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.

Growing Rod versus Posterior Spinal Fusion Treatment of Juvenile Idiopathic Scoliosis: Unique Characteristics and Surgical Outcomes.

Progressive spinal curvature in juvenile idiopathic scoliosis (JIS) is challenging to treat. When conservative management fails, treatments include growing rods (GRs) or posterior spinal fusion (PSF). The purpose of this study is to compare the patient characteristics and outcomes of GR and PSF treatment of JIS. We performed a retrospective review of demographic, radiographic, and surgical data for all JIS patients requiring surgical treatment between 2012 and 2020. Patients who underwent any GR treatment were compared to PSF patients. A total of 36 patients (13 GR, 23 PSF) were reviewed. PSF patients had a larger pre-operative spinal height (p = 0.002), but similar pre-operative major curve magnitudes (p = 0.558). PSF treatment resulted in similar change in the T1-S1 length (p = 0.002), but a greater correction of the curve magnitude (p < 0.055) compared to GR patients. Eight patients initially treated with GRs later underwent definitive PSF treatment. This subset of patients had a greater spinal height before PSF (p = 0.006), but similar immediate post-PSF T1-S1 lengths (p = 0.437) and smaller changes in spinal height from PSF (p = 0.020) than primary PSF patients. At final follow-up, patients who underwent primary PSF versus PSF after GR had similar spinal heights (p = 0.842). The surgical intervention chosen to manage progressive JIS often differs based on patient characteristics. While this choice may impact immediate outcomes, the outcomes at final follow up are similar.

Is spinal height gain associated with rod orientation and the use of cross-links in magnetically controlled growing rods in early-onset scoliosis?

Optimal orientation for magnetically controlled growing rods (MCGRs) is unclear. The objective of this study was to investigate associations of rod orientation with implant-related complications (IRCs) and spinal height gains. Using an international early-onset scoliosis (EOS) database, we retrospectively reviewed 57 patients treated with dual MCGRs from May 2013 to July 2015 with minimum 2-year follow-up. Outcomes of interest were IRCs and left/right rod length gains and thoracic (T1-T12) and spinal (T1-S1) heights. We compared patients with two rods lengthened in the cephalad ( standard; n  = 18) versus opposite ( offset; n  = 39) directions. Groups did not differ in age, sex, BMI, duration of follow-up, EOS cause, ambulatory status, primary curve magnitude, baseline thoracic height, or number of distractions/year. We compared patients whose constructs used ≥1 cross-link (CL group; n  = 22) versus no CLs (NCL group; n  = 35), analyzing thoracic height gains per distraction ( α  = 0.05). Offset and standard groups did not differ in left or right rod length gains overall or per year or in thoracic or spinal height gain. Per distraction, the CL and NCL groups did not differ significantly in left or right rod length or thoracic or spinal height gain. Complications did not differ significantly between rod orientation groups or between CL groups. MCGR orientation and presence of cross-links were not associated with differences in rod length gain, thoracic height, spinal height, or IRCs at 2-year follow-up. Surgeons should feel comfortable using either MCGR orientation. Level of evidence: 3, retrospective.

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.

Maintenance of curve correction and unplanned return to the operating room with magnetically controlled growing rods: a cohort of 24 patients with follow-up between 2 and 7 years.

