Anterior Instrumented Fusion Research Articles

Anterior instrumented fusion for adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional deformity of the spine consisting of a lateral curvature, apical vertebral rotation, and an impairment of the sagittal profile. Surgical options include anterior and posterior approaches. Anterior instrumented fusion is suitable in Lenke type 1 and 5 curves. It supplies excellent results in coronal plane correction and is superior in the restoration of the sagittal profile and apical derotation. Fusion is shorter compared to posterior correction, and the complication rate is low. Pulmonary function is impaired postoperatively but recovers within a few years.

Image-Guided Navigation in Anterior Cervical Spine Surgery using a Cranial Frame

Background Data: Cervicothoracic, high thoracic, and craniocervical instrumented anterior spinal procedures pose a considerable challenge to the surgeon, mainly because intraoperative imaging by fluoroscopy is inadequate. To a certain extent the surgeon can make use of 3D-fluoroscopy for intraoperative control of the implants. To ease this process, the surgeon can make use of the so-called cranial frame which is attached to the Mayfield clamp, in combination with navigated 3D-fluoroscopy. The use of the cranial frame for navigated anterior craniocervical approaches as in the case of transnasal procedures at the clivus and foramen magnum is quite widespread. In the literature, the use of this technique for spine approaches is limited to a few case reports.Purpose: To present the feasibility of 3D-fluoroscopy navigation in anterior cervical spine procedures with the use of cranial frame.Study Design: Retrospective clinical case cohort.Patients and Methods: We present our experience in the technique of navigation in 5 patients of anterior cervical spine procedures. Anterior instrumented fusion in the cervicothoracic spine was performed in 4 patients and in the last patient anterior C1/2 fixation was performed. We used a system composed of Arcadis Orbic 3D C-arm by Siemens Medical Solutions, Erlangen, Germany, for acquisition of 3D images and the Stealth Station system by Medtronic Inc., Louisville, USA, for navigation. We used a so-called cranial frame for navigation that is fixed to the Mayfield head holder; a preoperative 3D scan was performed in some patients. The intraoperative 3D scan was performed after removal of the retractors, and additional 3D scan was beneficial in some patients during the surgical procedure.Results: Navigation was helpful in identification of the entry points and trajectories of the screws especially in the cervicothoracic region with no need for fluoroscopy. Additional advantage of the use of this system is the possibility of performing intraoperative 3D scan after instrumentation to verify hardware placement.Conclusion: The illustrated cases demonstrate the advantages of 3D-fluoroscopy navigation with use of the cranial frame in the upper transitional zones. Disadvantages of this method are the complex intraoperative draping and logistics and the possible inaccuracy because of long distances and spinal mobility. Carbon Mayfield may facilitate positioning but is not mandatory. (2018ESJ173)

Surgical treatment of advanced congenital kyphoscoliosis: A case report

Clinical case of surgical treatment of advanced congenital kyphoscoliosis in 12 years old child is reported. Radiographs and CT at presentation failed to reveal the entire anomaly. By analysis of priorly made radiographs hemivertebra L1 was recognized. At genitourinary assessment L-shaped kidney was detected. A full-size 3D-printed model was used for surgical planning. Vertebral column resection as treatment option was discussed, but due to high neurologic complication rate this approach was refused. After preoperative 35 days halo-femoral traction anterior instrumented fusion was performed. Right ureter was stented for intraoperative urologic injury prevention. Scoliosis correction of 32% and kyphosis of 14% was achieved. 5 months later definitive posterior uninstrumented fusion was performed. Spinal deformities caused by vertebral malformations progress dramatically unless they are treated early. An advanced case is a clinical challenge because of technical difficulties and poor result. Vertebral column resection is a treatment option for severe kyphoscoliosis, but it’s indications should be strictly individualized. Preoperative halo-femoral traction is the most safe correction method in spinal deformity due to prolonged and gradual action. 3d-printed models are practical for surgical planning. The model may be used intraoperatively as a 3D-reference. In congenital scoliosis genitourinary system should be assessed meticulously, and urologist advice in relevant case is necessary.

Clinical value of oblique lateral interbody fusion in the treatment of adult degenerative scoliosis

