Yoshiaki Oda

Background/Objectives: Vertebral body stenting (VBS) and balloon kyphoplasty (BKP) are widely used for the treatment of osteoporotic vertebral fractures (OVFs). However, it remains unclear whether the theoretical biomechanical advantages of VBS translate to superior clinical or radiographic outcomes. This study aimed to compare VBS and BKP with respect to clinical outcomes, radiographic parameters, and complications. Methods: In this multicenter retrospective comparative cohort study, 123 patients with OVF treated with VBS (n = 24) or BKP (n = 99) were analyzed. VBS was indicated for complex fracture patterns, including severe endplate injury, split-type fractures, and absence of interbody sclerosis; other fractures were treated with BKP. Pain outcomes, operative parameters, cement volume and leakage, and radiographic measures of vertebral kyphosis angle (VKA) and local kyphosis angle (LKA) were assessed. For group comparisons, we used independent-samples t tests or Mann–Whitney U tests for continuous variables and chi-squared or Fisher’s exact tests for categorical variables. Results: Baseline demographics and bone mineral density were comparable between groups. Surgical time was longer for VBS (39 ± 6 vs. 35 ± 9 min, p = 0.007). Both procedures produced significant pain reductions (p < 0.001), and postoperative VAS did not differ between VBS and BKP (18 ± 11 vs. 13 ± 12 mm, p = 0.06). Although VKA immediately after surgery was lower for VBS (4.8 ± 4.4° vs. 7.0 ± 4.9°, p = 0.03), the magnitude of correction, VKA, and LKA at final follow-up were comparable. Cement volume was similar (6.4 ± 1.4 vs. 6.7 ± 1.9 mL, p = 0.45), but cement leakage occurred more frequently with VBS (54% vs. 24%, p = 0.005). Rates of adjacent vertebral fracture (13% vs. 26%, p = 0.12) and revision surgery (4% vs. 8%, p = 0.44) were comparable between groups. Conclusions: Despite VBS being reserved for more complex fracture morphologies with split-type fractures and severe endplate defects, while BKP was generally used for uncomplicated OVF cases, VBS provided pain relief and radiographic correction comparable to BKP.

Objective: Major cause of low‐back pain is intervertebral disc degeneration ( IVDD ), with mechanical stress playing a crucial role in its progression. A mechanosensitive ion channel, PIEZO1 , is involved in various musculoskeletal tissues, but its role in the annulus fibrosus ( AF ) remains unclear. This study aimed to elucidate the function of PIEZO1 in AF cells under mechanical stimulation. Methods: Primary rat AF cells were subjected to cyclic tensile strain ( CTS ) at low (2%) and high (12%) strain levels to investigate strain‐dependent effects on osteogenic gene expression. We evaluated the effects of Piezo1 , Piezo2 , and Trpv4 knockdown by RNA interference to identify the upstream mechanotransducer. Furthermore, PIEZO1 was activated using the agonist Yoda1, followed by RNA ‐sequencing analysis and evaluation of its effects on BMP2 ‐induced osteogenesis in rat AF cells. We also examined the effects of Yoda1 in primary human AF cells. Results: Low‐strain CTS significantly suppressed osteogenic marker expression, which was not observed with high strain. Piezo1 knockdown reversed this suppression, whereas Piezo2 and Trpv4 had no effect. Piezo1 activation by Yoda1 produced similar anti‐osteogenic effects in both rat and human AF cells. RNA sequencing revealed the enrichment of ossification and calcineurin signaling pathways in rat cells. Furthermore, Piezo1 activation inhibited BMP2 ‐induced osteogenesis and nuclear translocation of p‐Smad1/5/9. Conclusions: Piezo1 maintains AF cell homeostasis under mechanical stress by suppressing osteogenic changes via calcineurin‐mediated inhibition of BMP signaling, which may represent a novel therapeutic target for IVDD .