PURPOSE: Early onset scoliosis (EOS) is defined as spinal curvature affecting children below 10 years of age. Non-operative treatment can consist of casting and bracing. When curvature progresses despite these treatments, operative intervention is indicated. Traditional growing rods (TGR) have been a mainstay of treatment. Unfortunately, TGR's require planned return to the operating room every 6-9 months. Magnetic controlled growing rods (MCGR) ideally provide curve correction and allow the spine to grow without frequent surgeries. However, the ability to correct and maintain correction after MCGR has not been well-characterized. The purpose of this study is to evaluate maintenance of curve correction in patients treated primarily with MCGR and analyze the rate of complications including unplanned return to the operating room (UPROR). METHODS: 24 patients with EOS were retrospectively reviewed. These patients were subdivided into 4 subcategories: congenital, idiopathic, neuromuscular (NMS), and syndromic. The major curve correction (%) and T1-S1 distance were assessed utilizing scoliosis plain film radiographs over time. Complications and return to the operating room for any reason were recorded. Patients were followed until conversion to posterior spinal fusion (PSF) or most recent lengthening of MCGR. RESULTS: There were 11 male and 13 female patients averaging 8 years at the time of index surgery. The average preoperative curve angle was 61.1°. Initial curve correction with MCGR obtained at the index procedure was 46.2%, reducing the mean curve angle to 32.7° (p < 0.05). Curve correction at a mean 6.2 years (2.4-7.4) follow-up was 36.1°, 40.9% curve correction. 75% of patients underwent conversion to PSF during the study period 4.8 years (2.4-7.0) after initial MCGR surgery. 15% of patients were still undergoing MCGR lengthening after 6.1 years. 54.2% of patients had at least one UPROR. CONCLUSIONS: For patients with EOS with curve progression, MCGRs can maintain curve correction well after 2 years. Furthermore, MCGR allowed patients to grow over time to safely delay timing to definitive fusion. On average, patients underwent conversion to PSF after 4.7 years at an average age of 13.5. Although the complication rate in the first 2 years is relatively low, 54.2% of patients underwent an UPROR. As the use of MCGR increases, surgeons should be aware of possible complications associated with this technology and counsel patients accordingly. Further research is needed to continue to evaluate the efficacy and safety of MCGR in this challenging patient population.

Re-evaluating consensus and uncertainty among treatment options for early onset scoliosis: a 10-year update.

PURPOSE: Consensus and uncertainty in early onset scoliosis (EOS) treatment were evaluated in 2010. It is currently unknown how treatment preferences have evolved over the past decade. The purpose of this study was to re-evaluate consensus and uncertainty among treatment options for EOS patients to understand how they compare to 10 years ago. METHODS: 11 pediatric spinal surgeons (similar participants as in 2010) were invited to complete a survey of 315 idiopathic and neuromuscular EOS cases (same cases as in 2010). Treatment options included the following: conservative management, distraction-based methods, growth guidance/modulation, and arthrodesis. Consensus was defined as ≥ 70% agreement, and uncertainty was < 70%. Associations between case characteristics and consensus for treatments were assessed via chi-squared and multiple regression analyses. Case characteristics associated with uncertainty were described. RESULTS: Eleven surgeons [31.7 ± 7.8 years of experience] in the original 2010 cohort completed the survey. Consensus for conservative management was found in idiopathic patients aged ≤ 3, whereas in 2010, some of these cases were selected for surgery. There is currently consensus for casting idiopathic patients aged 1 or 2 with moderate curves, whereas in 2010, there was uncertainty between casting and bracing. Among neuromuscular cases with consensus for surgery, arthrodesis was chosen for patients aged 9 with larger curves. CONCLUSION: Presently, preferences for conservative management have increased in comparison to 2010, and casting appears to be preferred over bracing in select infantile cases. Future research efforts with higher levels-of-evidence should be devoted to elucidate the areas of uncertainty to improve care in the EOS population. LEVEL OF EVIDENCE: Level V.

Lengthening Behavior of Magnetically Controlled Growing Rods in Early-Onset Scoliosis: A Multicenter Study.