Objective To evaluate the clinical outcomes of oblique lateral interbody fusion (OLIF) in the treatment of adult degenerative scoliosis (ADS). Methods From January 2015 to May 2016, 17 ADS patients, 4 males and 13 females were enrolled with ages from 46 to 80 (average 69.5±9.2 years). The Cobb angle of all was greater than 10°. According to Lenke-Silva classification systems: I level, 2 cases, decompression alone; II level, 2 cases, decompression and limited instrumented spinal fusion; III levels, 4 cases, decompression and lumbar curve instrumented fusion; IV levels, 5 cases, decompression with anterior and posterior spinal instrumented fusion; V level, 4 cases, thoracic instrumentation and fusion extension. The operation time, blood loss, blood transfusion, and preoperative and postoperative complications were recorded. Clinical and radiological outcomes were evaluated using visual analogue scale (VAS), Oswestry disability questionnaire (ODI) scores, sagittal vertical axis (SVA) and coronal Cobb. All cases were followed up in 3, 6, 12 and 24 months. Results All of 17 cases underwent OLIF, one level 4 cases, two levels 2 cases, three levels 7 cases and four levels 4 cases. Alone OLIF was 5 cases (2 case of I level, 1 case of II level, 1 case of III level and 1 case of IV level). OLIF combined with posterior approach was 12 cases and the interval time were 1-2 weeks, the mean were 1.7±0.5 weeks. Among these 12 cases, posterior fixation was 6 cases, posterior fixation and decompression was 2 cases, and L5/S1 interbody fusion was 4 cases. The operation lasted for 50-460 min, with a mean duration of 230.6±132.0 min. Blood loss during the operation was 30-640 ml, with a mean of 306.5±213.8 ml. No patient had blood transfusion. The follow-up was 12-28 months and the mean was 17.9±4.5 months. The preoperative Cobb angles were 16.2°-37.7°, the mean was 29.1°±6.4°. The postoperative Cobb angle were 1.5°-10.2°, and the mean were 5.6°±2.4°. The Cobb of all cases improved significantly. The SVA was returned to the normal level in 4 cases of Lenke-Silva V level. The VAS and ODI score decreased from 7.1±0.7 preoperatively to 2.4±0.9 at last follow-up, and from 37.9±2.5 to 10.9±3.0, respectively, and both of them were improved significantly. 2 cases of OLIF had cage malposition. Left hip flexor weakness occurred in 5 cases and recovered completely within 2 weeks. Left anterior thigh pain occurred in 1 case and disappeared within 2 weeks. Left sympathetic chain injury happened in 1 case and recovered at last follow-up. Conclusion OLIF as a management of ADS showed excellent short-term outcomes. Clinical and radiological results, such as VAS, ODI and Cobb angle, were improved in all cases. OLIF will be a good choice for the treatment of ADS. Key words: Lumbar vertebrae; Adult; Scoliosis; Spinal fusion

Surgical Correction of Severe Lumbar Spine Instability and Sagittal Deformity in a Patient with Rheumatoid Arthritis Without the Utilization of an Osteotomy

Purpose: Complications from RA can involve the thoracolumbar spine and cause severe spine instability and sagittal deformity. We present a surgical strategy to restore sagittal balance in a patient with chronic rheumatoid arthritis. Methods: A retrospective chart review was performed. Results: We report the case of a 53-year-old woman with RA and severe back pain. She had dynamic instability of her lumbar spine with spondylolithesis at L3-L4 and L4-L5 as well as hypermobility at the C1-2 level without rheumatoid pannus. On 36-inch standing films, she had a sagittal vertical axis (SVA) of 219 mm. She underwent anterior and posterior instrumented fusion to restore her sagittal imbalance, which resulted in excellent relief of her back pain and marked improvement in ambulation and function. Conclusion: Patients with RA can develop severe sagittal deformity that could be the source of back pain. In patients with advanced RA, chronic inflammation could lead to ligament laxity that can result in spinal deformity under axial load. This deformity is amenable to reconstruction without the utilization of an osteotomy, which can produce excellent pain relief and restoration of function.

Mini Anterior Lumbar Interbody Fusion: One Year Follow up for a Novel Device

Introduction This study is a prospective cohort observational trial, to evaluate the ROI-A (Radiolucent Open Implant-ALIF) and VerteBRIDGE plate construct, in the treatment of symptomatic lumbar degenerative disc disease. The principal advantage of anterior approach is that the risks associated with exploration of the spinal canal through a posterior approach can be avoided and damage to the muscles of the back is eliminated. The anterior approach offers superior visualization of the disc space itself, and can be done without disruption of the otherwise healthy posterior elements. The Mini ALIF retroperitoneal approach facilitates rapid patient recovery. Materials and Methods The ROI-A (Radiolucent Open Implant-ALIF) is made from PEEK (Polyetheretherketone), a medical grade plastic, and two metallic anchoring plates, marketed as VerteBridge, which provide both stability at the site of desired bony fusion and fixation of the implant to the vertebrae adjacent to the interbody device. Inclusion Criteria: 18 patients between the ages 31 and 65 years of age; Disc disease between L2-S1; Patients may have up to grade I spondylolisthesis or retrolesthesis at the involved site; Maximum two diseased vertebral motion segments to be instrumented; Has had no more than two previous non-fusion surgeries to the lumbar soine at the same level(s); Has failed to respond to an appropriate attempt at conservative treatment. Exclusion Criteria: More than two vertebral motion segments involved; Prior anterior, retroperitoneal approach; Has had previous anterior instrumented fusion at the proposed operative level; Higher than grade I spondylolisthesis or retrolisthesis at the involved level(s); Has reported active malignancy, localized or systemic infection; Morbid obesity, as defined by NIH Clinical Guidelines Body Mass Index (BMI > 40); Patients with a diagnosis of osteoporosis, osteopenia, Paget's or other metabolic bone disease; Patients who smoke more than 1 pack per day; Has an active workers compensation claim relative to the involved part. Outcome Measures: Subjects are evaluated clinically pre-operatively, 6 weeks and 12 months post op by the pain questionnaire (VAS), and function questionnaire (ODI); The radiological measures included the segmental lordosis, integrity of the construct, and presence of bridging bone; Fusion success is defined as presence of bridging bone, and postoperative intervertebral motion at 12 months which is less than 5 degrees, via manual radiographic angular measurements (Cobb Method) of the implanted level(s) on flexion and extension radiographs at the 12 month follow up visit. Results The VAS has improved from an average of 9 preop to an average of 2 postop. ODI score has reduced an average 30 points from preop measurement. 83% (15 patients) went on bony fusion at the radiological assessment 12 month post op. None of the patients underwent revision, removal of implant, supplemented fixation, or re-operation. One patient developed mechanical ileus for 48 hours postop, resolved with NG tube. Conclusion Mini anterior inter-body fusion is a valid option when treating degenerative/discogenic back pain, the ROI-A implant is a safe and simple, with satisfactory results up to 12 month, according to our pilot study.

