The effects of vertebral body tethering on sagittal parameters: evaluations from a 2-years follow-up.

INTRODUCTION: While the effects of VBT on coronal parameters have been investigated in various studies, this has not yet been the case for sagittal parameters. This is of particular relevance considering that VBT does not allow direct correction of the sagittal profile. Thus, we investigated the effects of VBT on sagittal parameters in patients with adolescent idiopathic scoliosis. MATERIALS AND METHODS: Retrospective, 2-Center study. Patients who underwent VBT and presented a 2-years follow-up were included. The differences in sagittal parameters were evaluated, along with modifications of sagittal profile following Abelin-Genevois' classification. RESULTS: Data from 86 patients were obtained. Mean Cobb angle was 52.4 ± 13.9° at thoracic level and 47.6 ± 14.3° at lumbar level before surgery, and 28.5 ± 13.6 and 26.6 ± 12.7° at the 2-year follow-up, respectively. Mean thoracic kyphosis increased from 28.3 ± 13.8 to 33 ± 13°, the lumbar lordosis (LL) was unvaried (from 47.5 ± 13.1 to 48.4 ± 13.5°), PT decreased from 9.4 ± 8.5 to 7.4 ± 6.1°, the sagittal vertical axis SVA decreased from 4.5 ± 31.4 to - 3.6 ± 27.9 mm. No kyphotic effect on LL in patients who underwent lumbar instrumentation was observed. Before surgery, 39 patients had a type 1 sagittal profile, 18 were type 2a, 14 type 2b and 15 type 3. Postoperatively, 54 were type 1, 8 were 2a, 13 were 2b and 11 were type 3. CONCLUSIONS: VBT positively influences sagittal parameters and does not have a kyphotic effect on LL.

An arthroscopic repair technique for proximal anterior cruciate tears in children to restore active function and avoid growth disturbances.

PURPOSE: The aim of this study was to assess midterm clinical outcomes in Tanner 1-2 patients with proximal anterior cruciate ligament (ACL) tears following arthroscopic-surgical repair using an absorbable or an all-suture anchor. METHODS: Fourteen (9.2 ± 2.9 years-old) of 19 skeletally immature patients reached the 2 years of clinical follow-up. Physical examinations included the Lachman test, Pivot-shift test, One-leg Hop test, Pedi-IKDC as well as Lysholm and Tegner activity scores; knee stability was measured with a KT-1000 arthrometer. Overall re-rupture rates were also evaluated in all operated patients. RESULTS: At 2 years post-surgery, the Lysholm score was 93.6 ± 4.3 points, and the Pedi-IKDC score was 95.7 ± 0.1. All patients returned to the same sport activity level as prior to ACL lesion within 8.5 ± 2.9 months, with one exception who reported a one-point reduction in their Tegner Activity score. No leg-length discrepancies or malalignments were observed. Four patients presented grade 1 Lachman scores, and of these, three presented grade 1 (glide) score at Pivot-shift; clinical stability tests were negative for all other patients. Anterior tibial shift showed a mean side-to-side difference of 2.2 mm (range 1-3 mm). The One-leg Hop test showed lower limb symmetry (99.9% ± 9.5) with the contralateral side. Overall, 4 out of 19 patients presented a re-rupture of the ACL with a median time between surgery and re-rupture of 3.9 years (range 1-7). CONCLUSION: This surgical technique efficiently repairs proximal ACL tears, leading to a restoration of knee stability and a quick return to an active lifestyle, avoiding growth plate disruption. LEVEL OF EVIDENCE: IV.

Clinical presentation and surgical treatment of distal fibular non-union with talus chondral lesions in a pediatric patient: a case report.

BACKGROUND: In children, fracture non-union is uncommon yet, curiously, non-union of distal fibula fractures are rarely reported. Historically, the most common treatment of a lateral malleolus fracture after an ankle sprain is conservative, which usually leads to fracture union. However, even in clinically stable ankles, subsequent pain arising from fracture site could suggest non-union, thereby necessitating reexamination and possible secondary treatment. CASE PRESENTATION: We report the case of an 8-year-old girl with an epiphyseal distal fibula fracture complicated with a symptomatic non-union associated with the chondral flap of the talar dome after conservative treatment. Surgical excision of the fragment and chondroplasty was performed and resulted in an excellent clinical outcome. CONCLUSION: This case report illustrates the necessity of particularly meticulous evaluation of pediatric post-traumatic ankle pain. Surgical treatment as well as talar chondral evaluation should be taken into consideration in the treatment of pediatric distal fibular nonunion.

