Spontaneous induced bone fusion in minimally invasive fusionless bipolar fixation in neuromuscular scoliosis: a computed tomography analysis.

PURPOSE: Posterior spinal fusion (PSF) at skeletal maturity is still the gold standard in children with neuromuscular scoliosis (NMS) who underwent fusionless surgery. The aim of this computed tomography (CT) study was to quantify the spontaneous bone fusion at the end of a lengthening program by minimally invasive fusionless bipolar fixation (MIFBF), that could avoid PSF. METHODS: NMS operated on with MIFBF from T1 to the pelvis and at final lengthening program were included. CT was performed at least five years postoperatively. The autofusion was classified as completely or not fused at the facets joint (on both coronal and sagittal plane, right and left side, from T1 to L5), and around the rods (axial plane, right and left side, from T5 to L5). Vertebral body heights were assessed. RESULTS: Ten patients were included (10.7y ± 2 at initial surgery). Mean Cobb angle was 82 ± 20 preoperatively and 37 ± 13 at last follow-up. CT were performed on average 6.7y ± 1.7 after initial surgery. Mean preoperative and last follow-up thoracic vertebrae height were respectively 13.5 mm ± 1.7 and 17.4 mm ± 1.7 (p < 0.001). 93% facets joints were fused (out of 320 analyzed joints), corresponding to 15/16 vertebral levels. Ossification around the rods was observed in 6.5±2.4 levels out of 13 in the convex side, and 4.2 ± 2.2 in the concave side (p = 0.04). CONCLUSIONS: This first computed quantitative study showed MIFBF in NMS preserved spinal growth, while it induced 93% of facet joints fusion. This could be is an additional argument when questionning the real need for PSF at skeletal maturity.

Intraoperative neuromonitoring in non-idiopathic pediatric scoliosis operated with minimally fusionless procedure: A series of 290 patients.

BACKGROUND: One of the worst complications of surgery for spinal deformity is postoperative neurological deficit. Multimodal intraoperative neuromonitoring (IONM) can be used to detect impending neurological injuries. This study aimed to analyze IONM in non-idiopathic scoliosis using a minimally invasive fusionless surgical technique. METHODS: This retrospective, single-center study was performed from 2014 to 2018. Patients with non-idiopathic scoliosis who underwent a minimally invasive fusionless procedure and had at least 2 years of follow-up were included. IONM was performed using a neurophysiological monitoring work station with somatosensory evoked potentials (SSEP) and neurogenic mixed evoked potentials (NMEP). RESULTS: A total of 290 patients were enrolled. The mean age at surgery was 12.9±3 years. The main etiology was central nervous system (CNS) disorders (n=139, 48%). Overall, 35 alerts (11%) in the SSEP and 10 (7%) in the NMEP occurred. There were two neurological deficits with total recovery after 6 months. There were no false negatives in either SSEP or NMEP, although there was one false positive in SSEP and two false positives for NMEP in the group without signal recovery. There was no significant relationship between the incidence of SSEP or NMEP loss and age, body mass index (BMI), number of rods used, upper instrumented vertebrae (p=0.36), lower instrumented vertebrae, or type of surgery. A preoperative greater Cobb angle was associated with a significantly higher risk of NMEP loss (p=0.02). In CNS patients, a higher BMI was associated with a statistically significant risk of NMEP loss (p=0.004). The use of a traction table was associated with a higher risk of signal loss (p=0.0005). CONCLUSION: A preoperative higher Cobb angle and degree of correction were associated with a significant risk of NMEP loss. In CNS scoliosis, a higher BMI was associated with a significant risk of NMEP loss. The use of a traction table was associated with a higher risk of signal loss.

One-Way Self-Expanding Rod in Neuromuscular Scoliosis: Preliminary Results of a Prospective Series of 21 Patients.

