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.

Incidence of Tether Breakage in Anterior Vertebral Body Tethering.

BACKGROUND: Thoracic anterior vertebral body tethering (TAVBT) is an emerging treatment for adolescent idiopathic scoliosis. Tether breakage is a known complication of TAVBT with incompletely known incidence. We aim to define the incidence of tether breakage in patients with adolescent idiopathic scoliosis who undergo TAVBT. The incidence of tether breakage in TAVBT is hypothesized to be high and increase with time postoperatively. METHODS: All patients with right-sided, thoracic curves who underwent TAVBT with at least 2 and up to 3 years of radiographic follow-up were included. Tether breakage between 2 vertebrae was defined a priori as any increase in adjacent screw angle >5 degrees from the minimum over the follow-up period. The presence and timing of tether breakage were noted for each patient. A Kaplan-Meier survival analysis was performed to calculate expected tether breakage up to 36 months. χ 2 analysis was performed to examine the relationship between tether breakage and reoperations. Independent t test was used to compare the average final Cobb angle between cohorts. RESULTS: In total, 208 patients from 10 centers were included in our review. Radiographically identified tether breakage occurred in 75 patients (36%). The initial break occurred at or beyond 24 months in 66 patients (88%). Kaplan-Meier survival analysis estimated the cumulative rate of expected tether breakage to be 19% at 24 months, increasing to 50% at 36 months. Twenty-one patients (28%) with a radiographically identified tether breakage went on to require reoperation, with 9 patients (12%) requiring conversion to posterior spinal fusion. Patients with a radiographically identified tether breakage went on to require conversion to posterior spinal fusion more often than those patients without identified tether breakage (12% vs. 2%; P =0.004). The average major coronal curve angle at final follow-up was significantly larger for patients with radiographically identified tether breakage than for those without tether breakage (31 deg±12 deg vs. 26 deg±12 deg; P =0.002). CONCLUSIONS: The incidence of tether breakage in TAVBT is high, and it is expected to occur in 50% of patients by 36 months postoperatively. LEVEL OF EVIDENCE: Level IV.

Comparison of Distal Spine Anchors and Distal Pelvic Anchors in Children With Hypotonic Neuromuscular Scoliosis Treated With Growth-friendly Instrumentation.

BACKGROUND: Lower preoperative pelvic obliquity (PO) and L5 tilt have been associated with good radiographic outcomes when the fusion ended short of the pelvis in children with neuromuscular scoliosis (NMS). Our purpose was to identify indications to exclude the pelvis in children with hypotonic NMS treated with growth-friendly instrumentation. METHODS: This was a multicenter retrospective review. Children with spinal muscular atrophy and muscular dystrophy treated with dual traditional growing rod, magnetically controlled growing rod, or vertical expandable prosthetic titanium rib with minimum 2-year follow-up after the index surgery were identified. RESULTS: A total of 125 patients met the inclusion criteria. Thirty-eight patients had distal spine anchors (DSAs) and 87 patients had distal pelvic anchors (DPAs) placed at the index surgery. Demographics and length of follow-up were similar between the groups but there was a greater percentage of DPA patients who were nonambulatory [79 patients (91%) vs. 18 patients (47%), P <0.0001]. Preindex radiographic measures were similar except the DSA patients had a lower PO (11 vs. 19 degrees, P =0.0001) and L5 tilt (8 vs. 12 degrees, P =0.001). Postindex and most recent radiographic data were comparable between the groups. There was no difference in the complication and unplanned returns to the operating room rates.Subanalysis of the DSA group based on ambulatory status showed similar radiographic measures except the ambulatory patients had a lower PO at all time points (preindex: 5 vs. 16 degrees, P =0.011; postindex: 6 vs. 10 degrees, P =0.045; most recent follow-up: 5 vs. 14 degrees, P =0.028). Only 1 ambulatory DSA patient had a PO ≥10 degrees at most recent follow-up compared with 6 nonambulatory DSA patients. Three (8%) DSA patients, all nonambulatory, underwent extension of their instrumentation to the pelvis. CONCLUSIONS: Pelvic fixation should be strongly considered in nonambulatory children with hypotonic NMS treated with growth-friendly instrumentation. At intermediate-term follow-up, revision surgery to include the pelvis was rare but DSAs do not seem effective at maintaining control of PO in nonambulatory patients. DSA and DPA were equally effective at maintaining major curve control, and complication and unplanned returns to the operating room rates were similar. LEVEL OF EVIDENCE: Level III-therapeutic.

