An investigation of range of motion preservation in fusionless anterior double screw and cord constructs for scoliosis correction.

PURPOSE: To evaluate the motion-preserving properties of vertebral body tethering with varying cord/screw constructs and cord thicknesses in cadaveric thoracolumbar spines. METHODS: In vitro flexibility tests were performed on six fresh-frozen human cadaveric spines (T1-L5) (2 M, 4F) with a median age of 63 (59-to-80). An ± 8 Nm load was applied to determine range of motion (ROM) in flexion-extension (FE), lateral bending (LB), and axial rotation (AR) in the thoracic and lumbar spine. Specimens were tested with screws (T5-L4) and without cords. Single (4.0 mm and 5.0 mm) and double (4.0 mm) cord constructs were sequentially tensioned to 100 N and tested: (1) Single 4.0 mm and (2) 5.0 mm cords (T5-T12); (3) Double 4.0 mm cords (T5-12); (4) Single 4.0 mm and (5) 5.0 mm cord (T12-L4); (6) Double 4.0 mm cords (T12-L4). RESULTS: In the thoracic spine (T5-T12), 4.0-5.0 mm single-cord constructs showed slight reductions in FE and 27-33% reductions in LB compared to intact, while double-cord constructs showed reductions of 24% and 40%, respectively. In the lumbar spine (T12-L4), double-cord constructs had greater reductions in FE (24%), LB (74%), and AR (25%) compared to intact, while single-cord constructs exhibited reductions of 2-4%, 68-69%, and 19-20%, respectively. CONCLUSIONS: The present biomechanical study found similar motion for 4.0-5.0 mm single-cord constructs and the least motion for double-cord constructs in the thoracic and lumbar spine suggesting that larger diameter 5.0 mm cords may be a more promising motion-preserving option, due to their increased durability compared to smaller cords. Future clinical studies are necessary to determine the impact of these findings on patient outcomes.

Best Practice Guidelines for Surgical Site Infection in High-risk Pediatric Spine Surgery: Definition, Prevention, Diagnosis, and Treatment.

BACKGROUND: Prior "best practice guidelines" (BPG) have identified strategies to reduce the risk of acute deep surgical site infection (SSI), but there still exists large variability in practice. Further, there is still no consensus on which patients are "high risk" for SSI and how SSI should be diagnosed or treated in pediatric spine surgery. We sought to develop an updated, consensus-based BPG informed by available literature and expert opinion on defining high-SSI risk in pediatric spine surgery and on prevention, diagnosis, and treatment of SSI in this high-risk population. MATERIALS AND METHODS: After a systematic review of the literature, an expert panel of 21 pediatric spine surgeons was selected from the Harms Study Group based on extensive experience in the field of pediatric spine surgery. Using the Delphi process and iterative survey rounds, the expert panel was surveyed for current practices, presented with the systematic review, given the opportunity to voice opinions through a live discussion session and asked to vote regarding preferences privately. Two survey rounds were conducted electronically, after which a live conference was held to present and discuss results. A final electronic survey was then conducted for final voting. Agreement ≥70% was considered consensus. Items near consensus were revised if feasible to achieve consensus in subsequent surveys. RESULTS: Consensus was reached for 17 items for defining high-SSI risk, 17 items for preventing, 6 for diagnosing, and 9 for treating SSI in this high-risk population. After final voting, all 21 experts agreed to the publication and implementation of these items in their practice. CONCLUSIONS: We present a set of updated consensus-based BPGs for defining high-risk and preventing, diagnosing, and treating SSI in high-risk pediatric spine surgery. We believe that this BPG can limit variability in practice and decrease the incidence of SSI in pediatric spine surgery. LEVEL OF EVIDENCE: Not applicable.

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.

Incidence of complications in the management of non-ambulatory neuromuscular early-onset scoliosis with a rib-based growing system: high- versus low-tone patients.

