Clinical Significance of Improved Intraoperative Neurophysiological Monitoring Signal during Spine Surgery: A Retrospective Study of a Single-Institution Prospective Cohort

Application of Intraoperative Electromyography Intelligent Monitoring in Orthopedic Surgery under General Anesthesia

To study the application of intraoperative EMG intelligent monitoring in orthopedic surgery under general anesthesia, a total of 53 patients who underwent orthopedic surgery from February 2021 to February 2022 were selected. The combined monitoring of somatosensory evoked potential (SEP), motor evoked potential (MEP), and electromyography (EMG) was used to analyze the monitoring efficiency. In 38 of the 53 patients, the intraoperative signal was normal, and there was no postoperative neurological dysfunction; one case had abnormal signal, and the abnormality still existed after debugging, but no obvious neurological dysfunction was found after operation; the remaining 14 cases had abnormal signal. There were 13 early warnings in SEP monitoring; 12 early warnings in MEP monitoring; 10 early warnings in EMG monitoring. There were 15 cases of early warning in the joint monitoring of the three, and the sensitivity of the combined monitoring of SEP + MEP + EMG was significantly higher than that of the single monitoring of SEP, MEP, and EMG (p < 0.05). There was no significant difference in specificity, positive predictive value, and negative predictive value between combined monitoring and single monitoring (p > 0.05). The combined monitoring of EMG, MEP, and SEP in orthopedic surgery can significantly improve the safety of surgery, its sensitivity and negative predictive value were significantly higher than the monitoring effects of the two alone.

Feasibility and efficacy of spinal microtubular technique for resection of lumbar dumbbell-shaped tumors

Objective

Minimally invasive surgical resection of lumbar dumbbell-shaped tumors is rarely reported. We retrospectively collected clinical data of lumbar dumbbell-shaped tumors treated with the spinal microtubular technique to evaluate the feasibility, complications and efficacy of the surgical methods.

Methods

From September 2013 to August 2021, clinical data of patients with lumbar dumbbell-shaped tumors that underwent paravertebral approach and micro-tubular tumorectomy (PAMT) were collected; neurological function was assessed using the pain visual analog scale (VAS) and the Japanese Orthopaedic Association (JOA) score.

Results

A total of 46 patients that underwent PAMT were included in this study. In all patients, total resection of the tumor was performed at one stage (100%). The median follow-up period was 27.5 months (P25, P75: 16.5- 57 months). Symptoms such as pain or lower extremity weakness were significantly relieved in 46 patients. The postoperative VAS score and JOA score were significantly higher compared with preoperative scores (p &lt;0.001), and the patients had no tumor recurrence or spinal instability. According to the Eden classification, there were 7 cases of type I, 8 cases of type II, 15 cases of type III, and 16 cases of type IV. In the comparison of the improvement of VAS score at 12 months after PAMT, there were significant differences among different types of tumors (H =15.756, p =0.001); type I was better than type III (Z =2.768, p =0.029) and type IV (Z =2.763, p =0.029), and type II was also better than type III (Z =2.679, p =0.037) and type IV (Z =2.708, p =0.034). With respect to estimated blood loss (Z =-3.041, p =0.013) and postoperative hospital stays (Z =-3.003, p =0.014), type IV was less than type III; and type IV was also less than type II about operation time (Z =-2.653, p =0.040).

Conclusion

In small lumbar dumbbell-shaped tumors, PAMT is indicated for Eden types I-IV and different pathological types of tumors, and can achieve complete resection of the tumor (GTR) in one stage with a good prognosis.

Machine Learning Application of Transcranial Motor-Evoked Potential to Predict Positive Functional Outcomes of Patients

Intraoperative neuromonitoring (IONM) has been used to help monitor the integrity of the nervous system during spine surgery. Transcranial motor-evoked potential (TcMEP) has been used lately for lower lumbar surgery to prevent nerve root injuries and also to predict positive functional outcomes of patients. There were a number of studies that proved that the TcMEP signal's improvement is significant towards positive functional outcomes of patients. In this paper, we explored the possibilities of using a machine learning approach to TcMEP signal to predict positive functional outcomes of patients. With 55 patients who underwent various types of lumbar surgeries, the data were divided into 70 : 30 and 80 : 20 ratios for training and testing of the machine learning models. The highest sensitivity and specificity were achieved by Fine KNN of 80 : 20 ratio with 87.5% and 33.33%, respectively. In the meantime, we also tested the existing improvement criteria presented in the literature, and 50% of TcMEP improvement criteria achieved 83.33% sensitivity and 75% specificity. But the rigidness of this threshold method proved unreliable in this study when different datasets were used as the sensitivity and specificity dropped. The proposed method by using machine learning has more room to advance with a larger dataset and various signals' features to choose from.