Pregnancy and Childbirth After Spinal Fusion for Adolescent Idiopathic Scoliosis.

BACKGROUND: Little data exist on pregnancy and childbirth for adolescent idiopathic scoliosis (AIS) patients treated with a spinal fusion. The current literature relies on data from patients treated with spinal fusion techniques and instrumentation, such as Harrington rods, that are no longer in use. The objective of our study is to understand the effects of spinal fusion in adolescence on pregnancy and childbirth. METHODS: Prospectively collected data of AIS patients undergoing posterior spinal fusion that were enrolled in a multicenter study who have had a pregnancy and childbirth were reviewed. Results were summarized using descriptive statistics and compared with national averages using χ 2 test of independence. RESULTS: A total of 78 babies were born to 53 AIS patients. As part of their pre-natal care, 24% of patients surveyed reported meeting with an anesthesiologist before delivery. The most common types of delivery were spontaneous vaginal delivery (46%, n=36/78) and planned cesarean section (20%, n=16/78). Compared with the national average, study patients had a higher rate of cesarean delivery ( P =0.021). Of the women who had a spontaneous vaginal birth, 53% had no anesthesia (n=19/36), 19% received intravenous intermittent opioids (n=7/36), and 31% had regional spinal or epidural anesthesia (n=11/36). spontaneous vaginal delivery patients in our study cohort received epidural or spinal anesthesia less frequently than the national average ( P <0.001). Of those (n=26 pregnancies) who did not have regional anesthesia (patients who had no anesthesia or utilized IV intermittent opioids), 19% (n=5 pregnancies) were told by their perinatal providers that it was precluded by previous spine surgery. CONCLUSION: The majority of AIS patients reported not meeting with an anesthesiologist before giving birth and those who had a planned C-section did so under obstetrician recommendation. The presence of instrumentation after spinal fusion should be avoided with attempted access to the spinal canal but should not dictate a delivery plan. A multidisciplinary team consisting of obstetrician, anesthesiologist, and orthopaedic surgeon can provide the most comprehensive information to empower a patient to make her decisions regarding birth experience anesthesia based on maternal rather than provider preference. LEVEL OF EVIDENCE: IV.

Consensus-Based Best Practice Guidelines for the Management of Spinal Deformity and Associated Tumors in Pediatric Neurofibromatosis Type 1: Screening and Surveillance, Surgical Intervention, and Medical Therapy.

BACKGROUND: Spinal conditions, such as scoliosis and spinal tumors, are prevalent in neurofibromatosis type 1 (NF1). Despite the recognized importance of their early detection and treatment, there remain knowledge gaps in how to approach these manifestations. The purpose of this study was to utilize the experience of a multidisciplinary committee of experts to establish consensus-based best practice guidelines (BPGs) for spinal screening and surveillance, surgical intervention, and medical therapy in pediatric patients with NF1. METHODS: Using the results of a prior systematic review, 10 key questions that required further assessment were first identified. A committee of 20 experts across medical specialties was then chosen based on their clinical experience with spinal deformity and tumors in NF1. These were 9 orthopaedic surgeons, 4 neuro-oncologists/oncologists, 3 neurosurgeons, 2 neurologists, 1 pulmonologist, and 1 clinical geneticist. An initial online survey on current practices and opinions was conducted, followed by 2 additional surveys via a formal consensus-based modified Delphi method. The final survey involved voting on agreement or disagreement with 35 recommendations. Items reaching consensus (≥70% agreement or disagreement) were included in the final BPGs. RESULTS: Consensus was reached for 30 total recommendations on the management of spinal deformity and tumors in NF1. These were 11 recommendations on screening and surveillance, 16 on surgical intervention, and 3 on medical therapy. Five recommendations did not achieve consensus and were excluded from the BPGs. CONCLUSION: We present a set of consensus-based BPGs comprised of 30 recommendations for spinal screening and surveillance, surgical intervention, and medical therapy in pediatric NF1.

Development of a Finite Element Model of the Pediatric Thoracic and Lumbar Spine, Ribcage, and Pelvis With Orthotropic Region-Specific Vertebral Growth.

