Preservation of Spine Motion in the Surgical Treatment of Adolescent Idiopathic Scoliosis Using an Innovative Apical Fusion Technique: A 2-Year Follow-Up Pilot Study.

BACKGROUND: This trial reports the 2-year and immediate postremoval clinical outcomes of a novel posterior apical short-segment (PASS) correction technique allowing for correction and stabilization of adolescent idiopathic scoliosis (AIS) with limited fusion. METHODS: Twenty-one consecutive female AIS patients were treated at 4 institutions with this novel technique. Arthrodesis was limited to the short apical curve after correction with translational and derotational forces applied to upper and lower instrumented levels. Instrumentation spanned fused and unfused segments with motion and flexibility of unfused segments maintained. The long concave rods were removed at maturity. Radiographic data collected included preoperative and postoperative data for up to 2 years as well as after long rod removal. RESULTS: All 21 patients are beyond 2 years postsurgery. Average age at surgery was 14.2 years (11-17 years). A mean of 10.5 ± 1 levels per patient were stabilized and 5.0 ± 0.5 levels (48%) were fused. Cobb angle improved from 56.1° ± 8.0° to 20.8° ± 7.8° (62.2% improvement) at 1 year and 20.9° ± 8.4°, (62.0% improvement) at 2 years postsurgery. In levels instrumented but not fused, motion was 26° ± 6° preoperatively compared to 10° ± 4° at 1 year postsurgery, demonstrating 38% maintenance of mobility in nonfused segments. There was no report of implant-related complications. CONCLUSIONS: PASS correction technique corrected the deformity profile in AIS patients with a lower implant density while sparing 52% of the instrumented levels from fusion through the 2-year follow-up.

Analysis of Segmental Mobility Following a Novel Posterior Apical Short-Segment Correction for Adolescent Idiopathic Scoliosis.

STUDY DESIGN: A prospective, nonrandomized, multicenter study. OBJECTIVES: The purpose of this study was to evaluate the amount of motion present at instrumented but unfused segments and at motion segments adjacent to the instrumentation following application of a new posterior apical short-segment correction technique for correcting adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: High-density pedicle screw instrumentation and posterior arthrodesis of all instrumented levels is the most common surgical treatment for AIS stabilization. The consequence of long fusion is an abnormal load on adjacent levels with an increased risk of future adjacent segment degeneration. METHODS: This new system applied translational and derotational forces over a short apical segment. The short apical region was prepared for fusion while maintaining motion of unfused vertebral segments. Radiographic data were collected pre-operatively, at surgery, and at 3, 6, and 12 months after surgery. RESULTS: Twenty-one female patients, mean age of 14.2 years (10.6-16.9 years) with Lenke 1A/1B curves, were enrolled. The range of motion in the unfused instrumented segment was significantly higher than the apical fused segment (11 vs. 0.9, P < 0.001). The range of motion of unfused vertebral levels distal to the construct at one year did not differ significantly from their respective pre-op values. When the analysis was extended to understand the impact of lower instrumented vertebra (LIV) on motion of unfused segments distal to the construct, it appeared that (1) the change in motion from pre-op to 12 months post-op as a function of LIV is not statistically significant; and (2) The motion of the unfused distal vertebral segments at 12 months does not statistically increase with a lower LIV. CONCLUSION: Through one year, this novel technique achieved and maintained similar AIS correction to current posterior fusion techniques while maintaining the mobility of unfused motion segments with less implant density. LEVEL OF EVIDENCE: 4.

Complications associated with thoracic pedicle screws in spinal deformity.

