Comparison of Three Different Options for C7 Posterior Vertebral Anchor in the Indian Population—Lateral Mass, Pedicle, and Lamina: A Computed Tomography-Based Morphometric Analysis

Vibhu Krishnan Viswanathan,Surabhi Subramanian,Sushma Viswanathan 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.4

Study Design: Radiological cohort study. Purpose: The options of posteriorly stabilizing C7 vertebra include using lateral mass, pedicle or lamina, as bony anchors. The current study is a computed tomography (CT)-based morphometric analysis of C7 vertebra of 100 Indian patients and discusses the feasibility of these different techniques. Overview of Literature: C7 is a peculiar vertebra with unique anatomy, which poses challenges for each of these fixation modalities. There are no reports available in the literature, which discuss and compare the feasibility of diverse posterior C7 fixation techniques in Indian population. Methods: We included 100 consecutive cervical spine CT scans of Indian patients performed between July 2016 and September 2016. We excluded CT scans with any significant congenital anomaly or other pathological lesions of C7 and patients with non-Indian ethnicity. Regarding screw placement, we assessed and studied various dimensions of the C7 lateral mass, pedicles, and laminae in relevant sections. Results: The mean age of our patients was 49.5±16.1 years. We included 56 male and 44 female patients. The mean anteroposterior and mediolateral dimensions of the lateral mass were 11.38±1.76 and 12.91±1.82 mm, respectively. The mean length of the lateral mass screw (Magerl technique) was 12.17±1.9 mm; 92% of patients could accommodate a lateral mass screw at least 10-mm long (unicortical), whereas 48% could accommodate a screw (unicortical) longer than 12 mm. Foramen transversarium was found in 30.5% of lateral masses. The mean outer and inner cortical widths of the pedicles were 6.5±0.71 mm and 3.72±0.61 mm, respectively. Approximately 58% of pedicles could accommodate 3.5-mm screws (based on the inner cortical pedicle width). The outer cortical and inner cortical widths of the laminae were 6.21±1.2 mm and 3.23±0.9 mm, respectively. Subsequently, 37% of the laminae could accommodate 3.5-mm screws. The mean angle of intralaminar screw trajectory was 50.7°±5.1°, and the mean length of the intralaminar screw was 32.6±3.05 mm. In addition, 96.4% and 60.7% of male patients could accommodate lateral mass screws longer than 10 mm and 12 mm, respectively. However, only 86.4% and 31.8% of female patients could accommodate 10- and 12-mm long lateral mass screws, respectively. Furthermore, 75% of male patients and 36% of female patients had pedicles that could accommodate 3.5-mm diameter screws, and 48.2% of male patients had laminae that could accommodate 3.5-mm screws; however, only 22.7% of female patients could accommodate 3.5-mm laminar screws. Conclusions: Based on our CT-guided morphometric analysis, 92% and 48% of Indian patients could accommodate at least 10- and 12-mm long lateral mass screws, and 58% of pedicles and 37% of laminae could accommodate 3.5-mm screws. Thus, lateral mass screws (between 10- and 12-mm long) seem to be the safest feasible option for C7 fixation. In case of the need for an alternative mode of stabilization (pedicle or intralaminar screw), particularly in female patients, careful preoperative planning with a CT scan is of utmost importance.

Performance and evaluation of MoS2 based machining using PVD-TiAlN coated tool

Viswanathan Sivaraman,Subramanian Prakash 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.9

A recent trend on turning of difficult-to-machine (DTM) materials using environmentally friendly vegetable oil has became popular due to its immense machinability aids. Conventional cutting oils fail to give cooling/lubrication at higher cutting speed-feed combination and create environmental pollution. The present work investigated the effect of molybdenum disulphide nanoparticle (nMoS 2 ) dispersed in castor oil, as a cutting fluid, sprayed using minimum quantity lubrication (MQL) technique on turning of AISI O1 cold worked tool steel. The machining was carried out by varying the speed ranging from 110-170 m/min, a feed rate of 0.02-0.08 mm/rev and depth of cut of 0.7 mm. PVD-TiAlN coated tungsten carbide insert was used for the experimentation. The experimental results of nMQL condition were compared with the dry and wet condition. The results proved that application nMQL has given 15-49 % enhanced tool life with better surface finish as compared with dry and wet condition, respectively. No major phase change occurs in nMQL when compared with other conditions because of their low cutting temperature.