Background: Intraoperative neurophysiological monitoring (IONM) has become an invaluable tool for spinal deformity surgery. This study aims to present our experience of using transcranial motor evoked potential (Tc-MEP) as an IONM tool in adolescent idiopathic scoliosis patients undergoing navigation-assisted deformity correction and explore the potential risk factors associated with false-positive and true-positive IONM findings. Methods: A retrospective study was conducted in 103 patients (mean age 16.2 ± 4.0 years) undergoing corrective surgery for spinal deformity. All pediatric spinal deformity correction surgeries at the center were performed by a single senior spine surgeon, utilizing navigation and Tc-MEP to enhance the neurological safety profile. The sensitivity and the specificity of Tc-MEP were calculated. Results: Of the total cases, 87 patients (84.5%) exhibited no IONM signal alert and did not experience any postoperative neurological deficits, representing true negatives. There were no false-negative cases, which gives a negative predictive value of 100%. Significant IONM signal alerts were observed in 16 patients (15.5%), but only two patients (1.9%) experienced a postoperative motor deficit, representing true positives, which yielded a positive predictive value of 12.5%. Conclusions: This study demonstrated the sensitivity and specificity of Tc-MEP to be 100% and 86.3%, respectively, with a false-positive rate of 13.7%. Blood loss was the only factor significantly associated with IONM alerts, while age, gender, surgical duration, and anesthetic modality showed no significant differences.

Study Design: A retrospective multicenter cohort study.Purpose: We sought to determine whether occipitocervical (OC) fusion is followed by more postoperative complications and revision surgery than is atlantoaxial (AA) fusion. We aim to compare postoperative complications and revision surgery associated with OC fusion and AA fusion.Overview of Literature: OC and AA fusion are established techniques for restoring upper cervical stability. However, the outcomes of the two methods have not been compared.Methods: This study included 90 patients who underwent upper spinal fusion surgery for mechanical instability, performed by three surgeons in two hospitals from 2011 to 2023; OC fusion was indicated for irreducible AA subluxation, os odontoideum, and severe upper C1 fracture. Of the patients, 38 (mean age, 58.7 years) underwent OC fusion, and 52 (mean age, 62.8 years) underwent AA fusion. To evaluate surgical outcomes, we documented surgical time, intraoperative blood loss, postoperative complications, and the rate of revision surgery. Radiographs were obtained to identify screw malposition, rod breakage, and nonunion. To compare the outcomes of the two techniques, we used the Mann-Whitney U test for continuous variables and the chi-square or Fisher’s exact test for dichotomous variables.Results: OC fusion took significantly longer (175.4 minutes) than AA fusion (150.7 minutes, p=0.020) and had a higher complication rate (39.5% vs. 11.5%, p <0.0001). The reoperation rate was 23.7% (9/38) after OC fusion and 3.8% (2/52) after AA fusion; the difference was statistically significant (p=0.0073). Average amounts of blood loss were 224 mL during OC fusion and 224 mL during AA fusion; the difference was not significant (p=0.947).Conclusions: Although OC fusion is indispensable for certain conditions, particularly basilar invagination, it entails more risk than dose AA fusion; the choice of technique thus warrants careful consideration.

Charcot spinal arthropathy, a rare refractory progressive disease, is characterized by symptoms such as pain, deformity, and neurological impairment, which can significantly reduce functional ability, quality of life, and life expectancy. We report a case of Charcot spine at the L5/S1 level with long segment ankylosis to the L5 vertebra. We first performed thorough debridement via a posterior approach. We used antibiotic-containing cement as a spacer to fill the dead space, facilitating the second surgery approach. In the second surgery, transdiscal screws, which have a low profile and strong force, were used as anchors, and bulk bone harvested from both iliac bones was grafted to the intervertebral space. The lumbosacral alignment was kyphotic, and the patient could sit and move independently. Disimpaction was impossible, and a stoma had to be created.