BACKGROUND: The "law of diminishing returns" is described for traditional growing rods. Magnetically controlled growing rods (MCGRs) have become a preferred implant for the surgical treatment of early-onset scoliosis (EOS). We examined a large cohort of patients with EOS to determine whether the law of diminishing returns applies to MCGRs. METHODS: A prospectively collected, multicenter registry was queried for patients with EOS treated with MCGRs. Patients with only spine-based implants and a minimum of 2 years of follow-up were included; patients with congenital scoliosis, single rods, <3 lengthenings, or >25% missing data were excluded. Patients were analyzed in 3 cohorts: primary MCGR (pMCGR) had first-time MCGR implants, secondary MCGR (sMCGR) were converted from an MCGR to a new MCGR, and conversion MCGR (cMCGR) were converted from a non-MCGR implant to MCGR. RESULTS: A total of 189 patients in the pMCGR group, 44 in the cMCGR group, and 41 in the sMCGR group were analyzed. From post-MCGR placement to the most recent follow-up or pre-definitive procedure, there were no differences in the changes in major Cobb angle, T1-S1 height, or T1-T12 height over time between the pMCGR and cMCGR groups. There was a decrease in length achieved at subsequent lengthenings in all cohorts (p < 0.01), and the sMCGR group had a significantly poorer ability to lengthen at each subsequent lengthening versus the pMCGR and cMCGR groups (p < 0.02). The 1-year survival rate was 90.5% for pMCGR, 84.1% for sMCGR, and 76.4% for cMCGR; 2-year survival was 61.5%, 54.4%, and 41.4%, respectively; and 3-year survival was 37.6%, 36.7%, and 26.9%, respectively. Excluding MCGRs still expanding, 27.6% of pMCGRs, 8.8% of sMCGRs, and 17.1% of cMCGRs reached the maximum excursion. Overall, 21.7% reached the maximum excursion. Within the pMCGR cohort, idiopathic and neuromuscular etiologies had a decline in lengthening achieved over time (p < 0.001), while syndromic EOS demonstrated a preserved ability to lengthen over time (p = 0.51). When the etiological groups were compared with each other, the neuromuscular group had the least ability to lengthen over time (p = 0.001 versus syndromic, p = 0.02 versus idiopathic). CONCLUSIONS: The MCGR experiences the law of diminishing returns in patients with EOS. We found that only 21.7% of rods expanded to within 80% of the maximum excursion. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

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.

Evaluating the Efficacy of Rib-to-pelvis Growth-friendly Surgery for the Treatment of Non-ambulatory Early-Onset Scoliosis Myelomeningocele Patients.

INTRODUCTION: Early-onset scoliosis (EOS) is a well-known orthopaedic manifestation in patients with myelomeningocele. The rib-based growing system (RBGS) has been proposed as an alternative for these individuals because of the poor outcomes with traditional surgical techniques. We aimed to describe the effect of RBGS in patients with nonambulatory EOS myelomeningocele. METHODS: We retrospectively reviewed the Pediatric Spine Study Group Multicenter Database for all patients with nonambulatory EOS myelomeningocele treated with RBGS from 2004 to 2019. Demographics, surgical data, radiographic findings, and postoperative complications were obtained. The quality-of-life parameters were assessed postoperatively using the Early-onset Scoliosis Questionnaire-24. RESULTS: Thirty patients (18 women; 60%) were patients with nonambulatory EOS myelomeningocele treated with RBGS. The mean age at the initial surgery was 5.3 years. The thoracic (T1-T12) spine height showed a significant increase from initial surgery to the most recent follow-up (P < 0.001). Spine (T1-S1) height was also significantly increased (P < 0.001). The postoperative complication rate was 87%. The Early-onset Scoliosis Questionnaire-24 demonstrates significant improvements in the quality-of-life scores (P = 0.037). CONCLUSION: This study demonstrated that RBGS could improve the reported quality-of-life scores in patients with nonambulatory EOS myelomeningocele when assessed with an EOS-oriented tool. Moreover, we confirmed the ability of RBGS to hold or even correct spinal deformity.

Mortality in Early-Onset Scoliosis During the Growth-friendly Surgery Era.

