Okayama University Medical School Acta Medica Okayama 0386-300X 79 1 2025 Could the Trabecular Bone Score Be a Complementary Tool for Evaluating Degenerative Lumbar Vertebrae? 39 45 EN Shinichiro Takao Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Koji Uotani Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Haruo Misawa Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomoko Tetsunaga Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kensuke Shinohara Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kentaro Yamane Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshiaki Oda Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hironori Tsuji Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yuya Kajiki Department of Orthopaedic Surgery, 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/68360 Evaluating vertebral bone mass and quality in the elderly poses challenges due to degenerative changes. This study aims to elucidate the usefulness of the trabecular bone score (TBS) by examining the relationship between bone mineral density (BMD), TBS, and Hounsfield unit (HU) values. A retrospective analysis of 599 vertebrae from 152 patients (mean age 69.0 years; range 44-89; 74 males and 78 females) undergoing dual-energy X-ray absorptiometry (DXA) and CT scans was conducted. Vertebrae were categorized into three grades based on the degree of degeneration. The TBS was calculated from DXA images, and the HU value was measured by placing a region of interest on an axial image of the vertebral mid-body. One-way analysis of variance and Pearson’s correlation tests were employed to investigate the relationship between BMD and TBS or HU values. While lumbar BMD significantly increased (p<0.01) with degenerative changes, TBS and HU values showed no significant differences. The correlations between lumbar BMD and TBS values, and between BMD and HU values, were stronger without degenerative changes than with degenerative changes. Significantly different HU values were observed between the right and left sides of severely degenerated vertebrae. Severe degenerative changes, particularly those associated with sclerosis, may impact HU values. TBS exhibits greater potential than HU values as a complementary tool. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 78 5 2024 Factors Affecting Dynamic Postural Control Ability in Adolescent Idiopathic Scoliosis 357 362 EN Ryoko Yamawaki Division of Physical Medicine and Rehabilitation, Okayama University Yoshiaki Oda Department of Orthopaedic Surgery, Science of Functional Recovery and Reconstruction, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Shuhei Yamane Division of Physical Medicine and Rehabilitation, Okayama University Koji Uotani Department of Orthopaedic Surgery, Okayama University Haruo Misawa Ryusoh Orthopaedic Hospital Yoshimi Katayama Division of Physical Medicine and Rehabilitation, Okayama University Masanori Hamada Division of Physical Medicine and Rehabilitation, Okayama University Toshifumi Ozaki Division of Physical Medicine and Rehabilitation, Okayama University Original Article 10.18926/AMO/67655 Research on postural control in patients with adolescent idiopathic scoliosis (AIS) has focused on static postural control, with few studies assessing dynamic postural control. We aimed to identify factors affecting index of postural stability (IPS), a dynamic postural control parameter, in patients with AIS. The participants comprised 50 female patients with AIS. We measured the IPS using stabilometry to evaluate dynamic postural control ability. We investigated age of the participants, major curve position (thoracic or thoracolumbar/lumbar), Cobb angle, and coronal balance. We then assessed the relationships between stabilometry parameters and other variables. IPS was analyzed with a linear regression model. Coronal balance, major curve position, and age each correlated with dynamic postural control ability. The Cobb angle showed no correlation with any of the parameters. Our results offer new insights into the assessment of postural control in patients with AIS. No potential conflict of interest relevant to this article was reported.

