Spatio-Temporal Variability of Rainfall Indices and their Teleconnections with El Niño-Southern Oscillation for Tapi Basin, India

Gehlot Lalit Kumar,Jibhakate Shubham M.,Sharma Priyank J.,Patel P. L.,Timbadiya P. V. 한국기상학회 2021 Asia-Pacific Journal of Atmospheric Sciences Vol.57 No.1

The long-term spatio-temporal variability in twelve rainfall indices across Tapi basin are investigated for period 1944–2013. The temporal trends in aforesaid indices, representing magnitude, intensity, frequency and duration of rainfall, are analysed using nonparametric tests. The total annual rainfall exhibit uniformly increasing trends over Lower Tapi basin (LTB), while heterogeneous trends are observed across Upper (UTB) and Middle (MTB) Tapi basins. The rainy days portrays decreasing trends at 75% stations in the basin, while rainfall intensity displays increasing trends across LTB and UTB. On other hand, LTB and Purna sub-catchment (in UTB) show coherent increasing trends in extreme rainfall, while decreasing trends are observed over Burhanpur sub-catchment (in UTB) and MTB. A considerable increase in duration of dry spells is reported at 92.5% stations in the basin, indicating a marked shift towards drier climatic regime. Further, Principal Component Analysis (PCA) is carried out to address the space-time variability of rainfall indices. The results of PCA were adopted in cluster analysis to identify the stations exhibiting similar characteristic variations in rainfall trends. The hydroclimatic teleconnections between rainfall indices and large-scale oceanic-atmospheric circulations of the tropical Pacific Ocean (viz., El Niño-Southern Oscillation) revealed the prevalence of wet conditions in the basin during moderate to strong La-Niña, while dry conditions were encountered during moderate to strong El-Niño and weak La-Niña events. The spatial estimates of rainfall indices are derived corresponding to 2-, 10- and 50-year return periods which would be helpful in hydrologic design and risk assessment of rainfall-induced disasters in near future.

Endoscopic Spine Surgery

Choi, Gun,Pophale, Chetan S,Patel, Bhupesh,Uniyal, Priyank The Korean Neurosurgical Society 2017 Journal of Korean neurosurgical society Vol.60 No.5

Surgical treatment of the degenerative disc disease has evolved from traditional open spine surgery to minimally invasive spine surgery including endoscopic spine surgery. Constant improvement in the imaging modality especially with introduction of the magnetic resonance imaging, it is possible to identify culprit degenerated disc segment and again with the discography it is possible to diagnose the pain generator and pathological degenerated disc very precisely and its treatment with minimally invasive approach. With improvements in the optics, high resolution camera, light source, high speed burr, irrigation pump etc, minimally invasive spine surgeries can be performed with various endoscopic techniques for lumbar, cervical and thoracic regions. Advantages of endoscopic spine surgeries are less tissue dissection and muscle trauma, reduced blood loss, less damage to the epidural blood supply and consequent epidural fibrosis and scarring, reduced hospital stay, early functional recovery and improvement in the quality of life & better cosmesis. With precise indication, proper diagnosis and good training, the endoscopic spine surgery can give equally good result as open spine surgery. Initially, endoscopic technique was restricted to the lumbar region but now it also can be used for cervical and thoracic disc herniations. Previously endoscopy was used for disc herniations which were contained without migration but now days it is used for highly up and down migrated disc herniations as well. Use of endoscopic technique in lumbar region was restricted to disc herniations but gradually it is also used for spinal canal stenosis and endoscopic assisted fusion surgeries. Endoscopic spine surgery can play important role in the treatment of adolescent disc herniations especially for the persons who engage in the competitive sports and the athletes where less tissue trauma, cosmesis and early functional recovery is desirable. From simple chemonucleolysis to current day endoscopic procedures the history of minimally invasive spine surgery is interesting. Appropriate indications, clear imaging prior to surgery and preplanning are keys to successful outcome. In this article basic procedures of percutaneous endoscopic lumbar discectomy through transforaminal and interlaminar routes, percutaneous endoscopic cervical discectomy, percutaneous endoscopic posterior cervical foraminotomy and percutaneous endoscopic thoracic discectomy are discussed.

Does Three-Dimensional Printed Patient-Specific Templates Add Benefit in Revision Surgeries for Complex Pediatric Kyphoscoliosis Deformity with Sublaminar Wires in Situ? A Clinical Study

Shah Kunal,Gadiya Akshay,Shah Munjal,Vyas Devarsh,Patel Priyank,Bhojraj Shekhar,Nene Abhay 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.1

