Evidence of spinal stiffening following fusionless bipolar fixation for neuromuscular scoliosis: a shear wave elastography assessment of lumbar annulus fibrosus.

OBJECTIVES: There are no established criteria for stiffness after fusionless surgery for neuromuscular scoliosis (NMS). As a result, there is no consensus regarding the surgical strategy to propose at long-term follow-up. This study reports the first use of shear wave elastography for assessing the mechanical response of lumbar intervertebral discs (IVDs) after fusionless bipolar fixation (FBF) for NMS and compares them with healthy controls. The aim was to acquire evidence from the stiffness of the spine following FBF. PATIENTS AND METHODS: Nineteen NMS operated on with FBF (18 ± 2y at last follow-up, 6 ± 1 y after surgery) were included prospectively. Preoperative Cobb was 89 ± 20° and 35 ± 1° at latest follow-up. All patients had reached skeletal maturity. Eighteen healthy patients (20 ± 4 y) were also included. Shear wave speed (SWS) was measured in the annulus fibrosus of L3L4, L4L5 and L5S1 IVDs and compared between the two groups. A measurement reliability was performed. RESULTS: In healthy subjects, average SWS (all disc levels pooled) was 7.5 ± 2.6 m/s. In NMS patients, SWS was significantly higher at 9.9 ± 1.4 m/s (p < 0.05). Differences were significant between L3L4 (9.3 ± 1.8 m/s vs. 7.0 ± 2.5 m/s, p = 0.004) and L4L5 (10.3 ± 2.3 m/s vs. 7.1 ± 1.1 m/s, p = 0.0006). No difference was observed for L5S1 (p = 0.2). No correlation was found with age at surgery, Cobb angle correction and age at the SWE measurement. CONCLUSIONS: This study shows a significant increase in disc stiffness at the end of growth for NMS patients treated by FBF. These findings are a useful adjunct to CT-scan in assessing stiffness of the spine allowing the avoidance of surgical final fusion at skeletal maturity.

Kyphectomy in myelomeningocele revisited: risk factors for failure.

PURPOSE: Lumbar kyphosis occurs in approximately 8-20% of patients with myelomeningocele (MMC). The purpose of this article is to analyze the risks and benefits of vertebrectomy and spinal stabilization in MMC children with severe lumbar kyphosis and to establish treatment guidelines. METHODS: This is an IRB-approved retrospective analysis of 59 patients with MMC who underwent kyphectomy and posterior instrumentation in three centers. Average age at surgery was 7.9 years (2 weeks-17 years). Sitting trunk position, skin status, kyphosis angle, and thoracic lordosis were analyzed preoperatively, postoperatively, and at an average follow-up of 8.2 years (range 2.5-16). The correction was maintained by applying a short posterior instrumentation in 6 patients, and extending to the pelvis in 53 cases. Pelvic fixation was achieved using the Warner and Fackler technique in 24 patients, the Dunn-McCarthy in 8, Luque-Galveston in 8, sacral screws in 2, and ilio-sacral screws in 11. RESULTS: Sitting position improved postoperatively in 47 of the 53 patients who underwent pelvic fixation and only in one patient with short instrumentation. All 6 patients with long instrumentation and poor postoperative sitting balance were in the Dunn-McCarthy fixation group. Skin sores at the apex of the deformity disappeared postoperatively in all patients but recurred in two patients with short instrumentations. Kyphosis angle improved from 109° (45°-170°) preoperatively to 10° (0°-45°) postoperatively and 21° (0°-55°) at last follow-up. The best results were seen in cases where a cross-k-wire fixation of the kyphectomy site was used, augmented with a long thoraco-pelvic instrumentation consisting of Luque sublaminar wires in the thoracic region and a Warner-Fackler type of pelvic fixation. Good results were also found with the bipolar technique and ilio-sacral screw fixation. Six over 24 patients with the Warner and Fackler technique showed gradual dislodgment or hardware failure, with subsequent nonunion of the kyphectomy site in four. Infection, with or without wound dehiscence and/or hardware exposure, occurred in 17 cases, necessitating hardware removal in 9 patients. CONCLUSION: Lumbar kyphosis in MMC children is best managed by resection of enough vertebrae from the apex to produce a flat lumbar spine, with perfect bone-to-bone contact and long thoraco-pelvic instrumentation using the Warner and Fackler technique through the S1 foramina or the bipolar technique with ilio-sacral screw fixation. Additional local fixation of the osteotomy site using cross-wires with or without cerclage increases the stability of the construct. The majority of complications occurred in patients with short instrumentations or where residual kyphosis persisted postoperatively regardless of the type of pelvic fixation or hardware density. The Dunn-McCarthy technique for pelvic fixation following kyphectomy in MMC was less successful in producing stable pelvic fixation and should not be considered in this patient category.