Prediction of brace effect in scoliotic patients: blinded evaluation of a novel brace simulator-an observational cross-sectional study.

PURPOSE: Bracing is the most commonly used treatment for scoliosis. But braces remain predominantly "handcrafted." Our objective was to create a novel brace simulator using a high-fidelity 3D "avatar" of the patient's trunk. METHODS: An observational cross-sectional study was constructed. The inclusion criteria were patients with a moderate idiopathic scoliosis (between 15° and 35° of Cobb angle) aged between 9 and 15 years old with an indication of brace treatment. Twenty-nine scoliotic patients, 25 girls and four boys, with a mean age of 12.4 years were included. Twenty right thoracic and 14 left lumbar were measured with a mean Cobb angle of 24°. 3D "avatars" were generated using a novel technology called the "anatomy transfer." Biomedical simulations were conducted by engineers who were blinded to the clinical effect of the real patient brace. The in-brace Cobb angle effect (real effect) was compared with the virtual numeric in-brace Cobb angle observed using the blindly constructed avatar (simulation effect). RESULTS: Real and simulated in-brace Cobb angle were compared using a paired two-sided Student's t test. The real mean Cobb angle was 11° and 17° in the simulation which was statistically significant. The strength of prediction of the simulation was assessed for each individual patient; 76% of the real in-brace Cobb angles had good and moderate prediction (± 10°). CONCLUSIONS: Incorporating high-fidelity copy of the entire 3D shape of the patient's trunk and multiple 3D-reconstructed bony images into an anatomical reference avatar resulted in moderate-to-good prediction of brace effect in three quarters of patients. These slides can be retrieved under Electronic Supplementary Material.

Congenital lumbar kyphosis with skin ulceration and osteomyelitis in a myelomeningocele child: a case report.

INTRODUCTION: Kyphosis is a frequent problem in children with spina bifida, and this deformity may cause different complications as respiratory insufficiency, bowel dysfunction, and skin ulcers. CASE REPORT: We report on a 13-year-old myelomeningocele male with a lumbar kyphoscoliosis associated to a septic skin ulceration that resulted in an acute sepsis. An X-ray revealed a kyphosis of 110° and a scoliosis of 25° between T9 and L5. The wound and blood cultures showed Staphylococcus aureus colonization, and an appropriate antibiotic therapy was started. An MRI showed a wedged vertebra at T12, a laminae defects from T8 to the sacrum, and a spondylitis at T12-L1. Ulcer resection and kyphectomy from T12 to L3 were performed "en bloc," and the spine was instrumented fromT7 to S1. After the surgery, the kyphosis was corrected to 10°, and the scoliosis was corrected to 0°. At an 18-month follow-up, a solid bony fusion was obtained, and no recurrence of skin ulcer was reported. CONCLUSION: Antibiotherapy associated to one-step "en-bloc" surgical debridement and kyphectomy should be considered as a valid option to eradicate the infection and to correct the spine deformity in kyphosis due to myelomeningocele associated to septic skin ulcer and spondylitis.

A New Paradigm for the Management of Thoracolumbar Pediatric Spine Traumas.

OBJECTIVES: The transient breath holding sign (TBHS) is a clinical sign often associated with magnetic resonance imaging (MRI) spine traumatic lesions. The aims of this study were to prospectively evaluate the TBHS in the detection of thoracolumbar lesions in a large cohort of children and to establish a comprehensive strategy on the use of MRI in spine traumas in children. STUDY DESIGN: All conscious 5- to 16-year-old patients admitted for a spine trauma in our institution were prospectively included in the study. All patients were asked for the TBHS and underwent a full spine MRI. Sensitivity and specificity of the TBHS were derived from the confusion matrix. All MRI lesions were analyzed and classified. RESULTS: One hundred ninety-eight patients were included. The sensitivity of the TBHS was 92%, the specificity was 83%, the positive predictive value was 83%, and the negative predictive value was 91%. The x-rays missed 67% of the vertebrae injured in the MRI. The MRI lesions consisted in an upper end plate injury, in the sagittal plane only, in 90% of the cases. The vertebral canal and the spinal cord were never injured. CONCLUSIONS: This study confirms that the TBHS is a relevant clinical tool that should be added in the routine questionnaire after any trauma at admission. Magnetic resonance imaging should be restricted to patients with a TBHS positive at admission. A single T2 Short T1 Inversion Recovery (STIR) sagittal sequence seems sufficient to make the diagnosis and could replace the use of standard x-rays in pediatric spine traumas.