Finite element (FE) modeling of the spine has increasingly been applied in orthopedic precision-medicine approaches. Previously published FE models of the pediatric spine growth have made simplifications in the geometry of anatomical structures, material properties, and representation of vertebral growth. To address those limitations, a comprehensive FE model of a pediatric (10-year-old) osteo-ligamentous thoracic and lumbar spine (T1-L5 with intervertebral discs (IVDs) and ligaments), ribcage, and pelvis with age- and level-specific ligament properties and orthotropic region-specific vertebral growth was developed and validated. Range of motion (ROM) measures, namely, lateral bending, flexion-extension, and axial rotation, of the current 10 YO FE model were generally within reported ranges of scaled in vitro adult ROM data. Changes in T1-L5 spine height, as well as kyphosis (T2-T12) and lordosis (L1-L5), angles in the current FE model for two years of growth (from ages 10 to 12 years) were within ranges reported from corresponding pediatric clinical data. The use of such comprehensive pediatric FE models can provide clinically relevant insights into normative and pathological biomechanical responses of the spine, and also contribute to the development and optimization of clinical interventions for spine deformities.

Outcomes of Operatively Managed Lumbar and Sacral Facet Fractures in Pediatric Athletes: A Case Series.

BACKGROUND: Facet fractures have been reported in a total of 6 young athletes in 4 previous publications. These injuries were not diagnosed on magnetic resonance imaging (MRI) or radiographs, and were identified on computed tomography (CT). Our purpose was to report a series of athletes with operatively managed facet fractures. This may be an under-recognized diagnosis. METHODS: Retrospective review of pediatric patients with operatively managed isolated lumbar or sacral facet fractures from 3 tertiary pediatric hospitals from 2014 to 2019. Clinical records and imaging studies were reviewed. RESULTS: Ten patients with symptomatic lumbar or sacral facet fractures met inclusion criteria (mean age at presentation; 13.3±2.1 years, 70% Female). All patients reported competitive participation in sports. On physical examination, 10/10 (100%) of patients had lower back pain that was exacerbated with lumbar spine extension. Limited CT scans demonstrated facet fractures in 10/10 (100%) patients not detected on plain film or MRI. All patients experienced significant relief of pain following excision of the facet fracture fragment. At time of first postoperative visit, 9/10 (90%) patients were pain free while one had generalized back pain thought to be related to fibromyalgia and not facet pathology. At time of last follow-up, 2/10 (20%) of patients reported nonspecific back pain that was not localized in the area of the facet fracture, while 80% (8/10) remained pain free. All patients 100% (10/10) returned to full participation to sports. There were no complications noted in this series. Average follow-up was 27 months (range: 1 to 68 mo). CONCLUSIONS: Athletes with localized back pain exacerbated by spine extension may have a facet fracture. As facet fractures are usually not identified with radiographs or MRI, a limited CT scan should be considered in the evaluation of pediatric athletes with localized back pain exacerbated by extension. In this series, surgical excision of facet fracture fragments was safe and provided predictable pain relief.

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.

Impact of growth friendly interventions on spine and pulmonary outcomes of patients with spinal muscular atrophy.

PURPOSE: Patients with spinal muscular atrophy (SMA) are often treated with growth friendly devices such as vertical expandable prosthetic titanium rib(VEPTR) and magnetically controlled growing rods(MCGR) to correct spinal deformity and improve pulmonary function. There is limited data on this topic, and the purpose of this study was to assess the effect of these constructs and the addition of chest wall support (CWS) on spinal deformity, thorax morphology and pulmonary outcomes. METHODS: This is a retrospective analysis of prospectively collected data. We included patients with chest wall deformity and scoliosis secondary to SMA who were treated with growth friendly interventions and had two-year follow-up. Descriptive statistics and univariate analyses were performed. RESULTS: This study included 66 patients (25% MCGR, 73% VEPTR, 2% unknown). Approximately 23% of constructs included CWS. The average Cobb angle improved from 67° (SD: 27°) to 50° (SD: 26°) at 2 years in patients with CWS (p = 0.02), and from 59° (SD: 20°) to 46° (SD: 15°) at 2 years in patients without CWS (p < 0.01). Hemithorax height improved in patients treated with and without CWS (p = 0.01), but hemithorax width only improved in patients with CWS (p = 0.01). One patient with CWS and two patients without CWS required additional respiratory support at 2 years. The rates of postoperative complications were not significantly different in patients treated with and without CWS (p = 0.31). CONCLUSIONS: Growth friendly constructs improve spinal deformity and may be effective in altering the progression toward respiratory failure in patients with SMA. Patients treated with CWS have significant improvements in thorax morphology compared to patients without CWS.