Posterior Vertebral Column Resection: A Salvage for Thoracolumbar Kyphosis after Failed Anterior Instrumented Fusion

Introduction Anterior thoracolumbar spine surgery is typically indicated for restoration of structural stability and /or decompression of neural element secondary to trauma, tumor or infection. But postoperative complications especially kyphosis poses distinct challenges to the spinal surgeon. The aim of this study was to explore the effects of posterior vertebral column resection of thoracolumbar kyphosis after failed anterior instrumented fusion. Material and Methods A retrospective study was conducted of 10 patients of kyphotic deformity with previous failed anterior surgery in our department from October 2005 to December 2009. The indications for revision surgery included pain refractory to conservative treatment, progressive neurological deficit and kyphosis. Anterior removal of the implant and posterior vertebral column resection (PVCR) was performed. Mean operating time, average intraoperative blood loss, kyphosis angle, the visual analog scale (VAS), Oswestry disability index (ODI), bone fusion time and complications were used for clinical assessment in a minimum 18-month follow-up (18 – 60 months). Results The mean age was 38.7 years old (ranging from 24 to 56 years old) and the average kyphosis angle was 54.60 (ranging from 45 0 to 74 0). Mean operating time was 323.5 (range 245 minute to 420 minute) with average intraoperative blood loss of 1189 ml (range 850 ml to 1550 ml). After revision surgery, Kyphosis angle was 4.800 (range3- 70) immediately and 6.80 (range 5 to 90) at the 18 months follow-up and there was good bony fusion in every case. The average time of bony fusion was 6.8 months (range 5–9 months). All patients had satisfied spinal sagittal and coronal balance at the last follow-up. None of our patients experienced implant failure. The average preoperative VAS was 6.2, falling to 2.6 at the 18 months follow-up with significant improvement. None of the patients suffered any surgery-related neurological deterioration and one patient whose neurological status was Frankel Grade C improved to Grade D. The ODI changed form a mean value of 39.8 (rang 31–48) preoperatively to 24.5 (rang 15–29) at the final follow-up. The difference was statistically significant. Complications occurred in four patients (40%); these included three with tearing of the lung and one with a superficial wound infection. Conclusion Despite the technically demanding procedure, anterior removal of the implant and posterior vertebral column resection was a safe and effective revision surgery for patients with prior anterior fusion with rigid post-surgical deformities.

Respiratory Arrest in a Patient with severe Cervical Dystrophic Kyphosis Secondary to Neurofibromatosis Type 1: A Case Report

Background: Cases of severe cervical kyphosis due to neurofibromatosis type 1 (NF1) and requiring tracheal intubation are rare. Dystrophic-type NF1 needs a combination of anterior and posterior spinal fusion, and use of sublaminar tape with rods appears reasonable and safe for posterior corrective spinal surgery in patients with this pathology. Case presentation: A 61-year-old woman with severe cervical kyphosis of 139 presented with sudden respiratory arrest before planned spinal surgery. Two-stage posterior and anterior corrective instrumented fusion using multiple segmental sublaminar tape and rods was performed under spinal cord monitoring. Cervical kyphosis was corrected from 104° to 83° and upper thoracic lordosis was corrected from 70° to 37°. Finally, she underwent additional posterior C1-C2 fusion with transarticular screwing for postoperative atlantoaxial subluxation. Solid bone fusion was demonstrated on 2-year follow-up Computed tomography, correction was maintained for 4 years after first surgery, and respiratory function was improved. Conclusion: Rib cage hypoplasia with upper thoracic lordosis secondary to severe cervical kyphosis can lead to acute-on-chronic respiratory failure. Planned corrective posterior spinal fusion with sublaminar tape, followed by anterior spinal fusion with a fibular strut bone resulted in successful solid bone fusion and improvement of respiratory function.