A thoracic spinal bone giant cell tumor in a skeletally immature girl. A case report and literature review.

PURPOSE: Giant cell tumors (GCT) are benign primary bone tumors, locally aggressive, affecting in long bones in young adults during the third decade. It is rare to experience this lesion in skeletally immature patients. GCT are related to a risk of local recurrence and malignant transformation. METHOD: We report a rare case of a giant cell tumor of the thoracic spine in a skeletally immature girl presenting with a painful right scoliosis. RESULTS: MRI, CT scan, and bone scintigraphy were discordant and the percutaneous biopsy non-contributive. CONCLUSION: A marginal "en bloc" resection was performed and revealed the GCT. Based on a literature review, the diagnosis and the surgical management of this case are discussed.

In vitro implant-bone interface pressure measurements for a cementless femoral implant. A preliminary study.

PURPOSE: Implants endurance as well as a good clinical tolerance depends on the recovery of a physiological stress distribution within bone after implantation. The purpose of the present work was to develop an alternative technique using Force Sensing Resistors (FSR) to gather in vitro pressure values at the implant-bone interface for a cementless implant. METHOD: Eight cementless femoral stems were instrumented with six calibrated FSR bonded on each facet and then implanted in eight cadaver femurs. Compression tests were performed until failure and FSR pressure values were recorded. RESULTS: The average failure load was 4241 N. The maximum contact pressure measured with the FSR averaged 1.965 MPa. CONCLUSION: FSR reached many of the requirements for an ideal implant-bone interfacial sensor. This experimentation provided in vitro quantitative data on contact pressure at the implant-bone interface, which could help understanding stress shielding phenomenon and developing relevant numerical model.

Vertebroplasty for vertebral hemangioma in children: a report of two cases with 2-year follow-up.

PURPOSE: To describe two cases of a dorsal vertebral hemangioma diagnosed in a 12- and 14-year-old child successfully treated with vertebroplasty. METHOD: Cases reports. RESULTS: Two cases of aggressive vertebral hemangiomas were diagnosed and treated in two independent institutions. Percutaneous vertebroplasty was then decided. Bipedicular vertebroplasty was performed under general anesthesia, under biplanar fluoroscopic guidance. The injection of acrylic cement filled the entire vertebral body without significant leakage. At last follow-up, the clinical and radiographic outcome was very good. In one patient, last control radiographs showed a gap between the end plates and the cement, spinal growth seemed to have resumed. CONCLUSION: Vertebral hemangioma is rare in pediatric patients, and its diagnosis requires meticulous and regular clinical examinations and a combination of imaging studies, particularly an MRI and a CT scan, which can assess the aggressiveness of the lesion. Vertebroplasty seems to be an effective and safe treatment of this benign tumor in children with stable outcome at 2-year follow-up. Spinal growth may resume despite the aggressiveness of both the tumor and the treatment.

The change on vertebral axial rotation after posterior instrumentation of idiopathic scoliosis.

PURPOSE: Agreement between the correction objectives and the instrumentation strategies remains controversial in idiopathic scoliosis. Most studies have focus on the frontal and sagittal plane. The goal of this study was to evaluate the change on vertebral axial rotation after posterior instrumentation in fused and unfused segments. METHODS: Fourteen patients operated on for idiopathic scoliosis were prospectively included. Fusion and instrumentation were done by posterior approach. All patients had a pre-operative and a 10-day post-operative radiological evaluation with the EOS system. Axial orientation of the vertebrae with special interest to the apical, junctional, and unfused areas was obtained thanks to the reconstruction software. RESULTS: Mean apical vertebra axial rotation statistically decreased from 21° pre-operatively to 13° post-operatively. But, there were no statistically significant differences between pre-operative and post-operative mean axial intervertebral rotations in the main curve and axial rotation of the non-instrumented lower counter curve. CONCLUSIONS: 3D analysis of the spine in standing position is a great advancement for post-operative analysis of adolescent idiopathic scoliosis (AIS) corrections. This study confirmed that actual instrumentations are able to achieve "en bloc" 3D correction of the spine but not intervertebral axial rotation correction.