INTRODUCTION: Early-onset scoliosis (EOS) is a spinal deformity that occurs in patients 9 years of age or younger. Severe deformity may result in thoracic insufficiency, respiratory failure, and premature death. The purpose of this study is to describe the modern-day natural history of mortality in patients with EOS. METHODS: The multicenter Pediatric Spine Study Group database was queried for all patients with EOS who are deceased, without exclusion. Demographics, underlying diagnoses, EOS etiology, operative and nonoperative treatments or observation, complications, and date of death were retrieved. Descriptive statistics and survival analysis with Kaplan-Meier curves were performed. RESULTS: There were 130/8009 patients identified as deceased for a registry mortality rate of 16 per 1000 patients. The mean age at death was 10.6 years (range: 1.0 to 30.2 y) and the most common EOS etiology was neuromuscular (73/130, 56.2%; P<0.001). Deceased patients were more likely be treated operatively than nonoperatively or observed (P<0.001). The mean age of death for patients treated operatively (12.3 y) was older than those treated nonoperatively (7.0 y) or observed (6.3 y) (P<0.001) despite a larger deformity and similar index visit body mass index and ventilation requirements. Kaplan-Meier analysis confirmed an increased survival time in patients with a history of any spine operation compared with patients without a history of spine operation (P<0.0001). Operatively treated patients experienced a median of 3.0 complications from diagnosis to death. Overall, cardiopulmonary related complications were the most common (129/271, 47.6%; P<0.001), followed by implant-related (57/271, 21.0%) and wound-related (26/271, 9.6%). The primary cause of death was identified for 78/130 (60.0%) patients, of which 57/78 (73.1%) were cardiopulmonary related. CONCLUSIONS: This study represents the largest collection of EOS mortality to date, providing surgeons with a modern-day examination of the effects of surgical intervention to better council patients and families. Both fatal and nonfatal complications in children with EOS are most likely to involve the cardiopulmonary system. LEVEL OF EVIDENCE: Level IV-therapeutic.

Does Implant Density Impact Three-Dimensional Deformity Correction in Adolescent Idiopathic Scoliosis with Lenke 1 and 2 Curves Treated by Posterior Spinal Fusion without Ponte Osteotomies?

STUDY DESIGN: Retrospective cohort study. PURPOSE: To determine whether implant density impact three-dimensional deformity correction in posterior spinal fusion (PSF) without Ponte osteotomies (POs) for patients with Lenke 1 and 2 adolescent idiopathic scoliosis (AIS). OVERVIEW OF LITERATURE: Currently, the optimal pedicle screw (PS) density for flexible moderate-sized thoracic AIS curve correction is still controversial. There are limited data regarding the impact of implant density on three-dimensional correction in PSF without the use of PO for thoracic AIS surgery. METHODS: A database of patients with AIS with Lenke 1 and 2 curves treated with PSF without PO and instrumented with PSs and ≥2-year follow-up was reviewed. The preoperative, immediate, and final follow-up postoperative radiographs were analyzed. The correlation between PS density and the following factors were determined: major curve correction (MCC), correction index (CI; MCC/curve flexibility), kyphosis angle change, and rib index (RI) correction. Then, patients were divided into low-density (LD) and high-density (HD) groups according to mean PS density for the entire cohort (1.5 PS per level). Demographics and radiographic and clinical outcomes were compared between groups. RESULTS: The study included 99 patients with Lenke 1 and 23 patients with Lenke 2 AIS. The average MCC was 67.2%. There was no correlation between screw density and these parameters: MCC (r=0.10, p=0.26), CI (r=0.16, p=0.07), change in T2-T12 kyphosis angle (r=-0.13, p=0.14), and RI correction (r=-0.09, p=0.37). Demographic and preoperative radiographic parameters were similar between the LD and HD groups. At the latest follow-up, there were no differences between the two groups in regard to MCC, CI, change in T2-T12 kyphosis angle, RI correction, and Scoliosis Research Society-30 scores (all p>0.05). CONCLUSIONS: This study revealed no significant correlation between screw density and curve correction in any planes. HD construct may not provide better deformity correction in patients with flexible and moderate thoracic AIS undergoing PSF without PO.

How much does depth matter? Magnetically controlled growing rod distraction directly influenced by rod tissue depth.

