Simultaneous decompression of all stenotic regions versus decompression of only the most symptomatic region in patients with tandem spinal stenosis: a systematic review and meta-analysis.

PURPOSE: Selection of anatomic region of spine for decompression in patients with symptomatic tandem spinal stenosis (TSS) remains a challenge due to the confusing clinical presentation as well as uncertain evidence. A systematic review and meta-analysis of observational studies were conducted to compare the outcomes between simultaneous decompression of all stenotic regions (cervical and lumbar, Group 1) and decompression of only the most symptomatic stenotic region (cervical/lumbar, Group 2) in patients with TSS. METHODS: A systematic review was conducted, and a comprehensive literature search with well-established inclusion and exclusion criteria with JOA score as an outcome measure was done on PubMed, Google Scholar, and EMBASE database (till January 2021). Observational studies reporting outcomes after simultaneous decompression or only the most symptomatic region were included. NIH quality assessment tool was used to check the quality of each study, and treatment effects were calculated using Dersimonian and Laird random effects model. RESULTS: Ten studies were included in the analysis out of which all were retrospective observational studies (Level 4 evidence) except one (Level 3 evidence). Overall proportional meta-analysis showed no significant difference in change in JOA scores, operative time, blood loss, total and major complications between Group 1 and Group 2. However, minor complications were significantly increased on performing decompression of both regions simultaneously (p = 0.04). On performing subgroup analysis comparing cervical surgery cohort with lumbar surgery cohort, no difference was found in change in JOA score and requirement of second-stage surgery. CONCLUSION: Decompression of the most symptomatic region alone irrespective of its location has equal clinical outcomes with less complication rate than simultaneous decompression in patients with TSS.

Role of local streptomycin in prevention of surgical site infection in TB spine.

PURPOSE: Surgical site infection (SSI) continues to be one of the most common post-operative complications in most spine surgeries. Patients with tuberculosis (TB) of spine are more at risk of developing this complication due to a number of reasons. This adds to significant morbidity and economic burden on patients adversely affecting the mental status and quality of life of patients. The aim of this study was to investigate the role of local streptomycin in preventing SSI in patients undergoing surgical management of spinal TB. METHODS: In total, 56 patients who underwent surgical management for radiologically proven TB spine divided into two groups were included in the study. Group A included 30 patients with no local streptomycin administered intraoperatively, while group B included 26 patients operated in the later part of study with the use of local streptomycin intraoperatively. The two groups were compared and the outcome criteria analysed were SSI rate, length of hospital stay, duration of post-operative antibiotics and need for debridement. RESULTS: Length of hospital stay (group A: 18.4 ± 6.9 days; group B: 9.7 ± 3.9 days) and duration of post-operative antibiotics (group A: 8.1 ± 1.6 days; group B: 6.2 ± 2.1 days) were significantly higher in group A when compared with group B. SSI rate (group A: 13.34%; group B: 3.84%) and need for debridement (group A: 10%; group B: 3.84%) were higher in group A, but the difference was not statistically significant. CONCLUSION: Intraoperative administration of local streptomycin significantly reduces the length of hospital stay and duration of antibiotic administration in post-operative period in patients undergoing surgery for TB spine.

Multiple-choice questions in assessment: Perceptions of medical students from low-resource setting.

BACKGROUND: In curriculum reforms under Competency-Based Medical Education (CBME) introduced by the National Medical Commission, medical students are recognized as one of the stake holders. The well-designed multiple-choice questions (MCQs) help students in assessment as well as promote deep learning. The objective of this study is to assess the perceptions of the Indian medical students towards the examination patterns in their undergraduate curriculum with particular reference to MCQs. MATERIALS AND METHODS: An observational cross-sectional study was conducted among the medical colleges in India. A total of 7875 students took part in the study. The study instrument was a validated pretested self-administered questionnaire. The study was conducted as an online survey using the Google Forms platform. Inclusion criteria were students from all professional years as well as interns and those who were willing to participate in the study. RESULTS: For the question of initiation of MCQs as a tool for the assessment, many of the students (46%) expressed that it should start from the 1st MBBS itself. The majority of the students (85%) felt that MCQ oriented preparation will be helpful for MBBS professional (theory and practical) examinations. Most of the students (90.9%) preferred that the MCQs should be concept and case scenario based. To the question of whether the current system of the university theory examinations of essays and short notes be replaced in total with MCQs so that they are more prepared for NEXT and USMLE examination, 65.5% responded with an answer of yes. CONCLUSION: The findings of this study provide input to the regulatory authorities and other stakeholders responsible for designing and implementing the medical curriculum.

Recurrent multifocal cutaneous Kaposiform hemangioendothelioma: A rare vascular tumor of infancy and childhood.

Kaposiform hemangioendothelioma (KHE) is a locally aggressive vascular tumor of childhood although cases occurring in adulthood are also described. The features overlap with juvenile capillary hemangioma and Kaposi sarcoma. We report a rare case of recurrent, multifocal (nose and chin) cutaneous KHE initially occurring in a 3-year-old female child, uncomplicated by Kasabach-Merritt syndrome. Recurrences occurred over the next 6 years and resulted in complete distortion of the nose, requiring plastic repair.

