[Clinical efficacy of resection of extramedullary subdural tumor in thoracic spinal canal via muscle-pedicle open-door laminoplasty approach].

In order to evaluate the efficacy of resecting extramedullary subdural tumors, located in the thoracic spinal canal, via the muscle-pedicle open-door laminoplasty approach, clinical data of fifteen patients with thoracic spinal tumors admitted to the Department of Spinal Surgery in the Affiliated Hospital of Qingdao University from December 2018 to June 2021 were analyzed retrospectively. All patients received surgical treatment to remove the tumors via the muscle-pedicle open-door laminoplasty approach. The clinical data of the patient was recorded. The Japanese Orthopedic Association (JOA) score, the thoracic kyphosis angle in the standing position before and after the operation, and the visual analog score (VAS) of thoracic back incision pain before and after the operation were compared. CT scan was performed three months after the surgery and at the last follow-up to measure the healing of the lamina. In addition, MRI was used to detect the healing of the posterior ligament at the last follow-up. The tumors of all fifteen patients were completely removed, the operating time was (91±15) minutes, blood loss was (117±56) ml. Cerebral spinal fluid leakage occurred in three patients, but the incisions healed smoothly following compression and no complication was observed. All patients were followed-ups for more than 6 months. The VAS score of thoracic back incision pain was (3±1.3) points at three days post operation and it dropped to (1.3±0.9) points three months post-operation. The JOA score improved significantly after the operation, it was (11.9±2.4) points before operation, and it was (14.0±1.6) points three months post operation and increased to (16.1±0.7) points at the last follow-up (both P<0.001). The Cobb angle was 10.1°±5.3° before the operation and it was 10.4°±6.2° at the last follow-up (P=0.420). Three months after operation, partial callus formation or even complete healing on the muscle pedicle side was observed on the CT scans of all patients. At the last follow-up, CT scans showed complete healing on the muscle pedicle side. There were different degrees of sclerosis and healing on the open-door side. There was no necrosis, displacement, or secondary spinal canal stenosis in any vertebral lamina. It indicated that the muscle-pedicle open-door laminoplasty approach is an effective way to resection extramedullary subdural tumors located in the thoracic spinal canal.

[The difference of surface electromyography data processing method based on simulated manal-lifting-task].

Objective: To study the differences of different signal processing method of surface electromyography (sEMG) in judging muscle fatigue. Methods: From July to October 2019, based on the model of simulated manual lifting operation, the original sEMG signals from 13 volunteers of brachial radial muscle, brachial two-headed muscle, triangle muscle, left vertical spine muscle, right vertical spine muscle and lateral femoral muscle were collected in the operation activities. Three different electromyography signal processing methods (all signal from motion beginning to the end, peak signal and ehe specified motion signal) were used to analyze the original data in time domain (RMS) and frequency domain (MDF) , the data difference between different electromyography signal processing methods was analyzed by using Wilcoxon rank and sum test and nonlinear curve fitting method. Results: The age of the subjects of the simulated lifting operation was (24.31±2.02) years old, height (173.78±4.84) cm, weight (66.28±5.58) kg, body mass index (BMI) 21.94±1.58. The thickness of triceps skinfold was (14.08±4.86) mm, and the thickness of the skin fold under the scapula was (15.54±3.59) mm. After processing the original signal data by using different sEMG signal interception methods, the normality test, Levene's test, and the Wilcoxon test showed that, except for the MDF index of the brachial two-headed muscle, the differences in the RMS and MDF signals of the other muscles were statistically significant (P<0.016) . The all signal processing method dealed with data distribution dispersion better than other methods, and the rate of change of RMS signal slope was higher than other methods. Non-linear regression results showed that all signal processing method had low volatility in processing data, and the regression equation had a high degree of fit. Conclusion: Different electromyography signal processing methods have differences. The all signal processing method which intercepts from starting point to the end point of action cycle has the least data volatility, and electromyography time domain and frequency domain index with the highest sensitivity of time, which is suitable for the application of surface electromyography to judge muscle fatigue in dynamic and complex operations.