Rare case of real-time observation of paralytic deterioration after cervical dislocation in the hyperacute phase.

BACKGROUND: There have been no prior reports of real-time detailed records leading to complete quadriplegia immediately after fracture dislocation in high-energy trauma. Here, we report a case of cervical dislocation in which the deterioration to complete motor paralysis (modified Frankel B1) and complete recovery (Frankel E) could be monitored in real time after reduction in the hyperacute phase. CASE PRESENTATION: A 65-year-old man was involved in a car accident and sustained a dislocation at the C5/6 level (Allen-Ferguson classification: distractive flexion injury stage IV). His paralysis gradually deteriorated from Frankel D to C 2 hours after the injury and from Frankl C to B 5 hours after the injury. His final neurological status immediately before reduction was Frankel B1 (complete motor paralysis with sensation only in the perianal region). Reduction was completed within 6 h and 5 min after injury, and spinal fusion was subsequently performed. The patient exhibited rapid motor recovery immediately after surgery, and was able to walk independently on postoperative day 14. CONCLUSIONS: This case suggests that there is a mixture of cases in which the spinal cord has not been catastrophically damaged, even if the patient has complete motor paralysis. Prompt reduction has the potential to improve neurological function in such cases.

Delayed lumbar plexus palsy due to giant psoas hematoma associated with vertebral compression fracture and direct oral anticoagulants: a case report.

BACKGROUND: Osteoporotic vertebral compression fractures (VCFs) are commonly observed in elderly people and can be treated by conservatively with minimal risk of complications in most cases. However, utilization of direct oral anticoagulants (DOACs) increases the risks of secondary hematoma even after insignificant trauma. The use of DOACs increased over the past decade because of their approval and recommendation for both stroke prevention in non-valvular atrial fibrillation and treatment of venous thromboembolism. It is well known that DOACs are safer anticoagulants than warfarin in terms of major and nonmajor bleeding; however, we noted an increase in the number of bleeding events associated with DOACs that required medical intervention. This report describes the first case of delayed lumbar plexus palsy due to DOAC-associated psoas hematoma after VCF to draw attention to potential risk of severe complication associated with this type of common and stable trauma. CASE PRESENTATION: An 83-year-old man presented with his left inguinal pain and inability to ambulate after falling from standing position and was prescribed DOACs for chronic atrial fibrillation. Computed tomography angiography revealed a giant psoas hematoma arising from the ruptured segmental artery running around fractured L4 vertebra. Because of motor weakness of his lower limbs and expansion of psoas hematoma revealed by contrast computed tomography on day 8 of his hospital stay, angiography aimed for transcatheter arterial embolization was tried, but could not demonstrate any major active extravasation; therefore spontaneous hemostasis was expected with heparin replacement. On day 23 of his stay, hematoma turned to decrease, but dysarthria and motor weakness due to left side cerebral infarction occurred. His pain improved and bone healing was achieved about 2 months later from his admission, however the paralysis of the left lower limb and aftereffects of cerebral infarction remained after 1 year. CONCLUSION: In patients using DOACs with multiple risk factors, close attention must be taken in vertebral injury even if the fracture itself is a stable-type such as VCF, because segmental artery injury may cause massive psoas hematoma followed by lumbar plexus palsy and other complications.

Comparison of the Efficacy and Renal Safety of Bisphosphonate Between Low-Dose/High-Frequency and High-Dose/Low-Frequency Regimens in a Late-Stage Chronic Kidney Disease Rat Model.