Health insurance policy on surgical treatment of adult spinal deformity

Background: Recent burgeoning research on adult spinal deformity (ASD) has unveiled the benefits of surgical treatment and how to gain the benefits although these have only been around for 10 years.Current Concepts: During the last decade, the significance of pelvic incidence in the global spinal sagittal alignment and introductions of the Scoliosis Research Society-Schwab classification for ASD have been the guidelines of surgical treatment for ASD and the milestones for promising surgical results. However, one of the unsolved problems for the surgical treatment of ASD is the proximal junctional kyphosis, for which multifactorial causative factors have been suggested. Recent studies have focused on dynamic natures in patients with ASD during daily activities, which might be a clue for both prevention of proximal junctional kyphosis and a better level of surgical results. Even though a recent remarkable advancement for surgical treatment for ASD is present, the national guideline for reimbursement is still following the surgical indication for lumbar degenerative kyphosis published in 1988.Discussion and Conclusion: A significant gap exists between the national reimbursement guideline and generally held surgical indication for ASD surgery. Consequently, this huge gap raises trouble in both patients and surgeons. The patients with ASD cannot take an appropriate surgery for ASD, while the spine surgeons experience unreasonable adjustment of the cost by the Health Insurance Review and Assessment Service.

Transcranial Electrical Motor Evoked Potential in Predicting Positive Functional Outcome of Patients after Decompressive Spine Surgery: Review on Challenges and Recommendations towards Objective Interpretation

Spine surgeries impose risk to the spine's surrounding anatomical and physiological structures especially the spinal cord and the nerve roots. Intraoperative neuromonitoring (IONM) is a technology developed to monitor the integrity of the spinal cord and the nerve roots via the surgery. Transcranial motor evoked potential (TcMEP) (one of the IONM modalities) is adopted to monitor the integrity of the motor pathway of the spinal cord and the motor nerve roots. Recent research suggested that the IONM is conducive as a prognostic tool towards the patient's functional outcome. This paper summarizes the researches of IONM being adopted as a prognostic tool. In addition, this paper highlights the problems associated with the signal parameters as the improvement criteria in the previous researches. Lastly, we review the challenges of TcMEP to achieve a prognostic tool focusing on the factors that could interfere with the generation of a stable TcMEP response. The final section will discuss recommendations for IONM technology to achieve an objective prognostic tool.

Which Factors Affect the Stress of Intraoperative Orthopedic Surgeons by Using Electroencephalography Signals and Heart Rate Variability?

Can we recognize intraoperative real-time stress of orthopedic surgeons and which factors affect the stress of intraoperative orthopedic surgeons with EEG and HRV? From June 2018 to November 2018, 265 consecutive records of intraoperative stress measures for orthopedic surgeons were compared. Intraoperative EEG waves and HRV, comprising beats per minute (BPM) and low frequency (LF)/high frequency (HF) ratio were gathered for stress-associated parameters. Differences in stress parameters according to the experience of surgeons, intraoperative blood loss, and operation time depending on whether or not a tourniquet were investigated. Stress-associated EEG signals including beta 3 waves were significantly higher compared to EEG at rest for novice surgeons as the procedure progressed. Among senior surgeons, the LF/HF ratio reflecting the physical demands of stress was higher than that of novice surgeons at all stages. In surgeries including tourniquets, operation time was positively correlated with stress parameters including beta 1, beta 2, beta 3 waves and BPM. In non-tourniquet orthopedic surgeries, intraoperative blood loss was positively correlated with beta 1, beta 2, and beta 3 waves. Among orthopedic surgeons, those with less experience demonstrated relatively higher levels of stress during surgery. Prolonged operation time or excessive intraoperative blood loss appear to be contributing factors that increase stress.

A Comparative Study on the Minimal Invasiveness of Full-Endoscopic and Microendoscopic Cervical Foraminotomy Using Intraoperative Motor Evoked Potential Monitoring

Background and Objectives: Full-endoscopic cervical foraminotomy (FECF) and microendoscopic cervical foraminotomy (MECF) are effective surgeries for cervical radiculopathy and are considered minimally invasive in terms of damage to paraspinal soft tissue. However, no studies have quantitatively compared FECF and MECF in terms of neurological invasiveness. The aim of this study was to compare the neurological invasiveness of FECF and MECF using intraoperative motor evoked potential (MEP) monitoring. Materials and Methods: A chart review was conducted of 224 patients with cervical radiculopathy who underwent FECF or MECF between April 2014 and March 2020. Patients were 37 women and 187 men, with a mean age of 51 (range, 21–86) years. FECF was performed in 143 cases and MECF was performed in 81 cases. Results: Average MEP amplitude significantly increased from 292 mV before to 677 mV after nerve root decompression in patients who underwent the FECF. The average improvement rate was 273%. In patients who underwent the MECF, average MEP amplitude significantly increased from 306 mV before to 432 mV after nerve root decompression. The average improvement rate was 130%. The improvement rate was significantly higher for FECF compared with MECF. Conclusions: MEP amplitude increased after nerve root decompression in both FECF and MECF, but the improvement rate was higher in FECF. These results suggest that FECF might be more minimally invasive than MECF in terms of neurological aspects.