Risk of Scoliosis Progression in Nonoperatively Treated Adolescent Idiopathic Scoliosis Based on Skeletal Maturity.

BACKGROUND: Hand radiographs for skeletal maturity staging are now frequently used to evaluate remaining growth potential for patients with adolescent idiopathic scoliosis (AIS). Our objective was to create a model predicting a patient's risk of curve progression based on modern treatment standards. METHODS: We retrospectively reviewed all AIS patients presenting with a major curve <50 degrees, available hand radiographs, and complete follow up through skeletal maturity at our institution over a 3-year period. Patients with growth remaining underwent rigid bracing of curves >25 degrees, whereas patients between 10 and 25 degrees were observed. Treatment success was defined as reaching skeletal maturity with a major curve <50 degrees. Four risk categories were identified based on likelihood of curve progression. RESULTS: Of 609 AIS patients (75.4% female) presenting with curves over 10 degrees and reaching skeletal maturity at most recent follow up, 503 (82.6%) had major thoracic curves. 16.3% (82/503) of thoracic curves progressed into surgical treatment range. The highest risk group (Sanders 1 to 6 and curve 40 to 49 degrees, Sanders 1 to 2 and curve 30 to 39) demonstrate a 30% success rate with nonoperative treatment. This constitutes an 111.1 times (95% confidence interval: 47.6 to 250.0, P<0.001) higher risk of progression to surgical range than patients in the lowest risk categories (Sanders 1 to 8 and curve 10 to 19 degrees, Sanders 3 to 8 and curve 20 to 29 degrees, Sanders 5 to 8 and curve 30 to 39 degrees). CONCLUSIONS: Skeletal maturity and curve magnitude have strong predictive value for future curve progression. The results presented here represent a valuable resource for orthopaedic providers regarding a patient's risk of progression and ultimate surgical risk. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

Rib-based Distraction Device Implantation Before Age 3 Associated With Higher Unplanned Rate of Return to the Operating Room.

BACKGROUND: Surgical treatment of early-onset scoliosis (EOS) with rib-based implants such as the vertical expandable prosthetic titanium rib (VEPTR) is associated with a high rate of complications including surgical site infection, skin breakdown, and implant migration. Many of these complications warrant the need for unplanned reoperations, increasing the burden on an already vulnerable patient population, and introducing the further risk of infection. To provide insight into the risks of early intervention, we investigate the relationship between initial device implantation before the age of 3 and the rate of unplanned reoperation. METHODS: A retrospective review was performed of all patients at a single institution who had undergone VEPTR insertion for EOS with at least a 2-year follow-up from 2007 to 2016. Patients were stratified into the case-cohort (0 to 2 y of age) or the comparison cohort (3 to 10 y of age) based on age at the time of device implantation. Multivariate regression accounting for age and scoliosis etiology was performed to identify factors predictive of unplanned reoperation. RESULTS: A total of 137 of 185 patients treated with VEPTR were identified with 76 (56%) undergoing at least 1 unplanned reoperation during the study time period. There were 68 and 69 patients in the age 0- to 2-year and 3- to 10-year cohorts, respectively. Patients aged 0 to 2 years underwent a higher number of total procedures compared with those aged 3 to 10 (13.1±6.5 vs. 10.6±4.8, P=0.032). A significant difference was found in the rate of unplanned reoperation between the 2 cohorts with 44 (65%) patients aged 0 to 2 and 32 (46%) patients aged 3 to 10 undergoing at least 1 unplanned reoperation (P=0.031). Binary logistic multivariate regression accounting for age and scoliosis etiology demonstrated that patients aged 0 to 2 had a significantly greater odds of undergoing an unplanned reoperation (odds ratio=3.050; 95% confidence interval: 1.285-7.241; P=0.011) compared with patients aged 3 to 10 years. CONCLUSION: Overall, EOS patients aged 0 to 2 at initial VEPTR implantation are up to 3 times higher risk of undergoing an unplanned reoperation compared with those aged 3 to 10. LEVEL OF EVIDENCE: Level III.

Radiographic Coronal Imbalance and Shoulder Asymmetry Continue to Improve Between 2 and 5 Years Following Surgery of Adolescent Idiopathic Scoliosis.