The efficacy and renal safety of low-dose/high-frequency (LDHF) dosing and high-dose/low-frequency (HDLF) dosing of bisphosphonates (BPs) are comparable in patients with normal kidney function but might be different in patients with late-stage chronic kidney disease (CKD). This study aimed to compare the efficacy and renal safety of two different dosage regimens of a BP, alendronate (ALN), in stage 4 CKD using a rat model. Male, 10-week-old Sprague-Dawley rats were subjected to either 5/6 nephrectomy or sham surgery. The animals received subcutaneous administration of vehicle (daily) or ALN in LDHF dosage regimen (LDHF-ALN: 0.05 mg/kg/day) or HDLF dosage regimen (HDLF-ALN: 0.70 mg/kg/2 weeks). Medications commenced at 20 weeks of age and continued for 10 weeks. Micro-computed tomography, histological analysis, infrared spectroscopic imaging, and serum and urine assays were performed to examine the efficacy and renal safety of the ALN regimens. Both LDHF-ALN and HDLF-ALN increased bone mass, improved micro-structure, and enhanced mechanical properties, without causing further renal impairment in CKD rats. Histologically, however, HDLF-ALN more efficiently suppressed bone turnover, leading to more mineralized trabecular bone, than LDHF-ALN in CKD rats, whereas such differences between LDHF-ALN and HDLF-ALN were not observed in sham rats. Both LDHF-ALN and HDLF-ALN showed therapeutic effects on high bone turnover osteoporosis in CKD stage 4 rats without causing further renal impairment. However, as HDLF-ALN more efficiently suppressed bone turnover than LDHF-ALN in late-stage CKD, HDLF-ALN might be more appropriate than LDHF-ALN for fracture prevention in high bone turnover osteoporosis patients with late-stage CKD.

Incidence and risk of antiresorptive agent-related osteonecrosis of the jaw (ARONJ) after tooth extraction in patients with autoimmune disease.

INTRODUCTION: Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is a rare but serious complication in patients receiving antiresorprtive agents (AR). However, the incidence of ARONJ after tooth extraction in patients with autoimmune disease (AID) remains unclear. The present study aimed to clarify the high-risk population of ARONJ in patients with AID. MATERIALS AND METHODS: The study population comprised 232 patients treated with AR, AID or non-AID, who had undergone dental extraction from January 2011 to September 2017. The incidence and risk factors of ARONJ were analysed retrospectively. Additionally, the relationship between ARONJ and osteoporotic fracture (OF) and AR discontinuation during dental procedures was investigated. RESULTS: Of 232 patients, 10 developed ARONJ within 1 year of dental extraction. The incidence of ARONJ in patients with AID was higher than that in non-AID patients (2.0/100 person-year vs 0.5/100 person-year; p = 0.03). Among the AID patients, RA patients had strikingly high incidence of ARONJ (3.6/100 person-year). The incidence of neither ARONJ nor OF significantly differed between patients who continued and discontinued AR in the perioperative period. CONCLUSION: Patients with AID who undergo dental extraction are at high risk of ARONJ. Discontinuation of AR would not significantly contribute to reduce the incidence of ARONJ in those patients.

Ten years change in post-fracture care for hip fracture patients.

INTRODUCTION: This multicenter, retrospective study aimed to clarify the changes in postoperative care provided by orthopaedic surgeons after hip fractures and clarify the incidence of secondary fractures requiring surgery. MATERIALS AND METHODS: Subjects were patients with hip fracture treated surgically in seven hospitals during the 10-year period from January 2008 to December 2017. Data on patient demographics, comorbidities, preoperative and postoperative osteoporosis treatments, and secondary fractures were collected from the medical records. RESULTS: In total, 4764 new hip fractures in 982 men and 3782 women (mean age: 81.3 ± 10.0 years) were identified. Approximately 10% of patients had a history of osteoporosis drug treatment and 35% of patients received postoperative drug treatment. The proportion of patients receiving postoperative drug therapy increased by approximately 10% between 2009 and 2010, 10% between 2010 and 2011, and 10% between 2011 and 2013. Although the rate of secondary fractures during the entire period and within 3 years decreased from 2011, the rate of secondary fracture within 1 year remained at around 2% every year. CONCLUSIONS: The approval of new osteoporosis drugs and the establishment of osteoporosis liaison services have had a positive effect on the use of postoperative drug therapy in the orthopedic field. Our finding that the rate of secondary fracture within 1 year of the initial fracture remained around 2% every year, despite improvements in postoperative drug therapy, suggests that both rehabilitation for preventing falls and early postoperative drug therapy are essential to prevent secondary fractures.