BACKGROUND: Fusionless techniques for the treatment of neuromuscular early-onset scoliosis (EOS) are increasingly used to preserve spinal and thoracic growth and to postpone posterior spinal fusion (PSF). These techniques have greatly improved thanks to magnetically controlled growing rods, which allow the avoidance of repeated surgery. However, the surgery-related complication rate remains high. The objective of the current study was to report the preliminary outcomes of 21 patients with neuromuscular EOS who were treated with a 1-way self-expanding rod (OWSER). This device was designed to avoid repeated surgery and preserve spinal and thoracic growth thanks to its free rod sliding. METHODS: Patients with neuromuscular EOS who underwent OWSER fixation were prospectively reviewed; follow-up was a minimum of 3 years. The instrumentation relies on a bipolar construct from T1 to the sacrum, with proximal fixation by double thoracic hook-claws and distal fixation by iliosacral screws. The device comprises a rod with a notched part sliding in 1 direction inside a domino. Changes in Cobb angle, pelvic obliquity, thoracic kyphosis, lumbar lordosis, T1-S1 and T1-T12 length, space available for the lung, and chest width were assessed. Complications were reviewed. RESULTS: The mean age at surgery was 10.5 years. The mean follow-up was 3.9 years. The mean pelvic obliquity improved from 20° preoperatively to 8° postoperatively and to 6° at the latest follow-up. The mean Cobb angle improved from 66° preoperatively to 38° postoperatively and to 32° at the latest follow-up. The mean preoperative kyphosis was reduced from 41° to 26° at the latest follow-up (p = 0.14). The mean lordosis was 34° preoperatively and 38° at the latest follow-up. The mean growth per month was 0.8 mm for the T1-T12 segment and 1.5 mm for T1-S1. The global complication rate was 38% (2 surgical site infections, 3 cases of lack of rod expansion, 1 case of pyelonephritis, and 2 central venous catheter-related infections). No PSF had been performed at the latest follow-up. CONCLUSIONS: Use of the OWSER with a minimally invasive bipolar technique for neuromuscular EOS provided satisfactory correction of spinal and pelvic deformities at 3 years of follow-up. A longer follow-up is required. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Biomechanical cadaver study of proximal fixation in a minimally invasive bipolar construct.

STUDY DESIGN: Biomechanical human cadaver study. OBJECTIVE: To determine the three-dimensional intervertebral ranges of motion (ROMs) of intact and hook-instrumented thoracic spine specimens subjected to physiological loads, using an in vitro experimental protocol with EOS biplane radiography. Pedicle screws are commonly used in thoracic instrumentation constructs, and their biomechanical properties have been widely studied. Promising clinical results have been reported using a T1-T5 thoracic hook-claw construct for proximal rod anchoring. Instrumentation stability is a crucial factor in minimizing mechanical complications rates but had not been assessed for this construct in a biomechanical study. METHODS: Six fresh-frozen human cadaver C6-T7 thoracic spines were studied. The first thoracic vertebrae were instrumented using two claws of supra-laminar and pedicle hooks, each fixed on two adjacent vertebrae, on either side of a single free vertebra. Quasi-static pure-moment loads up to 5 Nm were applied to each specimen before and after instrumentation, in flexion-extension, right and left bending, and axial rotation. Five steel beads impacted in each vertebra allowed 3D tracking of vertebral movements on EOS biplanar radiographs acquired after each loading step. The relative ranges of motion (ROMs) of each pair of vertebras were computed. RESULTS: Mean ROMs with the intact specimens were 17° in flexion-extension, 27.9° in lateral bending, and 29.5° in axial rotation. Corresponding values with the instrumented specimens were 0.9°, 2.6°, and 7.3°, respectively. Instrumentation significantly (P < 0.05) decreased flexion-extension (by 92-98%), lateral bending (by 87-96%), and axial rotation (by 68-84%). CONCLUSION: This study establishes the biomechanical stability of a double claw-hook construct in the upper thoracic spine, which may well explain the low mechanical complication rate in previous clinical studies. LEVEL OF EVIDENCE: Not applicable, experimental cadaver study.

Fusionless surgery in early-onset scoliosis.