Meticulous clinical examination is essential for spinal disorders to utilize the diagnostic methods and technologies that strongly support physicians and enhance clinical practice. A significant change in the approach to diagnosing spinal disorders has occurred in the last three decades, which has enhanced a more nuanced understanding of spine pathology. Traditional radiographic methods such as conventional and functional X-rays and CT scans are still the first line in the diagnosis of spinal disorders due to their low cost and accessibility. As more advanced imaging technologies become increasingly available worldwide, there is a constantly increasing trend in MRI scans for detecting spinal pathologies and making treatment decisions. Not only do MRI scans have superior diagnostic capabilities, but they also assist surgeons in performing meticulous preoperative planning, making them currently the most widely used diagnostic tool for spinal disorders. Positron Emission Tomography (PET) can help detect inflammatory lesions, infections, and tumors. Other advanced diagnostic tools such as CT/MRI fusion image, Functional Magnetic Resonance Imaging (fMRI), Upright and Kinetic MRI, magnetic resonance spectroscopy (MRS), diffusion-weighted imaging (DWI), and diffusion tensor imaging (DTI) could play an important role when it comes to detecting more special pathologies. However, some technical difficulties in the daily praxis and their high costs act as obstacles to their further spread. Integrating artificial intelligence and advancements in data analytics and virtual reality promises to enhance spinal procedures’ precision, safety, and efficacy. As these technologies continue to develop, they will play a critical role in transforming spinal surgery. This paradigm shift emphasizes the importance of continuous innovation and adaptability in improving the diagnosis and treatment of spinal disorders.

Objective: Postoperative lymphopenia is reported as an excellent indicator to predict surgical-site infection (SSI) after spine surgery. However, there is still controversy concerning which serological markers can predict spinal SSI. This study aims to evaluate excellent and early indicators for detecting SSI, focusing on spine instrumented surgery. Materials and Methods: This study included 268 patients who underwent spinal instrumented surgery from January 2022 to December 2023 (159 female and 109 male, average 62.9 years). The SSI group included 20 patients, and the non-SSI group comprised 248 patients. Surgical time, intraoperative blood loss, and glycemic levels were measured in both groups. The complete blood cell counts, differential counts, albumin, and C-reactive protein (CRP) levels were measured pre-surgery and postoperative on Days 1, 3, and 7. In comparing the groups, the Mann–Whitney U test analysis was used for continuous variables, while the chi-squared test and Fisher’s exact test were used for dichotomous variables. Results: The incidence of SSI after spinal instrumentation was 7.46% and was relatively higher in scoliosis surgery. The SSI group had significantly longer surgical times (248 min vs. 180 min, p = 0.0004) and a higher intraoperative blood loss (772 mL vs. 372 mL, p < 0.0001) than the non-SSI group. In the SSI group, the Day 3 (10.5 ± 6.2% vs. 13.8 ± 6.0%, p = 0.012) and Day 7 (14.4 ± 4.8% vs. 18.8 ± 7.1%, p = 0.012) lymphocyte ratios were lower than the non-SSI group. Albumin levels on Day 1 in the SSI group were lower than in the non-SSI group (2.94 ± 0.30 mg/dL vs. 3.09 ± 0.38 mg/dL, p = 0.045). There is no difference in CRP and lymphocyte count between the two groups. Conclusions: SSI patients had lower lymphocyte percentages than non-SSI patients, which was a risk factor for SSI, with constant high inflammation. The Day 3 lymphocyte percentage may predict SSI after spinal instrumented surgery.

Insomnia can coexist with chronic pain and is a major cause of rapidly increasing medical expenses. However, insomnia has not been fully evaluated in patients with chronic pain. This retrospective study aimed to identify the risk factors for insomnia in patients with chronic non-cancer pain. A total of 301 patients with chronic non-cancer pain were enrolled. Patients with the Athens insomnia scale scores ≥ 6 and < 6 were classified into insomnia (+) and insomnia (−) groups, respectively. All patients completed self-report questionnaires as part of their chronic pain treatment approach. Univariate and multivariate analyses were performed to predict insomnia. We found that 219 of 301 (72.8%) patients met the AIS criteria for insomnia. Significant differences were depicted between patients with and without insomnia in terms of body mass index, numeric rating scale, pain catastrophizing scale, hospital anxiety, and depression scale (HADS), pain disability assessment scale, EuroQol 5 dimension (EQ5D), and pain self-efficacy questionnaire. Multiple regression analysis identified the numeric rating scale, HADS, and EQ5D scores as factors related to insomnia in patients with chronic non-cancer pain. Anxiety, depression, and disability were associated with a greater tendency toward insomnia. HADS and EQ5D scores are useful screening tools for preventing insomnia in patients with chronic non-cancer pain.