Surgical treatment of neuromuscular Early Onset Scoliosis with a bilateral posterior one-way rod compared to the Spring Distraction System: study protocol for a limited-efficacy Randomized Controlled Trial (BiPOWR).

BACKGROUND: Early Onset Scoliosis (EOS) is a progressive spinal deformity in children, and a potentially life-threatening disease. "Growth-friendly" surgical techniques aim to control the deformity, while allowing the spine and trunk to maintain growth. Current "growth-friendly" systems such as the traditional growing rod (TGR) and magnetically controlled growing rod (MCGR) have limitations that reduce their efficacy and cost-effectiveness. Recently, two "growth-friendly" systems have been developed that mitigate many of these limitations, the Spring Distraction System (SDS) and the One Way Self-Expanding Rod (OWSER). The purpose of the multicenter BiPOWR trial is to investigate, describe and compare the 1-year limited-efficacy and -safety of both strategies in the treatment of neuromuscular EOS. METHODS: After informed consent, 28 neuromuscular EOS patients will be randomized to receive either the SDS or the OWSER. Patients and caregivers will be blinded to allocation until after surgery. Primary outcomes will be maintenance of coronal curve correction and the occurrence of serious adverse events. In addition, spinal growth, implant lengthening, and perioperative findings are recorded systematically. At each follow-up moment, the Early Onset Scoliosis Questionnaire (EOSQ-24) will be used to assess health-related quality of life. All outcomes will be compared between groups. DISCUSSION: The BiPOWR trial is the first randomized controlled trial that compares two specific "growth-friendly" implants in a specified EOS population. It will determine the 1-year limited-efficacy and safety of the SDS and OWSER implants. TRIAL REGISTRATION: Clinicaltrials.gov: NCT04021784 (13-06-2019). CCMO registry: NL64018.041.17 (06-05-2019).

Long-term outcomes of ilio-sacral screws in minimally invasive bipolar fusionless technique for neuromuscular scoliosis: a retrospective study in 167 patients.

INTRODUCTION: Pelvic fixation in patients with neuromuscular scoliosis is difficult, due to their fragile general condition and poor bone quality. Many techniques have been described, associated with high rates of mechanical complications. The objective of this work was to evaluate the mechanical complications and long-term radiological results of ilio-sacral screw pelvic fixation. MATERIALS AND METHODS: 167 consecutive patients with neuromuscular scoliosis who underwent minimally invasive bipolar fixation with ilio-sacral screw pelvic fixation were retrospectively reviewed. The instrumentation consisted in a bilateral sliding rods construct extended from T1 to the sacrum, anchored proximally by double-hook claws and distally by ilio-sacral screws through a minimally invasive approach. Mechanical complications and radiographic measurements (angle of the major coronal curve, pelvic obliquity, lumbar lordosis) were evaluated preoperatively, postoperatively, and at the last follow-up. RESULTS: Mean operative age was 12 ± 3 years, and follow-up 6.4 years (3.0-10.4 years). Pelvic obliquity decreased from 20° preoperatively to 5° (77% correction) at last follow-up, Angle of the major coronal curve from 75° to 36° (52% correction), and lumbar lordosis from 28° to 38°. 16 mechanical complications in nine patients occurred: screw prominence (n = 1), connector failure (n = 4), screw malposition (n = 11). Unplanned surgery was required in seven cases, two were managed during rod lengthening, seven did not require treatment. CONCLUSION: In this series of neuromuscular patients operated by ilio-sacral screws as pelvic fixation, the results were stable with a mean follow-up of more than 6 years and the complication rate was reduced comparatively to the literature.