BACKGROUND: Surgical treatment of early-onset scoliosis has greatly developed in recent years. Early-onset scoliosis covers a variety of etiologies (idiopathic, neurologic, dystrophic, malformative, etc.) with onset before the age of 5 years. Progression and severity threaten respiratory development and may result in respiratory failure in adulthood. Many surgical techniques have been developed in recent years, aiming to protect spinal and thoracic development. MATERIAL AND METHODS: Present techniques are based on one of two main principles. The first consists in posterior distraction of the spine in its concavity (single growing rod, or vertical expandable prosthetic titanium rib [VEPTR]), or on either side (dual rod); this requires iterative surgery, for lengthening, unless motorized using energy provided by a magnetic system. The second option is to use spinal growth force to lengthen the assembly; these techniques (Luque Trolley, Shilla), using a sliding assembly, are known as growth guidance. RESULTS: These techniques are effective in controlling early scoliotic deformity, and to some extent restore spinal growth. However, they show a high rate of complications: infection, rod breakage, spinal fixation pull out and, above all, progressive spinal stiffness, reducing long-term efficacy. Respiratory gain is harder to assess, as thoracic expansion does not systematically improve respiratory function, particularly due to impaired compliance of the thoracic cage.

Round and angular kyphosis in paediatric patients.

Structural kyphosis is a posterior convex deformity of the spine that may appear in childhood then worsen with growth, most notably during the pubertal growth spurt. The abnormal curvature may be smooth, defining round kyphosis, or may display a sharp angular pattern. Angular kyphosis is the more severe of the two forms. The main causes of round kyphosis are postural kyphosis and Scheuermann's disease. The spontaneous outcome is favourable, and round kyphosis is well tolerated in adulthood. The treatment relies on orthopaedic methods in the overwhelming majority of cases. Surgery is reserved for severe rigid kyphosis in older children and for kyphosis responsible for refractory pain or neurological deficits. Surgical treatment carries a non-negligible risk of neurological, gastrointestinal, mechanical, and septic complications, which should be explained clearly to the family. Advances in contemporary posterior instrumentation have considerably limited the indications for anterior approaches. Many conditions may cause angular kyphosis, whose greater severity is related to a greater potential for progression and neurological impairment. Clinical investigations are in order to identify the cause and to plan the surgical strategy. Early surgery may be indicated, via a combined anterior and posterior approach. Anterior strut grafting, anterior or posterior osteotomies, or even vertebral column resections may be necessary to correct a major deformity.

Congenital scoliosis: a frontal plane evaluation of 251 operated patients 14 years old or older at follow-up.

INTRODUCTION: Congenital scoliosis, carrying an incidence between 0.5 and 1 per 1000 births, raise the problem of their evolutive potential. HYPOTHESIS: Some predictive factors for the evolution of scoliotic curvature due to congenital vertebral malformation (CVM) can be found. MATERIAL AND METHODS: This was a retrospective multicenter study of 251 patients, at least 14 years old when evaluated at end of follow-up, with CVM and spinal deformity predominating in the frontal plane. RESULTS: 38.8% of patients showed associated neurologic, visceral or orthopedic abnormalities. CVM was single in 60.6%, double in 20.3%, triple in 6.4% and multiple in 12.7% of cases. 34.1% of CVMs were thoracic. Congenital scoliosis curvature was single in 88.8% of patients, double in 10% and triple in 1.2%. Mean curvature angle was 31.7° at diagnosis (range, 0-105°) and 41.3° preoperatively (range, 10-105°). Sixty-one patients showed associated kyphosis. Mean change in postoperative curvature angle over follow-up was 1.6° (range, -20° to 38°) in the 73 patients managed by arthrodesis, -0.4° (-24° to 30°) in the 64 managed by epiphysiodesis, and 0.4° (-18° to 35°) in the 49 managed by hemivertebral (HV) resection. Results were found to correlate significantly with age at surgery for patients managed by epiphysiodesis, but not for those managed by HV resection or arthrodesis. DISCUSSION: More than 30% of congenital scolioses involve associated intraspinal abnormality. All CVM patients should therefore undergo medullary and spinal MRI to assess the CVM in all three planes, and the medullary canal and its content. The evolution of scoliotic curvature induced by CVM is hard to predict. Several factors are to be taken into account: CVM type, number and location, and patient age. Curvature progression may be slow or very fast. It accelerates during the peak of puberty, stabilizing with bone maturity. Surgery is mandatory in evolutive scoliosis. Four procedures may be recommended, according to type of CVM and especially to patient age: arthrodesis, convex epiphysiodesis, HV resection or rib distraction. Surgery seeks to correct the spinal deformity induced by the CVM and prevent compensatory curvature and neurologic complications, while conserving sagittal and frontal spinal balance and sparing as many levels as possible. In case of HV involvement, the procedure of choice is CVM resection, which provides 87.5% good results in this indication; the procedure is relatively safe, conservative of spinal levels, and without age limit. LEVEL OF EVIDENCE: Level IV. Retrospective study.