Potential association with early changes in serum calcium level after starting or switching to denosumab combined with eldecalcitol.

The aims of this study are to investigate changes in serum calcium (Ca) level after switching from either non-therapy, bisphosphonate, selective estrogen receptor modulators (SERM) or teriparatide treatments to a combination therapy of denosumab (DMAb), and eldecalcitol, and the association between early changes in serum calcium and changes in bone metabolic markers and bone mineral density (BMD). 129 patients with postmenopausal osteoporosis (32 non-pretreatment, 50 bisphosphonates, 18 SERM, and 29 teriparatide) were recruited and switched to DMAb plus eldecalcitol. Serum calcium levels, bone metabolism markers, and BMD measurements of the lumbar spine and femoral neck were evaluated. All groups showed an increase in BMD 6 months and 1 year after DMAb administration compared to baseline via suppression of bone metabolism markers. The TPD group showed a significant decrease in serum calcium level 1 week after the first injection of DMAb and eldecalcitol compared to baseline and the bisphosphonate group. Changes in serum calcium level from baseline to 1 week after the first injection of DMAb trended to correlate with changes in bone metabolism markers and lumbar BMD. The risks of DMAb-induced hypocalcemia are different between starting and switching from bone resorption inhibitors and bone formation promoters. Therefore, appropriate assessment before administration of DMAb, including pretreatment therapy as well as serum Ca and bone metabolic markers will help identify the risk of hypocalcemia following DMAb in combination with eldecalcitol. Our findings also showed that early change in serum Ca level after DMAb initiation could potentially predict the efficacy for therapy reaction.

Optimal administration frequency and dose of teriparatide for acceleration of biomechanical healing of long-bone fracture in a mouse model.

Despite preclinical studies demonstrating the effectiveness of teriparatide for skeletal repair in small animals, inconclusive data from clinical trials have raised questions regarding the optimal teriparatide dosing regimen for bone repair. To address this, we assessed the effect of teriparatide frequency and dose on long-bone healing using a mouse femur osteotomy/fracture model. Eight-week-old male ICR mice were subjected to open femur osteotomies, then randomized into following five groups (n = 8 per group): vehicle; low dose/high frequency: 3 µg/kg/dose, 3 times/day; low dose/low frequency: 9 µg/kg/dose, 1 time/day; high dose/high frequency: 9 µg/kg/dose, 3 times/day; high dose/low frequency: 27 µg/kg/dose, 1 time/day. Skeletal repair was assessed by microcomputed tomography, mechanical testing, and histology 4 weeks after surgery. High-dose and/or high-frequency teriparatide treatment increased callus bone volume but failed to have a significant impact on the biomechanical recovery of fractured femurs, possibly because of impaired cortical shell formation in fracture calluses. Meanwhile, low-dose/low-frequency teriparatide therapy enhanced callus bone formation without interfering with cortical shell formation despite a lesser increase in callus bone volume, leading to significant two and fourfold increases in ultimate load and stiffness, respectively. Our findings demonstrate that administering teriparatide at higher doses and/or higher frequencies raises fracture callus volume but does not always accelerate the biomechanical recovery of fractured bone, which points to the importance of finding the optimal teriparatide dosing regimen for accelerating skeletal repair.

Teriparatide Improves Trabecular Osteoporosis but Simultaneously Promotes Ankylosis of the Spine in the Twy Mouse Model for Diffuse Idiopathic Skeletal Hyperostosis.