Study Design: Case-control study.Purpose: To evaluate the accuracy of three-dimensional (3D) printed patient-specific templates (PSTs) for placement of pedicle screws (PAs) in patients undergoing revision surgeries for complex kyphoscoliosis deformity with sublaminar wires in situ.Overview of Literature: Revision kyphoscoliosis correction surgery in pediatric patients is a challenging task for the treating surgeon. In patients with sublaminar wires in situ, the native anatomical landmarks are obscured, thus making the freehand screw placement technique a highly specialized task. Hence, the concept of using PSTs for insertion of PAs in such surgeries is always intriguing and attractive.Methods: Five consecutive patients undergoing revision deformity correction with sublaminar wires in situ were included in this study. Patients were divided in two groups based on the technique of PA insertion. A total of 91 PAs were inserted using either a freehand technique (group A) or 3D printed templates (group B) (34 vs. 57). The placement of PAs was classified according to a postoperative computed tomography scan using Neo’s classification. Perforation beyond class 2 (>2 mm) was termed as a misplaced screw. The average time required for the insertion of screws was also noted.Results: Mean age, surgical time, and blood loss were recorded. The change in mean Cobb’s angle in both groups was also recorded. The difference in rates of misplaced screws was noted in group A and group B (36.21% vs. 2.56%); however, the mean number of misplaced PAs per patient in group A and group B was statistically insignificant (6.5±3.54 vs. 4.67±1.53, p =0.4641). The mean time required to insert a single PA was also statistically insignificant (120±28.28 vs. 90±30 seconds, p =0.3456).Conclusions: Although 3D printed PSTs help to avoid the misplacement of PAs in revision deformity correction surgeries with sublaminar wires in situ, the mean number of misplaced screws per patient using this technique was found to be statistically insignificant when compared with the freehand technique in this study.

Management of Andersson Lesion in Ankylosing Spondylitis Using the Posterior-Only Approach: A Case Series of 18 Patients

Ismail Shaik,Shekhar Yeshwant Bhojraj,Gautam Prasad,Premik Bhupendra Nagad,Priyank Mangaldas Patel,Aaditya Dattatreya Kashikar,Nishant Kumar 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.6

Study Design: This retrospective study was conducted including 18 patients who underwent posterior-only stabilization and fusion procedure for pseudoarthrosis in the ankylosed spine from October 2007 to May 2015. Purpose: This study aimed to describe the treatment outcomes in 18 patients with Andersson lesion (AL) who were managed using the posterior-only approach. Literature Review: AL is an unstable, localized, vertebral, or discovertebral lesion of the spine. It is observed in patients with ankylosing spondylitis. The exact etiology of this disorder remains unclear, and the treatment guidelines are not clearly described. Methods: We analyzed 18 patients with AL who were treated with posterior long segment spinal fusion without any anterior interbody grafting or posterior osteotomy. Pre- and postoperative radiography, computed tomography, and recent follow-up images were examined. The pre- and postoperative Visual Analog Scale score and the Oswestry Disability Index score were evaluated for all patients. Whiteclouds’ outcome analysis criteria were applied at the follow-up. Moreover, at study completion, patient feedback was collected; all the patients were asked to provide their opinion regarding the surgery and were asked whether they would recommend this procedure to other patients and them self undergo the same procedure again if required. Results: The most common site was the thoracolumbar junction. The symptom duration ranged from 1 month to 10 years preoperatively. Most patients experienced fusion by the end of 1 year, and the fusion mass could be observed as early as 4 months. Pseudoarthrosis void of up to 2.5 cm was noted to be healed in subsequent imaging. In addition, clinically, the patients reported good symptomatic relief. No patient required revision surgery. Whiteclouds’ outcome analysis score at the latest follow-up revealed goodto- excellent outcomes in all patients. Conclusions: ALs can be treated using the posterior-only approach with long segment fixation and posterior spinal fusion. This is a safe, simple, and quick procedure that prevents the morbidity of anterior surgery.

Analysis of the Functional and Radiological Outcomes of Lumbar Decompression without Fusion in Patients with Degenerative Lumbar Scoliosis

Akshay Dharamchand Gadiya,Mandar Deepak Borde,Nishant Kumar,Priyank Mangaldas Patel,Premik Bhupendra Nagad,Shekhar Yeshwant Bhojraj 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.1

Study Design: Retrospective study. Purpose: This study aimed to analyze the functional and radiological outcomes of lumbar decompression in patients with degenerative lumbar scoliosis (DLS). Overview of Literature: Patients with DLS have symptoms related to lumbar canal stenosis (LCS) and those due to compensated spinal imbalance. Whether the deformity is the cause of pain or is an adaptive change for the ongoing LCS remains debatable. The extensive surgery for deformity correction along with spinal fusion is reported to have high perioperative morbidity and complication rate. Methods: This retrospective analysis involved 51 patients who underwent lumbar decompression for LCS associated with DLS from October 2006 to October 2016. The magnitude of the curve was determined using Cobb’s angle and lumbar lordosis (D12–S1) on the preoperative and final follow-up, respectively. The Visual Analog Scale (VAS) and modified Oswestry Disability Index (mODI) scores at the preoperative and final follow-up indicated the functional outcome. Statistical analyses were performed using Student t -test. Results: All 51 patients were included in the statistical analyses. The mean patient age at presentation was 63.88±7.21 years. The average follow-up duration was 48±18.10 months. The average change in the Cobb’s angle at the final follow-up was statistically insignificant (1°±1.5°, p =0.924; 20.8°±5.1° vs. 21.9°±5.72°). The mean change in lumbar lordosis at the final follow-up was statistically insignificant (3.29°±1.56°, p =0.328; 30.2°±7.9° vs. 27.5°±7.1°). There was statistically insignificant worsening in the back VAS scores at the final follow-up (4.9±1.9 vs. 6.0±1.2, p =0.07). There was statistically significant improvement in the leg pain component of the VAS score at the final follow-up (5.8±1.05 vs. 2.6±1.2, p <0.001). There was statistically significant improvement in the mODI scores at the final follow-up (p <0.001). Conclusions: Lumbar decompression in DLS is associated with good functional outcome, especially when the symptoms are related to LCS. Curve progression following lumbar decompression is very less at mid-term and is similar to that in the natural course of the disease.