Computer-assisted Minimally Invasive Posterior Lumbar Interbody Fusion without C-arm Fluoroscopy

Computer-assisted spinal surgery is becoming more common; however, this is the first technical report to describe the technique of minimally invasive spinal posterior lumbar interbody fusion (MIS-PLIF) without using C-arm fluoroscopy. The authors report 2 years of follow-up of a 49-year-old female patient with L4 degenerative spondylolisthesis. The patient suffered from low back pain and intermittent claudication for more than 6 years. The authors performed computer-assisted MIS-PLIF without C-arm fluoroscopy. Instead, O-arm® navigation, the use of which reduces radiation exposure to patients as well as others in the operating room, was employed. Surgery was successful, and correct lumbar alignment was maintained. She had neither neurological deficits nor low back pain at her 12-month final follow-up. In conclusion, computer-assisted MIS-PLIF without C-arm fluoroscopy is a useful technique that reduces radiation exposure to the surgeon and operating room staff

A Rare Course of Scoliosis Associated with Chiari Malformation and Syringomyelia

Spinal deformity is an important clinical manifestation of Chiari I malformation (CM-I) and syringomyelia. Here we report the result of an 8-year follow-up of a 13-year-old girl with severe scoliosis associated with Chiari malformation and a large syringomyelia. The patient presented at our hospital at the age of 13 with a 68° scoliosis. Magnetic resonance imaging showed Chiari malformation and a large syringomyelia. Neurosurgical treatment involved foramen magnum decompression and partial C1 laminectomy, but the scoliosis still progressed. We present the first case report of a rare course of scoliosis in a patient with CM-I and a large syringomyelia

Chiari Type I Malformation Caused by Craniometaphyseal Dysplasia

Craniometaphyseal dysplasia is a rare genetic condition characterized by progressive thickening of bones in the skull and metaphyseal abnormalities in the long bones. This disorder often causes progressively symptomatic cranial nerve compression, but in rare cases foramen magnum stenosis may lead to quadriplegia. Chiari I malformation with craniometaphyseal dysplasia is extremely rare. The authors report on a 25-year-old woman with myelopathy due to Chiari I malformation along with craniometaphyseal dysplasia. There are only four previous case reports of this condition. The authors present here the fifth case report of this rare condition and summarize its characteristics

Biomechanical Comparison of Posterior Fixation Using Spinal Instrumentation and Conventional Posterior Plate Fixation in Unstable Vertical Sacral Fracture

Vertical sacral fracture is one of the most difficult fractures to treat. Posterior fixation using spinal dual rods is a novel method for treating this fracture, but its biomechanical strength has not yet been reported. The aim of this study was to evaluate the biomechanical strength produced by posterior fixation using spinal instrumentation. Sacral fractures were created in eight pelvic bone models and classified into a posterior plate fixation group [P group, n＝4] and a spinal instrumentation group [R group, n＝4]. The biomechanical strength was tested by pushing down on the S1 vertebra from the top. The mean maximum loads were 1,057.4 N and 1,489.4 N in the P and R groups, respectively (p＝0.014). The loads applied to the construct at displacements of 5mm and 7.5mm from the start of the universal testing machine loading were also significantly higher in the R group. The mean stiffness levels in the P and R groups were 88.3N/mm and 119.6N/mm, respectively (p＝0.014). Posterior fixation using spinal instrumentation is biomechanically stronger than conventional posterior plate fixation. This procedure may be the optimal method for treating unstable sacral fracture fixation

Transtubular Endoscopic Posterolateral Decompression of the L5 Root under Navigation and O-arm: A Technical Note

Among studies evaluating minimally invasive surgical (MIS) decompression of the L5 root, techniques involving transtubular endoscopic decompression under O-arm navigation are rare. We present the case of a 68-yearold woman with left leg pain, muscle weakness and gait disturbance of one month duration. The patient underwent transtubular endoscopic decompression under O-arm navigation. There is no radiation hazard to the operating room staff with this procedure. After surgery, the patient had significant pain relief and her left lower limb motor function had improved by follow-up at one year. C-arm-free endoscopic L5 root decompression is a safe and effective procedure

Comparative Study of Bilateral Dual Sacral-Alar-Iliac Screws versus Bilateral Single Sacral-Alar-Iliac Screw for Adult Spine Deformities