Perioperative complications after posterior spinal fusion versus minimally invasive fusionless surgery in neuromuscular scoliosis: a comparative study.

INTRODUCTION: Early-onset scoliosis is a common deformity in neuromuscular disease. When conservative treatment becomes ineffective, several surgical options can be proposed. The most common technique is posterior spinal fusion (PSF) consisting of performing a multiple segmental instrumentation with pedicular screws on the full spine associated with decortication and bone graft. Minimally invasive fusionless surgery (MIFS) is an alternative to correct and fix definitively the spine without graft. The objective of this study was to compare early surgical inpatient period between PSF and MIFS in neuromuscular scoliosis. MATERIAL AND METHODS: 140 NMS operated by PSF or MIFS between 2012 and 2017 was retrospectively reviewed. The following data were compared between groups: general characteristics (age, sex, etiology), preoperative preparation (halo traction, noninvasive ventilation or tracheostomy), Cobb angle and pelvic obliquity correction, use of drugs (vasopressor and/or inotropes, expansion fluids, transfusion and volumes), postoperative complications, and need of noninvasive ventilation. RESULTS: 75 patients were managed by PSF with a mean age of 14.3 ± 2.3y and 65 by MIFS with a mean age of 11.8 ± 3y. Average pelvic obliquity and major curve correction were similar postoperatively. Intraoperative blood transfusion was significantly more common in PSF group (OR, 14; 95% CI [6.3-33.0]). Vasopressors were used non-significantly more often in the PSF group and expansion fluids similar in the two groups. PSF group had more overall complications (OR, 4.6; 95% CI [2.3-9.8]), more infections (OR, 3.6; 95% CI [1.5-9.3]) and more hemodynamic complications (OR, 4.1; 95% CI [1.4-15.1]). Average intubation duration was 5 days in the PSF and 4 days in MIFS (p = 0.05). CONCLUSION: In this series of neuromuscular patients, the complication rate was reduced in MIFS comparatively to PSF, with lower blood transfusion and less infections.

One-way self-expanding rod for early-onset scoliosis: early results of a clinical trial of 20 patients.

PURPOSE: Progressive early-onset scoliosis raises major challenges for surgeons, as growth must be preserved. With traditional growing rods, the need for repeated surgery is associated with numerous complications, high costs, and heavy psychosocial burden on the patient and family. We assessed the safety and efficacy of a new one-way self-expanding rod (OWSER). METHODS: This prospective single-centre phase 2 study included two groups of children with progressive EOS treated by the OWSER in 2016-2017: Ten received a unilateral construct to treat progressive non-neuromuscular curves and 10 others a bilateral construct for neuromuscular scoliosis. Clinical and radiological data were assessed at surgery and 3, 6, 12, 18 months later. The primary endpoint was success defined as the absence of repeated surgery at 12 months. RESULTS: In the non-neuromuscular group, rod expansion occurred in 5 of 10 patients [95% CI 19-81]; in the five other patients, rotational conflict inside the domino prevented rod expansion, four of them required surgery within the first 12 months. Rod expansion occurred spontaneously and during monthly traction sessions in all 10 neuromuscular patients [95% CI 69-100], without mechanical or device-related complications. Residual pelvic obliquity was improved by -3° [- 6.0 to 9.5] at 18 months. Lung function improved in the non-neuromuscular group. CONCLUSION: In neuromuscular diseases, the OWSER bilateral construct seems to be safe and less aggressive. Used as unilateral construct in non-neuromuscular group, it was less effective. Accordingly, we recommend the bilateral construct for all aetiologies. That device could avoid further surgery and reduce the rate of complications after long follow-up.

Minimally Invasive Fusionless Surgery for Scoliosis in Spinal Muscular Atrophy: Long-term Follow-up Results in a Series of 59 Patients.