Degenerative Spondylolisthesis

Analysis of the Nationwide Inpatient Sample database. To investigate national trends, risks, and benefits of surgical interventions for degenerative spondylolisthesis (DS). The surgical management of DS continues to evolve whereas the most clinically and cost-effective treatment is debated. With an aging US population and growing restraints on a financially burdened health care system, a clear understanding of national trends in the surgical management of DS is needed. The Nationwide Inpatient Sample database was queried for patients with DS undergoing lumbar fusions from 2001 to 2010, using International Classification of Diseases, Ninth Revision (ICD-9) diagnosis and procedure codes. Analyses compared instrumented posterolateral fusion (PLF), posterolateral fusion with anterior lumbar interbody fusion (ALIF + PLF), PLF with posterior interbody fusion (P/TLIF + PLF), anterior instrumented interbody fusion (ALIF), and posterior interbody fusion with posterior instrumentation (P/TLIF). Clinical data were analyzed representing the initial acute phase care after surgery. There were 48,911 DS surgical procedures identified, representing 237,383 procedures. The percentage of patients undergoing PLF, ALIF + PLF, or ALIF increased whereas the percentage of P/TLIF or P/TLIF + PLF decreased over time. Total charges were less (P < 0.001), average length of hospital stay was shorter (P < 0.01), and average age was older (P < 0.01) for patients who underwent PLF compared with any other procedure. Type of procedure varied on the basis of the geographic region of the hospital, teaching versus nonteaching hospital, and size of hospital (P < 0.01). Patients who had P/TLIF + PLF or ALIF had a higher risk of mortality than patients who had PLF (odds ratios: 5.02, 2.22, respectively). Patients were more likely to develop a complication if they had ALIF + PLF, P/TLIF + PLF, ALIF, and P/TLIF than if they had PLF (odds ratios: 1.45, 1.23, 1.49, 1.12, respectively). Variation in the surgical management of DS related to patient demographics, hospital charges, length of hospital stay, insurance type, comorbidities, and complication rates was found within the Nationwide Inpatient Sample database. During the acute phase of care immediately after surgery, PLF procedures were found to reduce length of hospital stay, hospital charges, and postoperative complications. 3.

5-year minimum follow-up study of Surgical &amp; Radiological outcomes of Thoracoscopic assisted Anterior Instrumented fusion compared to posterior hook and pedicle screw instrumentation in the treatment of Adolescent Idiopathic Scoliosis

Group 2 &3 Posterior Instrumentation (PI): 91 patients, average age 14.2 yrs. The posterior group was divided into all Hook/ hybrid (Group 2, n=45) and all Pedicle screw construct (Group 3, n=46), for evaluation of radiological outcomes. The groups were compared for various surgical and radiological outcomes at immediate post-op, 2 and 5 year intervals. Average follow-up 6.6 years (5-12 yrs). Results The groups were similar with regards to age, Risser grade, and Cobb angle of Main Thoracic curve.

СРАВНИТЕЛЬНЫЙ АНАЛИЗ ПОДВИЖНОСТИ ПОЗВОНОЧНИКА У ПАЦИЕНТОВ С ИДИОПАТИЧЕСКИМ СКОЛИОЗОМ ПОСЛЕ ВЕНТРАЛЬНОГО И ЗАДНЕГО ИНСТРУМЕНТАЛЬНОГО СПОНДИЛОДЕЗА

Objective. To analyze spinal mobility after anterior and posterior instrumented fusion in patients with idiopathic scoliosis, and to compare the obtained data with those in healthy subjects. Material and Methods. The study included 45 individuals divided into three groups of 15 subjects in each. Group I consisted of patients after anterior spinal fusion, Group II after posterior spinal fusion, and Group III included healthy individuals. Spinal mobility was assessed using Spinal Mouse device. The obtained data were processed by pairwise comparisons using t-tests. Results. Results of t-statistic calculation in Groups I and II, compared with those in group of healthy individuals showed that index t is less for 19 out of 32 investigated parameters in the group of the anterior spinal fusion. Comparison of t-statistics of Group I and Group II revealed spine greater mobility in Group I. Conclusion. Both the anterior and posterior techniques of corrective instrumented fusion result in restrictions of spine mobility. Anterior spinal fusion for scoliosis is preferable from the viewpoint of spine mobility preservation. Hir. Pozvonoc. 2014;(2): 36-41.