Diffuse idiopathic skeletal hyperostosis (DISH) is a common skeletal disorder in the elderly, which can develop into periosteal hyperostosis and paradoxically into immobilization-associated trabecular osteoporosis. The bone anabolic agent, teriparatide (TPD), seems to be a rational treatment for the immobilization-associated osteoporosis. However, it can lead to development of hyperostosis lesions in DISH patients. Here, we demonstrate TPD effectively treats trabecular osteoporosis while simultaneously promoting ankylosis of the spine in DISH model tiptoe-walking Yoshimura (twy) mice, compared with the ICR mice. Eighteen male twy mice were divided into three groups, and ICR mice were used as a normal control. Subcutaneous injections of TPD or phosphate-buffered saline (PBS) were performed according to three dosing regimens; 40 µg/kg once daily (TPD × 1 group), 40 µg/kg three times daily (TPD × 3 group), and PBS (control; Ctl group). Treatment was commenced at the age of 7 weeks and continued for 5 weeks. Micro-computed tomography (µCT) and histological analysis were performed. Longitudinal µCT study revealed that trabecular bone volume in both the vertebral body and distal femur decreased with time in the Ctl group, but increased dramatically in the TPD × 3 group. The twy mice developed ankylosis of the spine, the progression of which was accelerated with TPD therapy. We also confirmed that TPD therapy promoted ossification of spinal ligaments. Histomorphometrical study revealed that TPD treatment increased bone formation at the vertebrae enthesis region and in the trabecular bone. TPD therapy effectively treats trabecular osteoporosis, but potentially promotes ankylosis of the spine in patients with DISH.

Synthesis and Structure-Activity Relationships of 2-Aminoacetamide Derivatives as Peroxisome Proliferator-Activated Receptor α/γ Dual Agonists.

We describe the design, syntheses, and structure-activity relationships of novel zwitterionic compounds as nonthiazolidinedion-based peroxisome proliferator-activated receptor (PPAR) α/γ dual agonists. In our previous report, we obtained compound 1 showing potent PPARα/γ dual agonistic activities, together with a sufficient glucose-lowering effect in db/db mice. However, this compound possessed an issue, i.e., the 1,3,4-oxadiazole ring was not stable in acidic conditions. Thus, we carried out further optimization to improve the stability while maintaining the other favorable profile features including potent PPARα/γ dual agonistic activity. We addressed the issue by changing the oxadiazole ring to a bioisostere amide group. These amide derivatives were stable in acidic conditions and decreased plasma glucose and plasma triglyceride levels significantly without marked weight gain.

Involvement of Siglec-15 in regulating RAP1/RAC signaling in cytoskeletal remodeling in osteoclasts mediated by macrophage colony-stimulating factor.

DNAX-associated protein 12 kD size (DAP12) is a dominant immunoreceptor tyrosine-based activation motif (ITAM)-signaling adaptor that activates costimulatory signals essential for osteoclastogenesis. Although several DAP12-associated receptors (DARs) have been identified in osteoclasts, including triggering receptor expressed on myeloid cells 2 (TREM-2), C-type lectin member 5 A (CLEC5A), and sialic acid-binding Ig-like lectin (Siglec)-15, their precise role in the development of osteoclasts and bone remodeling remain poorly understood. In this study, mice deficient in Trem-2, Clec5a, Siglec-15 were generated. In addition, mice double deficient in these DAR genes and FcεRI gamma chain (FcR)γ, an alternative ITAM adaptor to DAP12, were generated. Bone mass analysis was conducted on all mice. Notably, Siglec-15 deficient mice and Siglec-15/FcRγ double deficient mice exhibited mild and severe osteopetrosis respectively. In contrast, other DAR deficient mice showed normal bone phenotype. Likewise, osteoclasts from Siglec-15 deficient mice failed to form an actin ring, suggesting that Siglec-15 promotes bone resorption principally by modulating the cytoskeletal organization of osteoclasts. Furthermore, biochemical analysis revealed that Sigelc-15 activates macrophage colony-stimulating factor (M-CSF)-induced Ras-associated protein-1 (RAP1)/Ras-related C3 botulinum toxin substrate 1 (Rac1) pathway through formation of a complex with p130CAS and CrkII, leading to cytoskeletal remodeling of osteoclasts. Our data provide genetic and biochemical evidence that Siglec-15 facilitates M-CSF-induced cytoskeletal remodeling of the osteoclasts.

Effect of urgent surgery within 8 hours compared to surgery between 8 and 24 hours on perioperative complications and neurological prognosis in patients older than 70 years with cervical spinal cord injury: a propensity score-matched analysis.