Screw augmentation for spinopelvic fixation in neuromuscular spine deformities: technical note.

PURPOSE: The primary goal of curve correction in neuromuscular patients is to restore coronal and sagittal trunk balance, including the pelvis, to maximize sitting balance. For several years, it has been a common practice to inject polymeric cement into osteoporotic bone through specially designed, perforated pedicle screws in an effort to enhance screw stability. Therefore, we started using the association of a spinopelvic fixation with S1 pedicle screw augmentation, using bisphenol-a-glycidyl dimethacrylate composite resin in neuromuscular patients with pelvic obliquity, technique in neuromuscular patients to improve pedicle screw stability of our pelvic construct. METHODS: Ten patients undergoing spinopelvic fixation for a neuromuscular spinal deformity were enrolled in the study. Clinical and radiographic data were analyzed and presented. Minimal follow-up took place at 6 months to assess early complications. RESULTS: Five patients were diagnosed with spastic quadriplegia secondary to cerebral palsy, four had Duchenne's muscular dystrophy, and one had a T5-level traumatic flaccid paraplegia. Preoperative PO ranged from 8° to 34° (mean 19.16°). Postoperative PO ranged from 0° to 6.3° (mean 1.6°). After surgery, all patients returned to a full-time sitting position between days 5 and 12 without the need for additional bracing. No mechanical failure of the construct was noted during follow-up. CONCLUSIONS: We used sacral pedicle screw augmentation as a reliable tool to strengthen spinopelvic fixation in neuromuscular scoliosis without increasing the intraoperative morbidity. In our practice, sacral screw augmentation can definitely enhance PO correction obtained by a posterior procedure.

High-grade lumbosacral spondylolisthesis reduction and fusion in children using transsacral rod fixation.

PURPOSE: There is no consensus on how to treat surgically high-dysplastic developmental spondylolisthesis in children and adolescents. Although reducing spinal deformity seems mandatory, the issue of surgical reduction versus in situ fusion remains controversial. METHODS: The files of 12 consecutive patients surgically treated for a grade 3 or 4 spondylolisthesis were reviewed. The treatment consisted in L4 to sacrum reduction and fusion by posterior approach. The reduction of lumbopelvic imbalance was made intraoperatively using a trans-sacral rod fixation technique. RESULTS: Mean preoperative L5 anterior slippage was 72.3 % (60 to 95 %). The mean preoperative lumbosacral tilt angle was 70.5° (43 to 92°). Mean final lumbosacral tilt angle was 102° (91 to 114°). Mean final L5 anterior slippage was 19 % (7 to 63 %). Neurological complications (radicular L5 or S1 deficits) were noted in five patients. At final follow-up L4 to S1 fusion was achieved in all patients. No patient had persistent deficit or radicular pain. CONCLUSIONS: The fusion rate in our series proved to be optimal. Thanks to the trans-sacral rod fixation, lumbosacral kyphosis correction was very good. The intrasacral positioning of the screws reduces the risk of implant prominence especially in such pediatric patients. We stress the importance to avoid complete slip reduction in such patients to minimize stretching on L5 and S1 roots. No additional immobilization is needed due to solid posterior instrumentation. Doing such procedure only by posterior approach avoids anterior approach-related complications.

Bone morphogenetic protein and orthopaedic surgery: can we legitimate its off-label use?

PURPOSE: Bone morphogenetic proteins (BMP) are recombinant osteoinductive proteins with their primary role being to promote bone formation. The off-label use of BMP in orthopaedic surgery has dramatically increased. However, reports of complications with BMP have emerged, and the safety of these proteins in orthopaedics is questioned. The purpose of this review was to evaluate safe situations in which BMP should be used and situations in which their use should be restricted. METHOD: We recorded all studies from PubMed database from 2002 (date of first authorisation for both BMPs) until January 2014 using "BMP" or "bone morphogenetic protein". Then we screened and extracted all studies dealing with orthopaedic surgery. All situations in which BMP were used, even cases reports, were considered, and complications reported were then listed. RESULTS: Situations in which it seems safe and efficient to use BMP are long-bone nonunions, or arthrodesis as an alternative or combined to autograft in small-bone loss. Surgeons and patients should be aware of transient aseptic wound swelling when BMP is located superficially. The use of BMP in spine surgery for intersomatic fusion is efficient but should be restricted to approaches that respect the vertebral canal to avoid neurological complications. CONCLUSION: This review is an off-label map of BMP use in orthopaedics during the past 10 years. Our results could provide a useful tool to help decisions around when to use a BMP in a specific complex, and sometimes off-label, situation.