Diagnosis and treatment of a C2-osteoblastoma encompassing the vertebral artery

Osteoblastoma is a rare, benign bone tumor that accounts for approximately 1% of all primary bone tumors and 5% of spinal tumors, mostly arising within the posterior elements of the spine within the second and third decades of life. Nonspecific initial symptoms mainly neck or back pain and stiffness of the spine remain often undiagnosed and the destructive nature of the expanding tumor can cause even neurological deficits. CT and MRI scans constitute the basic imaging modalities employed in diagnosis and preoperative planning with the former delineating the location and osseous involvement of the mass and the latter providing appreciation of the effect on soft tissues and neural elements. In our case a 23-year-old male presented with persisting head and neck pain, after being involved in a car collision a month ago. Although the initial diagnostic imaging, including plain X-rays and MRI scan failed to reveal any pathological findings, the persistence of the symptoms led to repeating imaging (CT and MRI) that showed the existence of a benign osseous tumor of the C2 lamina that was destructing the surrounding osseous structures and encompassing the right vertebral artery. The suspicion of an osteoblastoma was raised and the decision for surgical removal of the tumor was made for treating the persistent symptoms and preventing a possible neurological deficit or vascular lesion. A marginal tumor resection was performed through a posterior approach, followed by an anterior instrumented fusion. Histological examination confirmed the diagnosis of an osteoblastoma. The recovery of the patient was uneventful and a significant symptom subsidence was reported following surgery. Eighteen months postoperatively the patient remains pain free without any indications for tumor recurrence. This case delineates the difficulties in diagnosing this tumor, as well as the challenges and problems encountered in its surgical management, and also the favorable prognosis when adequately treated.

Anterior Dual Rod Versus Posterior Pedicle Fixation Surgery for the Surgical Treatment in Lenke 5C Adolescent Idiopathic Scoliosis: A Multicenter, Matched Case Analysis of 42 Patients

Study DesignMulticenter matched case analysis. ObjectiveCompare patients with Lenke 5C scoliosis surgically treated with anterior spinal fusion with dual rod instrumentation and anterior column support versus posterior release and pedicle screw instrumentation. Summary of Background DataTreatment of single, structural, lumbar and thoracolumbar curves in patients with adolescent idiopathic scoliosis (AIS) has been the subject of some debate. Previous papers directly comparing these approaches are problematic because of heterogeneity of the groups, nonrandomized protocols, and surgeon bias and variation of instrumentation (upper instrumented vertebrae and lower instrumented vertebrae) in relation to the defined Cobb angle (upper end vertebra and lower end vertebrae). This report sought to remedy these flaws by analyzing a database of Lenke 5C AIS and performing matched cases. MethodsWe analyzed 96 patients with Lenke 5C AIS curves based on radiographic and clinical data at 3 institutions, surgically treated between 2001 and 2005 with minimum 2-year follow-up. Case matched criteria (age within 1 year, sex, curve within 5°, lower end vertebrae, and lower instrumented vertebrae) yielded 21 matched patient pairs. We evaluated and compared multiple clinical and radiographic parameters. ResultsWe observed no significant statistical differences between groups in any preoperative clinical or radiographic parameters. At final follow-up, the major curve measured 8° (83%) in the posterior spinal fusion group, compared with 13° (72%) in the anterior spinal fusion group (p = .002). Estimated blood loss was similar in both groups. Hospital stay was significantly shorter in the posterior spinal fusion group. There were no differences in radiographic complications, such as proximal junctional kyphosis. ConclusionsAt a minimum of 2 years' follow-up in a multicenter, matched case analysis, adolescents with Lenke 5C curves demonstrated statistically significantly better curve correction and shorter hospital stays when treated with a posterior release with pedicle screw instrumented fusion compared with an anterior instrumented fusion with dual rods for similar patient populations.

Secondary Curve Behavior in Lenke Type 1C Adolescent Idiopathic Scoliosis After Thoracoscopic Selective Anterior Thoracic Fusion

Analysis of a case series of 24 patients with Lenke 1C adolescent idiopathic scoliosis (AIS) receiving selective thoracoscopic anterior scoliosis correction. To report the behavior of the compensatory lumbar curve in a group of patients with Lenke IC AIS after thoracoscopic anterior scoliosis correction and to compare the results of this study with previously published data. Several prior studies have reported spontaneous lumbar curve correction for both anterior and posterior selective fusions in patients with Lenke 1C/King-Moe 2; however, to our knowledge no previous studies have reported outcomes of thoracoscopic anterior correction for this curve type. All patients with AIS with a curve classification of Lenke 1C and a minimum of 24-month follow-up were obtained from a consecutive series of 190 patients with AIS who underwent thoracoscopic anterior instrumented fusion. Cobb angles of the major curve, instrumented levels, compensatory lumbar curve, and T5-T12 kyphosis were recorded, as well as coronal spinal balance, T1 tilt angle, and shoulder balance. All radiographical parameters were measured before surgery and at 2, 6, 12, and 24 months after surgery. Twenty-four female patients with right thoracic curves had a mean thoracic Cobb angle of 53.0° before surgery, decreasing to 24.9° 2 years after surgery. The mean lumbar compensatory Cobb angle was 43.5° before surgery, spontaneously correcting to 25.4° 2 years after surgery, indicating balance between the thoracic and lumbar scoliotic curves. The lumbar correction achieved (41.8%) compares favorably to previous studies. Selective thoracoscopic anterior fusion allows spontaneous lumbar curve correction and achieves coronal balance of main thoracic and compensatory lumbar curves, good cosmesis, and patient satisfaction. Correction and balance are maintained 24 months after surgery.