Lippincott Williams & Wilkins Acta Medica Okayama 0025-7974 101 39 2022 Factors influencing caregiver burden in chronic pain patients: A retrospective study e30802 EN Hironori Tsuji Department of Orthopedic Surgery, Okayama Red Cross Hospital Tomoko Tetsunaga Department of Orthopedic Surgery, Okayama University Hospital Tomonori Tetsunaga Department of Orthopedic Surgery, Okayama University Hospital Haruo Misawa Department of Orthopedic Surgery, Okayama University Hospital Yoshiaki Oda Department of Orthopedic Surgery, Okayama University Hospital Shinichiro Takao Department of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Keiichiro Nishida Department of Orthopedic Surgery, Okayama University Hospital Toshifumi Ozaki Department of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Chronic pain coexists with disability, anxiety, depression, and sleep disturbances, which are factors of pain chronicity in the fear-avoidance model. Self-efficacy for managing pain plays a protective role against pain chronicity. For chronic pain sufferers, social support from caregivers is important. However, such caregivers face enormous physical and mental burdens. This study aimed to assess how self-efficacy and factors related to the fear-avoidance model affect caregiver burden. Participants were 135 chronic pain patients and their caregivers who visited our outpatient pain special clinic. In clinical assessments, numeric rating scale (NRS), pain catastrophizing scale (PCS), hospital anxiety and depression scale (HADS), Athens insomnia scale (AIS), pain disability assessment scale (PDAS), pain self-efficacy questionnaire (PSEQ) for the patients and Zarit Burden Interview (ZBI) for their caregivers were evaluated. Participants were divided into 2 groups (L group ZBI < 24 points and H group ZBI >= 24 points) and compared. Regression analyses were conducted to identify factors correlated with the ZBI scores. Compared to L group, H group showed significantly higher NRS and HADs depression scores, and lower PSEQ scores. In univariate regression analysis, ZBI scores were significantly correlated with NRS, PCS, HADS anxiety, HADS depression, PDAS and PSEQ. Multiple linear regression analysis revealed that ZBI scores were significantly correlated with PSEQ. The caregivers who perceived high caregiver burden had significantly higher patients' pain intensity, depression, and lower self-efficacy than those who perceived low caregiver burden. Caregiver burden correlated with the pain intensity, pain catastrophizing, anxiety, depression, disability, and self-efficacy of chronic pain patients. Among these factors, self-efficacy was the most negatively correlated with caregiver burden. Treatments focused on increasing self-efficacy for managing pain have the potential to reduce caregiver burden. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1010-660X 58 5 2022 Mechanical Study of Various Pedicle Screw Systems including Percutaneous Pedicle Screw in Trauma Treatment 565 EN Yoshiaki Oda Department of Orthopaedic Surgery, Okayama University Hospital Tomoyuki Takigawa Department of Orthopaedic Surgery, Kobe Red Cross Hospital Yasuo Ito Department of Orthopaedic Surgery, Kobe Red Cross Hospital Haruo Misawa Department of Orthopaedic Surgery, Okayama University Hospital Tomoko Tetsunaga Department of Orthopaedic Surgery, Okayama University Hospital Koji Uotani Department of Orthopaedic Surgery, Okayama University Hospital Toshifumi Ozaki Department of Orthopaedic Surgery, Dentistry, and Pharmaceutical Sciences, Graduate School of Medicine, Okayama University Background and Objectives: Spine surgery using a percutaneous pedicle screw placement (PPSP) is widely implemented for spinal trauma. However, percutaneous systems have been reported to have weak screw-rod connections. In this study, conventional open and percutaneous systems were biomechanically evaluated and compared. Material and Methods: The experiments were performed in two stages: the first stage was a break test, whereas the second stage was a fatigue test. Four systems were used for the experiments. System 1 was intended for conventional open surgery (titanium rod with a 6.0 mm diameter, using a clamp connecting mechanism). System 2 was a percutaneous pedicle screw (PPS) system for trauma (titanium alloy rod with a 6.0 mm diameter, using ball ring connections). System 3 was a PPS system for trauma (cobalt-chromium alloy rod with a 6.0 mm diameter, using sagittal adjusting screw connections). System 4 was a general-purpose PPS system (titanium alloy rod with a 5.5 mm diameter, using a mechanism where the adapter in the head holds down the screw). Results: Stiffness values of 54.8 N/mm, 43.1 N/mm, 90.9 N/mm, and 39.3 N/mm were reported for systems 1, 2, 3, and 4, respectively. The average number of load cycles in the fatigue test was 134,393, 40,980, 1,550,389, and 147,724 for systems 1 to 4, respectively. At the end of the test, the displacements were 0.2 mm, 16.9 mm, 1.2 mm, and 8.6 mm, respectively. System 1, with a locking mechanism, showed the least displacement at the end of the test. Conclusion: A few PPS systems showed better results in terms on stiffness and life than the open system. The experiments showed that mechanical strength varies depending on the spinal implant. The experiments conducted are essential and significant to provide the mechanical strength required for surgical reconstruction. No potential conflict of interest relevant to this article was reported.