OBJECTIVE: This study aimed to investigate the effect of surgery within 8 hours on perioperative complications and neurological prognosis in older patients with cervical spinal cord injury by using a propensity score-matched analysis. METHODS: The authors included 87 consecutive patients older than 70 years who had cervical spinal cord injury and who had undergone posterior decompression and fusion surgery within 24 hours of injury. The patients were divided into two groups based on the time from injury to surgery: surgery within 8 hours (group 8 hours) and between 8 and 24 hours (group 8-24 hours). Following the preliminary study, the authors established a 1:1 matched model using propensity scores to adjust for baseline characteristics and neurological status on admission. Perioperative complication rates and neurological outcomes at discharge were compared between the two groups. RESULTS: Preliminary analysis of 87 prematched patients (39 in group 8 hours and 48 in group 8-24 hours) revealed that the motor index score (MIS) on admission was lower for lower extremities (12.3 ± 15.5 vs 20.0 ± 18.6, respectively; p = 0.048), and total extremities (26.7 ± 27.1 vs 40.2 ± 30.6, respectively; p = 0.035) in group 8 hours. In terms of perioperative complications, group 8 hours had significantly higher rates of cardiopulmonary dysfunction (46.2% vs 25.0%, respectively; p = 0.039). MIS improvement (the difference in scores between admission and discharge) was greater in group 8 hours for lower extremities (15.8 ± 12.6 vs 9.0 ± 10.5, respectively; p = 0.009) and total extremities (29.4 ± 21.7 vs 18.7 ± 17.7, respectively; p = 0.016). Using a 1:1 propensity score-matched analysis, 29 patient pairs from group 8 hours and group 8-24 hours were selected. There were no significant differences in baseline characteristics, neurological status on admission, and perioperative complications between the two groups, including cardiopulmonary dysfunction. Even after matching, MIS improvement was significantly greater in group 8 hours for upper extremities (13.0 ± 10.9 vs 7.8 ± 8.3, respectively; p = 0.045), lower extremities (14.8 ± 12.7 vs 8.3 ± 11.0, respectively; p = 0.044) and total extremities (27.8 ± 21.0 vs 16.0 ± 17.5, respectively; p = 0.026). CONCLUSIONS: Results of the comparison after matching demonstrated that urgent surgery within 8 hours did not increase the perioperative complication rate and significantly improved the MIS, suggesting that surgery within 8 hours may be efficient, even in older patients.

Epidemic Preventive Management during the Coronavirus Disease 2019 Pandemic Is a Risk Factor for Delirium after Spinal Cord Injury Surgery.

Introduction: Epidemic preventive management during the coronavirus disease 2019 (COVID-19) pandemic may have negatively impacted perioperative outcomes in patients with traumatic spinal cord injury (SCI). However, little is known about the relationship between epidemic preventive management and delirium after traumatic SCI. Here, we clarified the predictors of delirium after SCI surgery. Methods: We retrospectively analyzed 231 patients (mean age, 66 years) who underwent SCI surgery between 2017 and 2021. Patients were categorized into the delirium and non-delirium groups. Preoperative characteristics and laboratory data related to the occurrence of delirium were assessed. During the study period, we continued early surgical intervention. However, early rehabilitation intervention was not performed in the hospital rehabilitation room from May 2020 due to epidemic preventive management, which involved performing rehabilitation on the bed for 8 days postoperatively. Results: Postoperatively, 33 (14.3%) patients experienced delirium. Univariate analysis showed that age (p<0.01), presence of a psychiatric disorder (p<0.05), dementia (p<0.05), serum albumin (p<0.05) and hemoglobin (p<0.01) levels, American Society of Anesthesiologists classification score (p<0.05), and treatment during the COVID-19 pandemic (p<0.01) differed significantly in the delirium and non-delirium groups. Multivariate logistic regression analysis showed that an age ≥73 years (odds ratio [OR], 15.78; 95% confidence interval [CI], 4.54-54.80; p<0.01), treatment during the COVID-19 pandemic (OR, 3.85; 95% CI, 1.61-9.22; p<0.01), and psychiatric disorder (OR, 29.38; 95% CI, 5.63-153.43; p<0.01) were associated with delirium. Conclusions: Our comprehensive preventive management during the COVID-19 pandemic was identified as one of the risk factors for delirium after SCI surgery. Patients with preventive management should be cautioned regarding the risk of delirium.