[Orthopedic treatment of spinal deformities in infancy and early childhood]. / Le traitement orthopédique dans la pathologie vertébrale du petit enfant.

Surgical treatment of spinal deformities in infancy and early childhood (before age 6) is often very useful if the lesion is localized and curable by one unique surgery, such as hemivertebra resection and fusion. On the contrary, if the lesion, whether idiopathic or paralytic, is extended to a large part of the spine, early surgical treatment in infancy gives very disappointing results and often worsens the status of the child, especially respiratory function if the lesion is mainly thoracic. The goal of this paper is to explain in detail indications and management of non-surgical treatment of such lesions. These are variable according to localization, etiology, and associated anomalies, and are mainly based on proper casting (often repeated), bracing (often intermittent between casting) and proper respiratory equipment. From time to time, a surgical treatment is locally indicated, but most of the time results are disappointing and the best is to repeat non-surgical treatment until proper definitive arthrodesis can be performed. This approach is not very rewarding for the child and family, but is clearly better than sudden extensive surgery in early childhood with very severe and disastrous results in adulthood. It is our hope that the recommendations and thoughts presented in this paper will help readers to manage young children using the most efficient, non-aggressive, but long-lasting therapy.

[Surgical treatment of lumbosacral spondylolisthesis with major displacement in children and adolescents: a continuous series of 20 patients with mean 5-year follow-up]. / Le traitement chirurgical du spondylolisthésis lombo-sacré à grand déplacement de l'enfant et de l'adolescent.

PURPOSE OF THE STUDY: This retrospective analysis involved a continuous series of twenty cases of lumbosacral spondylolisthesis with major displacement treated before maturity. We compared our experience using a non-instrumented lumbosacral fusion technique with the results of other techniques proposed in the literature. MATERIAL AND METHODS: We reviewed the cases of twenty children and adolescents who underwent surgery in our unit. For each case, we recorded the clinical history and course to last follow-up. X-rays were studied and manual measurements taken of the different parameters used to analyze the spine. Data were recorded in a database for statistical analysis. Sixteen of the twenty cases showed spinal deformation causing lumbalgia, generally associated with radiculalgia. Mean age at surgical treatment was 13 years 3 months, range 7 years 2 months to 17 years 6 months. All of the children has Meyerding stage 3 or 4 displacement associated with lumbosacral kyphosis. Surgical treatment followed a period of progressive reduction by traction and suspension in lordosis using a hammock. All twenty patients underwent posterolateral arthordesis using a cancellous graft between L4 and the sacrum. The fusion was performed after fashioning a thoraco-lumbo-pelvic cast including both thighs in the position of reduction. A complementary time for anterior arthodesis was needed for eight patients. RESULTS: The postoperative period was uneventful in twelve patients. Two children developed intestinal obstruction with a peritoneal bridle. Three children had an L5 radicular deficit and three sphincter disorders. All neurological disorders resolved in a few months. At mean postoperative follow-up of 5 years 3 months, the arthrodesis appeared to be fused in 19/20 cases. Only one patient presented a lucent line in the zone of the bone graft suggesting possible fibrous nonunion. Eighteen patients were symptom free and led a normal life. Two patients complained of moderately bothersome lower back pain. DISCUSSION: Many of the children in our series had major lumbosacral dysplasia with a verticalized sacrum, aggravating the lumbosacral kyphosis. This led to an increased pelvic tilt and decreased sacral slope. Progressive preoperative reduction of the lumbosacral kyphosis allowed conducting the lumbosacral fusion under favorable conditions. We did not open the spinal canal and avoided the mid line in order to protect as much as possible posterior spinal stability and preserve all the bone surfaces receiving the posterolateral graft. We reserved indications for complementary anterior lumbosacral arthrodesis to the most exaggerated cases of lumbosacral kyphosis. The therapeutic program is long due to the progressive preoperative reduction and the strict period of immobilization after surgery. In our experience, this approach allows quality lumbosacral fusion with good correction of the lumbosacral kyphosis. Neurological complications remain frequent and can occur during even slow progressive reduction.