BACKGROUND: Managing patients with coronal imbalance (CI) and shoulder height asymmetry following scoliosis surgery can be challenging. Little is known about the course of findings over time and whether they improve or persist. The aim was to report the rate of suboptimal radiographic CI or shoulder asymmetry (SA) at 5 years in patients who were already reported to have CI or SA 2 years after surgery for adolescent idiopathic scoliosis (AIS). METHODS: An AIS database was reviewed for patients with both 2- and 5-year follow-up after surgery. From this cohort, patients with CI>2 cm or SA>2 cm at their 2-year follow-up were identified and reevaluated, using the same parameters, at 5-year follow-up. RESULTS: Of 916 patients, 157 (17%) patients had CI and 69 (8%) patients had SA at 2-year follow-up. At 5 years this improved to 53 (6%) and 11 patients (1%), respectively. CONCLUSIONS: Having coronal or shoulder imbalance 2 years after surgery for AIS does not guarantee continued imbalance 5 years after surgery. Most patients demonstrate some improvement in these measures of clinical deformity. Anticipating the potential course following a postoperative coronal balance and shoulder height differences can help surgeons manage and counsel their patients appropriately. LEVELS OF EVIDENCE: Level II-therapeutic.

Hand Bone Age Radiography: Comparison Between Slot-scanning and Conventional Techniques.

BACKGROUND: Determination and longitudinal monitoring of progressive skeletal maturity are essential in the management of children with scoliosis. Although different methods for determining skeletal maturity exists, the most widely practiced method relies on the ossification pattern of the bones of the hand and wrist, which is traditionally acquired using conventional techniques and after the acquisition of the spine using the low-dose slot-scanning technique. Whereas the existing published literature has published promising results on the use of the slot-scanning technique to acquire these hand and wrist radiographs, image quality and radiation dose have not been systematically compared between these techniques. Thus, the objective of our study is to compare image quality, interpretation reliability, and radiation dose of hand bone age radiographs between slot-scanning and conventional techniques using age- and sex-matched children. METHODS: This retrospective study included children who underwent hand radiographs using slot-scanning between October 1, 2019 and December 31, 2019; and matched children who underwent conventional radiography. Blinded to technique, 5 readers reviewed all radiographs after randomization to rate image quality and to determine bone age using the Greulich and Pyle classification. Dose area product was recorded. Mann-Whitney and t tests were used to compare variables between techniques and intraclass correlation (ICC) to determine observer agreement. RESULTS: Our study cohort of 194 children (128 girls, 66 boys; mean age: 13.7±2.3 y) included 97 slot-scanning and 97 conventional radiographs. One (1%) slot-scanning and no conventional radiograph was rated poor in image quality. There was almost perfect interpretation reliability with slot-scanning with high interobserver (ICC=0.948) and intraobserver (ICC=0.996) agreements, comparable with conventional radiographs (ICCs=0.919 and 0.996, respectively). Dose area product (n=158) was lower (P<0.002) with slot-scanning than with conventional techniques. CONCLUSION: Almost perfect interobserver reliability and intraobserver reproducibility with slot-scanning radiographs (performed using significantly lower radiation doses) suggest that this technique for hand bone age determination can be a reliable adjunct to scoliosis monitoring. LEVEL OF EVIDENCE: Level III.

Outcomes and Complications in Management of Congenital Myopathy Early-Onset Scoliosis.

BACKGROUND: Congenital myopathies (CMs) are complex conditions often associated with early-onset scoliosis (EOS). The purpose of this study was to investigate radiographic outcomes in CM patients undergoing EOS instrumentation as well as complications. Secondarily, we sought to compare these patients to a population with higher prevalence, cerebral palsy (CP) EOS patients. METHODS: This is a retrospective study of a prospectively collected multicenter registry. The registry was queried for EOS patients with growth-sparing instrumentation (vertical expandable prosthetic titanium ribs, magnetically controlled growing rods, traditional growing rod, or Shilla) and a CM or CP diagnosis with minimum 2 years follow-up. Outcomes included major curve magnitude, T1-S1 height, kyphosis, and complications. RESULTS: Sixteen patients with CM were included. Six (37.5%) children with CM experienced 11 complications by 2 years. Mean major curve magnitude for CM patients was improved postoperatively and maintained at 2 years (P<0.01), with no significant increase in T1-S1 height or maximum kyphosis(P>0.05). Ninety-seven patients with CP EOS were included as a comparative cohort. Fewer CP patients required baseline respiratory support compared with CM patients (20.0% vs. 92.9%, P<0.01). Fifty-four (55.7%) CP patients experienced a total of 105 complications at 2 years. There was no evidence that the risk of complication or radiographic outcomes differs between cohorts at 2 years, though CP EOS patients experienced significant improvement in all measurements at 2 years. CONCLUSIONS: EOS CM children face a high risk of complication after growing instrumentation, with similar curve correction and risk of complication to CP patients. LEVEL OF EVIDENCE: Level III.

