASA scores (P=0.22), and number of lengthenings (10±4 in both groups, P=0.40). Preoperative and most recent major Cobb angles were not significantly different between the 2 groups [66±22 and 60±20 degrees (group 1) vs. 63±19 and 57±23 degrees (group 2), respectively] (P=0.38). The change in T1-T12 was significantly correlated with the number of lengthenings (P<0.001); however, there was no difference between age groups (P=0.55). There were 118 complications in 33 subjects in group 1 and there were 69 complications in 28 subjects in group 2. The number of complications per lengthening was significantly different between the 2 age groups (P<0.001). Subjects in group 2 had 41% fewer complications per lengthening compared with subjects in group 1 (P<0.001). CONCLUSIONS: VEPTR treatment resulted in similar deformity control and thoracic growth in both age groups with lower complication rates in the older population. The rate of complications was similar between the 2 groups for the first 2 years postimplantation, but after 2 years, the rate of complications increased over time faster for the younger group compared with the older group. LEVEL OF EVIDENCE: Level III-retrospective chart and radiographic review.

Major perioperative complications after spine surgery in patients with cerebral palsy: assessment of risk factors.

PURPOSE: A prospective, longitudinal cohort was studied to determine the incidence, consequences, and risk factors of major perioperative complications in patients with cerebral palsy (CP) treated with spinal fusion. There is a wide variety of data available on the complications of spine surgery; however, little exists on the perioperative complications in patients with CP. METHODS: A prospective multicenter dataset of consecutive patients with CP treated with spinal fusion was evaluated. All major perioperative complications were identified and stratified into categories: pulmonary, gastrointestinal, other medical, wound infection, neurological, instrumentation related, and unplanned staged surgery. Univariate and multivariate analyses were performed to identify various risk factors for major perioperative complications. RESULTS: 127 patients were identified with a mean age of 14.3 ± 2.6 years. Overall, 39.4% of the patients had a major perioperative complication. Occurrence of a complication [no complication (NC), yes complication (YC)] resulted in significantly increased intensive care unit (ICU) (NC = 3.2 days, YC = 7.8 days, p < 0.05) and hospital stays (NC = 7.7 days, YC = 15.6 days, p < 0.05). Variables associated with greater risk of a complication included: increased estimated blood loss (EBL) (p < 0.001), larger preoperative kyphosis (p = 0.05), staged procedures (p < 0.05), a lack of antifibrinolytic use (p < 0.05), and a trend toward lower body mass index (BMI) (p = 0.08). Multivariate regression analysis revealed an increased EBL as independently associated with a major perioperative complication (p < 0.05). CONCLUSIONS: In this cohort of patients with CP who underwent spinal fusion, 39.4% experienced a major perioperative complication, with pulmonary being the most common. The occurrence of a major perioperative complication lengthened both ICU and hospital stay. Risk factors for major perioperative complications included greater preoperative kyphosis, staged procedures, a lack of antifibrinolytic use, and increased EBL, with the latter being an independent predictor of a major perioperative complication. LEVEL OF EVIDENCE: 2.

Minimally Invasive Lateral Interbody Fusion in the Treatment of Scoliosis Associated with Myelomeningocele.

INTRODUCTION: Surgical correction of spinal deformity in myelomeningocele is associated with high rates of pseudarthrosis and implant failure. The anterior fusion is traditionally a wide exposure from the thorax to the sacrum. We report minimally invasive lateral interbody fusion (MILIF) to address the issue of fusion between vertebrae with marginal posterior elements while minimizing the morbidity of an open approach. MATERIALS AND METHODS: We performed a single-center, retrospective review of patients with myelomeningocele and severe scoliosis who underwent posterior spinal fusion (PSF) and staged MILIF for anterior fusion of the thoracolumbar/lumbar spine. We identified four patients with high risk of curve progression who met the following inclusion criteria: diagnosis of myelomeningocele, severe scoliosis (Cobb angle>70°), PSF using greater than 80% pedicle screws, age greater than 10 years at time of surgery, and a minimum follow-up of two years. Radiographic, clinical, and complication data were reviewed. RESULTS: All four patients achieved fusion (100%). The average age at index surgery was 12.8 years (range, 11-16) and follow-up was 3.2 years (range, 2-4.9). The average preoperative coronal Cobb angle measured 111° (range, 74-140°). The average postoperative Cobb angle at follow-up measured 37° (range, 23-42°). The MILIF procedure was performed an average of six months after the index procedure. After anterior fusion, all patients spent one day in the pediatric ICU and an average of 5.5 days in the hospital (range, 4-7). One patient (25%) developed a postoperative wound infection after PSF which required irrigation and debridement in the operating room. CONCLUSION: MILIF as an adjunct to posterior spinal fusion for severe scoliosis associated with myelomeningocele may provide acceptable fusion rates, curve correction, maintenance of correction at mid-term follow-up, and be associated with less morbidity than the traditional anterior approach.