BACKGROUND: Treatment of spinal muscular atrophy (SMA) scoliosis has evolved in the last decade, with the emergence of fusionless surgical techniques that allow correction of the deformity before the end of growth spurt. These techniques are expected to delay definitive spine fusion and preserve trunk growth. PURPOSE: The aim was to evaluate long-term clinical, radiologic, and respiratory outcomes of a minimally invasive fusionless surgery (MIFLS) in SMA scoliosis. METHODS: All children affected with SMA scoliosis who underwent MIFLS in our department from 2011 to 2019 were included. The instrumentation consisted in a bilateral sliding rod construct from T1 to the sacrum, anchored proximally by double-hook claws and distally by iliosacral screws. Clinical, genetic, respiratory and radiographic data were retrospectively reviewed. A patient's satisfaction survey was performed. RESULTS: A total of 59 children with genetic confirmation of SMA (9SMA1c, 47SMA2, and 3SMA3) underwent MIFLS at a mean age of 11±1.9 years. All of them were nonwalker at the time of surgery. Twenty-six were treated with intrathecal Nusinersen. Mean follow-up was 5.2 years (2 to 9.6 y). Mean major coronal curve improved from 79±15 to 41±16 degrees and pelvic obliquity decreased from 24±11 to 5.9±4 degrees. Mean space available for lung improved from 77% to 93%. Mechanical or infectious complications occurred in 9 patients, with removal of the implant in 1. 6 children required unplanned surgeries. Postoperative bracing was needed in 13 children. Mean gain weight 3 years after the first surgery was 6 kg. 91.5% of patients had a positive satisfaction of the surgery. There was no significant impact in respiratory function postoperatively. Only 30 children required rod lengthening procedures, with a mean interval between procedures of 1.9 years (0.5 to 3.7 y). No arthrodesis was required at last follow-up in any patient. CONCLUSION: Bipolar MIFLS in SMA preserves spinal and thoracic growth without interference with respiratory function. It provides a significant correction of spinal deformity and pelvic obliquity, having a reduced rate of complications. The correction of spinal deformity was maintained at long term, not requiring definitive fusion at the end of growth. LEVEL OF EVIDENCE: Level IV.

Cobb-1 versus cobb-to-cobb anterior fusion for adolescent idiopathic scoliosis Lenke 5C curves: a radiological comparative study.

PURPOSE: Anterior fusion is a well-established procedure for the treatment of Lenke 5C adolescent idiopathic scoliosis (AIS). This retrospective study aimed to assess preoperative and postoperative radiographic differences between the conventional anterior fusion and anterior short fusions (ASF) in Lenke 5C AIS. METHODS: Radiographic data of 42 consecutive cases of Lenke 5C AIS, which were surgically treated through anterior segmental fusion, were analyzed retrospectively. Patients have been divided into two groups: C group (n = 19) treated by the conventional fusion from the proximal end vertebra to the distal end vertebra of the main curve and C-1 group (n = 23) treated by ASF, sparing the lowest end vertebra of the main curve. Cobb angles of main curve, apical vertebra tilt, C7 coronal tilt, lowest instrumented vertebra angle (LIV angle), LIV adjacent level disc angulation (LIVDA), and the first uninstrumented vertebra angle (FUV angle) were measured on anteroposterior radiographs of the entire spine. LIVDA, FUV wedging, and rotation were measured on stretch films. C7 sagittal tilt, lumbar lordosis, thoracic kyphosis, and proximal kyphosis junction were measured on lateral radiographs of the entire spine. Repeated-measures analysis of variance and fisher test were used for the statistical analysis. RESULTS: The preoperative main curve was 39.9 ± 9.1° in the C group vs. (versus) 42.8 ± 11.8° in the C-1 group. At a mean follow-up of 26.2 months (range 10.5-66.3 months), postoperative main curve improved of 75.8 ± 21.2 % (10.4 ± 9.2°, p < 0.001) in the C group and of 52.7 ± 18.7 % (20.1 ± 8.1°, p < 0.001) in the C-1 group. All parameters improved except the LIVDA, which was slightly impaired, especially in the C-1 group with 5.6 ± 4.2° vs. 4.4 ± 2.2° in the C group. On stretch films, FUV rotation was the only parameter to differ; it was graded at 1 ± 0.7 in the C-1 group vs. 0.6 ± 0.5 in the C group (p = 0.04). No disk obliquity just under the future instrumentation and equivalent FUV wedging were found in any of the two groups. CONCLUSIONS: The conventional anterior fusion and ASF give equivalent correction in Lenke 5C AIS, but ASF seems to induce adding-on of the disk below the LIV. FUV rotation on stretch films does not seem to be a predictive factor of postoperative radiological outcome.