Anatomical study of the paraspinal approach to the lumbar spine.

The original description of the paraspinal posterior approach to the lumbar spine was for spinal fusion, especially regarding lumbosacral spondylolisthesis treatment. In spite of the technical details described by Wiltse, exact location of the area where the sacrospinalis muscle has to be split remains somewhat unclear. The goal of this study was to provide topographic landmarks to facilitate this surgical approach. Thirty cadavers were dissected in order to precisely describe the anatomy of the trans-muscular paraspinal approach. The level of the natural cleavage plane between the multifidus and the longissimus part of the sacrospinalis muscle was noted and measurements were done between this level and the midline at the level of the spinous process of L4. A natural cleavage plane between the multifidus and the longissimus part of the sacrospinalis muscle was present in all cases. There was a fibrous separation between the two muscular parts in 55 out of 60 cases. The mean distance between the level of the cleavage plane and the midline was 4 cm (2.4-5.5 cm). In all cases, small arteries and veins were present, precisely at the level of the cleavage plane. We found it possible to easily localize the anatomical cleavage plane between the multifidus part and the longissimus part of the sacrospinalis muscle. First the superficial muscular fascia is opened near the midline, exposing the posterior aspect of the sacrospinalis muscle. Then, the location of the muscular cleft can be found by identifying the perforating vessels leaving the anatomical inter-muscular space.

Osteotomy and distraction of the anterior segment of the pelvic ring in epispadias repair: case report.

We report a new therapeutic approach for bladder exstrophy and epispadias in one case of failed epispadias repair. The width of the pelvis was measured by what we defined as the anteroposterior diameter (APD) on combined transverse computed tomography (CT) scan cuts of the pelvis. The APD was half the normal value in an incontinent patient with failed epispadias repair. He underwent a supraacetabular osteotomy of the pelvis with progressive anterior distraction of the anterior segment of the pelvic ring. Four months later, hardware was removed, and the APD was near normal value. Within 9 months of follow-up, the patient was dry day and night. We believe that in patients with failed exstrophy and epispadias repair, APD seems to be a predictive criterion for continence, and results of the reconstructive surgery with osteotomy should be improved by distraction of the anterior segment of the pelvic ring.

Iliosacral screw fixation for pelvic obliquity in neuromuscular scoliosis. A long-term follow-up study.

STUDY DESIGN: This was a retrospective review of a consecutive series of patients with neuromuscular spinal deformity who underwent posterior fusion and pelvic fixation using a long construct and an iliosacral screw. OBJECTIVES: To evaluate the risks and benefits of iliosacral screw fixation. SUMMARY OF BACKGROUND DATA: Neuromuscular scoliosis with pelvic obliquity poses one of the most challenging instrumentation problems, mainly because of the poor bone quality frequently found within the sacrum. Complications include failure of instrumentation, loss of sacral fixation, loss of lumbar lordosis, and a high rate of nonunion. METHODS: One hundred fifty-four patients with neuromuscular scoliosis and pelvic obliquity underwent posterior arthrodesis with pelvic fixation using an iliosacral screw. Anteroposterior scoliosis Cobb angle, frontal pelvic obliquity, and sacral inclination angle were measured before surgery, immediately after surgery, and at the 5-year and 3-month follow-up examination. Influence of etiology, severity of deformity, and associated anterior release at the scoliotic curve above also were assessed. RESULTS: Correction of scoliosis Cobb angle ranged from 53% to 70%, and loss of correction ranged from 3% to 14% at the last follow-up examination. Correction of pelvic obliquity ranged from 60% to 84%, and loss of correction was mild. Sacral inclination angle approached normal values in all patients, except for those with myelomeningocele who had preoperative pelvic retroversion. Loss of correction ranged from 0.3 degree to 5.4 degrees at the last follow-up examination. Complications and loss of correction mostly were encountered in patients with myelomeningocele and spinal muscular atrophy. CONCLUSIONS: Iliosacral screw fixation in neuromuscular scoliosis is technically standardized and easy and offers mechanically efficient and stable fixation.

