1.Current trends in intraoperative neurophysiological monitoring among Asia–Pacific countries: an Asia–Pacific Spine Society survey
Hideki SHIGEMATSU ; Akimasa YASUDA ; Ronald TANGENTE ; Chris Yin Wei CHAN ; Ajoy Prasad SHETTY ; Jason Pui Yin CHEUNG ; Yong HAI ; Daisuke SAKAI ; Kyu-Jung CHO ; Chih-Wei CHEN ; Gabriel LIU ; I Gusti Lanang Ngurah Agung Artha WIGUNA ; Brian HSU ; Mun Keong KWAN
Asian Spine Journal 2024;18(6):813-821
Methods:
Spine surgeons of the Asia–Pacific Spine Society were asked to respond to a web-based survey on IONM. The questionnaire covered various aspects of IONM, including its common modality, Tc-MEP details, necessities for consistent use, and recommended modalities in major spine surgeries and representative surgical procedures.
Results:
Responses were received from 193 of 626 spine surgeons. Among these respondents, 177 used IONM routinely. Among these 177 respondents, 17 mainly used SEP, whereas the majority favored Tc-MEPs. Although a >50% decrease is the commonly used alarm point in Tc-MEP, half of the Tc-MEP users had no protocols planned for such scenarios. Moreover, half of the Tc-MEP users experienced complications, with bite injuries being the most common. Most respondents strongly recommended IONM in deformity surgery for pediatric and adult populations and tumor resection surgery for intramedullary spinal cord tumors. Conversely, IONM was the least recommended in lumbar spinal canal stenosis surgery.
Conclusions
Spine surgeons in Asia–Pacific countries favored IONM use, indicating widespread routine utilization. Tc-MEP was the predominant modality for IONM, followed by SEPs.
2.Current trends in intraoperative neurophysiological monitoring among Asia–Pacific countries: an Asia–Pacific Spine Society survey
Hideki SHIGEMATSU ; Akimasa YASUDA ; Ronald TANGENTE ; Chris Yin Wei CHAN ; Ajoy Prasad SHETTY ; Jason Pui Yin CHEUNG ; Yong HAI ; Daisuke SAKAI ; Kyu-Jung CHO ; Chih-Wei CHEN ; Gabriel LIU ; I Gusti Lanang Ngurah Agung Artha WIGUNA ; Brian HSU ; Mun Keong KWAN
Asian Spine Journal 2024;18(6):813-821
Methods:
Spine surgeons of the Asia–Pacific Spine Society were asked to respond to a web-based survey on IONM. The questionnaire covered various aspects of IONM, including its common modality, Tc-MEP details, necessities for consistent use, and recommended modalities in major spine surgeries and representative surgical procedures.
Results:
Responses were received from 193 of 626 spine surgeons. Among these respondents, 177 used IONM routinely. Among these 177 respondents, 17 mainly used SEP, whereas the majority favored Tc-MEPs. Although a >50% decrease is the commonly used alarm point in Tc-MEP, half of the Tc-MEP users had no protocols planned for such scenarios. Moreover, half of the Tc-MEP users experienced complications, with bite injuries being the most common. Most respondents strongly recommended IONM in deformity surgery for pediatric and adult populations and tumor resection surgery for intramedullary spinal cord tumors. Conversely, IONM was the least recommended in lumbar spinal canal stenosis surgery.
Conclusions
Spine surgeons in Asia–Pacific countries favored IONM use, indicating widespread routine utilization. Tc-MEP was the predominant modality for IONM, followed by SEPs.
3.Current trends in intraoperative neurophysiological monitoring among Asia–Pacific countries: an Asia–Pacific Spine Society survey
Hideki SHIGEMATSU ; Akimasa YASUDA ; Ronald TANGENTE ; Chris Yin Wei CHAN ; Ajoy Prasad SHETTY ; Jason Pui Yin CHEUNG ; Yong HAI ; Daisuke SAKAI ; Kyu-Jung CHO ; Chih-Wei CHEN ; Gabriel LIU ; I Gusti Lanang Ngurah Agung Artha WIGUNA ; Brian HSU ; Mun Keong KWAN
Asian Spine Journal 2024;18(6):813-821
Methods:
Spine surgeons of the Asia–Pacific Spine Society were asked to respond to a web-based survey on IONM. The questionnaire covered various aspects of IONM, including its common modality, Tc-MEP details, necessities for consistent use, and recommended modalities in major spine surgeries and representative surgical procedures.
