Feasibility of Sub-Axial Cervical Laminar Screws, Including C7, in the Indian Population: A Study on 50 Patients Using Computed Tomography-Based Morphometry Measurements

Study Design Observational study of computed tomography (CT) data. Purpose We performed a CT-based radiographic analysis of sub-axial cervical lamina in the Indian population to assess the feasibility of laminar screws. Overview of Literature Morphometric studies have been performed for populations of various ethnic groups, but none exist for Indian populations. Methods Cervical spine CT scans of 50 adults with a minimum slice thickness of <2 mm (0.5–2 mm) were obtained from the database of a single center in northern India. Measurements (e.g., length, thickness, and height) were taken in millimeters along the axial, coronal, and sagittal planes. Three measurements were made to assess laminar anatomy, namely, the translaminar/screw length, laminar thickness, and sagittal laminar height. Results The final sample comprised 500 laminae in 50 patients, resulting in 1,500 measurements. The mean translaminar lengths of the C3, C4, C5, C6, and C7 laminae were 19.48 mm, 19.60 mm, 19.61 mm, 20.49 mm, and 22.85 mm, respectively. The mean thick- , 19.60 , 19.60 mm, 19.61 mm, 20.49 mm, and 22.85 mm, respectively. The mean thick- mm, 19.61 mm, 20.49 mm, and 22.85 mm, respectively. The mean thick- , 19.61 , 19.61 mm, 20.49 mm, and 22.85 mm, respectively. The mean thick- mm, 20.49 mm, and 22.85 mm, respectively. The mean thick- , 20.49 , 20.49 mm, and 22.85 mm, respectively. The mean thick- mm, and 22.85 mm, respectively. The mean thick- , and 22.85 mm, respectively. The mean thick , and 22.85 mm, respectively. The mean thicknesses of these cervical laminae were 3.12 mm, 2.62 mm, 2.56 mm, 3.47 mm, and 5.20 mm, respectively. The mean sagittal heights of these laminae were 9.38 mm, 9.80 mm, 10.12 mm, 11.31 mm, and 13.84 mm, respectively. Except for the C7 vertebrae, all other levels had a success rate of <10% in the Indian population using the criteria of a laminar height of at least 9 mm and thickness of 4.5 mm. Limited success was achieved at the C5, C6, and C3 levels. Conclusions To the best of our knowledge, the present study is the only series on the feasibility of laminar screws in the sub-axial cervical spine in the Indian population. We found that Indian patients have smaller anatomical dimensions and thus, are not suitable for laminar screws in the sub-axial cervical spine, barring C7, which is contrary to findings for populations in western and south Asian countries

SALMONELLA OSTEOMYELITIS OF THE LUMBAR SPINE: AN UNUSUAL PRESENTATION IN AN IMMUNOCOMPETENT MALE

  Prevalence of Salmonella vertebral osteomyelitis has increased in recent years due to greater number of spinal surgical procedures, ageing population, and intravenous drug abuse. It is a rare complication of Salmonella infection. We report a case of a 17-year-old male who presented with low back pain for past 1 month. Physical examination revealed spinal tenderness over L2-L5 spine with sensory and motor deficit. Magnetic resonance imaging of dorsolumbar spine showed spondylodiscitis at L2-L5 and epidural collection at L4-L5 level. The patient did not respond to conservative treatment and trial of antitubercular drugs. He underwent open discal biopsy and decompression laminotomy. Intraoperatively, he was found to have epidural abscess and discitis at L3-L4 level. Tissue and wound culture grew Salmonella typhi, and with antibiotic susceptibility guidance, he was treated with intravenous cefuroxime for 4 weeks. On his latest follow-up, there was complete recovery and fusion at diseased vertebrae level

Evolution of materials for implants in metastatic spine disease till date - Have we found an ideal material?

"Metastatic Spine Disease" (MSD) often requires surgical intervention and instrumentation with spinal implants. Ti6Al4V is widely used in metastatic spine tumor surgery (MSTS) and is the current implant material of choice due to improved biocompatibility, mechanical properties, and compatibility with imaging modalities compared to stainless steel. However, it is still not the ideal implant material due to the following issues. Ti6Al4V implants cause stress-shielding as their Young's modulus (110 gigapascal [GPa]) is higher than cortical bone (17-21 GPa). Ti6Al4V also generates artifacts on CT and MRI, which interfere with the process of postoperative radiotherapy (RT), including treatment planning and delivery. Similarly, charged particle therapy is hindered in the presence of Ti6Al4V. In addition, artifacts on CT and MRI may result in delayed recognition of tumor recurrence and postoperative complications. In comparison, polyether-ether-ketone (PEEK) is a promising alternative. PEEK has a low Young's modulus (3.6 GPa), which results in optimal load-sharing and produces minimal artifacts on imaging with less hinderance on postoperative RT. However, PEEK is bioinert and unable to provide sufficient stability in the immediate postoperative period. This issue may possibly be mitigated by combining PEEK with other materials to form composites or through surface modification, although further research is required in these areas. With the increasing incidence of MSD, it is an opportune time for the development of spinal implants that possess all the ideal material properties for use in MSTS. Our review will explore whether there is a current ideal implant material, available alternatives and whether these require further investigation