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.Functional and Radiological Outcomes of All-Posterior Surgical Correction of Dystrophic Curves in Patients with Neurofibromatosis Type 1
Ajoy Prasad SHETTY ; Jalaj MEENA ; Chandhan MURUGAN ; Rounak MILTON ; Rishi Mugesh KANNA ; Shanmuganathan RAJASEKARAN
Asian Spine Journal 2024;18(2):174-181
Methods:
This study included patients who underwent all-posterior surgical deformity correction for dystrophic NF-1 curves. Coronal and sagittal Cobbs angles, apical rotation, and the presence of dystrophic features were evaluated before surgery. Postoperatively, sagittal, coronal, and axial correction, implant position, and implant densities were evaluated. The decline in curve correction and implant-related complications were evaluated at follow-up. Clinical outcomes were evaluated using the Scoliosis Research Society-22 revised index.
Results:
This study involved 50 patients with a mean age of 13.6 years and a mean follow-up duration of 5.52 years. With a mean coronal flexibility of 18.7%, the mean apical vertebral rotation (AVR), preoperative coronal Cobb angle, and sagittal kyphosis were 27.4°, 64.01°, and 47.70°, respectively. The postoperative mean coronal Cobb angle was 30.17° (p <0.05), and the sagittal kyphosis angle was 25.4° (p <0.05). The average AVR correction rate was 41.3%. The correction remained significant at the final mean follow-up, with a coronal Cobb angle of 34.14° and sagittal kyphosis of 25.02° (p <0.05). The average implant density was 1.41, with 46% of patients having a high implant density (HID). The HID had a markedly higher mean curve correction (29.30° vs. 38.05°, p <0.05) and a lower mean loss of correction (5.7° vs. 3.8°, p <0.05).
Conclusions
Utilizing computer-assisted navigation, hybrid instrumentation, and multiple anchor point technique and attaining high implant densities, this study demonstrates successful outcomes following posterior-only surgical correction of dystrophic scoliosis in patients with NF-1.
5.Does Magnetic Resonance Imaging Predict Neurological Deficit in Patients with Traumatic Lower Lumbar Fractures?
Karthik RAMACHANDRAN ; R Dinesh IYER ; Prashasth Belludi SURESH ; Ajoy Prasad SHETTY ; Puspha Bhari THIPPESWAMY ; Rishi Mugesh KANNA ; Shanmuganathan RAJASEKARAN
Asian Spine Journal 2024;18(2):200-208
Methods:
In total, 108 patients who underwent surgery for traumatic LLFs between January 2010 and January 2020 were reviewed to obtain their demographic details, injury level, and neurology status at the time of presentation (American Spinal Injury Association [ASIA] grade). Preoperative computed tomography scans were used to measure parameters such as anterior vertebral body height, posterior vertebral body height, loss of vertebral body height, local kyphosis, retropulsion of fracture fragment, interpedicular distance, canal compromise, sagittal transverse ratio, and presence of vertical lamina fracture. MRI was used to measure the canal encroachment ratio (CER), cross-sectional area of the thecal sac (CSAT), and presence of an epidural hematoma.
Results:
Of the 108 patients, 9 (8.3%) had ASIA A, 4 (3.7%) had ASIA B, 17 (15.7%) had ASIA C, 21 (19.4%) had ASIA D, and 57 (52.9%) had ASIA E neurology upon admission. The Thoracolumbar Injury Classification and Severity score (p =0.000), CER (p =0.050), and CSAT (p =0.019) were found to be independently associated with neurological deficits on the multivariate analysis. The receiver operating characteristic curves showed that only CER (area under the curve [AUC], 0.926; 95% confidence interval [CI], 0.860–0.968) and CSAT (AUC, 0.963; 95% CI, 0.908–0.990) had good discriminatory ability, with the optimal cutoff of 50% and 65.3 mm2, respectively.
Conclusions
Based on the results, the optimal cutoff values of CER >50% and CSAT >65.3 mm2 can predict the incidence of neurological deficits in LLFs.
6.Analysis of Postoperative Clinical Outcomes in Cervical Myelopathy due to Ossification of Posterior Longitudinal Ligament Involving C2
Ajoy Prasad SHETTY ; Neerav Anand SINGH ; Guna Pratheep KALANJIYAM ; Jalaj MEENA ; Shanmuganathan RAJASEKARAN ; Rishi Mugesh KANNA
Asian Spine Journal 2023;17(3):461-469
Methods:
We retrospectively studied 61 patients with C2 (+) OPLL who had posterior instrumented laminectomy and fusion at Ganga Hospital, Coimbatore between July 2011 and January 2021, with a minimum follow-up of 2 years. Data on demographics, clinical outcomes, radiology, and post-surgical outcomes were gathered.