Results:
Responses were received from 193 of 626 spine surgeons. Among these respondents, 177 used IONM routinely. Among these 177 respondents, 17 mainly used SEP, whereas the majority favored Tc-MEPs. Although a >50% decrease is the commonly used alarm point in Tc-MEP, half of the Tc-MEP users had no protocols planned for such scenarios. Moreover, half of the Tc-MEP users experienced complications, with bite injuries being the most common. Most respondents strongly recommended IONM in deformity surgery for pediatric and adult populations and tumor resection surgery for intramedullary spinal cord tumors. Conversely, IONM was the least recommended in lumbar spinal canal stenosis surgery.
Conclusions
Spine surgeons in Asia–Pacific countries favored IONM use, indicating widespread routine utilization. Tc-MEP was the predominant modality for IONM, followed by SEPs.
4.Thoracolumbar Injury Classification and Severity Score Is Predictive of Perioperative Adverse Events in Operatively Treated Thoracic and Lumbar Fractures
Gabriel LIU ; Jiong Hao TAN ; Jun Cheong KONG ; Yong Hao Joel TAN ; Nishant KUMAR ; Shen LIANG ; Seah Jing Sheng SHAWN ; Chiu Shi TING ; Lau Leok LIM ; Hey Hwee Weng DENNIS ; Naresh KUMAR ; Joseph THAMBIAH ; Hee-Kit WONG
Asian Spine Journal 2022;16(6):848-856
Methods:
We performed a retrospective review of 199 patients with surgically treated thoracolumbar fractures operated between January 2007 and January 2018. The potential risk factors for the development of AEs as well as the development of common complications were evaluated by univariate analysis, and a multivariate logistic regression analysis was performed to identify independent risk factors predictive of the above.
Results:
The overall rate of AEs was 46.7%; 83 patients (41.7%) had nonsurgical AEs, whereas 24 (12.1%) had surgical adverse events. The most common AEs were urinary tract infections in 43 patients (21.6%), and hospital-acquired pneumonia in 21 patients (10.6%). On multivariate logistic regression, a Thoracolumbar Injury Classification and Severity (TLICS) score of 8–10 (odds ratio [OR], 6.39; 95% confidence interval [CI], 2.33–17.51), the presence of polytrauma (OR, 2.64; 95% CI, 1.17–5.99), and undergoing open surgery (OR, 2.31; 95% CI, 1.09–4.88) were significant risk factors for AEs. The absence of neurological deficit was associated with a lower rate of AEs (OR, 0.47; 95% CI, 0.31–0.70).
Conclusions
This study suggests the presence of polytrauma, preoperative American Spinal Injury Association score, and TLICS score are predictive of AEs in patients with surgically treated thoracolumbar fractures. The results might also suggest a role for minimally invasive surgical methods in reducing AEs in these patients.
5.Sagittal Radiographic Parameters of the Spine in Three Physiological Postures Characterized Using a Slot Scanner and Their Potential Implications on Spinal Weight-Bearing Properties
Hwee Weng Dennis HEY ; Nathaniel Li-Wen NG ; Khin Yee Sammy LOH ; Yong Hong TAN ; Kimberly-Anne TAN ; Vikaesh MOORTHY ; Eugene Tze Chun LAU ; Gabriel LIU ; Hee-Kit WONG
Asian Spine Journal 2021;15(1):23-31
Methods:
We recruited young patients with nonspecific low back pain for <3 months, who were otherwise healthy. Each patient had EOS images taken in the flexed, erect and extended positions, in random order, as well as magnetic resonance imaging to assess for disk degeneration. Angular and disk height measurements were performed and compared in all three postures using paired t-tests. Changes in disk height relative to the erect posture were caclulated to determine the alignment-specific load-bearing area of each FSU.
Results:
Eighty-three patients (415 lumbar intervertebral disks) were studied. Significant alignment changes were found between all three postures at L1/2, and only between erect and flexion at the other FSUs. Disk height measurements showed that the neutral axis of the spine, marked by zones where disk heights did not change, varied between postures and was level specific. The load-bearing areas were also found to be more anterior in flexion and more posterior in extension, with the erect spine resembling the extended spine to a greater extent.