Current Concepts in Cervical Spine Surgery: Editorial Comment

Cervical spine surgery has greatly matured over the last few decades, evolving in terms of surgical technique, equipment, and instrumentation. This surgery typically represents a field of shared competence between orthopaedic surgeons and neurosurgeons. We had the opportunity to invite surgeons from different countries to demonstrate current ways to address issues related to surgery at the cervical spine. This Symposium explores current approaches to various problems in the cervical spine: degenerative cervical spine disease, cervical spine metastasis, cervical spine fractures and spinal cord injury, and inflammatory diseases affecting the axial cervical spine. We are pleased the Symposium explores some “cutting edge” topics such as the recent advances in percutaneous vertebroplasty for cervical spine tumors and the comparison between laminoplasty and laminectomy and instrumented fusion for cervical stenosis. Fig. 1 Vincenzo Denaro, MD, Full Professor, Dean, is shown. We also intend to emphasize the newer SLIC classification system for cervical spine fractures developed by the Spine Trauma Study Group. The goal is standardization of management of the cervical spine by suggesting surgical indications based on patient scores. European and American surgeons tend to have different approaches to standardization in surgery. In particular, European surgeons tend not to trust scoring systems to pose surgical indications, whereas Americans usually follow guidelines throughout the surgical decision-making process. Another focus is incidence and management of complications in cervical spine surgery, beginning with an epidemiological study on surgical risk and immediate postoperative outcomes in anterior or posterior procedures at the cervical spine. Other papers explore the role of defined risk factors (such as smoking) in terms of fusion rates, after which studies on complications and outcomes associated to several surgical procedures are presented. We also report the first results of a clinical case series on the use of a new low-profile instrumentation aimed at reducing the bulk effect and dysphagia in anterior instrumented fusion. The issue of cervical spine arthroplasty has been discussed in terms of risk factors (sagittal alignment) and spinal biomechanics of segmental motion sparing. Finally, the proposed systematic review on spinal cord injury represents a useful tool for updating on the most recent advances in this special field. Fig. 2 Alberto Di Martino, MD, PhD, is shown. We believe the content of this Symposium will be interesting and useful to any surgeon dedicated to the treatment of cervical spine diseases. The considerable interest by the scientific community in this area is confirmed by the number of congresses and meetings on these issues. We would like to personally thank all the contributing Symposium authors for their excellent research and the reviewers who critically reviewed all the manuscripts and upheld strict scientific rigor. We wish to dedicate this Symposium to two masters in the field of cervical spine surgery: Professor Mario Boni from Pavia for his work in the pathophysiology and surgery of the degenerative cervical spine and Professor Raymond Roy-Camille from Paris for his contributions to the treatment of the unstable cervical spine and the introduction of screw-based systems for posterior spinal stabilization in clinical practice.

The Surgical Treatment of Congenital Kyphosis

Retrospective study with clinical and radiologic evaluation of 15 patients with congenital kyphosis or kyphoscoliosis who underwent anterior instrumented spinal fusion for posterolateral or posterior hemivertebra (HV). The management of congenital kyphosis has been described in the literature using a variety of techniques. The presentation of patients at diagnosis is discussed. The question of when to begin treatment is reviewed. The pitfalls in the management and how to avoid these are discussed. The different published techniques are reviewed. We present our own techniques and our results of treatment of congenital kyphosis in very young children. To evaluate the safety and efficacy of early surgical anterior instrumented fusion with partial preservation of the HV in the treatment of progressive congenital kyphosis in children below the age of 3. We discuss the management of patients presenting with neurologic compromise. We aim to systematically review the literature and to present our own experience in the management of these deformities, so that the issues common to treating physicians may be explored. A variety of treatments have been described in the literature for the treatment of congenital kyphosis due to HV. We report the results of our technique. Between 1997 and 2005 we have treated 15 consecutive patients with progressive congenital kyphosis with anterior instrumented fusion and strut grafting. Thirteen patients had a single posterolateral HV and 2 patients had a single posterior HV. Of the 15 patients in the study, 5 were girls and 10 boys. Mean age at surgery was 22 months (range, 8-33). Mean follow-up period was 6.8 years. Thirteen HV were located in the thoracolumbar junction (T10-L2) and 2 in the thoracic spine. The average operating time of procedure was 150 minutes (range, 130-210 minutes). The average blood loss was 180 mL (range, 100-330 mL), equivalent to a mean external blood volume loss of 15% (range, 11%-24%).Preoperative segmental Cobb angle averaging 34 degrees at last follow-up. Compensatory coronal cranial and caudal curves were corrected by 50%. The angle of segmental kyphosis averaged 39 degrees (range, 20 degrees-80 degrees) before surgery and 21 degrees (range, 11 degrees-40 degrees) at last follow-up. This represents a 43% of improvement of the segmental kyphosis, and a 64% of improvement of the segmental scoliosis at last follow-up. One case with initial kyphosis of 80 degrees continued to progress and required revision anterior and posterior surgery. There were no neurologic complications.