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.

Elsevier Inc. Acta Medica Okayama 18788750 156 2021 Comparative Study of Bilateral Dual Sacral-Alar-Iliac Screws versus Bilateral Single Sacral-Alar-Iliac Screw for Adult Spine Deformities e300 e306 EN Koji Uotani Department of Orthopaedic surgery, Okayama Rosai Hospital Masato Tanaka Department of Orthopaedic surgery, Okayama Rosai Hospital Sumeet Sonawane Department of Orthopaedic surgery, Okayama Rosai Hospital Sameer Ruparel Department of Orthopaedic surgery, Okayama Rosai Hospital Yoshihiro Fujiwara Department of Orthopaedic surgery, Okayama Rosai Hospital Shinya Arataki Department of Orthopaedic surgery, Okayama Rosai Hospital Taro Yamauchi Department of Orthopaedic surgery, Okayama Rosai Hospital Haruo Misawa Department of Orthopaedic surgery, Okayama University Hospital 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. No potential conflict of interest relevant to this article was reported.

Nature Research Acta Medica Okayama 2045-2322 11 1 2021 Quantification of patellar tendon reflex using portable mechanomyography and electromyography devices 2284 EN Hironori Tsuji Department of Orthopaedic Surgery, Dentistry, and Pharmaceutical Sciences, Okayama University Graduate School of Medicine Haruo Misawa Department of Orthopaedic Surgery, Okayama University Hospital Tomoyuki Takigawa Department of Orthopaedic Surgery, Kobe Red Cross Hospital Tomoko Tetsunaga Department of Orthopaedic Surgery, Okayama University Hospital Kentaro Yamane Department of Orthopaedic Surgery, Okayama University Hospital Yoshiaki Oda Department of Orthopaedic Surgery, Okayama University Hospital Toshifumi Ozaki Department of Orthopaedic Surgery, Dentistry, and Pharmaceutical Sciences, Okayama University Graduate School of Medicine Deep tendon reflexes are one of the main components of the clinical nervous system examinations. These assessments are inexpensive and quick. However, evaluation can be subjective and qualitative. This study aimed to objectively evaluate hyperreflexia of the patellar tendon reflex using portable mechanomyography (MMG) and electromyography (EMG) devices. This study included 10 preoperative patients (20 legs) who had a pathology that could cause bilateral patellar tendon hyperreflexia and 12 healthy volunteers (24 legs) with no prior history of neurological disorders. We attached MMG/EMG sensors onto the quadriceps and tapped the patellar tendon with maximal and constant force. Our results showed a significantly high amplitude of the root mean square (RMS) and low frequency of the mean power frequency (MPF) in the rectus femoris, vastus medialis, and vastus lateralis muscles in both EMG and MMG with both maximal and constant force. Especially in the patients with cervical and thoracic myelopathy, the receiver operating characteristic (ROC) curve for diagnosing hyperreflexia of the patellar tendon showed a moderate to very high area under the curve for all EMG-RMS, EMG-MPF, MMG-RMS, and MMG-MPF values. The use of EMG and MMG for objectively quantifying the patellar tendon reflex is simple and desirable for future clinical applications and could help diagnose neurological disorders. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 75 2 2021 Maximal Resection of Intramedullary Lipoma Using Intraoperative Ultrasonography: A Technical Note 239 242 EN Haruo Misawa Department of Orthopaedic Surgery, Okayama University Hospital Yoshiaki Oda Department of Orthopaedic Surgery, Okayama University Hospital Kentaro Yamane Department of Orthopaedic Surgery, Okayama University Hospital Tomoko Tetsunaga Department of Orthopaedic Surgery, Okayama University Hospital Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Hospital Case Report 10.18926/AMO/61907 One of the problems during surgery for intramedullary lipoma is the ambiguous boundary between the lipoma and the spinal cord, resulting in either incomplete resection or damage to the spinal cord. We report a case of intramedullary lipoma resection on a 61-year-old man in which the boundary between the tumor and spinal cord was repeatedly visualized with intraoperative ultrasonography. We focused on the distinctive features of fat as hyperechoic, in contrast to low-echo neural tissue. Subtotal resection of the tumor was achieved without any aggravation of neurological symptoms. Intraoperative ultrasonography may be useful for confirming tumor boundaries during intramedullary lipoma resection. No potential conflict of interest relevant to this article was reported.