Conclusions
Load-bearing areas of the lumbar spine are sagittal alignment-specific and level-specific. This may imply that, depending on the surgical realignment strategy, attention should be paid not just to placing an intervertebral cage “as anterior as possible” for generating lordosis, but also on optimizing load-bearing in the lumbar spine.
6.Making a Traditional Spine Surgery Clinic Telemedicine-Ready in the “New Normal” of Coronavirus Disease 2019
Ka-Po Gabriel LIU ; Wei Loong Barry TAN ; Wei Luen James YIP ; Jun-Hao TAN ; Hee-Kit WONG
Asian Spine Journal 2021;15(2):164-171
Methods:
We reviewed the evidence behind telemedicine and described our clinical protocol, patient selection criteria, and workflow for telemedicine. We discussed a simple methodology to convert pre-existing traditional clinic resources into telemedicine tools, along with future challenges.
Results:
Our methodology was successfully and easily applied in our clinical practice, with a streamlined workflow allowing our spine surgery service to implement telemedicine as a consultation modality in line with the national recommendations of social distancing.
Conclusions
Telemedicine was well incorporated into our outpatient practice using the above workflow. We believe that the use of telemedicine via videoconferencing can become part of the new normal and a safe strategy for healthcare systems as both a medical and an economic countermeasure against COVID-19.
7.Symptomatic Construct Failure after Metastatic Spine Tumor Surgery
Naresh KUMAR ; Ravish PATEL ; Jiong Hao TAN ; Joshua SONG ; Naveen PANDITA ; Dennis Hwee Weng HEY ; Leok Lim LAU ; Gabriel LIU ; Joseph THAMBIAH ; Hee-Kit WONG
Asian Spine Journal 2021;15(4):481-490
Methods:
We conducted a retrospective analysis on 288 patients (246 for final analysis) who underwent MSTS between 2005–2015. Data collected were demographics and peri/postoperative clinical and radiological features. Early and late radiological SF were defined as presentation before and after 3 months from index surgery, respectively. Univariate and multivariate models of competing risk regression analysis were designed to determine the risk factors for SF with death as a competing event.
Results:
We observed 14 SFs (5.7%) in 246 patients; 10 (4.1%) underwent revision surgery. Median survival was 13.4 months. The mean age was 58.8 years (range, 21–87 years); 48.4% were women. The median time to failure was 5 months (range, 1–60 months). Patients with SF were categorized into three groups: (1) SF when the primary implant was revised (n=5, 35.7%); (2) peri-construct progression of disease requiring extension (n=5, 35.7%); and (3) SFs that did not warrant revision (n=4, 28.5%). Four patients (28.5%) presented with early failure. SF commonly occurred at the implant-bone interface (9/14) and all patients had a spinal instability neoplastic score (SINS) >7. Thirteen patients (92.8%) who developed failure had fixation spanning junctional regions. Multivariate competing risk regression showed that preoperative Eastern Cooperative Oncology Group score was a significant risk factor for implant failure (adjusted sub-hazard ratio, 7.0; 95% confidence interval, 1.63–30.07; p<0.0009).
Conclusions
The incidence of SF (5.7%) was low in patients undergoing MSTS although these patients did not undergo spinal fusion. Preoperative ambulators involved a 7 times higher risk of failure than non-ambulators. Preoperative SINS >7 and fixations spanning junctional regions were associated with SF. Majority of construct failures occurred at the implant-bone interface.
8.Asymptomatic Construct Failure after Metastatic Spine Tumor Surgery: A New Entity or a Continuum with Symptomatic Failure?
Naresh KUMAR ; Ravish PATEL ; Barry Wei Loong TAN ; Jiong Hao TAN ; Naveen PANDITA ; Dhiraj SONAWANE ; Keith Gerard LOPEZ ; Khin Lay WAI ; Hwee Weng Dennis HEY ; Aravind KUMAR ; Gabriel LIU
Asian Spine Journal 2021;15(5):636-649
Methods:
We conducted a retrospective analysis of 288 patients (246 for final analysis) who underwent MSTS between 2005–2015. Data collected were demographics and peri/postoperative clinical and radiological features. Early and late radiological AsCF were defined as presentation before and after 3 months, respectively. We analyzed patients with AsCF for risk factors and survival duration by performing competing risk regression analyses where AsCF was the event of interest, with SF and death as competing events.