Results:
Among 61 patients, 56 were males and five were females. The OPLL pattern was mixed in 32 cases (52.5%), continuous in 26 cases (42.6%), segmental in two cases (3.3%), and circumscribed in one patient (1.6%). All of our patients showed signs of neurological improvement after a 24-month follow-up. The mean preoperative modified Japanese Orthopaedic Association (mJOA) score was 10.6 (range, 5–11) and the postoperative mJOA score was 15.8 (range, 12–18). The recovery rate was >75% in 27 patients (44.6%), >50% in 32 patients (52.5%), and >25% in two patients (3.3%). The average recovery rate was 71% (range, 33%–100%). The independent risk factor for predicting recovery rate is the preoperative mJOA score.
Conclusions
In C2 (+) OPLL, posterior instrumented decompression and fusion provide a relatively safe approach and satisfactory results.
7.In Vertebral Hemangiomas with Neurological Deficit, Is a Less Extensive Approach Adequate
Guna Pratheep K. ; Ajoy Prasad SHETTY ; Sri Vijay Anand K. S. ; Rohit KAVISHWAR ; Rishi Mugesh KANNA ; Shanmuganathan RAJASEKARAN
Asian Spine Journal 2023;17(1):37-46
Methods:
Twenty-one patients who underwent surgery for AVH between 2009 and 2018 were analyzed. Demographic and clinical details of patients were retrieved from hospital information system. Imaging information (i.e., radiography, computed tomography, magnetic resonance imaging) of all patients was accessed and analyzed in picture archiving and communication system. Tumor staging was performed using Enneking and Weinstein–Boriani–Biagini classifications and Spinal Instability Neoplastic Score. At followup, neurological and radiological evaluations were performed.
Results:
Twenty-one patients (13 [61.9%] females and 8 [38.1%] males) were included with a mean age of 44.29 years (range, 14–72 years). All patients in the study had neurological deficit. Back pain was present in 80.9% of patients. Mean duration of symptoms was 4.6 months (range, 1 day to 10 months). Most common lesion location was thoracic spine (n=12), followed by thoracolumbar (D11– L2; n=7) and lumbar (n=2) regions. Ten patients had multiple level lesions. All patients underwent preoperative embolization. Nine patients underwent intralesional spondylectomy with reconstruction; another nine patients underwent stabilization, decompression, and vertebroplasty; three patients underwent decompression and stabilization. Neurology improved in all patients, and only one case of recurrence was noted in a mean follow-up of 55.78±25 months (range, 24–96 months).
Conclusions
In AVH, good clinical and neurological outcomes with low recurrence rates can be achieved using less extensive procedures, such as posterior instrumented decompression with vertebroplasty and intralesional tumor resection.
8.Type I Arnold Chiari Malformation with Syringomyelia and Scoliosis: Radiological Correlations between Tonsillar Descent, Syrinx Morphology and Curve Characteristics: A Retrospective Study
Sivaraj SHANMUGASUNDARAM ; Vibhu Krishnan VISWANATHAN ; Ajoy Prasad SHETTY ; Nimish RAI ; Swapnil HAJARE ; Rishi Mukesh KANNA ; Shanmuganathan RAJASEKARAN
Asian Spine Journal 2023;17(1):156-165
Methods:
Data regarding patients, who underwent PFD for ACM-I presenting with SM and scoliosis between January 2009 and December 2018, were retrospectively collected. Only patients with 2-year follow-up were included. Sagittal/coronal deformity and sagittal spinopelvic parameters were examined. Symmetry and extent of tonsillar descent, as well as morphology (configuration/variation) and extent of syrinx were determined.