Objective To evaluate the feasibility of O-arm navigation of bilateral dual sacral-alar-iliac (SAI) screws compared with conventional bilateral single SAI and S1 pedicle screws for pelvic anchors in cases of adult spinal deformity. Methods This retrospective, comparative study included 39 patients who underwent corrective fusion using SAI screws from T10 to the pelvis. Patients were divided into 2 groups according to the number of SAI screws placed during adult spinal deformity surgery: single SAI screw (group S, 17 cases) and dual SAI screws (group D, 22 cases). The incidence of rod breakage, proximal junctional kyphosis, screw loosening, reoperation, and global alignment in each group was estimated. Postoperative patient-reported outcomes were measured using the Oswestry Disability Index, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire, and visual analog scale. Results The incidence of SAI screw loosening was significantly lower in group D than in group S (23% vs. 65%, P = 0.011). The rod breakage incidence was 0% and 12% in groups D and S, respectively (P = 0.17). There were no significant differences in the postoperative global alignment and clinical outcomes between the 2 groups. Conclusions Dual SAI screws were associated with a significantly reduced incidence of screw loosening compared with single SAI screws. The bilateral dual SAI screws technique for pelvic anchors is feasible for the treatment of patients with adult spinal deformity

Is Proximal Triangular Fixation Better than the Conventional Method in Adult Spinal Deformity Surgery?

In adult spinal deformity (ASD) surgery, one of the key factors working to prevent proximal junctional kyphosis is the proximal anchor. The aim of this study was to compare clinical and radiographic outcomes of triangular fixation with conventional fixation as proximal anchoring techniques in ASD surgery. We retrospectively evaluated 54 patients who underwent corrective spinal fusion for ASD. Fourteen patients underwent proximal triangular fixation (Group T; average 74.6 years), and 40 patients underwent the conventional method (Group C; average 70.5 years). Clinical and radiographic outcomes were assessed using visual analogue scale (VAS) values for back pain and the Oswestry disability index (ODI). Radiographic evaluation was also collected preoperatively and postoperatively. Surgical times and intraoperative blood loss of the two groups were not significantly different (493 vs 490 min, 1,260 vs 1,173 mL). Clinical outcomes such as VAS and ODI were comparable in the two groups. Proximal junctional kyphosis in group T was slightly lower than that of group C (28.5% vs 47.5%, p=0.491). However, based on radiology, proximal screw pullout occurred significantly less frequently in the triangular fixation group than the conventional group (0.0% vs 22.5%, p=0.049). Clinical outcomes in the two groups were not significantly different

Impact of Rotation Correction after Brace Treatment on Prognosis in Adolescent Idiopathic Scoliosis

Study DesignLevel 4 retrospective review.PurposeBrace treatment is the standard nonoperative treatment for adolescent idiopathic scoliosis (AIS). Rotation correction is also important, because AIS involves a rotation deformity. The purpose of this study was to evaluate the impact of rotation correction after Osaka Medical College (OMC) brace treatment on clinical outcomes in AIS.Overview of LiteratureBrace treatment has a significant effect on the progression of AIS. However, few reports have examined rotation correction after brace treatment.MethodsA total of 46 patients who wore the OMC brace were retrospectively reviewed. The curve magnitude was determined according to the Cobb method, and the rotation angle of the apical vertebrae was measured by the modified Nash-Moe method. Based on the difference in the rotation angle before and after the initial brace treatment, patients were divided into two groups. Group A (n=33) was defined as no change or improvement of the rotation angle; group B (n=13) was defined as deterioration of the rotation angle. If the patients had curve or rotation progression of 5° or more at skeletal maturity, or had undergone surgery, the treatment was considered a failure.ResultsDifferences of rotation angle between before and after the initial brace treatment were 2°±2° in group A and –3°±2° in group B (p<0.001). The rates of treatment failure were 42% in group A and 77% in group B (p<0.05). This study included 25 patients with Lenke type 1 (54%). Group A (24%) with Lenke type 1 also had a significantly better success rate of brace treatment than group B (75%) (p<0.05).ConclusionsInsufficient rotation correction increased brace treatment failure. Better rotation correction resulted in a higher success rate of brace treatment in patients with Lenke type 1

Posterolateral Floating Technique for the Thoracic Ossification of the Posterior Longitudinal Ligament with Navigation: A Technical Note

We describe a floating technique via a posterolateral approach with intraoperative O-arm navigation to facilitate decompression of the spinal cord in thoracic myelopathy due to severe ossification of the posterior longitudinal ligament (OPLL). A 62-year-old man with myelopathy due to thoracic OPLL had left-leg muscle weakness, urinary disturbance, and spastic gait. Bilateral leg pain and gait disturbance had persisted for 2 years. He was successfully treated by the posterolateral OPLL floating procedure and posterior pedicle fixation under O-arm navigation. At a 2-year follow-up, manual muscle testing results and sensory function of the left leg had recovered fully. His cervical Japanese Orthopedic Association score had improved from 5/12 to 11/12. The novel intraoperative O-arm navigation-guided posterolateral floating procedure for thoracic OPLL is effective for achieving precise decompression and strong fixation with a posterior approach only and can provide an excellent result for severe thoracic OPLL without the risk of adverse events from intraoperative radiation