MDPI Acta Medica Okayama 1010-660X 58 5 2022 Long-Term Results of Posterior Vertebral Column Resection for Severe Thoracolumbar Kyphosis with Achondroplastic Patients: A Case Series 605 EN Masato Tanaka Department of Orthopaedic Surgery, Okayama University Hospital Tsang-Tung Chan Department of Orthopaedic Surgery, Okayama University Hospital Haruo Misawa Department of Orthopaedic Surgery, Okayama University Hospital Koji Uotani Department of Orthopaedic Surgery, Okayama University Hospital Shinaya Arataki Department of Orthopaedic Surgery, Okayama University Hospital Tomoyuki Takigawa Department of Orthopaedic Surgery, Okayama University Hospital Tetsuro Mazaki Department of Orthopaedic Surgery, Okayama University Hospital Yoshihisa Sugimoto Department of Orthopaedic Surgery, Okayama University Hospital Background and Objectives: Thoracolumbar kyphosis is one of the most frequent skeletal manifestations in patients with achondroplasia. Few papers have been published on the surgical treatment of this condition, especially in skeletally mature patients. With this study, we presented a retrospective case series of long-term surgical results for achondroplastic patients with severe thoracolumbar kyphosis. This study was conducted to evaluate the outcome of surgical treatment for thoracolumbar kyphosis in patients associated with achondroplasia presenting with paraparesis. Materials and Methods: Three patients with achondroplasia who developed neurologic deficits due to severe thoracolumbar kyphosis and underwent surgical treatment were evaluated (mean age 22.3 years; mean follow-up 9.3 years). All patients were treated with posterior vertebral column resection (p-VCR) of hypoplastic apical vertebrae with a cage and segmental instrumentation. Neurologic outcomes (JOA scores), correction of kyphosis, and operative complications were assessed. Results: All patients had back pain, neurological deficits, and urinary disturbance before surgery. The average preoperative JOA score was 8.3/11 points, which was improved to 10.7/11 points at the final follow-up (mean recovery rate 83%). All patients obtained neurologic improvement after surgery. The mean preoperative kyphotic angle was 117 degrees (range 103 degrees-126 degrees). The postoperative angles averaged 37 degrees (range 14 degrees-57 degrees), resulting in a mean correction rate of 67%. All patients had postoperative complications such as rod breakage and/or surgical site infection. Conclusions: The long-term results of p-VCR were acceptable for treating thoracolumbar kyphosis in patients with achondroplasia. To perform this p-VCR safely, spinal navigation and neuromonitoring are inevitable when resecting non anatomical fused vertebrae and ensuring correct pedicle screw insertion. However, surgical complications such as rod breakage and surgical site infection may occur at a high rate, making informed consent very important when surgery is indicated. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 71 2 2017 Scoliosis in Patients with Severe Cerebral Palsy: Three Different Courses in Adolescents 119 126 EN Yoshiaki Oda Department of Orthopaedic Surgery, Okayama University Hospital Tomoyuki Takigawa Department of Orthopaedic Surgery, Okayama University Hospital Yoshihisa Sugimoto Department of Orthopaedic Surgery, Okayama University Hospital Masato Tanaka Department of Orthopaedic Surgery, Okayama University Hospital Hirofumi Akazawa Asahikawasou Ryouiku Iryou Center Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital Original Article 10.18926/AMO/54980 Patients with cerebral palsy (CP) frequently present with scoliosis; however, the pattern of curve progression is difficult to predict. We aimed to clarify the natural course of the progression of scoliosis and to identify scoliosis predictors. This was a retrospective, single-center, observational study. Total of 92 CP patients from Asahikawasou Ryouiku Iryou Center in Okayama, Japan were retrospectively analyzed. Cobb angle, presence of hip dislocation and pelvic obliquity, and Gross Motor Function Classification System (GMFCS) were investigated. Severe CP was defined as GMFCS level IV or V. The mean observation period was 10.7 years. Thirtyfour severe CP patients presented with scoliosis and were divided into 3 groups based on their clinical courses: severe, moderate and mild. The mean Cobb angles at the final follow-up were 129°, 53°, and 13° in the severe, moderate, and mild groups, respectively. The average progressions from 18 to 25 years were 2.7°/year, 0.7°/year, and 0.1°/year in the severe, moderate, and mild curve groups, respectively. We observed the natural course of scoliosis and identified 3 courses based on the Cobb angle at 15 and 18 years of age. This method of classification may help clinicians predict the patients’ disease progression. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 70 6 2016 Neurological Recovery after Posterior Spinal Surgery in Patients with Metastatic Epidural Spinal Cord Compression 449 453 EN Noriyuki Watanabe Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshihisa Sugimoto Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masato Tanaka Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tetsuro Mazaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shinya Arataki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomoyuki Takigawa Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masaki Kataoka Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Toshiyuki Kunisada Department of Medical Materials for Musculoskeletal Reconstruction, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Original Article 10.18926/AMO/54807 Metastatic epidural spinal cord compression (MESCC) is a common complication in patients with a malignant tumor, but it is difficult to decide the proper time to perform the necessary surgery. Here we analyzed the prognostic factors for postoperative walking ability. We retrospectively reviewed the cases of 112 MESCC patients treated surgically at our institute and divided them into ambulatory (n＝ 88) and non-ambulatory (n＝24) groups based on their American Spinal Injury Association (ASIA) Impairment Scale grades at the final follow-up. We also classified the patients preoperatively using the revised Tokuhashi score. We assessed the correlation between preoperative or intraoperative factors and postoperative walking ability in both groups. Of the 10 patients classified preoperatively as grade A or B, 2 (20 ) were ambulatory at the final follow-up. Of the 102 patients classified preoperatively as grade C, D or E, 86 (84 ) were ambulatory at the final follow-up (p＜0.001). There were no significant differences between the groups in the average total Tokuhashi score. Our analysis revealed that the severity of paralysis significantly affects neurological recovery in patients with MESCC. Patients with MESCC should receive surgery before the preoperative ASIA Impairment Scale grade falls below grade C. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 68 5 2014 Spinal Metaplastic Meningioma with Osseous Differentiation in the Ventral Thoracic Spinal Canal 313 316 EN Kentaro Yamane Masato Tanaka Yoshihisa Sugimoto Kouichi Ichimura Toshifumi Ozaki Case Report 10.18926/AMO/52901 Ossified meningioma is classified histologically as a phenotype of metaplastic meningioma, and it is extremely rare. There are only 12 cases involving ossified spinal meningiomas in the literature. We present the case of a 61-year-old female with a primary tumor within the ventral spinal canal at T12. Although we performed a total tumor excision using an ultrasonic bone aspirator, a temporary deterioration of motor evoked potentials (MEPs) was observed during curettage with a Kerrison rongeur. The neurologic findings worsened immediately after surgery. Histologically, the tumor was diagnosed as a metaplastic meningioma with osseous differentiation. In order to avoid spinal cord injury, great care must be taken when removing an ossified meningioma located on the ventral spinal cord. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 68 5 2014 A Rare Course of Scoliosis Associated with Chiari Malformation and Syringomyelia 303 306 EN Masato Tanaka Yoshihisa Sugimoto Shinya Arataki Tomoyuki Takigawa Toshifumi Ozaki Case Report 10.18926/AMO/52899 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. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 67 6 2013 Chiari Type I Malformation Caused by Craniometaphyseal Dysplasia 385 389 EN Masato Tanaka Shinya Arataki Yoshihisa Sugimoto Tomoyuki Takigawa Tomoko Tetsunaga Toshifumi Ozaki Case Report 10.18926/AMO/52012 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. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 67 6 2013 Factors Predicting Clinical Impairment after Surgery for Cervical Spinal Schwannoma 343 349 EN Kentaro Yamane Tomoyuki Takigawa Masato Tanaka Syuhei Osaki Yoshihisa Sugimoto Toshifumi Ozaki Original Article 10.18926/AMO/52007 Cervical spinal schwannoma is benign, and outcomes after surgical resection are generally excellent. A surgical dilemma sometimes arises as to whether to perform total tumor removal, which carries a risk of sacrificing the nerve root, or subtotal removal, where the risk can be tumor recurrence. The purpose of this study was to identify factors with the potential to predict clinical impairment after surgery for cervical spinal schwannomas. Thirty cases of cervical schwannomas treated surgically in our institute were retrospectively reviewed;initial symptoms, tumor location, Eden classification, surgical method, functional outcome, and tumor recurrence were investigated. All permanent motor deficits were the result of resecting functionally relevant nerve roots (i.e., C5-8). The rate of permanent sensory deficit was 11% after C1-4 nerve root resection, and 67% after C5-8 nerve root resection. Permanent neurological deficits occurred in 14% of patients younger than 40 years and 38% of those older than 40. Dumbbell tumors were associated with the need for total or ventral nerve root transection, as well as with a high incidence of tumor recurrence. The incidence of permanent neurological deficit was significantly higher in patients undergoing C5-8 nerve root resection, and tended to be higher in those over 40. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 67 2 2013 Management of Lumbar Artery Injury Related to Pedicle Screw Insertion 113 116 EN Yoshihisa Sugimoto Masato Tanaka Hideo Gobara Haruo Misawa Toshiyuki Kunisada Toshifumi Ozaki Case Report 10.18926/AMO/49670 We report on 2 patients who experienced injury to one of their lumbar arteries related to pedicle screw misplacement. In this report, the lumbar pedicle screw holes were made laterally with resultant injury to the lumbar artery. During surgery, arterial bleeding was controlled with pressure and gauze; however, the patients experienced vital shock after surgery. Vital shock ensued and they were rescued by catheter embolization. If patients receiving lumbar instrumentation surgery experience severe anemia or vital shock postoperatively, the surgeon should assume lumbar artery injury as a differential diagnosis. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 66 6 2012 Surgical Treatment for Congenital Kyphosis Correction Using Both Spinal Navigation and a 3-dimensional Model 499 502 EN Yoshihisa Sugimoto Masato Tanaka Ryuichi Nakahara Haruo Misawa Toshiyuki Kunisada Toshifumi Ozaki Case Report 10.18926/AMO/49047 An 11 year-old girl had 66 degrees of kyphosis in the thoracolumbar junction. For the purpose of planning for kyphosis correction, we created a 3-D, full-scale model of the spine and consulted spinal navigation. Three-dimensional models are generally used as tactile guides to verify the surgical approach and portray the anatomic relations specific to a given patient. We performed posterior fusion from Th10 to L3, and vertebral column resection of Th12 and L1. Screw entry points, directions, lengths and diameters were determined by reference to navigation. Both tools were useful in the bone resection. We could easily detect the posterior element to be resected using the 3D model. During the anterior bony resection, navigation helped us to check the disc level and anterior wall of the vertebrae, which were otherwise difficult to detect due to their depth in the surgical field. Thus, the combination of navigation and 3D models helped us to safely perform surgery for a patient with complex spinal deformity. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 66 6 2012 Recovery of Motor Function in Patients with Subaxial Cervical Spine Injury Relevant to the Fracture Pattern 469 473 EN Yasuyuki Shiozaki Yasuo Ito Yoshihisa Sugimoto Masao Tomioka Tetsuya Shimokawa Tetsuro Mazaki Koichiro Koshimune Masato Tanaka Toshifumi Ozaki Original Article 10.18926/AMO/49043 In this study, we studied the relationship between fracture patterns and motor function recovery in 70 consecutive patients with cervical spinal cord injury. Fractures were categorized into 6 fracture types and subdivided into stages according to the Allen-Ferguson classification system:compressive flexion (CF), distractive flexion (DF), compressive extension (CE), distractive extension (DE), vertical compression (VC) and lateral flexion (LF). Paralysis was evaluated using the American Spinal Injury Association (ASIA) impairment scale at the time of injury and 3 months afterwards. The residual rate of complete motor palsy (ASIA grade A or B) at the final examination was higher in those patients with DE fractures than those with CF, DF or CE. The final outcomes were as follows. Of the 14 patients who were classified with CF fractures, residual palsy was frequently seen in patients who had stage 5 injury. Of the 27 patients with DF fractures, residual palsy occurred in about half of the patients who had stage 4 or 5 injury. Of the 18 patients with CE fractures, residual palsy occurred in half of the patients with stage 3 injury or higher. Finally, of the 7 patients with DE fractures, the rate of residual palsy was high even for the stage 1 and 2 cases;indeed, all DE patients who had complete motor palsy at the first examination had residual palsy at the final examination. Accordingly, we conclude that motor recovery may be related to fracture pattern. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 66 3 2012 Statistical Analysis of Prognostic Factors for Survival in Patients with Spinal Metastasis 213 219 EN Masaki Kataoka Toshiyuki Kunisada Masato Tanaka Ken Takeda Satoru Itani Yoshihisa Sugimoto Haruo Misawa Masuo Senda Shinnosuke Nakahara Toshifumi Ozaki Original Article 10.18926/AMO/48560 There are a variety of treatment options for patients with spinal metastasis, and predicting prognosis is essential for selecting the proper treatment. The purpose of the present study was to identify the significant prognostic factors for the survival of patients with spinal metastasis. We retrospectively reviewed 143 patients with spinal metastasis. The median age was 61 years. Eleven factors reported previously were analyzed using the Cox proportional hazards model:gender, age, performance status, neurological deficits, pain, type of primary tumor, metastasis to major organs, previous chemotherapy, disease-free interval before spinal metastasis, multiple spinal metastases, and extra-spinal bone metastasis. The average survival of study patients after the first visit to our clinic was 22 months. Multivariate survival analysis demonstrated that type of primary tumor (hazard ratio [HR]＝6.80, p＜0.001), metastasis to major organs (HR＝2.01, p＝0.005), disease-free interval before spinal metastasis (HR＝1.77, p＝0.028), and extra-spinal bone metastasis (HR＝1.75, p＝0.017) were significant prognostic factors. Type of primary tumor was the most powerful prognostic factor. Other prognostic factors may differ among the types of primary tumor and may also be closely associated with primary disease activity. Further analysis of factors predicting prognosis should be conducted with respect to each type of primary tumor to help accurately predict prognosis. No potential conflict of interest relevant to this article was reported.