Lengthening Less Than 7 Months Leads to Greater Spinal Height Gain With Rib-based Distraction.

BACKGROUND: Severe early-onset scoliosis (EOS) has been associated with a multitude of comorbidities, chief among them being deficient thoracic spine growth and pulmonary complications. EOS management with rib-based instrumentation involves repeated lengthening. Despite expansion practice patterns, there is limited literature and no evidence-based guidelines for optimal expansion intervals. Our study evaluates clinical outcomes in relation to lengthening intervals with the aim of optimizing the timing of surgical expansion in EOS patients. METHODS: A single-institution retrospective review of 60 EOS patients treated with rib-based growth instrumentation with a minimum of 3-year follow-up and 3 expansion/revision surgeries. Patients were separated into 2 expansion cohorts: (1) more frequent lengthening [MFL group (≤7 mo)] and (2) less frequent lengthening [LFL group (>7 mo)]. Demographic information and clinical factors were recorded. Univariate and bivariate analyses were performed. RESULTS: Both the MFL group (35 patients) and LFL group (25 patients) were similar in sex distribution, diagnosis, preoperative parameters of interest, and treatment duration. The mean follow-up was 6.0 years. There was an increase in postoperative T1-S1 spine height gained in the MFL group (P=0.006) as well as a higher percent expected spine growth based on normative values (P=0.03) when compared with the LFL group. The MFL group had more expansion/revision surgeries (P=0.003) but no increase in the number of complications (P=0.86). CONCLUSIONS: More frequent lengthenings were associated with statistically significant overall spinal height gain and percent expected growth without a significant increase in complication rates. It was shown that change in major curve and space available for the lungs was not associated with the lengthening intervals. LEVEL OF EVIDENCE: Level III-a comparative retrospective study.

The Impact of Posterior Spinal Fusion (PSF) on Coronal Balance in Adolescent Idiopathic Scoliosis (AIS): A New Classification and Trends in the Postoperative Period.

INTRODUCTION: One of the primary goals of scoliosis surgery is to balance the head over the pelvis (or avoid creating imbalance). Historically, a normal coronal balance was defined as the C7 plumb line (C7PL) within 2 cm of the central sacral vertical line (CSVL); however, there is limited published information regarding the speed/magnitude and success/failure of balancing, rebalancing, or unbalancing in the postoperative period. The purpose of this study is to classify and quantify coronal plane balance postoperatively in adolescent idiopathic scoliosis when using pedicle screw instrumentation. METHODS: Evaluated patients with adolescent idiopathic scoliosis who had a posterior spinal fusion withstanding 2-view, posteroanterior and lateral radiographs of the entire spine performed at first erect visit, 6, 12, and 24 months. To measure coronal balance, a C7PL was measured and compared with the CSVL. A negative value denotes the leftward deviation of the C7PL and a positive value a rightward deviation. The authors then created a novel coronal balance classification system. RESULTS: A total of 954 patients met the inclusion criteria. There was a strong trend toward improving coronal balance, especially between first erect and 6 months; the proportion of out of balance patients declined throughout the 2-year period: preoperative 372 of 954 (39%), first erect 297 of 954 (31.1%), 6 months 167 of 954 (17.5%), 1 year 136 of 954 (14.3%), and 2 years 115 of 954 (12.0%). Analyzing the patients most out of balance immediately after posterior spinal fusion, 35 of 50 (70%) in group 3 regained balance by 2 years. Out of the remaining 15 patients, 12 corrected to group 1 (24%), 2 patients to group 2 (4%), and 1 patient remained in group 3 (2%). CONCLUSIONS: This large, longitudinal postoperative study of coronal balance documents a strong trend toward postoperative rebalancing, with the largest gains between first erect image and 6 months. The 31% of patients out of balance at first erect declined to only 12.1% at 2 years.