Results:
A total of 42 patients (20 females; age: 14.2±5.8 years) were included; 35 patients (83.3%) had atypical curves. Mean preoperative coronal Cobb was 57.7°±20.9°; and 12 (28.6%) had significant coronal imbalance. Tonsillar descent was classified as grade 1, 2, and 3 in 16 (38.1%), 11 (26.2%), and 15 (35.7%) patients; 35 patients (83.3%) had asymmetric tonsillar descent; 17 (40.4%), 3 (7.1%), 16 (38.1%), and 6 (14.4%) had circumscribed, moniliform, dilated, and slender syrinx patterns; and 9 (21.4%), 12 (28.6%), and 21 (50%) of syrinx were right-sided, left-sided, and centric. There was no significant relationship between side of tonsillar dominance (p =0.31), grade of descent (p =0.30), and convexity of deformity. There was significant association between side of syrinx and convexity of scoliosis (p =0.01). PFD was performed in all, and deformity correction was performed in 23 patients. In curves ≤40°, PFD alone could stabilize scoliosis progression (p =0.02). There was significant reduction in syrinx/cord ratio following PFD (p <0.001).
Conclusions
ACM-I+SM patients had atypical curve patterns in 83% of cases, and the side of syrinx deviation correlates with scoliosis convexity. Syrinx shrinks significantly following PFD. PFD may not stabilize scoliosis in curves >40°.
9.Novel Biomarkers of Health and Degeneration in Human Intervertebral Discs: In-depth Proteomic Analysis of Collagen Framework of Fetal, Healthy, Scoliotic, Degenerate, and Herniated Discs
Shanmuganathan RAJASEKARAN ; Dilip Chand Raja SOUNDARARAJAN ; Sharon Miracle NAYAGAM ; Chitraa TANGAVEL ; Muthuraja RAVEENDRAN ; Sri Vijay Anand K S ; Ajoy Prasad SHETTY ; Rishi Mugesh KANNA
Asian Spine Journal 2023;17(1):17-29
Methods:
Forty NP tissues were snap-frozen in liquid nitrogen (–196°C) immediately before being subjected to proteomic and bioinformatic analyses from five different disk phenotypes (eight each).
Results:
Tandem mass spectrometric analysis revealed a total of 1,050 proteins in FDs, 1,809 in ND, 1,487 in SD, 1,859 in DH, and 1,538 in the DD group. Of 28 major collagens reported in the human body, this study identified 24 different collagens with 34 subtypes in NP. Fibril-forming collagens (COL-1, 2, and 11A1) and fibril-associated collagens with interrupted triple helices (COL-9A1, 12A1, and 14A1) were abundantly expressed in FDs, representing their role in the development of NP. Multiplexin (COL-15), a hybrid proteoglycan–collagen molecule, was discovered only in FDs. Degeneration was associated with COL2A1 downregulation and COL-10A1 upregulation.
Conclusions
COL10 was discovered to be a new biomarker for disk degeneration. Besides COL-1 and 2, other important COLs (6, 9, 11, 12, 14, 15) with anabolic potential and abundant expression in the fetal phenotype could be investigated for tissue engineering and novel DDD therapy.
10.Impact of Acute Lumbar Disk Herniation on Sexual Function in Male Patients
Keerthivasan PANNEERSELVAM ; Rishi Mugesh KANNA ; Ajoy Prasad SHETTY ; Shanmuganathan RAJASEKARAN
Asian Spine Journal 2022;16(4):510-518
Methods:
We evaluated sexually active male patients (n=22, 40.8±6.8 years) admitted for microdiscectomy with a questionnaire for assessing sexual function before and 8 weeks after surgery. The questionnaire included the Oswestry Disability Index, Hospital Anxiety Depression Score, and Brief Sexual Function Inventory (BSFI), as well as questions about perceived sexual dysfunction (frequency, performance, satisfaction).
Results:
The average preoperative Visual Analog Scale (VAS) score was 4.36±2.59 (n=18) for low back pain (LBP) and 6.81±2.1 (n=22) for leg pain. The mean preoperative BSFI score was 27.8±11.2. Among the five BSFI components, sexual drive was reduced in 63.0% of patients, while erection and ejaculation were affected in 40.9% and 31.8%, respectively. The VAS score for LBP had a negative correlation with the preoperative BSFI score (p <0.03). After LDH onset, 54.5% of patients noted a decrease in frequency, and 77.2% described a decrease in desire and satisfaction. At 8 weeks after surgery, the mean BSFI score significantly improved to 33.23 (p =0.002). Sexual drive was normal in 77.7% of patients, and erection and ejaculation were normal in 77.7% and 91.0%, respectively. Overall, 59.1% had resumed sexual intercourse within 6 weeks of surgery.
Conclusions
LDH resulted in sexual dysfunction in up to 77% of patients, which significantly improved after surgery. By 6 weeks, the majority had resumed sexual activity without undue discomfort. Therefore, this study supports counseling for patients with LDH about sexual function.

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