PURPOSE: Magnetically controlled growing rod (MCGR) for the treatment of early-onset scoliosis (EOS) is a relatively innovative technique. MCGR benefits over traditional growing rods are known but limitations and complications are being revealed. The purpose of this study was to examine the importance of tissue depth on rod lengthening. METHODS: A single-institution retrospective review of 72 MCGR patients was performed. Ultrasound measured rod distraction. Differences in programmed and actual distraction, and complications were recorded. Tissue depths and achieved length were averaged and used to construct a regression to account for variability. RESULTS: Percentage of std and offset orientation rod lengthening relative to the programmed distraction was inversely proportional to rod depth (std R = 0.50, p = 0.002) (offset R = 0.60, p < 0.001). Expected std rod lengthening achieved decreased by 1.46%/mm depth. Expected offset rod lengthening achieved decreased by 1.68%/mm depth. 28 pts (38.9%) sustained complications. Age, sex, BMI, standard tissue depth, and/or offset tissue depth had no predictive ability with respect to complications sustained (overall model R = 0.31, p = 0.36). CONCLUSION: In a series of EOS surgical patients treated with MCGRs, the relationship between percentage of programmed lengthening achieved as well as total lengthening was inversely proportional to tissue depth of the rod. There was a trend towards increasing frequency of complications recorded with decreasing tissue depth though this was not significant. These data can help with surgical planning during MCGR placement.

The role of traditional growing rods in the era of magnetically controlled growing rods for the treatment of early-onset scoliosis.

PURPOSE: To describe the clinical and radiographic profile of early-onset scoliosis (EOS) patients treated with traditional growing rods (TGR) during the magnetically-controlled growing rod (MCGR) era. METHODS: A US multicenter EOS database was reviewed to identify (1) patients who underwent TGR after MCGR surgery was introduced at their institution, (2) patients who underwent MCGR during the same time period. Of 19 centers, 8 met criteria with all EOS etiologies represented. Clinical notes were reviewed to determine the indication for TGR. Patient demographics and pre-operative radiographs were compared between groups. RESULTS: A total of 25 TGR and 127 MCGR patients were identified. The TGR patients were grouped by indication into the sagittal plane profile (n = 11), trunk height (n = 6), co-morbidities/need for MRI (n = 4), and other (ex: behavioral issues, remaining growth). Four patients had a combination of sagittal profile and short stature with sagittal profile listed as primary factor. The TGR short trunk group had a mean T1-S1 length of 192 mm vs 273 mm for the MCGR group (p = 0.0002). The TGR sagittal profile group, had a mean maximal kyphosis of 61° vs 55° for the MCGR group (p = 0.09). CONCLUSION: TGR continues to have a role in the MCGR era. In this study, the most commonly reported indications for TGR were sagittal plane profile and trunk height. These results suggest that TGR is indicated in patients of short stature with stiff hyperkyphotic curves. As further experience is gained with MCGR, the indications for TGR will likely be refined.

A report of two conservative approaches to early onset scoliosis: serial casting and bracing.

PURPOSE: Previous reports have demonstrated the effectiveness of casting for EOS. Brace treatment for EOS has not been studied. The purpose of this multicenter retrospective study was to compare radiographic outcomes, complications, and rates of conversion to surgery in children with EOS treated with casting or bracing. METHODS: Children aged 2-6 years with idiopathic or neuromuscular EOS treated with casting or bracing with minimum follow-up of 2 years were identified. RESULTS: 68 patients (36 cast, 32 brace) were analyzed. Diagnosis, age at start of treatment, and duration of follow-up were similar. Although the cast patients had a larger pre-treatment major curve magnitude (50° vs 31°, p < 0.001), both groups had a similar major curve magnitude at most recent follow-up (36° vs 32°, p = 0.456). T1-T12 and T1-S1 length increased in both groups. The cast and brace patients had similar complications and conversions to surgery. Sub-analysis showed that while casting resulted in curve improvement regardless of etiology, bracing was able to prevent curve progression in patients with idiopathic EOS but not in patients with non-idiopathic EOS (Δ- 15° vs 27°, p = 0.006). Regression analysis (significance p = 0.10) controlling for baseline age, major curve magnitude, and T1-T12 and T1-S1 length showed that treatment method was associated with difference in major curve magnitude (p = 0.090) and T1-T12 length (p = 0.024). CONCLUSION: In our study, serial casting led to curve improvement in children with idiopathic and neuromuscular EOS, whereas brace treatment appeared to prevent curve progression in patients with idiopathic EOS but did not appear to control the curve in neuromuscular EOS.

Contouring the magnetically controlled growing rods: impact on expansion capacity and proximal junctional kyphosis.