Acute pancreatitis following scoliosis surgery: description and clinical course in 14 adolescents.

PURPOSE: Acute pancreatitis is a possible complication after scoliosis surgery. Although some risk factors have been documented in the literature, clinical description of pancreatitis diagnosis and ensuing course still remain very poor. The aim of this study was to describe characteristics of acute pancreatitis after scoliosis surgery. METHODS: A descriptive, retrospective and single-center study of fourteen adolescents with postoperative acute pancreatitis after spine fusion surgery in scoliosis management between April 2003 and August 2012 was performed. RESULTS: Acute pancreatitis occurred within 9.5 days (4-51) after surgery. Abdominal pain was atypical and was expressed in only half of the children. Ileus, nausea and vomiting were the most frequent signs. None of the acute pancreatitis cases was severe. CONCLUSION: Acute pancreatitis is an early complication of scoliosis surgery. Clinical signs are atypical and non-severe and can induce misleading forms. Presence of delayed digestive problems should alert the clinician to the risk of pancreatitis in the aftermath of scoliosis surgery.

A novel technique for treatment of progressive scoliosis in young children using a 3-hook and 2-screw construct (H3S2) on a single sub-muscular growing rod: surgical technique.

INTRODUCTION: Several different growing rod techniques have been described in the literature to treat progressive scoliosis in young children. Nevertheless, none of these techniques has shown a real superiority, and the rate of complications remains high. The purpose of this report is to describe an original fusionless method of treatment for this problem. MATERIALS AND METHODS: The 3 hooks-2 screws (H3S2) construct consists of a single 5.5 mm titanium rod with three hooks proximally and two monoaxial pedicle screws distally, and some extra length of rod located distally and/or proximally that can be used for future lengthenings. To date, a total of 103 H3S2 constructs have been performed in our institution. This paper reports the preliminary results on 38 patients, with a minimum follow-up of 2 years. RESULTS: This procedure was found to be effective in maintaining scoliosis correction while allowing continued spinal growth and was associated with a low rate of complications. CONCLUSIONS: The H3S2 construct was found to have several advantages over the growing rod techniques as previously described in the literature. These include no need for post-operative bracing, fewer lengthening procedures and a lower rate of complications.

The Minimally Invasive Bipolar Fixation for Pediatric Spinal Deformities: A Narrative Review.

Growing rod techniques are increasingly used for early-onset scoliosis in children. Unfortunately, they are associated with many complications, particularly neuromuscular scoliosis, favored by the poor general condition of these patients and the fragility of their osteoporotic bones. Furthermore, these interventions are often iterative and usually followed by vertebral fusion at the end of growth. This is a review of the literature on a recent fusionless technique, minimally invasive bipolar fixation, which is more stable than the traditional growing rod techniques and less aggressive than vertebral arthrodesis. It allows the avoidance of arthrodesis, owing to the solidity of the construct and the stability of the results, leading to progressive spinal stiffening that occurs over time. The results of this technique have been published with a long follow-up period and have confirmed that it can completely replace posterior vertebral arthrodesis, especially in the most complicated scoliosis. Because it preserves growth, this technique should be recommended for early-onset scoliosis before the age of 10 years. The use of a self-expanding rod can avoid the need for repeated surgery, thereby reducing the risk of complications and the overall cost of treatment.

Pelvic Fixation Technique Using the Ilio-Sacral Screw for 173 Neuromuscular Scoliosis Patients.

