ABSTRACT
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.
ABSTRACT
Minimally invasive transforaminal lumbar interbody fusion has proven effectiveness in treating spondylolisthesis, but there were few reports applying the technique from scarce resourcing developing countries. In this study, the authors report the results and share our experience of minimally invasive spinal transforaminal lumbar interbody fusion in spondylolisthesis treatment in Vietnamese patients. Materials and methods: In this study, the authors enroled 92 patients diagnosed with single-level, grade I or grade II lumbar spondylolisthesis from January 2019 to October 2022. Results: The median age in our study was 47.79±12.61 (range 15-75), the male/female ratio was 1/2.3. The mean disease duration was 28.57 months. Conventional X-ray images showed that there were 74 patients (80.43%) with spondylolisthesis grade I, 18 patients (19.57%) with grade II. Spondylolisthesis occured mainly in L4-L5 with 53 patients (57.61%). The isthmic sign was recorded in 16 patients (31.4%). The mean blood loss was 149.46 ml. Patients walked on average of 3.22 days after surgery. VAS score reduced significantly in both back and leg. Spinal function improved significantly with a preoperative Owestry Disability Index of 48.18% decrease to 15.18% 12 months after surgery. The surgical results were good and excellent at 95.00% after 12 months of surgery according to Macnab scale. The fusion rate reached 97.50%. Conclusions: The results of this Macnab's classification study show that minimally invasive spinal transforaminal lumbar interbody fusion is an effective treatment for spondylolisthesis with less pain, less blood loss after surgery, and high fusion rate.