OBJECTIVE: To quantitatively determine the relationship between the contouring of the magnetically controlled growing rods (MCGR), their expansion capacity and the risk of developing proximal junctional kyphosis in early onset scoliosis (EOS). MCGRs allow gradual expansion and correction of the spinal deformity in EOS while reducing the need for repeated surgeries. As the expansion of the MCGRs is controlled externally, several factors can impact the discrepancy between the intended and actual expansions of the rods. The expansion capacity of the growing rods as a function of the expanded length has been tested in experimental setups; however, no study has evaluated the role of contouring of the MCGRs on its function and long-term surgical outcome. METHODS: A total of 25 EOS patients, a total of 48 MCGRs, with right thoracic curves, were studied retrospectively. All patients had two view spinal radiographs at pre-operative, after MCGR implantation, and after 6 lengthening visits. The first post-operative radiographs were used to calculate the 3D contour of the MCGR at the proximal end. 2D ultrasound images before and after lengthening visits were used to measure the rod lengthening at each visit. The relationship between the increase in the rod length and rod curvature was determined. Finally, the rod curvature was correlated to the changes in proximal junctional kyphosis (PJK) angle between the pre-operative and the most recent follow-up, i.e., after 6 visits. RESULTS: The average rod 3D angle at the proximal end was 13.5° ± 9.7° [0°-37.2°]. The overall increased length after six lengthening visits for the rod at the concave side was 18.8 mm and at the convex side was 16.9 mm. 62% of the patients with a contoured rod at the proximal end developed a PJK exceeding 10° whereas in patients with a straight rod PJK occurred in 9.1%. CONCLUSIONS: Contouring the MCGR impacts both the mechanics of the rod expansion and the prevalence of PJK in EOS patient population.

Awake serial body casting for the management of infantile idiopathic scoliosis: is general anesthesia necessary?

STUDY DESIGN: It is a retrospective cohort study. OBJECTIVES: To compare the radiographic and clinical outcomes of serial body casting for infantile idiopathic scoliosis (IIS) with versus without the use of general anesthesia (GA). Serial body casting for IIS has traditionally been performed under GA. However, reports of neurotoxic effects of anesthetics in young children have prompted physicians to consider instead performing these procedures while patients are awake and distracted by electronic devices. METHODS: Patients from a multicenter registry who underwent serial casting for IIS were included. The patients were divided into asleep (GA) and awake (no GA) cohorts. Comparisons were made between pre-casting, first in-cast, and post-casting radiographic measures in each cohort. The rates of successful casting (≥ 10° major CA improvement), curve progression, and incidence of casting abandonment for surgical intervention were also compared. RESULTS: One-hundred and twenty-one patients who underwent serial casting for IIS were included. Ninety-two (76%) patients were asleep during casting procedures, while 29 (24%) were awake. Patients in the awake cohort were older (p < 0.01), had a lower BMI (p = 0.03), and more severe curve magnitudes (p < 0.01) at baseline. Patients in the awake cohort experienced greater first-in-cast correction of the major curve (p = 0.01) and improvement in thoracic spine height (p < 0.01). The rate of casting success was higher in the awake cohort (72%) as compared to the asleep cohort (48%) (p = 0.02), although the rate of curve progression (worsening) was similar (p = 0.880). Lastly, there was a lower rate of conversion to surgery at 2 years post-initiation of casting, although this was not statistically significant (0% vs. 8%; p = 0.126). CONCLUSIONS: Patients who underwent awake serial casting had similar radiographic outcomes as compared to those who were under general anesthesia during the procedures. Thus, awake casting may provide a safe and effective alternative to the use of general anesthesia in patients with idiopathic infantile scoliosis. LEVEL OF EVIDENCE: III.

Characterizing Use of Growth-friendly Implants for Early-onset Scoliosis: A 10-Year Update.