Clinical experience and complications with limited pleural dissection combined with a novel, simplified technique for thoracic Redon-like drain in vertebral body tethering.

PURPOSE: To report on our experience with a simplified, suction-bottle-drain technique of thoracic drain (Redon-like) combined with fully thoracoscopic vertebral body tethering (VBT) and a limited pleural approach, with particular focus on the rate of pulmonary complications. METHODS: A retrospective study was performed on all consecutive patients who underwent VBT for adolescent idiopathic scoliosis. For all subjects, a 10G Redon drain, an active drain system consisting of a perforated tube and a suction bottle, was placed intrathoracically and tunneled under the skin. All drains were removed on the first postoperative day. Perioperative and postoperative data such as type of access, length of surgery, amount of fluid collection in the drain, and length of hospital stay were collected. The type and number of pulmonary complications occurring in the first 3 months after surgery, along with their symptoms and management, were recorded. RESULTS: One Hundred eighty-two patients were included in the analysis. The mean length of surgery was 97 min (75-120). The average fluid collection in the drain was 30 ml (5-50), the mean length of hospital stay was 3 days (2-4). During the observation period, pulmonary complications occurred in five patients (2%). Two patients presented an aseptic right pleural effusion; for two patients, a residual pneumothorax was diagnosed on the X-rays in the recovery room and one patient developed a chylothorax. All patients recovered without sequelae. CONCLUSION: The simplified, Redon-like drain combined with a fully thoracoscopic VBT and limited pleural approach seems a safe and effective alternative to the chest drain. This technique allows to remove the drain on the first postoperative day, thus simplifying the management of the patients and improving their comfort.

Arthroscopic repair of proximal anterior cruciate ligament tears in children and adolescents: A systematic review.

Purpose: Anterior cruciate ligament repair techniques are of growing interest because they allow for minimally invasive surgery that avoids harvesting of the transplant, without risking growth deficiencies in young patients. The aim of this study is to summarize the published evidence about arthroscopic repair of anterior cruciate ligament proximal tears in skeletally immature patients. Methods: In total, four studies were included and processed for data extraction after screening for eligibility for this systematic review: one retrospective cohort study and three retrospective case series. Altogether, the four studies included in this review included 61 skeletally immature patients with a mean age of 12.1 years diagnosed with proximal anterior cruciate ligament tear who underwent arthroscopic repair with preservation of the native ligament. The mean follow-up period was 2.8 years. Results: The most relevant and objective outcome that we considered was re-rupture rate. One study reports a cumulative incidence of graft failure in the first 3 years after surgery of 48.8% while the others report a 0%, 0% and 21.5% re-rupture rate. No growth disturbances were reported in the included studies. Conclusion: Despite growing interest surrounding anterior cruciate ligament repair techniques, the presence of limited quality studies in the literature means repair cannot be strongly supported at present. Some encouraging data regarding the absence of growth disturbance and functional outcomes does exist, but studies with larger samples are required. Level of evidence: level IV.

Transverse plane 3D analysis of mild scoliosis.

PURPOSE: To demonstrate the reality of a transverse plane pattern independent of the scoliotic curve location and to show the importance of the transverse plane pattern in the assessment of the progression risk in a population of mild scoliosis. METHODS: Spines of 111 patients with adolescent idiopathic mild scoliosis were reconstructed using biplanar stereoradiography. The apical axial rotation, the intervertebral axial rotation at junctions and the torsion index were computed. Mean values of each parameter were compared between thoracic, thoracolumbar and lumbar curves. Then a cluster analysis was performed using these parameters on 78 patients with effective outcomes at skeletal maturity. The effective outcomes and the results reached with the statistical analysis were compared and analyzed (ROC and logistic regression). RESULTS: No statistical difference was observed when considering each parameter between the different types of curves. Two clusters independent of the curve type were identified. The mean values of transverse plane parameters were significantly higher in Cluster 1 than in Cluster 2. 91% of patients classified in Cluster 1 had progressive curve and 73% of patients classified in Cluster 2 remained stable at skeletal maturity. All parameters were good predictors but the best was the torsion index. CONCLUSIONS: This study demonstrated that a transverse plane pattern combining apical axial rotation, the intervertebral axial rotation at junctions and the torsion index is independent of the scoliotic curve location and significant in the determination of the progression risk of mild scoliosis.