Comparison of T1-S1 Spine Height of Postoperative Rib-based Implant Patients With Age-matched Peers.

BACKGROUND: Severe early-onset scoliosis leads to deficient spine height, thoracic growth inhibition, and ultimately pulmonary compromise. Rib-based growing instrumentation seeks to correct thoracic deformities, in part by correcting the spinal deformity, adding height, increasing thoracic volume, and allowing for continual spinal growth until maturity. However, the amount of growth in these patients relative to their peers is unknown. METHODS: Sixty patients who had undergone surgical intervention for the treatment of early-onset scoliosis were assessed via radiographic measurements of coronal T1-S1 height and major curve angle before implantation and again at most recent follow-up (minimum 2 years). T1-S1 measurements were then compared with age-matched peers to assess growth differences. Clinical information was examined for relevant parameters. RESULTS: The average age of our cohort at initial surgery and most recent follow-up was 4.4±3.8 and 10.0±4.4 years old, respectively. In this patient set, there was an average increase in T1-S1 height of 13.1±11.1 mm per year, with the majority of growth occurring in the first 2 years following implantation, and improvement in a major curve from 68±8 to 53±7 degrees. Overall, 77% of patients saw improvement in the major curve at most recent follow-up. Furthermore, a statistically significant greater percent of expected growth was seen in congenital compared with neuromuscular scoliosis (P<0.001). In addition, a weak negative correlation was observed between a number of surgical lengthenings and T1-S1 growth. CONCLUSIONS: Rib-based implant intervention has been shown to improve the major curve, but only improves growth potential to around 80% of expected growth. Scoliosis diagnosis type also influences growth rate potential, with congenital scoliosis patients being surgically treated earlier in life and having a growth rate approaching that of a healthy individual. LEVEL OF EVIDENCE: Level III-Case control.

Can We Save the Implant: Rib-based Implant Removal Rates and Risk Factors Following Irrigation and Debridement (I&D) Surgery?

BACKGROUND: In the event of a surgical site infection, management includes surgical debridement in an attempt to treat the infection and retain the implant; however they are often unsuccessful in this regard. Although studies have described the incidence of complications, current literature does not have sufficient evidence to provide clear recommendations regarding retention versus removal of implants. This study aims to identify predictive factors associated with the need for implant removal to decrease unnecessary attempts at implant retention. METHODS: A retrospective review of early-onset scoliosis patients at a single institution treated with rib-based vertical expandable prosthetic titanium rib implants who developed infection requiring irrigation and debridement (I&D) due to wound problems including surgical site infection, skin slough, and wound dehiscence. All patients had a minimum of a 2-year follow-up. Univariate and multivariate logistic regression analyses were conducted to determine the odds of implant removal. RESULTS: Fifty-nine of 181 patients (32%) required an I&D due to a wound problem. These patients underwent the initial implant procedure at a mean age of 4.6±3.8 years. In total, 29 patients ultimately underwent implant removal. Significant predictive factors for removal included total number of wound problems, total number of I&Ds, days from identification of wound problem to I&D procedure, days on antibiotics, total number of surgeries, presence of gastrostomy tube, and nonambulatory status (P<0.0001, 0.001, 0.095, 0.093, 0.082, 0.054, and 0.026, respectively). Multiple logistic regression results indicated a total number of wound problems [odds ratio (OR): 6.00, P=0.001], average days from identification of wound problem to I&D (OR: 1.03, P=0.039), and presence of a gastrostomy tube (OR: 5.7, P=0.07) as independent predictors for implant removal. CONCLUSIONS: Data suggests that time from the onset of signs of infection until debridement surgery inversely correlates with the ability to retain the implants. In addition, gastrostomy tube and history of previous wound infections may be predictive clinical factors for implant removal in patients with a rib-based vertical expandable prosthetic titanium rib instrumentation. Such information can be useful for clinicians in deciding on whom to attempt implant retention versus removal when a wound problem presents itself. LEVEL OF EVIDENCE: Level III.

Serial Casting in Neuromuscular and Syndromic Early-onset Scoliosis (EOS) Can Delay Surgery Over 2 Years.