PURPOSE: The purpose of this study is to evaluate whether patients with high-tone neuromuscular early-onset scoliosis have different surgical outcome and complication rate, when compared to patients with low-tone neuromuscular early-onset scoliosis treated with a rib-to-pelvis rib-based dual growing system. METHODS: This is a retrospective cohort study of 67 neuromuscular early-onset scoliosis patients, collected from a multicenter database, treated with a rib-to-pelvis rib-based dual growing system. All patients were divided into two groups: high tone and low tone. Pre-, intra- and postoperative data were compared between both groups. Complications were reported by a standardized system. RESULTS: Twenty-six high-tone and 41 low-tone patients were found homogeneous regarding gender, age at surgery, weight, height, estimated blood loss and surgery time. High-tone group (19/26 = 73.1%) experiences more postoperative complications than low-tone group (22/41 = 53.7%). Most common complications were infection, device migration, death and hardware failure. Permanent abandonment of rib-based growing technique and device removal was required in 21% of high-tone patients (P < 0.001). None of the low-tone patients required abandonment. CONCLUSION: High-tone patients had more complications than those with low tone in management of neuromuscular early-onset scoliosis treated with a rib-to-pelvis rib-based dual growing system. A different surgical approach may be required to treat the high-tone neuromuscular early-onset scoliosis.

Progressive decline in pulmonary function 5 years post-operatively in patients who underwent anterior instrumentation for surgical correction of adolescent idiopathic scoliosis.

PURPOSE: To evaluate changes in pulmonary function tests (PFT) at 5 years post-operatively in patients with adolescent idiopathic scoliosis (AIS) and to determine whether these changes are progressive or static after 2 years. METHODS: AIS surgical patients with pre-operative and 5 year post-operative forced expiratory volume (FEV) and forced vital capacity (FVC) were included. The percentage of patients with pulmonary impairment at 5 years was calculated. Repeated measures ANOVA was used to evaluate changes between pre-operative PFT and 5 years post-operative PFT and to determine whether the changes differed between curve types and approach. A sub-analysis of patients with 2 year data was performed to determine whether PFT changes were static or progressive. RESULTS: Two hundred and sixty-two patients had undergone pre-operative and 5 year post-operative PFTs. At 5 years, 42% were normal, 41% had mild impairment, and 17% had moderate-severe impairment. Overall, there was a decline in % predicted FVC (p < 0.05); FEV remained stable. There was no difference based on major curve type (p > 0.05). Anterior instrumentation cases declined significantly between pre-operative PFT and 5 years post-operative PFT (FEV: - 10% open, - 6% thoracoscopic; FVC: - 13% open, - 8% thoracoscopic) (p ≤ 0.02). The posterior cases remained stable (2% FEV, p = 0.7; - 0.6% FVC, p = 0.06). A subgroup of 90 patients with 2 year post-operative PFTs demonstrated that changes were progressive between 2 and 5 years post-operatively. The average change in FVC from 2 to 5 years was significantly different between the anterior open (- 9%) and posterior-only (0.7%) groups (p = 0.015). CONCLUSION: In patients who underwent anterior instrumentation, PFTs declined from the pre-operative to the 5 years post-operative time point. There was a progressive decline of 4-10% beyond 2 years post-operatively. Patients who underwent posterior instrumentation remained stable. These slides can be retrieved under Electronic Supplementary Material.

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.

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.

Serial Casting for Infantile Idiopathic Scoliosis: Radiographic Outcomes and Factors Associated With Response to Treatment.