Objectives and Background: To present a novel technique of treatment for a patient with basilar invagination. Basilar invagination (BI) is a congenital condition that can compress the cervicomedullary junction, leading to neurological deficits. Severe cases require surgical intervention, but there is debate over the choice of approach. The anterior approach allows direct decompression but carries high complication rates, while the posterior approach provides indirect decompression and offers good stability with fewer complications. Materials and Methods: A 15-year-old boy with severe myelopathy presented to our hospital with neck pain, bilateral upper limb muscle weakness, and hand numbness persisting for 4 years. Additionally, he experienced increased numbness and gait disturbance three months before his visit. On examination, he exhibited hyperreflexia in both upper and lower limbs, muscle weakness in the bilateral upper limbs (MMT 4), bilateral hypoesthesia below the elbow and in both legs, mild urinary and bowel incontinence, and a spastic gait. Radiographs revealed severe basilar invagination (BI). Preoperative images showed severe BI and that the spinal cord was severely compressed with odontoid process. Results: The patient underwent posterior surgery with the C-arm free technique. All screws including occipital screws were inserted into the adequate position under navigation guidance. Reduction was achieved with skull rotation and distraction. A follow-up at one year showed the following results: Manual muscle testing results and sensory function tests showed almost full recovery, with bilateral arm recovery (MMT 5) and smooth walking. The cervical Japanese Orthopedic Association score of the patient improved from 9/17 to 16/17. Postoperative images showed excellent spinal cord decompression, and no major or severe complications had occurred. Conclusions: Basilar invagination alongside Klippel–Feil syndrome represents a relatively uncommon condition. Utilizing a posterior approach for treating reducible BI with a C-arm-free technique proved to be a safe method in addressing severe myelopathy. This novel navigation technique yields excellent outcomes for patients with BI.

Study design: Technical note. Objectives: To present a novel technique of treatment for patient with basilar invagination. Background : Basilar invagination (BI) is considered a congenital condition and can compress the cervicomedullary junction, causing neurologic deficit. Severe neurological deficit due to BI should be treated surgically. However, there is controversy regarding whether an anterior or posterior approach should be used. Anterior approach is optimal for decompression of cervicomedullary junction, but this approach has high complication rates. Posterior reduction has a high risk of occipital screws backout and/or instrument failure. Materials and Methods : A 15-year-old boy with severe myelopathy was referred to our hospital. He had neck pain, muscle weakness of bilateral upper limbs, gait disturbance appeared 3 months before he visited our hospital, he drops a cup several times recently. In the examination, he had hyperreflexia of upper and lower limbs and muscle weakness of bilateral arms (MMT 4), hypoesthesis was observed bilaterally below elbow and both legs. He also had clumsiness of bilateral hands, mild urinary and bowel incontinence, and spastic gait. His 10 second grip and release test was 16 in both hands. His grip power was 20 kg in right and 17 kg in left. Radiograms showed severe BI and spinal cord was severely compressed with odontoid process.. Results : The patinet underwent posterior surgery with C-arm free technique. All screws including occipital screws were inserted adequate position under navigation guidance. Reduction was achieved with skull rotation and distraction. A follow-up at one year we have these results : Manual muscle testing results and sensory function tests showed almost full recovery, bilateral arms (MMT 5) ,walking smoothly. Cervical Japanese orthopedic association score of the patient has improved from 9/17 to 16/17. Post-operative images showed an excellent spinal cord decompression, and no major or severe complications has occured . Conclusions/Level of Evidence : Basilar invagination with Klippel-Feil syndrome is relatively rare condition. Posterior approach and occipito-cervical fixation for BI treatment with navigation technique is a safe method to treat severe myelopaty with reducible odontoid. This novel navigation technique provides an excellent results for a patient with BI. Level V.