Thoracic pedicle screws have superior anchoring strength compared with other available fixation techniques. However, these are not universally accepted in many developing countries because of the concerns regarding safety and complications. In addition, there is evidence that pedicle morphology is unique in Chinese patients. The goal of this study was to analyze the complications seen at our institution, while using thoracic pedicle screws for the treatment of thoracic deformity, and to determine the safety of our techniques for the treatment of thoracic deformity in a Chinese population. From 1998 to 2005, there were 208 thoracic deformity patients treated at our institution, 70 of whom were male and 138 were female. Their age ranged from 11 to 55 years (mean of 14.9 years). All of them underwent corrective deformity surgery using posterior pedicle screw systems and follow-up was available for at least 3 years. Etiologic diagnoses included adolescent idiopathic scoliosis in 119 patients, congenital kyphoscoliosis in 38, adult scoliosis in 37 and undetermined in 14. Screw positions were evaluated using intraoperative and postoperative radiographs and a CT scan was performed when a concern for screw malposition was present. All radiographic evaluations were carried out in a double-blinded fashion. A total of 1,123 thoracic pedicle screws were inserted (5.4 thoracic screws/patient). The deformity correction rate was 81, 65 and 62% for idiopathic, congenital and adult scoliosis patients, respectively. The overall complication rate was 16.5% at the final follow-up. Complication rates directly and indirectly related to pedicle screws were 7.2 and 9.3%, respectively. There were no significant screw-related neurologic or visceral complications that adversely affected long-term results. The complications seen with thoracic pedicle screws in a Chinese population were similar to other populations and could be utilized safely for the treatment of thoracic deformity in this population.

Endoscopically assisted anterior release and reduction through anterolateral retropharyngeal approach for fixed atlantoaxial dislocation.

STUDY DESIGN: A prospective study. OBJECTIVE: To evaluate a novel technique involving an endoscopically assisted anterior release and reduction through an anterolateral retropharyngeal approach with minimum follow-up interval of 31 months. SUMMARY OF BACKGROUND DATA: Irreducible atlantoaxial dislocation is typically a chronic process that requires surgical treatment. However, the current literature does not agree on the single best method of treatment. Previously, the best outcomes have been reported with transoral reduction followed by anterior or posterior fixation. Despite recent innovations, numerous complications remain associated with this approach. METHODS: About 21 consecutive irreducible atlantoaxial dislocation patients with mean age of 32 years underwent endoscopically assisted anterior release and reduction through the anterolateral retropharyngeal approach followed by posterior fixation. The primary pathologies included 8 late odontoid fractures, 7 cases of os odontoideum, 5 with laxity of the transverse ligament, and 1 with atlanto-occipital assimilation with a hypoplastic odontoid. Neurologic status was evaluated using the Japanese Orthopedic Association scoring system. Radiographic parameters including the atlantodental interval (ADI) and cervicomedullary angle were also measured. Follow-up data were obtained for a minimum of 31 months. RESULTS: Anatomic reduction was achieved in 20 cases and near-anatomic reduction in 1 case. All patients had an uneventful recovery with significant improvement in neurologic function and radiographic parameters. No complications were seen. The atlantodental interval was corrected from an average 6.3 mm before surgery to 2.7 mm after surgery (P < 0.01). The cervicomedullary angle was also corrected from an average 109 degrees before surgery to 152 degrees after surgery (P < 0.01). Preoperative muscle strength was on average 3.5 (on scale from 1 to 5) and improved after surgery to 4.5 (P < 0.01). The average preoperative and postoperative Japanese Orthopedic Association scores were 9.6 and 15.5, respectively, indicating 82.8% improvement. CONCLUSION: Endoscopically assisted anterior retropharyngeal release combined with posterior fixation is a safe and effective alternative for the treatment of irreducible atlantoaxial dislocation.

New conservative treatment of idiopathic scoliosis: effectiveness of therapy.

Background. This article provides basic information concerning a new conservative treatment for idiopathic scoliosis, with appropriate asymmetric flexion-rotation exercises and special redressing positions. Material and method. The analysis was based on 288 children with scoliosis and a control group of 268 children. The authors describe the most important exercises and provide a statistical analysis of treatment outcome in children with idiopathic scoliosis. Results and Conclusions. Early detection of the risk of scoliosis and correct therapy through new conservative treatment based on exercises make it possible not only to limit the progression of spinal deformity (61%), but also, in some cases of incipient scoliosis, to reduce the curvature (32%).