BACKGROUND: Serial casting for early-onset scoliosis has been shown to improve curve deformity. Our goal was to define clinical and radiographic features that determine response to treatment. METHODS: We retrospectively reviewed patients with idiopathic infantile scoliosis with a minimum of 2-year follow-up. Inclusion criteria were: progressive idiopathic infantile scoliosis and initial casting before 6 years of age. Two groups were analyzed and compared: group 1 (≥10-degree improvement in Cobb angle from baseline) and group 2 (no improvement). RESULTS: Twenty-one patients with an average Cobb angle of 48 degrees (range, 24 to 72 degrees) underwent initial casting at an average age of 2.1 years (range, 0.7 to 5.4 y). Average follow-up was 3.5 years (range, 2 to 6.9 y). Sex, age at initial casting, magnitude of spinal deformity, and curve flexibility (defined as change in Cobb angle from pretreatment to first in-cast radiograph) were not significantly different between groups (P>0.05). Group 1 had a significantly higher body mass index (BMI) than group 2 at the onset of treatment (17.6 vs. 14.8, P<0.05). Univariate analysis of demographic, radiographic, and treatment factors revealed that only BMI was predictive of Cobb improvement (P=0.04; odds ratio=2.38). Group 1 (n=15) had a significantly lower Cobb angle (21 vs. 56 degrees) and rib vertebral angle difference (13 vs. 25 degrees) compared with group 2 at latest follow-up (P<0.05). A significantly larger proportion of children who were casted at less than 1.8 years of age had a Cobb angle <20 degrees at latest follow-up (P=0.03). Group 2 maintained stable clinical and radiograph parameters from pretreatment to most recent follow-up. CONCLUSIONS: To maintain a homogeneous cohort, we excluded patients with syndromes and developmental delays. We believe that analyzing a homogeneous group provides more meaningful results than if we studied a heterogeneous sample. BMI was significantly associated with outcome such that for each unit increase in BMI, there is a 2.38× increase in the chance of improvement. Curve flexibility was similar between groups, which suggest that the amount of correction obtained at initial casting does not confirm treatment success. Key aspects of treatment that may determine success include age of less than 1.8 years at initiation of casting and derotation of the spine to correct rib vertebral angle difference of <20 degrees. LEVEL OF EVIDENCE: Level IV-Therapeutic.

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.

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.

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.

Posterior Spinal Fusion With Pedicle Screws in Patients With Idiopathic Scoliosis and Open Triradiate Cartilage: Does Deformity Progression Occur?

BACKGROUND: Anterior-posterior spinal fusion (APSF) is the traditional treatment for patients with idiopathic scoliosis and open triradiate cartilage (OTRC). Our goals were to assess whether posterior-only spinal fusion (PSF) with pedicle screws can halt deformity progression as effectively as APSF in patients with OTRC, and whether selection of the distal fusion level influences curve progression. METHODS: We studied a prospective multicenter database to identify all children with 2-year radiographic and clinical follow-up who were 11 years or younger with Risser grade 0 and OTRC who were treated with (1) PSF (OTRC-PSF group, N=20); or (2) APSF (OTRC-APSF group, N=9). A reference group was constructed of 20 children who were 18 years or younger with Risser grade 4 or 5 and closed triradiate cartilage (CTRC) and who were treated with PSF (CTRC-PSF group) and matched in preoperative curve magnitude and type to the OTRC-PSF group. The 3 groups were compared with respect to operative time, blood loss, length of hospital stay, and radiographic and functional outcomes (significance, P<0.05). RESULTS: OTRC-APSF patients had significantly longer operative time (P<0.01), greater blood loss (P=0.02), and longer hospital stays (P<0.01) than OTRC-PSF patients. At 2 years, 7 (35%) OTRC-PSF patients had >10 degrees of curve progression compared with no patients in the OTRC-APSF group (P=0.042) and 1 patient in the CTRC-PSF group (P=0.018). The OTRC-PSF group had the highest number of patients fused to the stable vertebra. Of the 11 OTRC-PSF patients fused to 1 vertebra short of stable, 6 (55%) had >10 degrees of curve progression. Of the 9 OTRC-PSF patients fused to at least the stable vertebra or lower, only 1 (11%) had curve progression. There were no significant differences in Scoliosis Research Society outcome scores between OTRC-PSF patients who did and those who did not have >10 degrees of curve progression. CONCLUSIONS: PSF with pedicle screws was associated with curve progression in a significantly greater proportion of patients with OTRC compared with APSF. Not fusing to stable was also associated with curve progression in patients treated with PSF but not APSF. LEVEL OF EVIDENCE: Level III-therapeutic.

Patterns of coping strategy use and relationships with psychosocial health in adolescents with spinal cord injury.