[Distal intra-articular resection of the calcaneus in the treatment of severe or recurrent congenital clubfoot]. / La résection distale intra-articulaire du calcanéum dans le traitement du pied bot congénital sévère ou récidivant.

INTRODUCTION: Secondary adaptive bone changes and joint distorsions in clubfoot may present a barrier to adequate correction of the deformity. The purpose of our study is to show how the lateral excision of the calcaneus distal part as described by Lichtblau, in combination with an appropriate medial release allows better correction of forefoot deformity, with less recurrence rate. MATERIAL AND METHODS: Between 1974 and 1982, 43 feet in 38 patients underwent this type of surgery. Lateral excision o the calcaneus was decided preoperatively in 34 feet, for recurrence of the forefoot deformity following previous surgery. In the remaining 9 feet, this lateral excision was decided intraoperatively, because of an uncomplete correction of the fore part of the foot, despite an adequate posteromedial release. The resected angle from the distal intra-articular part of the calcaneus varied from 10 to 30 degrees with an average of 15 degrees. RESULTS: All our results were evaluated at end of growth. Mean age at follow-up was 15 years and 4 months, with an average period of 10 years and 7 months following surgery. The average forefoot adduction moved from 21 degrees preoperatively to 1 degree at last follow-up. The clinical calcaneocuboid mobility was preserved in 37 cases. Four types of complications were encountered in 7 patients: pain in 5 cases, calcaneocuboid fusion in 6 cases, recurrence of deformity in 2 cases, and overcorrection in 5 cases; this last complication was related to intraoperative overcorrection rather than a progressive deterioration of the result, and had no clinical significance. No overcorrection was seen after calcaneocuboid fusion. We have found no relation between age at surgery, and the incidence of calcaneocuboid fusion, but the two cases operated on children under one year old, ended up with a bad result. DISCUSSION: The resection of a single side of a joint may permit normal joint function to be retained. The resected cartilage is replaced by a fibrocartilage that resembles the original articular cartilage, provided the resected defect is deep enough to allow vascularization from the underlying bone. CONCLUSION: The success of this method depends on an accurate surgical technique, as described by its promoter. It can be of great help in severe and complicated clubfeet. It achieves the goal with a calcaneocuboid function often preserved.

Posterior spinal fusion in neuromuscular scoliosis using a tibial strut graft. Results of a long-term follow-up.

STUDY DESIGN: Risks and benefits of using a tibial graft for posterior spinal fusion in neuromuscular scoliosis were evaluated in a long-term follow-up study. A consecutive series of 72 patients underwent posterior spinal fusion for neuromuscular scoliosis. OBJECTIVES: Radiologic outcome was assessed to evaluate the quality of the spinal fusion. Patients were followed serially to detect donor site complications. Mean follow-up was 17 years and 8 months (minimum: 6 years, 6 months). SUMMARY OF BACKGROUND DATA: Mean age of the patients at the time of surgery was 15 years. Progression of the curvature was minimal at last follow-up (mean progression at last follow-up: lumbar curve, 4.5 degrees; thoracic curve, 5.3 degrees). Concerning donor site complications, four patients had a leg length discrepancy of less than 2 cm at last follow-up. This complication was related to tibial overgrowth at the donor site. METHODS: Solid fusion was defined in this long-term study as the absence of modification of the radiologic aspect at last follow-up in addition to the presence of a massive contagious trabecular fusion mass. RESULTS: The fusion appeared to be solid in all patients. No obvious pseudarthrosis could be documented. The constant successful outcome differs significantly from spinal fusion that uses bank bone. The absence of stress fracture was correlated to the low level of constraint in this essentially nonambulatory population. CONCLUSION: This experience indicates that the tibial graft deserves consideration in posterior spinal fusion for neuromuscular scoliosis.

Histiocytosis X in the juvenile spine.

The authors studied 54 lesions, caused by histiocytosis X, that affected the spines of 28 children. The clinical, radiologic, biologic, and therapeutic aspects are described. The orthopaedic surgeon has a role to play in confirming the diagnosis, treating the lesion, and in following up.