Osteogenesis in calvarial defects: contribution of the dura, the pericranium, and the surrounding bone in adult versus infant animals.

Guided bone regeneration is a promising means for reconstructing bone defects in the cranium. The present study was performed to better define those factors that affect osteogenesis in the cranium. The authors studied a single animal model, investigating the contribution of the dura, the pericranium, and the adjacent calvarial bone in the process of calvarial regeneration in both mature and immature animals. Bilateral, 100-mm2, parietal calvariectomies were performed in immature (n = 16) and mature (n = 16) rabbits. Parietal defects were randomized to one of four groups depending on the differential blockade of the dura and/or the pericranium by expanded polytetrafluoroethylene membranes. Animals were humanely killed after 12 weeks, and histometric analysis was performed to quantitate the area of the original bone defect, new bone formation, and new bone density. Bone formation was quantified separately both at the periphery and in the center of the defects. Extrasite bone formation was also quantified both on the dural and on the pericranial sides of the barriers. Bone regeneration was incomplete in all groups over the 12-week study period, indicating that complete bone healing was not observed in any group. The dura was more osteogenic than the pericranium in mature and immature animals, as there was significantly more extrasite bone formed on the dural side in the double expanded polytetrafluoroethylene barrier groups. In both the dural and the double expanded polytetrafluoroethylene barrier groups, dural bone production was significantly greater in immature compared with mature animals. The dura appeared to be the source of central new bone, because dural blockade in the dural and double expanded polytetrafluoroethylene groups resulted in a significant decrease in central bone density in both mature and immature animals. Paradoxically, isolation of the pericranium in mature animals resulted in a significant reduction in total new bone area, whereas pericranial contact appeared to enhance peripheral new bone formation, with the control group having the greatest total new bone area. The present study establishes a model to quantitatively study the process of bone regeneration in calvarial defects and highlights differences in the contribution of the dura and pericranium to calvarial bone regeneration between infant and adult animals. On the basis of these findings, the authors propose that subsequent studies in which permeability of the expanded polytetrafluoroethylene membranes is altered to permit migration of osteoinductive proteins into the defect while blocking prolapse of adjacent soft tissues may help to make guided bone regeneration a realistic alternative for the repair of cranial defects.

Cherubism--a case report with long term follow up.

Cherubism is a rare non-neoplastic disease of the bone characterized by bilateral painless enlargement of the jaws giving a cherubic appearance to the patient. It is an autosomal dominant disorder but may occur sporadically. In this paper, we have tried to explain about the clinical, radiological and histopathologic features of cherubism by presenting a case study. A case study of a 7 year old male patient, who first presented with mandibular bilateral swellings to our department in 1998, has been presented. In-depth clinical, radiological and histopathologic examination was done. An extensive long-term follow-up till 11 years was maintained. When presented for the first time, radiological investigation showed characteristic multilocular lytic lesions of the mandible bilaterally. Histopathological examination of the biopsy specimen showed proliferating fibrous connective tissue interspersed by multinucleated giant cells. It was diagnosed as a case nonfamilial cherubism. Follow-up after 5 years showed involvement of the maxilla as well, which was then corrected by surgical methods. Upon follow up 11 years after the first presentation, it was seen that the lesion was regressing by itself and there was improvement in facial contour. The natural course of Cherubism through its progression, stabilization and involution of the disease after puberty, has been highlighted in this case. More, in-depth studies to understand the nature and the pathogenesis of this condition better are required.

Analytical shape computation of macromolecules: I. Molecular area and volume through alpha shape.

The size and shape of macromolecules such as proteins and nucleic acids play an important role in their functions. Prior efforts to quantify these properties have been based on various discretization or tessellation procedures involving analytical or numerical computations. In this article, we present an analytically exact method for computing the metric properties of macromolecules based on the alpha shape theory. This method uses the duality between alpha complex and the weighted Voronoi decomposition of a molecule. We describe the intuitive ideas and concepts behind the alpha shape theory and the algorithm for computing areas and volumes of macromolecules. We apply our method to compute areas and volumes of a number of protein systems. We also discuss several difficulties commonly encountered in molecular shape computations and outline methods to overcome these problems.

Analytical shape computation of macromolecules: II. Inaccessible cavities in proteins.

The structures of proteins are well-packed, yet they contain numerous cavities which play key roles in accommodating small molecules, or enabling conformational changes. From high-resolution structures it is possible to identify these cavities. We have developed a precise algorithm based on alpha shapes for measuring space-filling-based molecular models (such as van der Waals, solvent accessible, and molecular surface descriptions). We applied this method for accurate computation of the surface area and volume of cavities in several proteins. In addition, all of the atoms/residues lining the cavities are identified. We use this method to study the structure and the stability of proteins, as well as to locate cavities that could contain structural water molecules in the proton transport pathway in the membrane protein bacteriorhodopsin.