The Impact of Diffuse Idiopathic Skeletal Hyperostosis on Nutritional Status, Neurological Outcome, and Perioperative Complications in Patients with Cervical Spinal Cord Injury.

This retrospective study aimed to investigate the characteristics of patients with cervical spinal cord injuries (CSCI) with diffuse idiopathic skeletal hyperostosis (DISH). We included 153 consecutive patients with CSCI who underwent posterior decompression and fusion surgery. The patients were divided into two groups based on the presence of DISH. Patient characteristics, neurological status on admission, nutritional status, perioperative laboratory variables, complications, neurological outcomes at discharge, and medical costs were compared between the groups. The DISH group (n = 24) had significantly older patients (72.1 vs. 65.9, p = 0.036), more patients with low-impact trauma (62.5% vs. 34.1%, p = 0.009), and a lower preoperative prognostic nutritional index on admission (39.8 vs. 42.5, p = 0.014) than the non-DISH group (n =129). Patients with DISH had significantly higher rates of ventilator management (16.7% vs. 3.1%, p = 0.022) and pneumonia (29.2% vs. 8.5%, p = 0.010). There was no significant difference in medical costs and neurological outcomes on discharge. Patients with CSCI and DISH were older, had poor nutritional status, and were prone to postoperative respiratory complications, while no differences were found between the neurological outcomes of patients with CSCI with and without DISH.

Complications Associated with Preventive Management to Reduce the Risk of COVID-19 Spread After Surgery for Spinal Cord Injury.

BACKGROUND: Preventive management to reduce the risk of coronavirus disease-2019 (COVID-19) spread led to delays in active rehabilitation, which may have negatively impacted the outcomes of patients with traumatic spinal cord injury (SCI). Therefore, the aim of this study was to clarify the influence of preventive management on the rate of perioperative complications after surgical treatment for SCI. METHODS: This single-center retrospective study examined the cases of 175 patients who had SCI surgery between 2017 and 2021. We could not continue early rehabilitation interventions starting on April 30, 2020, because of our preventive management to reduce the risk of COVID-19 spread. Using a propensity score-matched model, we adjusted for age, sex, American Spinal Injury Association impairment scale score at admission, and risk factors for perioperative complications described in previous studies. Perioperative complication rates were compared between the COVID-19 pandemic and prepandemic groups. RESULTS: Of the 175 patients, 48 (the pandemic group) received preventive management. The preliminary analysis revealed significant differences between the unmatched pandemic and prepandemic groups with respect to age (75.0 versus 71.2 years, respectively; p = 0.024) and intraoperative estimated blood loss (152 versus 227 mL; p = 0.013). The pandemic group showed significant delays in visiting the rehabilitation room compared with the prepandemic group (10 versus 4 days from hospital admission; p < 0.001). There were significant differences between the pandemic and prepandemic groups with respect to the rates of pneumonia (31% versus 16%; p = 0.022), cardiopulmonary dysfunction (38% versus 18%; p = 0.007), and delirium (33% versus 13%; p = 0.003). With a propensity score-matched analysis (C-statistic = 0.90), 30 patients in the pandemic group and 60 patients in the prepandemic group were automatically selected. There were significant differences between the matched pandemic and prepandemic groups with respect to the rates of cardiopulmonary dysfunction (47% versus 23%; p = 0.024) and deep venous thrombosis (60% versus 35%; p = 0.028). CONCLUSIONS: Even with early surgical intervention, late mobilization and delays in active rehabilitation during the COVID-19 pandemic increased perioperative complications after SCI surgery. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Efficacy of a machine learning-based approach in predicting neurological prognosis of cervical spinal cord injury patients following urgent surgery within 24 h after injury.