Springer Acta Medica Okayama 1749-799X 15 1 2020 Short-term outcomes of mirogabalin in patients with peripheral neuropathic pain: a retrospective study 191 EN Tomoko Tetsunaga Department of Orthopedic Surgery, Okayama University Hospital Tomonori Tetsunaga Department of Orthopedic Surgery, Okayama University Hospital Keiichiro Nishida Department of Orthopedic Surgery, Okayama University Hospital Haruo Misawa Department of Orthopedic Surgery, Okayama University Hospital Tomoyuki Takigawa Department of Orthopedic Surgery, Okayama University Hospital Kentaro Yamane Department of Orthopedic Surgery, Okayama University Hospital Hironori Tsuji Department of Orthopedic Surgery, Okayama University Hospital Yoshitaka Takei Department of Orthopedic Surgery, Kurashiki Municipal Hospital Toshifumi Ozaki Department of Orthopedic Surgery, Okayama University Hospital Background Mirogabalin, which is approved for the treatment of peripheral neuropathic pain in Japan, is a ligand for the α2δ subunit of voltage-gated calcium channels. Both pregabalin and mirogabalin act as nonselective ligands at the α2δ-1 and α2δ-2 subunits. Mirogabalin has a unique binding profile and long duration of action. Pregabalin has been reported to produce intolerable adverse effects in some patients. This study investigated outcomes associated with mirogabalin administration in patients with peripheral neuropathic pain who ceased treatment with pregabalin. Methods We retrospectively assessed peripheral neuropathic pain using the neuropathic pain screening questionnaire (NeP score) in 187 patients (58 men, 129 women) who were treated with mirogabalin. All patients had switched from pregabalin to mirogabalin due to lack of efficacy or adverse events. Differences in the treatment course (i.e., numeric rating scale (NRS) scores) were compared using one-way analysis of variance with Bonferroni post hoc tests. Results The mean age of the patients was 72.3 years (range, 30–94 years), and the mean duration of disease was 37 months (range, 3–252 months). After treatment with mirogabalin for 1 week, NRS scores significantly decreased compared with baseline and continued to decrease over time. After 8 weeks, NRS scores improved by ≥ 30% from baseline in 113 patients (69.3%). Twenty-four patients (12.8%) stopped mirogabalin treatment due to adverse events. Somnolence (26.7%), dizziness (12.3%), edema (5.9%), and weight gain (0.5%) were noted as adverse events of mirogabalin. Conclusions The results of this investigation indicate that mirogabalin is safe and effective for reducing peripheral neuropathic pain. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1422-0067 20 23 2019 Multipotent Neurotrophic Effects of Hepatocyte Growth Factor in Spinal Cord Injury 6078 EN Kentaro Yamane Department of Intelligent Orthopaedic System Development, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Haruo Misawa 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 Yoshihiro Ito Nano Medical Engineering Laboratory, RIKEN Toshifumi Ozaki Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Akihiro Matsukawa Department of Pathology and Experimental Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Spinal cord injury (SCI) results in neural tissue loss and so far untreatable functional impairment. In addition, at the initial injury site, inflammation induces secondary damage, and glial scar formation occurs to limit inflammation-mediated tissue damage. Consequently, it obstructs neural regeneration. Many studies have been conducted in the field of SCI; however, no satisfactory treatment has been established to date. Hepatocyte growth factor (HGF) is one of the neurotrophic growth factors and has been listed as a candidate medicine for SCI treatment. The highlighted effects of HGF on neural regeneration are associated with its anti-inflammatory and anti-fibrotic activities. Moreover, HGF exerts positive effects on transplanted stem cell differentiation into neurons. This paper reviews the mechanisms underlying the therapeutic effects of HGF in SCI recovery, and introduces recent advances in the clinical applications of HGF therapy. No potential conflict of interest relevant to this article was reported.