BACKGROUND: Growth-friendly treatment of early-onset scoliosis (EOS) has changed with the development and evolution of multiple devices. This study was designed to characterize changes in the use of growth-friendly implants for EOS from 2007 to 2017. METHODS: We queried the Pediatric Spine Study Group database for patients who underwent index surgery with growth-friendly implants from July 2007 to June 2017. In 1298 patients, we assessed causes of EOS; preoperative curve magnitude; age at first surgery; patient sex; construct type; lengthening interval; incidence of "final" fusion for definitive treatment; and age at definitive treatment. α=0.05. RESULTS: From 2007 to 2017, the annual proportion of patients with idiopathic EOS increased from 12% to 33% (R=0.58, P=0.006). Neuromuscular EOS was the most common type at all time points (range, 33% to 44%). By year, mean preoperative curve magnitude ranged from 67 to 77 degrees, with no significant temporal changes. Mean (±SD) age at first surgery increased from 6.1±2.9 years in 2007 to 7.8±2.5 years in 2017 (R=0.78, P<0.001). As a proportion of new implants, magnetically controlled growing rods increased from <5% during the first 2 years to 83% in the last 2 years of the study. Vertically expandable prosthetic titanium ribs decreased from a peak of 48% to 6%; growth-guidance devices decreased from 10% to 3%. No change was seen in mean surgical lengthening intervals (range, 6 to 9 mo) for the 614 patients with recorded lengthenings. Final fusion was performed in 88% of patients who had undergone definitive treatment, occurring at a mean age of 13.4±2.4 years. CONCLUSIONS: From 2007 to 2017, neuromuscular EOS was the most common diagnosis for patients treated with growth-friendly implants. Patient age at first surgery and the use of magnetically controlled growing rods increased during this time. Preoperative curve magnitude, traditional growing rod lengthening intervals, and rates of final fusion did not change. LEVEL OF EVIDENCE: Level II.

MRI utilization and rates of abnormal pretreatment MRI findings in early-onset scoliosis: review of a global cohort.

STUDY DESIGN: Retrospective review OBJECTIVES: To report the frequency of pretreatment magnetic resonance imaging (MRI) utilization and rates and types of intra-spinal abnormalities identified on MRI in patients with early-onset scoliosis (EOS). MRI can help identify spinal cord abnormalities in patients with EOS. METHODS: We reviewed data from patients enrolled from 1993-2018 in an international EOS registry. Patients with incomplete/unverifiable data and those with spinal deformities secondary to infection or tumor were excluded, leaving 1343 patients for analysis. Demographic characteristics, pretreatment major curve magnitude, treatment type, and MRI findings were analyzed. Patients were categorized by EOS type (congenital, idiopathic, neuromuscular, syndromic), pretreatment MRI utilization, and presence of intra-spinal abnormality on MRI. Univariate testing and multivariate logistic regression were performed to identify demographic, radiographic, and clinical predictors of MRI utilization and abnormal MRI findings. RESULTS: MRI was used in 836 patients (62%). Pretreatment MRI utilization rates ranged from 42% in neuromuscular EOS to 74% in congenital EOS. Prevalence of abnormal MRI findings was 24% overall, ranging from 13% in patients with idiopathic EOS to 39% in neuromuscular EOS. Compared with white/Caucasian patients, Asian/Asian-American patients had higher odds of MRI utilization and abnormal MRI findings. Treatment type, pretreatment major curve magnitude, age at MRI, and age at treatment were not associated with abnormal MRI findings. Overall, 249 abnormalities were identified in 197 patients. The most common findings were syrinx and tethered cord. Syrinx with Chiari malformation was the most frequent combination of abnormal findings. CONCLUSION: In the two-thirds of patients who underwent MRI before EOS treatment, findings were abnormal in 24%. EOS type and race/ethnicity were associated with both MRI utilization and abnormal findings. The most frequent abnormalities were syrinx and tethered cord, and the type of abnormalities appeared to differ by EOS type. LEVEL OF EVIDENCE: Prognostic, Level III.

Establishing Consensus on the Best Practice Guidelines for Use of Halo Gravity Traction for Pediatric Spinal Deformity.