We aimed to develop a machine learning (ML) model for predicting the neurological outcomes of cervical spinal cord injury (CSCI). We retrospectively analyzed 135 patients with CSCI who underwent surgery within 24 h after injury. Patients were assessed with the American Spinal Injury Association Impairment Scale (AIS; grades A to E) 6 months after injury. A total of 34 features extracted from demographic variables, surgical factors, laboratory variables, neurological status, and radiological findings were analyzed. The ML model was created using Light GBM, XGBoost, and CatBoost. We evaluated Shapley Additive Explanations (SHAP) values to determine the variables that contributed most to the prediction models. We constructed multiclass prediction models for the five AIS grades and binary classification models to predict more than one-grade improvement in AIS 6 months after injury. Of the ML models used, CatBoost showed the highest accuracy (0.800) for the prediction of AIS grade and the highest AUC (0.90) for predicting improvement in AIS. AIS grade at admission, intramedullary hemorrhage, longitudinal extent of intramedullary T2 hyperintensity, and HbA1c were identified as important features for these prediction models. The ML models successfully predicted neurological outcomes 6 months after injury following urgent surgery in patients with CSCI.

Thrombocytopenia Associated with Unrecognized Non-Alcoholic Fatty Liver Disease Is an Independent Predictor of Perioperative Significant Blood Loss in Cervical Laminoplasty.

OBJECTIVE: To identify risk factors for significant blood loss (SBL) in cervical laminoplasty, especially regarding thrombocytopenia and coagulopathy resulting from non-alcoholic fatty liver disease (NAFLD). METHODS: We retrospectively investigated differences in patient background data, laboratory data at the time of admission, and surgery-related data of 317 patients who underwent cervical laminoplasty and were divided into SBL (estimated blood loss [EBL] + drainage [D] ≥500 g) and non-SBL (EBL + D < 500 g) groups. To evaluate liver status, we used the fibrous 4 index and considered fibrous 4 index ≥1.85 as a representative phenotype for NAFLD with liver fibrosis. In addition, the risk factor for perioperative SBL was investigated using multiple logistic regression analysis, and the cutoff value was calculated. RESULTS: Incidence of perioperative SBL in cervical laminoplasty was 7.3% (23/317). Compared with the non-SBL group, the SBL group demonstrated significantly lower platelet count (PLT), lower aspartate aminotransferase, longer operation time, and greater number of opened laminae. According to multivariate analysis, lower PLT and a greater number of opened laminae were identified as significant risk factors for perioperative SBL. The cutoff value of PLT for predicting SBL was determined to be 16.7 × 104/µL using a receiver operating characteristic curve. The liver fibrosis group revealed significantly lower PLT and greater EBL + D than the non-liver fibrosis group. CONCLUSIONS: Thrombocytopenia is an independent predictor of perioperative SBL in cervical laminoplasty. Thus, patients with mild thrombocytopenia that may be associated with NAFLD must be carefully monitored to avoid perioperative SBL.

[Two cases of cervical carotid artery stenosis with high risk post-operative hyperperfusion treated with dexmedetomidine after carotid endarterectomy].

Dexmedetomidine is a central alpha2 adrenoceptor agonist recently shown to be a safe and acceptable sedative agent for patients requiring sedation after brain surgery. We report two patients successfully treated by carotid endarterectomy (CEA) with postoperative management under dexmedetomidine anesthesia for transient ischemic attack (TIA) resulting from severe stenosis of the internal carotid artery (ICA). Case 1: A 75-year-old man was admitted to our hospital with aphasia and weakness of the right side of his body. Although no evidence of acute cerebral infarction was obtained on magnetic resonance imaging (MRI)/diffusion-weighted image (DWI), MR angiography (MRA) revealed severe stenosis of the left cervical ICA. (123)I-IMP-single photon emission tomography (SPECT) and transcranial Doppler (TCD) revealed marked reduction of cerebral blood flow in the left cerebral hemisphere. Although CEA induced hyperperfusion, aggressive control of blood pressure under dexmedetomidine anesthesia enabled effective management of the resulting hyperperfusion syndrome. The patient was discharged without neurological deficits. Case 2: A 68-year-old man was admitted to our hospital with amaurosis fugax and numbness of the right side of his body. Although no evidence of acute cerebral infarction was obtained on MRI/DWI, MRA disclosed severe stenosis of the left cervical ICA. (123)I-IMP-SPECT revealed extremely low perfusion and disturbance of vascular reactivity in the territory of the left ICA. Although conservative therapy was performed, crescendo TIA was noted. Revascularization using CEA was therefore performed. After surgery, hyperperfusion was observed in the same fashion as in case 1, and again aggressive control of blood pressure under dexmedetomidine anesthesia enabled effective management of the resulting hyperperfusion syndrome. The patient was discharged 1 month postoperatively without neurological deficits. Dexmedetomidine is a safe and acceptable sedative drugs preventing hyperperfusion syndrome after CEA.