Comparison of Surgical Treatment in Lenke 5C Adolescent Idiopathic Scoliosis: Anterior Dual Rod Versus Posterior Pedicle Fixation Surgery

Multicenter analysis of 2 groups of patients surgically treated for Lenke 5C adolescent idiopathic scoliosis (AIS). Compare patients with Lenke 5C scoliosis surgically treated with anterior spinal fusion with dual rod instrumentation and anterior column support with patients surgically treated with posterior release and pedicle screw instrumentation. Treatment of single, structural, lumbar, and thoracolumbar curves in patients with AIS has been the subject of some debate. Advocates of the anterior approach assert that their technique spares posterior musculature and may save distal fusion levels, and that with dual rods and anterior column support the issues with nonunion and kyphosis have been obviated. Advocates of the posterior approach assert that with the change to posterior pedicle screw based instrumentation that correction and levels are equivalent, and the posterior approach avoids the issues with nonunion and kyphosis. This report directly compares the results of posterior versus anterior instrumented fusions in the operative treatment of adolescent idiopathic Lenke 5C curves. We analyzed 62 patients with Lenke 5C based on radiographic and clinical data at 2 institutions: 31 patients treated with posterior, pedicle-screw instrumented fusions at 1 institution (group PSF); and 31 patients with anterior, dual-rod instrumented fusions at another institution (group ASF). Multiple clinical and radiographic parameters were evaluated and compared. The mean age, preoperative major curve magnitude, and preoperative lowest instrumented vertebral (LIV) tilt were similar in both groups (age: PSF = 15.5 years, ASF = 15.6 years; curve size: PSF = 50.3 degrees +/- 7.0 degrees , ASF = 49.0 degrees +/- 6.6 degrees ; LIV tilt: PSF = 27.5 degrees +/- 6.5 degrees , ASF = 27.8 degrees +/- 6.2 degrees ). After surgery, the major curve corrected to an average of 6.3 degrees +/- 3.2 degrees (87.6% +/- 5.8%) in the PSF group, compared with 12.1 degrees +/- 7.4 degrees (75.7% +/- 14.8%) in the ASF group (P < 0.01). At final follow-up, the major curve measured 8.0 degrees +/- 3.0 degrees (84.2% +/- 5.8% correction) in the PSF group, compared with 15.9 degrees +/- 9.0 degrees (66.6% +/- 17.9%) in the ASF group (P = 0.01). This represented a loss of correction of 1.7 degrees +/- 1.9 degrees (3.4% +/- 3.7%) in the PSF group, and 3.8 degrees +/- 4.2 degrees (9.4% +/- 10.7%) in the ASF group (P = 0.028). The LIV tilt decreased to 4.1 degrees +/- 3.4 degrees after surgery in the PSF group, and 4.5 degrees +/- 3.7 degrees in the ASF group. At final follow-up, the LIV tilt was 5.1 degrees +/- 3.5 degrees in the PSF group, and 4.5 degrees +/- 3.7 degrees in the ASF group. EBL was identical in both groups, and length of hospital stay was significantly (P < 0.01) shorter in the PSF group (4.8 vs. 6.1 days). There were no complications in either group which extended hospital stay or required an unplanned second surgery. At a minimum of 2-year follow-up, adolescents with Lenke 5C curves demonstrated statistically significantly better curve correction, less loss of correction over time, and shorter hospital stays when treated with a posterior release with pedicle screw instrumented fusion compared with an anterior instrumented fusion with dual rods for similar patient populations.

The Effect of Anterior Spinal Fusion on Spinal Canal Development in an Immature Porcine Model