Results:
We observed AsCF in 41/246 patients (16.7%). The mean time to onset of AsCF after MSTS was 2 months (range, 1–9 months). Median survival of patients with AsCF was 20 and 41 months for early and late failures, respectively. Early AsCF accounted for 80.5% of cases, while late AsCF accounted for 19.5%. The commonest radiologically detectable AsCF mechanism was angular deformity (increase in kyphus) in 29 patients. Increasing age (p<0.02) and primary breast (13/41, 31.7%) (p<0.01) tumors were associated with higher AsCF rates. There was a non-significant trend towards AsCF in patients with a spinal instability neoplastic score ≥7, instrumentation across junctional regions, and construct lengths of 6–9 levels. None of the patients with AsCF underwent revision surgery.
Conclusions
AsCF after MSTS is a distinct entity. Most patients with early AsCF did not require intervention. Patients who survived and maintained ambulation for longer periods had late failure. Increasing age and tumors with a better prognosis have a higher likelihood of developing AsCF. AsCF is not necessarily an indication for aggressive/urgent intervention.
9.Making a Traditional Spine Surgery Clinic Telemedicine-Ready in the “New Normal” of Coronavirus Disease 2019
Ka-Po Gabriel LIU ; Wei Loong Barry TAN ; Wei Luen James YIP ; Jun-Hao TAN ; Hee-Kit WONG
Asian Spine Journal 2021;15(2):164-171
Methods:
We reviewed the evidence behind telemedicine and described our clinical protocol, patient selection criteria, and workflow for telemedicine. We discussed a simple methodology to convert pre-existing traditional clinic resources into telemedicine tools, along with future challenges.
Results:
Our methodology was successfully and easily applied in our clinical practice, with a streamlined workflow allowing our spine surgery service to implement telemedicine as a consultation modality in line with the national recommendations of social distancing.
Conclusions
Telemedicine was well incorporated into our outpatient practice using the above workflow. We believe that the use of telemedicine via videoconferencing can become part of the new normal and a safe strategy for healthcare systems as both a medical and an economic countermeasure against COVID-19.
10.Symptomatic Construct Failure after Metastatic Spine Tumor Surgery
Naresh KUMAR ; Ravish PATEL ; Jiong Hao TAN ; Joshua SONG ; Naveen PANDITA ; Dennis Hwee Weng HEY ; Leok Lim LAU ; Gabriel LIU ; Joseph THAMBIAH ; Hee-Kit WONG
Asian Spine Journal 2021;15(4):481-490
Methods:
We conducted a retrospective analysis on 288 patients (246 for final analysis) who underwent MSTS between 2005–2015. Data collected were demographics and peri/postoperative clinical and radiological features. Early and late radiological SF were defined as presentation before and after 3 months from index surgery, respectively. Univariate and multivariate models of competing risk regression analysis were designed to determine the risk factors for SF with death as a competing event.
Results:
We observed 14 SFs (5.7%) in 246 patients; 10 (4.1%) underwent revision surgery. Median survival was 13.4 months. The mean age was 58.8 years (range, 21–87 years); 48.4% were women. The median time to failure was 5 months (range, 1–60 months). Patients with SF were categorized into three groups: (1) SF when the primary implant was revised (n=5, 35.7%); (2) peri-construct progression of disease requiring extension (n=5, 35.7%); and (3) SFs that did not warrant revision (n=4, 28.5%). Four patients (28.5%) presented with early failure. SF commonly occurred at the implant-bone interface (9/14) and all patients had a spinal instability neoplastic score (SINS) >7. Thirteen patients (92.8%) who developed failure had fixation spanning junctional regions. Multivariate competing risk regression showed that preoperative Eastern Cooperative Oncology Group score was a significant risk factor for implant failure (adjusted sub-hazard ratio, 7.0; 95% confidence interval, 1.63–30.07; p<0.0009).
Conclusions
The incidence of SF (5.7%) was low in patients undergoing MSTS although these patients did not undergo spinal fusion. Preoperative ambulators involved a 7 times higher risk of failure than non-ambulators. Preoperative SINS >7 and fixations spanning junctional regions were associated with SF. Majority of construct failures occurred at the implant-bone interface.

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