Atlantoaxial dislocation due to Os odontoideum in down syndrome: Literature review and case reports.

INTRODUCTION AND IMPORTANCE: Os odontoideum is a rare condition commonly associated with atlantoaxial instability (AAI) and leading to atlantoaxial dislocation. The incidence of Os odontoideum is higher in patients with Down syndrome. Similar to odontoid fractures, atlantoaxial dislocation in patients with Os odontoideum can result in neurological deficits, disability, and even mortality. CASE PRESENTATION: We present two cases of Os odontoideum accompanied by Down syndrome. Both patients were hospitalized due to progressive tetraparesis after falls several months prior. Upon examination, the patients exhibited myelopathy and were unable to walk or stand. MRI revealed spinal stenosis at the C1-C2 level due to atlantoaxial dislocation. C1-C2 fixation using Harms' technique was performed in both cases. One case experienced a complication involving instrument failure, necessitating revision surgery. CLINICAL DISCUSSION: Due to the characteristics of transverse ligament laxity, low muscle tone, excessive joint flexibility, and cognitive impairment, children with both Down syndrome and Os odontoideum are at a high risk of disability and even mortality from spinal cord injury. Most authors recommend surgical management when patients exhibit atlantoaxial instability. Additional factors such as low bone density, cognitive impairment, and a high head-to-body ratio may increase the risk of surgical instrument failure and nonunion postoperatively in patients with Down syndrome. CONCLUSION: Os odontoideum is a cause of AAI in patients with DS. Indication of surgery in the presence of AAI helps to resolve neurological injury and prevent further deterioration. The use of a cervical collar is considered to prevent instrument failure postoperatively.

1 Year-follow-up of transforaminal surgical approach in the management of migrated disc herniation: a cross-sectional study.

Transforaminal percutaneous endoscopic lumbar discectomy (TPELD) recently confirms its superiority compared to typical open discectomy in the treatment of very high-grade migrated disk herniation. In Vietnam, this technique has been applied in recent years; however; lack of reports and evidence. Objectives: In this study, the authors would like to share their surgical experience and report the initial results in their center, after successfully performing TPELD for very high-grade migrated disk herniation in 40 patients. Patients and methods: Forty patients, who underwent TPELD to remove the nucleus of very high-grade migrated disk herniation, were enrolled in this study. The study was carried out from April 2019 to April 2021. Preoperative and postoperative MRI were compared to demonstrate the removed disk. Postoperative visual analog score, oswestry disability index, and modified Macnab criteria were obtained after 1 month, 6 months, and 1 year and were compared. Results: There were no major complications related directly to this technique. Seven patients were operated at L3-4, 28 patients at L4-5, and 5 patients at l5-S1. Mean visual analog score for leg pain improved from 7.36±0.64 preoperatively to 1.22±1.16 at 6 months postoperatively and 1.34±1.47 at 1 year postoperatively (P<0.01). The mean preoperative oswestry disability index improved from 67.1±8.79 preoperatively to 12.1±13.48 at 1 year postoperatively (P<0.01). Excellent or good global outcomes were obtained in 95%. Conclusions: TPELD is a minimally invasive treatment with effective and safe results of very high-grade migrated disk herniation. Improvement of several pain scores can be observed in the 12-month follow-up after surgery.

Post-kyphoplasty secondary vertebral compression fractures in Vietnamese patients: A single-center prospective cross-sectional study.

Background: Despite its well-known effectiveness in vertebral compression fractures (VCFs), kyphoplasty could also bring the risk of developing subsequent VCFs post-augmentation, especially at adjacent vertebrae, which has been rarely reported in Asian countries. Methods: In this cross-sectional study, we performed cement augmentation on 69 vertebrae in 65 patients at the Spine Surgery Department, Viet Duc University Hospital, from June 2019 to November 2020. Cement augmentation was performed on 69 vertebrae in 65 patients. They then were followed and assessed for subsequent VCFs every 3, 6, 9 months after surgery. Results: 69 vertebrae in 65 patients were treated by kyphoplasty, 2 patients had 2 vertebrae treated and only one patient had 3 vertebrae injected. The average age recorded was 72 ± 8 years old. The average amount of cement injected was 5.4 ± 1.4 ml per vertebrae. At the end of the study, 63 patients did not develop subsequent VCFs. Two patients (3.07%) had new VCFs post-augmentation within the first two-month period post-injection. Age, gender, history of steroid injection and number of vertebrae treated with kyphoplasty showed no significant difference between the two groups. Conclusions: Kyphoplasty is an effective pain-reliving treatment for patients with osteoporotic VCFs and would pose no threats to subsequent VCFs. For patients developing abnormal acute pain within the period of two months, further examinations and MRI scan should be performed to detect subsequent VCFs in time.

Simple clinical and laboratory predictors to improve empirical treatment strategies in areas of high scrub typhus and dengue endemicity, central Vietnam.

BACKGROUND: Dengue fever is highly endemic in Vietnam, but scrub typhus-although recognized as an endemic disease-remains underappreciated. These diseases together are likely to account for more than half of the acute undifferentiated fever burden in Vietnam. Scrub typhus (ST) is a bacterial disease requiring antimicrobial treatment, while dengue fever (DF) is of viral etiology and does not. The access to adequate diagnostics and the current understanding of empirical treatment strategies for both illnesses remain limited. In this study we aimed to contribute to the clinical decision process in the management of these two important etiologies of febrile illness in Vietnam. METHODS: Using retrospective data from 221 PCR-confirmed scrub typhus cases and 387 NS1 protein positive dengue fever patients admitted to five hospitals in Khanh Hoa province (central Vietnam), we defined predictive characteristics for both diseases that support simple clinical decision making with potential to inform decision algorithms in future. We developed models to discriminate scrub typhus from dengue fever using multivariable logistic regression (M-LR) and classification and regression trees (CART). Regression trees were developed for the entire data set initially and pruned, based on cross-validation. Regression models were developed in a training data set involving 60% of the total sample and validated in the complementary subsample. Probability cut points for the distinction between scrub typhus and dengue fever were chosen to maximise the sum of sensitivity and specificity. RESULTS: Using M-LR, following seven predictors were identified, that reliably differentiate ST from DF; eschar, regional lymphadenopathy, an occupation in nature, increased days of fever on admission, increased neutrophil count, decreased ratio of neutrophils/lymphocytes, and age over 40. Sensitivity and specificity of predictions based on these seven factors reached 93.7% and 99.5%, respectively. When excluding the "eschar" variable, the values dropped to 76.3% and 92.3%, respectively. The CART model generated one further variable; increased days of fever on admission, when eschar was included, the sensitivity and specificity was 95% and 96.9%, respectively. The model without eschar involved the following six variables; regional lymphadenopathy, increased days of fever on admission, increased neutrophil count, increased lymphocyte count, platelet count ≥ 47 G/L and age over 28 years as predictors of ST and provided a sensitivity of 77.4% and a specificity of 90.7%. CONCLUSIONS: The generated algorithms contribute to differentiating scrub typhus from dengue fever using basic clinical and laboratory parameters, supporting clinical decision making in areas where dengue and scrub typhus are co-endemic in Vietnam.