OBJECTIVE: To investigate patterns of coping among adolescents with spinal cord injury (SCI). METHODS: Youth aged 13-18 years with SCI completed measures of participation, quality of life (QOL), mental health symptoms, and coping. A hierarchical agglomerative cluster analysis using Ward's method was conducted. Subsequent analyses examined relationships between clusters and psychosocial functioning. RESULTS: 199 youth were an average of 15.95 years (SD = 1.71) at interview and 11.02 years (SD = 5.45) at injury. 56% percent were male, 64% White, and 62% had paraplegia. Four groups of "copers" emerged: ineffective, active, avoidant, and cognitive. Cognitive copers reported significantly less mental health symptomatology and higher QOL, followed by avoidant, active, and ineffective copers. Active copers showed significantly greater participation relative to ineffective, avoidant, and cognitive copers. CONCLUSIONS: These results suggest that coping profiles have meaningful relationships with adjustment. Reliance on cognitive strategies, with low endorsement of other strategies, may be associated with better psychosocial health.

Anterior vertebral body tethering for immature adolescent idiopathic scoliosis: one-year results on the first 32 patients.

PURPOSE: This retrospective chart review evaluates the clinical and radiographic outcomes of anterior vertebral body tethering (VBT) at 1-year follow-up. Anterior VBT offers a fusionless treatment option for skeletally immature patients with adolescent idiopathic scoliosis. It is a growth-modulation technique, which utilizes patients' growth to attain progressive scoliosis correction. Numerous animal models support its promise; however, clinical data remain sparse. METHODS: Clinical and radiographic data were retrospectively analyzed. We reviewed 32 patients who underwent thoracic VBT with a minimum one-year follow-up. Pertinent clinical and radiographic data were collected. ANOVA, Student's t test and Fisher's exact test were utilized to compare different time points. RESULTS: 32 patients with thoracic idiopathic scoliosis (72 % female) with a minimum one-year follow-up were identified; mean age at surgery was 12 years. All patients were considered skeletally immature pre-operatively; mean Risser score 0.42, mean Sanders score 3.2. Patients underwent tethering of an average of 7.7 levels (range 7-11). Median blood loss was 100 cc. The mean pre-operative thoracic curve magnitude was 42.8° ± 8.0° which corrected to 21.0° ± 8.5° on first erect and 17.9° ± 11.4° at most recent. The pre-operative lumbar curve of 25.2° ± 7.3° demonstrated progressive correction (first erect = 18.0° ± 7.1°, 1 year = 12.6° ± 9.4°, p < 0.00001). Thoracic axial rotation measured 13.4° pre-operatively and 7.4° at the most recent measurement (p < 0.00001). One patient experienced prolonged atelectasis which required a bronchoscopy; otherwise, no major complications were observed. CONCLUSIONS: Our early results indicate that anterior VBT is a safe and potentially effective treatment option for skeletally immature patients with idiopathic scoliosis. These patients experienced an improvement of their scoliosis with minimal major complications. However, longer term follow-up of this cohort will reveal the true benefits of this promising technique. LEVEL OF EVIDENCE: IV.

Recurrence of rib prominence following surgery for adolescent idiopathic scoliosis with pedicle screws and direct vertebral body derotation.

PURPOSE: Pedicle screw constructs combined with direct vertebral body derotation (DVBD) provide a powerful corrective force of the rib prominence associated with adolescent idiopathic scoliosis (AIS). We wished to evaluate the incidence and correlative factors associated with recurrence of rib prominence (RRP) developing postoperatively despite adequate initial correction. METHODS: 103 patients with AIS underwent pedicle screw fixation with DVBD without thoracoplasty and had postoperative scoliometer readings at 6, 12, and 24 months. Patients with RRP, defined as a postoperative scoliometer increase ≥5°, were compared to those without recurrence. RESULTS: The mean rib prominence measured 14.0 ± 4.3° preoperatively, with a correction of 50.3 ± 26.7 % at 6 months, 49.0 ± 39.0 % at 1 year, and 49.1 ± 26.7 % at 2 years. RRP was identified in 15.5 % of the patients with a correction of 57.5 ± 25.5 % at 6 months, 47.2 ± 42.5 % at 1 year, and 40.4 ± 21.6 % at 2 years. At 2 years, the RRP group demonstrated a significantly larger major coronal Cobb (p < 0.05) and a trend towards less curve correction (p = 0.09). Patients with open triradiates had a significantly higher rate of RRP compared to those with closed (p = 0.01). Worsening apical vertebral rotation at 2 years post-operation occurred in 43.8 % (7/16) of the patients with RRP. CONCLUSION: RRP after posterior fusion for AIS with all pedicle screw constructs and DVBD occurred in 15.5 % of patients in our study. Patients with open triradiate cartilage had a significantly higher rate of RRP, although most with RRP were skeletally mature. There was a trend towards loss of coronal correction and increased apical vertebral rotation at 2 years in patients with RRP. The potential for RRP after adequate initial correction should be discussed with patients. 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.