Principles for Managing Patients with Spinal Ailments in the Coronavirus Disease 2019 Era: What Do We Know So Far? An Evidence-Based, Narrative Review

Vibhu Krishnan Viswanathan,Surabhi Subramanian,Arthi K. Rao 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.4

The coronavirus disease 2019 (COVID-19) pandemic has significantly affected all specialty practices in medicine, including the field of spinal surgery. Spinal surgery is unique in that the procedures include not only fully elective and fully emergent interventions, but also involve a separate group of semi-emergent surgeries, where delayed intervention may lead to permanent neurological deficits. Here, we present an evidence-based review on the impact of the COVID-19 pandemic on spinal surgery and our current knowledge about this issue. We conducted a thorough search of the PubMed, Medline, and Google Scholar databases using the keywords, “COVID-19,” “COVID-19 impact on spine surgery,” “coronavirus impact on spine surgery,” “COVID-19 impact on neurosurgery,” “coronavirus impact on neurosurgery,” “COVID-19 impact on spine surgeons,” and “coronavirus impact on spine surgeons” on May 6, 2020. A total of 8,322 articles were identified in the initial search. Articles that were duplicated, those that did not pertain to COVID-19 or spine surgeries, those with details not pertaining to the current topic of interest, and those published in languages other than English were excluded from our analyses. After complete screening, six articles were included in this review. During the previous few weeks, the COVID pandemic has significantly influenced all major aspects of spine surgery across the world. Outpatient care has been gradually shifted from physical visits to tele-health and online consultations. General recommendations have favored the conservative approach over surgeries, although no patient should be deprived of standard care owing to concerns about COVID. The general principles followed by spine surgeons should include early detection of COVID symptomatology; triaging of patients based on underlying spinal pathology; prescription of appropriate investigations to confirm the COVID status; isolation, as needed; selection of optimal management method as per the guidelines; adherence to best intraoperative practices; and ensuring protective measures for non-infected patients, family members, fellow heath care providers, and themselves against the disease.

Effect of certain trimethoxy flavones on paclitaxel - induced peripheral neuropathy in mice

Jagan Nadipelly,Vijaykumar Sayeli,Parimala Kadhirvelu,Jaikumar Shanmugasundaram,Binoy Varghese Cheriyan,Viswanathan Subramanian 한국한의학연구원 2018 Integrative Medicine Research Vol.7 No.2

Background: The anti - nociceptive effect of 7, 2′, 3′ – trimethoxy flavone, 7, 2′, 4′ – trimethoxy flavone, 7, 3′, 4′ – trimethoxy flavone and 7, 5, 4′ – trimethoxy flavone against inflammatory, neurogenic and thermal pain in mice was reported earlier. The present study was designed to investigate the effect of the above trimethoxy flavones in amelioration of peripheral neuropathy induced by paclitaxel. Methods: Peripheral neuropathy was induced in mice by administration of a single i.p. dose (10 mg/kg) of paclitaxel. The manifestations of peripheral neuropathy such as tactile allodynia, cold allodynia and thermal hyperalgesia were assessed 24 h later by employing hair aesthesiometer test, acetone bubble test and hot water tail immersion test respectively. Further, the role of inflammatory cytokines like TNF – α, IL - 1β and free radicals in the action of trimethoxy flavones was investigated using in vitro assays. Results: The test compounds dose dependently attenuated paclitaxel - induced tactile allodynia, cold allodynia and thermal hyperalgesia in mice. The test compounds inhibited TNF – α, IL - 1β and free radicals in a concentration dependent manner. Conclusion: The investigated trimethoxy flavones attenuated paclitaxel – induced peripheral neuropathy in mice. The inhibition of cytokines and free radicals in addition to many neuronal mechanisms reported earlier may contribute to this beneficial effect.