Pelvic fixation remains one of the main challenging issues in non-ambulatory neuromuscular scoliosis (NMS) patients, between clinical effectiveness and a high complication rate. The objective of this multicenter and retrospective study was to evaluate the outcomes of a technique that was applied to treat 173 NMS patients. The technique is not well-known but promising; it uses the ilio-sacral screw, combined with either the posterior spinal fusion or fusionless bipolar technique, with a minimum follow-up of two years. The mean operative age of the patients was 13 ± 7 years. The mean preoperative main coronal curve was 64° and improved by a mean of -39° postoperatively. The mean preoperative pelvic obliquity was 23°, which improved by a mean of -14° postoperatively. No decrease in the frontal or sagittal correction was observed during the last follow-up. The sitting posture improved in all cases. Twenty-nine patients (17%) had a postoperative infection: twenty-six were treated with local debridement and antibiotics, and three required hardware removal. Fourteen mechanical complications (8%) occurred: screw malposition (n = 6), skin prominence (n = 1), and connector failure (n = 1). This type of surgery is associated with a high risk for infection. Comorbidities, rather than the surgery itself, were the main risk factors that led to complications. The ilio-sacral screw was reliable and effective in correcting pelvic obliquity in NMS patients. The introduction of intraoperative navigation should minimize the risk of screw misplacement and facilitate revision or primary fixation.

H3S2 (3 hooks, 2 screws) construct: a simple growing rod technique for early onset scoliosis.

PURPOSE: The purpose of this study was to review the preliminary results of an original fusionless method of treatment for progressive scoliosis in young children. METHODS: This study retrospectively reviewed the clinical records and radiographs of 23 children with progressive scoliosis who failed to respond to conservative treatment and underwent fusionless surgery using a single solid growing rod construct. All of them were ambulatory and had a follow-up of minimum 2 years. Sixteen patients were treated by consecutive distraction of a single intramuscular rod, and seven patients with rodding and anterior apical convex fusion. The etiology of the scoliosis included 11 idiopathic, 6 syndromic, 4 congenital, and 2 neurofibromatosis. At initial surgery, the average age was 9.3 ± 2.8 years, with a mean Cobb angle of 68° ± 32°. Six patients underwent progressive scoliosis correction in a Stagnara cast prior to surgery, and one patient with an external halo-pelvic Ilizarov device. RESULTS: Fusionless single rodding allowed to maintain scoliosis correction in all patients. At an average of 3.5 ± 0.9 years after initial surgery, the 23 patients showed a correction of 57 % in the magnitude of the original curvature. Trunk height increase was documented in all patients and ranged from 1.5 to 11.9 cm. Rod failure was found in three patients and two patients had hardware infection. Only four cases of proximal junctional kyphosis were found at last follow-up. CONCLUSIONS: Preliminary results from these series of patients show that the presented fusionless single growing rod technique allows to maintain correction of progressive early onset scoliosis while permitting spinal growth, with low complication rate. With this technique, lengthening procedures are used only once in every 10 months and patients are more comfortable as no brace is needed in most cases. This technique does not require any specific spine device. The procedure is simple and efficacious as long as some guidelines are respected.

Sacropelvic fixation with iliosacral screws: applications and results in adult spinal deformities.

STUDY DESIGN: Retrospective radiographic and clinical review. OBJECTIVE: To determine the feasibility of iliosacral screw fixation in adult spinal deformations. SUMMARY OF BACKGROUND DATA: Pelvic fixation is one of the most challenging instrumentation problems. The poor bone quality frequently found within the sacrum and the large lumbosacral loads with cantilever pullout forces across this region explain its frequent failure. METHODS: Fourteen adult patients undergoing pelvic fixation using iliosacral screws with a minimal follow-up of 24 months were analyzed for radiographic outcomes. Radiographic data included the localization of the spinal deformity, the Cobb angle, T4-T12 thoracic kyphosis, L1-S1 lumbar lordosis, the T9 tilt, the pelvic parameters, and the POA. Mechanical and infectious complications were also noted. RESULTS: The lumbo-pelvic correction was performed with a large reduction of the POA in every case. The frontal and sagittal corrections obtained with this procedure were considered as being effective. There were no mechanical complications due to failure of the instrumentation, loss of sacral fixation, or loss of lumbar lordosis at the time of the last follow-up. One patient experienced local infection on the left iliosacral screw without any residual functional sequel. DISCUSSION: Iliosacral screwing can offer a pelvic fixation reliable enough to allow restoration of 3-dimensional trunk balance. This technique has a quite short learning curve and adequately permits frontal and sagittal corrections, increases stability, and decreases instrumentation-related complications. Our observations suggest that it is applicable to pelvic fixation in adult surgery.