Is there a role for the 5-degree rule in adolescent idiopathic scoliosis?

BACKGROUND: Nonstructural curves are defined in the Lenke classification system for adolescent idiopathic scoliosis as bending out to <25 degrees. A caveat in the original paper states, however, that if the difference in Cobb magnitude between the major and minor curves is <5 degrees, then the minor curve should be considered structural, regardless of its Cobb magnitude. It is unclear whether following this rule affects patient outcomes. METHODS: A multicenter retrospective study using a prospectively collected database was performed on surgical adolescent idiopathic scoliosis patients, with 2 years of minimum follow-up. All the lumbar curves measured <25 degrees on bending x-ray. Curves (major and minor) that were within <5 degrees of each other were analyzed in 2 treatment subsets: nonselective fusion (NS) and selective thoracic fusion (STF1), and compared with similar selective fusion cases with false double major curves with a lumbar curve between 5 and 10 degrees less in magnitude than the thoracic curve magnitude (STF2). Preoperative and 2-year postoperative radiographic and SRS-22 parameters were compared. RESULTS: Of 58 patients, there were 14 NS, 11 STF1, and 33 STF2. NS had larger preoperative curves than STF1, but achieved better lumbar correction (58%) than STF1 (32%) or STF2 (41%) (P=0.004). STF1 tended to have more preoperative coronal imbalance than STF2 (-2.26 vs. -1.12 cm) (P=0.066) but were similar at 2 years. Preoperative thoracic rib prominence measures were similar for all groups, but NS had significantly worse rib prominence than STF1 (NS: 8.4 vs. STF1: 4.4, P=0.046) at 2 years. There were no differences among the 3 groups in SRS-22 scores preoperatively and at 2 years. CONCLUSIONS: Almost half of the cases with curves within <5 degrees of each other did not follow the 5-degree rule, suggesting that there is variability among surgeons in their definition of what is truly structural. Selective thoracic fusion cases behaved similarly regardless of whether or not the curves were within 5 degrees of each other. The results of our analysis of the 5-degree caveat challenge its utility as a criterion for defining structural curves. LEVEL OF EVIDENCE: Level II.

Analysis of risk factors for loss of lumbar lordosis in patients who had surgical treatment with segmental instrumentation for adolescent idiopathic scoliosis.

PURPOSE: Iatrogenic flattening of lumbar lordosis in patients with adolescent idiopathic scoliosis (AIS) was a major downside of first generation instrumentation. Current instrumentation systems allow a three-dimensional scoliosis correction, but flattening of lumbar lordosis remains a significant problem which is associated with decreased health-related quality of life. This study sought to identify risk factors for loss of lumbar lordosis in patients who had surgical correction of AIS with the use of segmental instrumentation. METHODS: Patients were included if they had surgical correction for AIS with segmental pedicle screw instrumentation Lenke type 1 or 2 and if they had a minimum follow-up of 24 months. Two groups were created, based on the average loss of lumbar lordosis. The two groups were then compared and multivariate analysis was performed to identify parameters that correlated to loss of lumbar lordosis. RESULTS: Four hundred and seventeen patients were analyzed for this study. The average loss of lumbar lordosis at 24 months follow-up was an increase of 10° lordosis for group 1 and a decrease of 15° for group 2. Risk factors for loss of lumbar lordosis included a high preoperative lumbar lordosis, surgical decrease of thoracic kyphosis, and the particular operating surgeon. The lowest instrumented vertebra or spinopelvic parameters were two of many parameters that did not seem to influence loss of lumbar lordosis. CONCLUSION: This study identified important risk factors for decrease of lumbar lordosis in patients who had surgical treatment for AIS with segmental pedicle screw instrumentation, including a high preoperative lumbar lordosis, surgical decrease of thoracic kyphosis, and factors attributable to a particular operating surgeon that were not quantified in this study.