3D analysis of brace treatment in idiopathic scoliosis.

PURPOSE: We have evaluated the effect of bracing in scoliosis on coronal alignment in a cohort of patients. Current literature has not described the specific effect of bracing on the 3D shape of the scoliotic curves. The purpose of this study was to analyze the variability of the 3D effect of bracing on idiopathic scoliosis. MATERIALS AND METHODS: The spines of 30 patients with adolescent idiopathic scoliosis were reconstructed using biplanar stereoradiography with and without the brace. The Cobb angle, sagittal and pelvic parameters and transverse plane parameters were calculated. The variability and the mean values of each parameter, with and without a brace, were analyzed and compared using a student t test. RESULTS: The Cobb angle improved in 50% of patients but remained unchanged in 50% cases. In 90% of the cases lordosis was decreased. The thoracic kyphosis was decreased in 26% cases, unchanged in 57% of cases and increased in 17% cases. The AVR was improved (>5°) in 26% cases, worsened in 23% and unchanged in 50%. Only the differences of Cobb angle and the lordosis were statistically significant. CONCLUSIONS: Global statistics of this study concur with the literature. The Cobb angle was significantly improved. It also showed a significant hypolordotic effect. However, the results showed a high variability of the brace treatment effect in almost every parameter. Analysis of this variability by means of 3D reconstructions instead of global statistics should help characterize the mechanisms of correction of brace treatment.

Congenital Cervical Spinal Deformities.

Malformations of the cervical spine are a challenge in pediatric orthopedic surgery since the treatment options are limited. These congenital anomalies are often syndrome-related and have multiple repercussions on the function and statics of the cervical spine in all three planes. They are related to developmental abnormalities during the somite segmentation that occurs during the third week of embryonic development. Successful somitogenesis requires proper functioning of a clock regulated by complex signaling pathways that guide the steps needed to form the future spine. There is no specific classification for vertebral malformations at the cervical level. To characterize the progressive nature of a malformation, one must use general classifications. In the specific case of Klippel-Feil syndrome, these malformations can affect several vertebral levels in a continuous or discontinuous manner, but also the vertebral body and vertebral arch in a variable way. Thus, establishing a reliable prognosis in the coronal and sagittal planes is a complex undertaking. While technical mastery of certain osteotomy procedures has led to advances in the surgical treatment of rigid deformities of the cervical spine, the indications are still very rare. Nevertheless, the procedure has become safer and more accurate because of technical aids such as surgical navigation, robotics and 3D printed models or patient-specific guides. Occipitocervical transitional anomalies have embryological specificities that can explain the bony malformations seen at this level. However, most are rare, and the main concern is identifying any instability that justifies surgical stabilization. The presence of a cervical spine anomaly should trigger the search for occipitocervical instability and vice-versa.

Safety and Efficacy of Stand-Alone Bioactive Glass Injectable Putty or Granules in Posterior Vertebral Fusion for Adolescent Idiopathic and Non-Idiopathic Scoliosis.

Posterior spinal fusion (PSF) is the standard procedure for the treatment of severe scoliosis. PSF is a standard procedure that combines posterior instrumentation with bone grafting and/or bone substitutes to enhance fusion. The aim of this retrospective study was to evaluate and compare the post-operative safety and efficiency of stand-alone bioactive glass putty and granules in posterior spine fusion for scoliosis in a paediatric cohort. A total of 43 children and adolescents were included retrospectively. Each patient's last follow-up was performed at 24 months and included clinical and radiological evaluations. Pseudarthrosis was defined as a loss of correction measuring >10° of Cobb angle between the pre-operative and last follow-up measurements. There was no significant loss of correction between the immediate post-operative timepoint and the 24-month follow-up. There was no sign of non-union, implant displacement or rod breakage. Bioactive glass in the form of putty or granules is an easily handled biomaterial but still a newcomer on the market. This study shows that the massive use of bioactive glass in posterior fusion, when combined with proper surgical planning, hardware placement and correction, is effective in providing good clinical and radiological outcomes.