Is Minimally Invasive Bipolar Technique a Better Alternative to Long Fusion for Adult Neuromuscular Scoliosis?

STUDY DESIGN: Prospective cohort study. OBJECTIVES: To report the results for an alternative technique based on minimally invasive fusion-less surgery. This approach is original in that it corrects deformities by proximal and distal fixation, with reliable pelvic fixation through the use of iliosacral screws on osteoporotic bones. METHODS: Adult cerebral palsy patients requiring spinal correction surgery were included prospectively between 2015 and 2019. The technique involved the use of a double-rod construct anchored proximally by four clawed hooks and distally by iliosacral screws, in a minimally invasive approach. Cobb angle and pelvic obliquity were measured before and after initial surgery and at final follow-up. Complications and functional results were reviewed. This group (P) was compared with a second group (R) of patients who underwent surgery between 2005 and 2015, for whom data were collected retrospectively. RESULTS: Thirty-one patients were included in group P, and 15 in group R. The two groups were comparable for demographic data and deformity. At most recent follow-up (3 years for group P [2-6] and 5 years for group R [2-16]), neither correction nor surgical complications differed between the two groups. However, group P had 50% less blood loss and a lower medical complication rate than group R. CONCLUSIONS: Our results confirm the effectiveness of this minimally invasive technique for neuromuscular scoliosis in adults. The results were similar to those obtained with the usual techniques, but with fewer medical complications. Confirmation of these results is now required for a longer follow-up period.

Bipolar Fusionless Versus Standard Fusion Surgery in Neuromuscular Scoliosis: A Two-center Comparative Study.

STUDY DESIGN: Nonrandomized controlled cohort. OBJECTIVE: To compare early results between bipolar fusionless construct (BFC) and single posterior fusion (SPF) surgery in neuromuscular scoliosis (NMS). BACKGROUND: Surgical treatments for NMS have traditionally been characterized by high complication rates. A mini-invasive BFC was developed to reduce these risks while maintaining adequate curve reduction. There is, however, a current lack of studies comparing clinical and radiologic perioperative outcomes between both techniques. METHODS: All patients surgically treated for NMS with to-pelvis construct between 2011 and 2021 at 2 centers were included and divided into 2 groups according to the surgical technique (BFC or SPF). Gender, age, main deformity region, etiology, preoperative and postoperative main curve magnitude and pelvic obliquity, surgery time, estimated blood loss and transfusion rates, length of hospital stay, the magnitude of main curve and pelvic obliquity correction, and early complications were compared. Quantitative data were compared through ANOVA or Mann-Whitney test. Analysis of qualitative outcomes was performed through Fisher exact test and logistic regressions. Kruskal-Wallis test was used to compare complications between groups. RESULTS: Eighty-nine NMS patients were included: 48 in the SPF group and 41 in the BFC group. Surgery time (203 vs. 241 min), rate (32 vs. 52%) and severity of complications, unplanned returns to the operating room (15 vs. 39%), estimated blood loss (179 vs. 364 cc), and transfusion rates (27 vs. 73%) were lower in the BFC group ( P <0.05). There were no significant differences in age, maturity stage, preoperative curve magnitude, preoperative pelvic obliquity and postoperative curve, and pelvic obliquity correction between groups. CONCLUSIONS: BFC may be a safer and less invasive option for NMS surgical treatment, resulting in similar curve corrections while significantly decreasing the number and severity of complications as well as intraoperative blood loss when compared with SPF. LEVEL OF EVIDENCE: Level -lll.

Ilio-sacral screw pelvic fixation when correcting spinal deformities with or without pelvic obliquity: our experience over 40 years.