Experimental study. To investigate whether anterior spine fusion in the immature porcine spine has an adverse effect on the development of spinal canal. Neurocentral cartilage (NCC) is located in the posterior vertebral body and responsible for the development of posterior aspect of the spinal canal. Injury to the NCC interferes with the development of the spinal canal. Twelve 8-week-old domestic pigs were used to develop an anterior fusion model. A standard procedure as L3-L4, L4-L5 discectomy, and L3-L5 anterior instrumented spine fusion was performed. To evaluate the development of the spinal canal, all subjects had computed tomography scans before the procedure and at the final follow-up. The spinal canal area was measured at the control level (CL) (L2), arthrodesis level (AL) (L4), superior (L3), and inferior (L5) instrumented level (SIL and IIL). Percent change in spinal canal area from before surgery to final follow-up was also calculated. RESULTS.: Eleven subjects were available for the study. All subjects developed local kyphosis over the fused segments. The average area of L2 (CL) was 0.56 +/- 0.06 cm before surgery. The average areas of the L3 (SIL), L4 (AL), and L5 (IIL) were 0.62, 0.70, and 0.77 cm, respectively. At the final follow-up the average area of L2 was 1.20 cm. The average areas of the SIL, AL, and IIL were 1.16, 1.19, and 1.33 cm, respectively. The percent increase in spinal canal area at the CL was 116.6% whereas it was 85.8%, 71.0%, and 71.2% at SIL, AL, and IIL, respectively. Anterior spinal arthrodesis in the immature porcine spine results in iatrogenic retardation on spinal canal growth. This effect is most likely related to the tethering effect of the interbody fusion over the NCC. Although, it is difficult to directly extrapolate these findings to clinical practice, the spine surgeons operating on pediatric patients should be aware of this possibility.

Study of distal junctional kyphosis of adolescent idiopathic scoliosis following anterior or posterior selective instrumented fusion and its risk factors.

Objective To compare the sagittal measurements before and after surgery in patients with adolescent idiopathic scoliosis (AIS) treated with instrumented fusion, and determine the incidence of distal junctional kyphosis (DJK) and its risk factors. Methods Fifty-nine patients with Lenke 1 type A1S underwent anterior or posterior instrumented fusion. In anterior group, including thoracoscopic surgery in 8 cases and mini-open surgery in 19 cases, while in posterior group, including 13 cases with distal pedicle screw fixation and 19 cases with hook constructs. The standing long-cassette anteroposterior and lateral radiographs of spine were taken, and the coronal and sagittal parameters were measured before and after surgery and during follow-up. Results At recent follow-up, the T5-T12, T10,-L2 sagittal measurement and DJK of anterior group increased significantly versus preoperation, the T5-T12 kyphosis, T10,-L2 kyphosis, DJK and L1-S1 lordosis of posterior hook group increased significantly versus preoperation. The postoperative mean T10,-L2 kyphosis and DJK in the posterior hook group were 13.1° and 8.7° compared to 0.1° and -2.2° in the posterior distal pedicle screw group. When postoperative DJK developed in the posterior group, mean postoperative T5-T12 kyphosis, T10,-L2 kyphosis and L1-S1, lordosis 18.5°, 13.6° and 51.1°versus 11.6°, 0.5° and 42.2° preoperatively. When postoperative DJK developed in the posterior group, mean postoperative T10,-L2 was 13.6° kyphosis compared to 2.6° in the posterior group without DJK. Conclusion The AIS patients undergoing selective anterior fusion may develop sagittal decompensation in distal junctional segments without instrumentation for its risk factor of short fusion segments. The AIS patients undergoing selective posterior hook instrumented fusion may develop sagittal decompensation for its risk factor of instability. Key words: Scoliosis; Adolescent; Spinal fusion; Kyphosis

Treatment of Unstable Lower Cervical Spine Injuries by Anterior Instrumented Fusion Alone

Retrospective study of a prospectively followed cohort. To summarize the complications after instrumented stabilization of cervical spine injuries in a single-institution series, and to discuss management of unstable injuries with respect to the complication rate between the 2 approaches (anterior and posterior). The anterior approach to the cervical spine has been criticized for destruction of the anterior elements in the presence of posterior instability. The data came mainly from biomechanical studies and older clinical studies with earlier implants. However, there has been growing evidence ever since, that anterior decompression and instrumented fusion alone is an adequate form of treatment for unstable cervical spine injuries. Over a 16-year period (1989 to 2005), 112 patients were treated in our institution for unstable cervical spine injuries using either anterior, posterior stabilization, or both. A patient was considered to have an unstable injury if he had 5 points or more in the White and Panjabi instability checklist. At least 1-year follow-up was necessary for a patient to be included in the study, which yielded a total of 97 patients. Seventy-four patients underwent anterior stabilization (group A) and 23 patients underwent posterior stabilization (group B). Three patients in the posterior surgery group required supplemental anterior cervical stabilization. Clinically significant complications occurred in 9/74 (12.2%) patients of group A. Three of 74 patients (4%) were reoperated owing to significant screw backout causing dysphagia, no purchase of the screws being completely in the adjacent disc and screw breakage, respectively. In group B, clinically significant complications were recorded in 4 (17.4%) patients, with an overall reoperation rate of 4% (1/23). Statistical analysis did not reveal significant differences between the 2 groups. Anterior instrumented fusion is at least as efficient as the posterior procedure in the management of cervical spine injuries and it also has several advantages. Most of such injuries, including the dislocations, can be managed with anterior instrumented fusion alone. Simple means of immobilization such as the hard collar suffice, and secondary posterior fixation is rarely, if ever, necessary.