Thoracoscopic Anterior Vertebral Body Tethering in Lenke Type-1 Right Adolescent Idiopathic Scoliosis.

Background: Vertebral body tethering (VBT) is indicated for skeletally immature patients with progressive adolescent idiopathic scoliosis (AIS) who have failed or are intolerant of bracing and who have a major coronal curve of 40° to 65°. The vertebral body must be structurally and dimensionally adequate to accommodate screw fixation, as determined radiographically. The best indication for VBT is a flexible single major thoracic curve with nonstructural compensating lumbar and proximal thoracic curves (Lenke 1A or 1B). VBT allows for progressive correction of the deformity without spinal fusion by utilizing a minimally invasive fluoroscopic technique. Description: The procedure for a right thoracic curve is performed with use of a right thoracoscopic approach with the patient in the left lateral decubitus position. The thoracoscope is introduced through a portal at the apex of the curvature in the posterior axillary line. Instrument portals are created lateral to each vertebral body in the mid-axillary line. Screws are inserted into each vertebral body under biplanar fluoroscopic control and with intraoperative neuromonitoring. An electroconductivity probing device, while not mandatory, is routinely utilized at our practice. The tether is attached to the most proximal screw of the construct, and then reduction is obtained sequentially by tensioning the tether from one vertebral screw to the next. Alternatives: Bracing is the gold-standard treatment for progressive AIS involving the immature spine. The most commonly utilized surgical treatment is posterior spinal fusion (PSF), which should be considered when the major coronal curve exceeds 45°. Rationale: PSF has proven to be a dependable technique to correct scoliotic deformities. It has a low complication rate and good long-term outcomes. However, concerns exist regarding the stiffness conferred by PSF and the long-term effects of adjacent segment disease. Thus, interest had developed in non-fusion solutions for AIS correction. VBT utilizes the Hueter-Volkmann principle to guide growth and correct deformity. Compressive forces applied to the convexity of the deformity by a polyethylene tether allow the patient's growth to realign the spine. Intraoperative correction triggers growth modulation, and most of the modulation seems to occur during the first 12 months postoperatively. The best results have been seen with a short Lenke type-1A curve in a patient with closed triradiate cartilage, a Risser 3 or lower (ideally Risser 0) iliac apophysis, and a flexible curve characterized by a 50% reduction of the major coronal curve angle on side-bending radiographs. Expected Outcomes: In 57 immature patients with a Lenke type-1A or 1B curve (i.e., a 30° to 65° preoperative Cobb angle), Samdani et al.3 found a main thoracic Cobb angle reduction from 40° ± 7° preoperatively to 19° ± 13° at 2 years after VBT. In the sagittal plane, the T5-T12 kyphosis measured 15° ± 10° preoperatively, 17° ± 10° postoperatively, and 20° ± 13° at 2 years. No major neurologic or pulmonary complications occurred. A total of 7 (12.3%) of the 57 patients underwent surgical revision, including 5 for overcorrection and 2 to span additional vertebrae. In a study of 21 skeletally mature patients, Pehlivanoglu et al.4 found that the Cobb angle was reduced from 48° preoperatively to 16° on the first-erect postoperative radiograph and finally to 10° at the latest follow-up (mean, 27.4 months). The 2 main complications of VBT reported in the literature are overcorrection and tether breakage. Both may require revision, which explains the higher rate of revision observed for VBT compared with PSF. Important Tips: Good patient selection is important. VBT is most appropriate in cases of a flexible Lenke type-1A or 1B curve in an immature child before Risser stage 3 and after triradiate cartilage closure.Always monitor and control screw positioning in both anteroposterior and lateral planes fluoroscopically.The screws should be placed parallel to the vertebral end plates or, even better, be angled inferiorly for the upper vertebrae and angled superiorly for the lower vertebrae to decrease the risk of pull-out when tensioning the device and during growth modulation. Less tension on the uppermost and lowermost instrumented vertebrae than at the apex, as controlled by the tensioning device, can also help to limit pull-out. Acronyms and Abbreviations: VBT = vertebral body tetheringAIS = adolescent idiopathic scoliosisIONM = intraoperative neuromonitoringPSF = posterior spinal fusionUIV = upper instrumented vertebraLIV = lower instrumented vertebraAP = anteroposteriorK-wire = Kirschner wire.