Ilio-sacral screw fixation for treatment of spinal deformities with pelvic obliquity was used from more than 40 years in our department of pediatric orthopedics. Despite trying all the other systems published in the literature, the authors came back to iliosacral screw to address the pelvic fixation. Keeping the same anatomical and biomechanical principles, with no damage of the SI joint, they improve the technology over time, to allow an easy use. The fear about the precise insertion necessary to prevent any root irritation is now greatly reduced thanks to the modern navigation. The history of the establishment and the advantages of this technique are explained based on more than 250 cumulative cases with an excellent correction of the pelvic obliquity, without any case of complete pull out of the ilio-sacral screw. A very low rate of nonunion thanks to the 3D adaptation of the balance in erect standing or sitting posture of the patient, thanks to the motion of the intact SI joint, and the small sagittal motion existing in the linkage screw/connector. All this comparing favorably to the other techniques published in the current literature.

From in vitro evaluation of a finite element model of the spine to in silico comparison of spine instrumentations.

Growth-preserving spinal surgery suffer from high complications rate. A recent bipolar instrumentation using two anchoring points (thoracic and pelvic) showed lower rates, but its biomechanical behaviour has not been characterised yet. The aim of this work was to combine in vitro and in vivo data to improve and validate a finite element model (FEM) of the spine, and to apply it to compare bipolar and classical all-screws implants. Spinal segments were tested in vitro to measure range of motion (ROM). Thoracic segments were also tested with bipolar instrumentation to measure ROM and rod strain using a strain gage. A subject-specific FEM of the spine, pelvis and ribcage of an in vivo asymptomatic subject was built. Spinal segments were extracted from it to reproduce the in-vitro mechanical tests. Experimental and simulated ROM and rod strain were compared. Then, the full trunk FEM was used to compare bipolar and all-screws instrumentations. The FEM fell within 1° of the experimental corridors, and both in silico and in vitro instrumentation rods showed 0.01% maximal axial strain. Bipolar and all-screws constructs had similar maximal Von Mises stresses. This work represents a first step towards subject-specific simulation to evaluate spinal constructs for neuromuscular scoliosis in children.

Minimally Invasive Surgery for Neuromuscular Scoliosis: Results and Complications at a Minimal Follow-up of 5 Years.

STUDY DESIGN: A prospective study. OBJECTIVE: The aim of this study was to report the results of an alternative technique to growing rods (GR) for neuromuscular scoliosis using a minimally invasive fusionless surgery with a minimum of 5 years' follow-up. SUMMARY OF BACKGROUND DATA: Conservative treatment is not effective in progressive neuromuscular scoliosis. Early surgery using GR is increasingly advocated to control the deformity while preserving spinal and thoracic growth before arthrodesis. These techniques still provide a high rate of complications. METHODS: The technique relies on a bilateral double rod sliding instrumentation anchored proximally by four hooks claws and distally to the pelvis by iliosacral screws through a minimally invasive approach. The clinical and radiological outcomes of 100 consecutive patients with neuromuscular scoliosis who underwent this fusionless surgery with a minimum follow-up of 5 years were reviewed. RESULTS: 6.5 ±â€Š0.7 years after initial surgery, six patients were lost of follow-up and 11 died of unrelated raison. Of the 83 remaining patients at latest follow-up, mean Cobb angle was stable to 35.0° which correspond to 61% correction of the initial deformation. Mean pelvic obliquity was 29.6° (0.3°-80.0°) preoperatively and 7.2 (0.2°-23.5°) at latest follow-up. Correction of the hyper kyphosis remained stable. Skeletal maturitywas reached in 42 of 83 patients (50.6%). None of these patients has required spinal fusion. The global complication rate was 31.3%. CONCLUSION: The outcomes of this minimally invasive fusionless technique at 5 years follow-up showed a stable correction of spinal deformities and pelvic obliquity over time, with a reduced rate of complication. The arthrodesis was not required for all patients at skeletal maturity. This technique could be a good alternative to arthrodesis for neuromuscular scoliosis.Level of Evidence: 3.