Siglec-15-targeting therapy protects against glucocorticoid-induced osteoporosis of growing skeleton in juvenile rats.

Effective treatment of juvenile osteoporosis, which is frequently caused by glucocorticoid (GC) therapy, has not been established due to limited data regarding the efficacy and adverse effects of antiresorptive therapies on the growing skeleton. We previously demonstrated that sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) targeting therapy, which interferes with osteoclast terminal differentiation in the secondary, but not primary, spongiosa, increased bone mass without adverse effects on skeletal growth, whereas bisphosphonate, a first-line treatment for osteoporosis, increased bone mass but impaired long bone growth in healthy growing rats. In the present study, we investigated the efficacy of anti-Siglec-15 neutralizing antibody (Ab) therapy against GC-induced osteoporosis in a growing rat model. GC decreased bone mass and deteriorated mechanical properties of bone, due to a disproportionate increase in bone resorption. Both anti-Siglec-15 Ab and alendronate (ALN) showed protective effects against GC-induced bone loss by suppressing bone resorption, which was more pronounced with anti-Siglec-15 Ab treatment, possibly due to a reduced negative impact on bone formation. ALN induced histological abnormalities in the growth plate and morphological abnormalities in the long bone metaphysis but did not cause significant growth retardation. Conversely, anti-Siglec-15 Ab did not show any negative impact on the growth plate and preserved normal osteoclast and chondroclast function at the primary spongiosa. Taken together, these results suggest that anti-Siglec-15 targeting therapy could be a safe and efficacious prophylactic therapy for GC-induced osteoporosis in juvenile patients.

Breast cancer cells expressing cancer-associated sialyl-Tn antigen have less capacity to develop osteolytic lesions in a mouse model of skeletal colonization.

Breast cancer is one of the most prevalent malignancies in women, and approximately 75-80% of patients with advanced breast cancer develop bone metastasis. Expression of the cancer-associated carbohydrate antigen sialyl-Tn (STn) in breast cancer is associated with a poor prognosis; however, involvement of STn in the development of metastatic bone lesions remains unclear. We investigated whether STn expression on breast cancer cells influences intraosseous tumor growth and bone response in mice models of skeletal colonization. STn-positive (STn+) breast cancer cells were generated by stable transfection of an expression vector encoding ST6GaLNAc I into the breast cancer cell line MDA-MB-231. Parental MDA-MB-231 cells not expressing STn antigen were used as STn-negative (STn-) breast cancer cells. Contrary to expectations, STn expression attenuated the development of destructive bone lesions in the in vivo mice models. An in vitro study demonstrated that STn expression impaired adhesion of MDA-MB-231cells to bone marrow stromal cells. This finding in vitro was also confirmed by another breast cancer cell line MCF-7. Cell adhesion to fibronectin and type I collagen was also impaired in STn+ MDA-MB-231 cells compared to that in STn- MDA-MB-231 cells, suggesting integrin dysfunction. Given that the integrin ß1 subunit is the main carrier of the STn epitope, it is likely that changes in glycan structure impaired the adhesive capacity of ß1 integrin in the bone environment, leading to attenuation of tumor cell engraftment. In conclusion, breast cancer cells expressing STn antigen had less capacity for skeletal colonization, possibly due to impaired adhesive capability.