BACKGROUND: The primary goal in managing early-onset scoliosis (EOS) is delaying/preventing surgical intervention while allowing improved spinal growth and chest wall and lung development to improve life expectancy. The effectiveness of serial casting for patients with neuromuscular and syndromic EOS is unclear. METHODS: Patients from 2 multicenter registries who underwent serial casting for nonidiopathic scoliosis (NIS) were reviewed retrospectively. Comparisons were made between precasting and postcasting major and compensatory curves and spine height. The need for surgical intervention and any treatment complications were documented. Risk factors for major curve progression from baseline to casting cessation were evaluated via univariate analysis. RESULTS: Forty-four patients (23 females; 21 males) with NIS (26 syndromic, 18 neuromuscular) and a mean age of 3.2 years at baseline were included. Mean follow-up and casting duration was 3.9 and 2.0 years, respectively. There were no statistically significant differences between mean precasting and postcasting major curve (55 vs. 60 degrees; P=0.348), minor curve (31 vs. 33 degrees; P=0.510), or rib-vertebra angle difference (18 vs. 29 degrees; P=0.840). However, thoracic height (15.5 vs. 16.8 cm; P=0.031) and lumbar height (8.9 vs. 9.8 cm; P=0.013) were significantly greater upon casting cessation. Currently, 13 patients (30%) have had successful casting (improvement of major curve ≥10 degrees) while 24 patients (55%) experienced major curve progression (worsening), and 19 patients (43%) required surgical intervention. Mean time from first casting to surgery was 34.5±15.1 months. There were no statistically significant predictors for major curve progression on univariate analysis. CONCLUSIONS: Spinal deformity progression despite casting and the subsequent need for surgical intervention for NIS were significantly higher compared with those reported for idiopathic EOS. However, serial casting did afford a substantial delay in surgical intervention. Ultimately, serial casting for neuromuscular or syndromic EOS is an effective strategy for delaying surgical intervention, despite suboptimal radiographic outcomes. LEVEL OF EVIDENCE: Level III.

Prolonged Postoperative Intubation After Spinal Fusion in Cerebral Palsy: Are There Modifiable Risk Factors and Associated Consequences?

BACKGROUND: Instrumented spinal fusion is performed to correct severe spinal deformity that commonly complicates cerebral palsy (CP). Prolonged intubation (PI) is a common perioperative complication, though little is known about the risk factors and consequences of this phenomenon. QUESTIONS/PURPOSES: The purpose of this study was to determine (1) the preoperative and intraoperative risk factors associated with PI after spine surgery for CP; (2) the perioperative and postoperative complications associated with PI; and (3) any long-term impacts of PI with respect to health-related quality of life. PATIENTS AND METHODS: A retrospective case-control analysis of prospectively collected, multicenter data was performed on patients with Gross Motor Function Classification System (GMFCS) 4 or 5 CP who underwent instrumented spinal fusion. Patients extubated on postoperative day (POD) 0 were in the early extubation (EE) cohort and those extubated on POD 3 or later were in the PI cohort. Comparisons were made between PI and EE groups with respect to several preoperative and intraoperative variables to identify risk factors for PI. Multivariate logistic regression was performed to identify independent predictors of this outcome. The postoperative hospital course, rate of complications, and health-related quality of life at 2 years were also compared. RESULTS: This study included 217 patients (52% male individuals; mean age, 14.0±2.8 y) who underwent spinal fusion for CP. In this cohort, 52 patients (24%) had EE and 58 patients (27%) had PI. There were several independent predictors of PI including history of pneumonia [odds ratio (OR), 6.2; 95% confidence interval (CI), 1.6-24.3; P=0.01], estimated blood loss of >3000 mL (OR, 16.5; 95% CI, 2.0-134; P=0.01), weight of <37 kg (OR, 6.4; 95% CI, 1.5-27.1), and Child Health Index of Life with Disabilities (CPCHILD) Communication and Social Interaction score of <15 (OR, 10.8; 95% CI, 1.1-107.3; P=0.04). In addition, PI was associated with a higher rate of perioperative and postoperative respiratory (P<0.001), cardiovascular (P=0.014), gastrointestinal (P<0.001), and surgical site (0.027) complications, in addition to prolonged hospitalization (P<0.001) and intensive care unit stay (P<0.001). CONCLUSIONS: Surgeons should seek to optimize nutritional status and pulmonary function, and minimize blood loss in patients with CP to decrease the risk of PI after spinal fusion. Efforts should be made to extubate patients on POD 0 to decrease the risk of complications associated with PI.