Five-year clinical and radiographic outcomes using pedicle screw only constructs in the treatment of adolescent idiopathic scoliosis.

PURPOSE: To determine the mid-term clinical and radiographic impact of pedicle screw fixation in patients with adolescent idiopathic scoliosis (AIS). METHODS: A multicenter AIS database was retrospectively queried to identify 99 consecutive patients who underwent posterior spinal fusion using an all pedicle screw construct with a minimum of 5-year follow-up. Radiographic and clinical parameters were reviewed at regular intervals up to 5 years. RESULTS: The mean age was 14.4 ± 2.0 years with 79 % being female. The mean preoperative major curve was 51.7 ± 14.2° with a mean correction of 66 and 64 % at 2 and 5 years (p = 0.16). Pre-op thoracic kyphosis averaged 22.3 ± 12.9° and was 18.4 ± 10.6° at 5 years with no significant change from 2 years (p = 0.33). SRS total and domain scores demonstrated significant improvements at 2 years, which were slightly decreased at 5 years (p = 0.06). SRS scores of self-image (p = 0.99) and satisfaction (p = 0.18) were significantly improved after surgery with minimal change by 5 years. The change in SRS total scores from 2 to 5 years was attributed to differences in SRS scores of pain and mental health (p < 0.05). CONCLUSIONS: Intermediate follow-up of patients with AIS treated with an all pedicle screw construct demonstrates maintenance of their coronal, and sagittal plane correction between 2- and 5-year follow-up. At 5 years, improvements in SRS scores were consistent with 2-year values, except for a decline in pain and mental health scores.

VEPTR to treat nonsyndromic congenital scoliosis: a multicenter, mid-term follow-up study.

BACKGROUND: Traditional surgical management of multiple congenital vertebral anomalies in young children, including fusion in situ and hemiepiphyseodesis, do not promote spinal growth nor address the associated thoracic insufficiency syndrome. We hypothesize that vertical expandable prosthetic titanium rib (VEPTR) with expansion thoracoplasty may control spinal deformity, allow spinal growth, and address thoracic insufficiency syndrome in children with nonsyndromic complex congenital spinal deformities. METHODS: Eight pediatric spine centers prospectively entered clinical and radiographic data into a database on every congenital spinal deformity treated with VEPTR as part of an Food and Drug Administration study. We retrospectively reviewed these data and excluded patients with spina bifida, Jarcho-Levin, or other syndromes. Data analysis focused on surgical technique and expansion frequency, change in Cobb angle and thoracic heights, and adverse events for a consecutive series of patients with at least 2 years of follow-up. RESULTS: Twenty-four children with an average age at surgery of 3.3 years (range, 1.0 to 12.5 y) were treated with VEPTR insertion and expansion thoracostomy and were followed for an average of 40.7 months (range, 25 to 78 mo). Twenty-three (95.8%) had associated rib fusions. All patients had subsequent expansion surgery; 50% had 5 or more expansions. Twenty patients (83.3%) had an improvement in Cobb angle during treatment with an average improvement of 8.9 degrees. All had an increase in thoracic height, with a mean increase of 3.41 cm. The most common adverse events were device migration in 7 patients and infection or skin problems in 6 patients. CONCLUSIONS: VEPTR insertion with expansion thoracoplasty represents a successful treatment paradigm for nonsyndromic congenital spinal deformities. We report multicenter data with midterm follow-up of children without syndromic diagnoses, in which the vast majority had an improvement in Cobb angle and thoracic height over the treatment period. Challenges include the demands of multiple procedures, skin problems, and device migration. LEVEL OF EVIDENCE: Level IV-prognostic study.