BACKGROUND: Although halo gravity traction (HGT) has been used to treat children with severe spinal deformity for decades, there is a distinct lack of high-quality evidence to speak to its merits or to dictate ideal manner of implementation. In addition, no guidelines exist to drive research or assist surgeons in their practice. The aim of this study was to establish best practice guidelines (BPG) using formal techniques of consensus building among a group of experienced pediatric spinal deformity surgeons to determine ideal indications and implementation of HGT for pediatric spinal deformity. METHODS: The Delphi process and nominal group technique were used to formally derive consensus among leaders in pediatric spine surgery. Initial work identified significant areas of variability in practice for which we sought to garner consensus. After review of the literature, 3 iterative surveys were administered from February through April 2018 to nationwide experts in pediatric spinal deformity. Surveys assessed anonymous opinions on ideal practices for indications, preoperative evaluation, protocols, and complications, with agreement of 80% or higher considered consensus. Final determination of consensus items and equipoise were established using the Nominal group technique in a facilitated meeting. RESULTS: Of the 42 surgeons invited, responses were received from 32, 40, and 31 surgeons for each survey, respectively. The final meeting included 14 experts with an average 10.5 years in practice and average 88 annual spinal deformity cases. Experts reached consensus on 67 items [indications (17), goals (1), preoperative evaluations (5), protocols (36), complications (8)]; these were consolidated to create final BPG in all categories, including statements to help dictate practice such as using at least 6 to 8 pins under 4 to 8 lbs of torque, with a small, tolerable starting weight and reaching goal weight of 50% TBW in ∼2 weeks. Nine items remained items of equipoise for the purposes of guiding future research. CONCLUSIONS: We developed consensus-based BPG for the use and implementation of HGT for pediatric spinal deformity. This can serve as a measure to help drive future research as well as give new surgeons a place to begin their practice of HGT. LEVEL OF EVIDENCE: Level V-expert opinion.

Periapical-dropout Screws Strategy For 3-Dimensional Correction of Lenke 1 Adolescent Idiopathic Scoliosis in Patients Treated by Posterior Spinal Fusion.

STUDY DESIGN: This was a single-center, retrospective study. OBJECTIVE: The objective of this study was to compare periapical-dropout screws strategy (PDSS) with traditional-multilevel pedicle screws strategy (TMSS) for 3-plane correction of Lenke 1 adolescent idiopathic scoliosis deformity. SUMMARY OF BACKGROUND DATA: There are limited data in 3-plane correction and the optimal pedicle screw (PS) configuration for Lenke 1 adolescent idiopathic scoliosis surgery. MATERIALS AND METHODS: Sixty-one consecutive patients with Lenke 1 curves (range: 50-80 degrees), undergoing single-stage posterior spinal fusion with PS fixation, were included. Patients with a minimum follow-up of 1 year were divided into 2 groups according to PS strategy. The PDSS group included 33 patients with PS placement bilaterally at both ends and apex of the construct. The TMSS group included 28 patients with conventional PS placement. Baseline, immediate, and last follow-up demographic, radiographic, and clinical outcomes were analyzed. Radiographic outcomes were assessed in axial (using rib index and apical vertebral rotation using Raimondi ruler and Upasani methods), coronal, and sagittal planes. The implant costs were also evaluated. RESULTS: There were no differences in demographic, preoperative radiographic parameters and levels fused. The number of PSs per level fused was significantly lower in the PDSS group (1.3 vs. 1.4; P=0.0002). At last follow-up, major Cobb correction averaged 79% for the PDSS group and 69.5% for the TMSS group (P=0.001). T2-T12 kyphosis angle changes were 1 degree in the PDSS group and -2.5 degrees in the TMSS group (P=0.35). Rib index correction was 28.2% for the PDSS group and 17.7% for the TMSS group (P=0.02). Upasani grade apical vertebral rotation was significantly better in the PDSS group (0.7 vs. 1.4; P=0.0001). Clinical outcomes evaluated by Scoliosis Research Society-30 scores were similar in both groups. Total implant costs were significantly lower in the PDSS group ($16,852 vs. $18,926; P<0.001). CONCLUSION: The PDSS construct provides better deformity correction in all 3 planes and helps decrease implant costs compared with the TMSS construct. Thus, the PDSS construct can be considered as a rational strategy and cost-effective technique when treating moderate Lenke 1 curves with posterior spinal fusion.