Table of Content Volume 12 Issue 1 - October 2019
A morphometric study of dry human typical thoracic vertebral body in Marathwada region
M S Selukar1, S S Deshpande2, G B Sudke3*
1Associate Professor, 2Junior Resident II, 3Assistant Professor, Department of Anatomy, Government medical college, Latur, Maharashtra, INDIA. Email: mangesh70201@rediffmail.com
Abstract Background: In recent years, there have been considerable developments in instrumentation designed to stabilize and correct the thoracic spine. At present, artificial vertebral implants have proven to be effective in the treatment of spinal tumors, infections, fractures and other diseases. Studies show that the movable artificial vertebral implants needs further improvement and hence the present study has given importance to the morphometry of vertebral body in typical thoracic vertebrae. Objective: To measure various parameters of the vertebral body in typical thoracic vertebrae by digital vernier calliper. Materials and methods: Seventy five typical thoracic vertebrae of undetermined age and gender were selected for the study. Various measurements were taken with the help of digital vernier calliper. Results: The superior anteroposterior distance of the vertebral body in typical thoracic vertebrae ranged from 14.61-31.85mm with a mean of 22.37+3.80mm. The inferior anteroposterior distance ranged from 12.60-32.79mm with a mean of 23.21+ 3.79mm. The anterior height ranged from 11.92-27.23mm with a mean of 20.15+2.81mm. The posterior height ranged from 12.31-27.28mm with a mean of 21.12+2.78mm. The right lateral height ranged from 10.83-25.61mm with a mean of 20.60+2.84mm. The left lateral height ranged from 11.31-26.76mm with a mean of 20.37+2.89mm. The superior transverse diameter ranged from 18.70-34.87mm with a mean of 28.25+ 3.56mm.The inferior transverse diameter ranged from 19.75-35.58mm with a mean of 29.65+ 3.82mm. Conclusion: The data provided will be a useful reference for more accurate optimization of design and modelling of artificial vertebral body implants and instrumentation in Indian population. Key Word: Typical thoracic vertebra, anterior height, superior anteroposterior distance.
INTRODUCTION The adultvertebral column consists of 33 vertebral segments (7 cervical, 12 thoracic, 5 lumbar, 5 scaral, 5 coccygeal) and is one of the most complex structures of the human body. The vertebrae may be involved in various conditions like fractures, malignancies, inflammatory disorders, infections, abnormal curvatures such as kyphosis and scoliosis. In recent years there have been considerable developments in instrumentation designed to stabilize and correct the thoracic and lumbar spine. Majority of the previous studies have mainly focused on the pedicle diameters and their angulations and very little importance has been given to the vertebral body. In the thoracic curvature1, the compressive force tends to centre on the vertebral bodies. Similarly, a change in the structure and shape of the vertebral column in the thoracic region with respect to its two components, body and arch, might be due to change in the magnitude of compressive force distributed between the two components because of the change in curvature. Taking into account the complex nature of the thoracic spine, the present study has given importance to the vertebral body.
MATERIALS AND METHODS The study was conducted on 75 typical thoracic vertebrae obtained from department of Anatomy of various colleges in Marathwada region. The vertebrae were undamaged and of undetermined age and sex. Each vertebra was assigned a serial number. Anatomical measurements were taken on these specimens using a digital Vernier calliper. The following parameters were recorded in a proforma:
RESULTS
Figure 1: Illustration showing measurement of the superior transverse diameter in typical thoracic vertebra; Figure 2: Illustration showing measurement of the superior anteroposterior distance in typical thoracic vertebra; Figure 3: Illustration showing measurement of the anterior height in typical thoracic vertebra.
DISCUSSION Thoracic vertebrae have been studied by various authors by using different methods such as plain radiographs, quantitative 3 dimensional anatomic techniques and direct measurements. These include Panjabi MM et al, Tan et al, Patil Dhaval et al, M. Vasantha et al, Singh R et al, Kunkel et al. However, Berry JL et al studied only the second and seventh thoracic vertebrae. The following tables present the comparison of means of the various parameters obtained from previous studies with that of the present study. Table 1: Comparison of mean superior anteroposterior distance of the vertebral body in typical thoracic vertebrae with other studies
When compared, the mean superior anteroposterior distance of the vertebral body in the present study is lesser than the value found by Panjabi MM2et al but is greater than the findings of Tan3 et al, Patil Dhaval6 et al and M.Vasantha7 et al.
Table 2: Comparison of mean superior transverse diameter of the vertebral body in typical thoracic vertebrae
The mean superior transverse diameter of the vertebral body in the present study is greater than that of the other studies.
Table 3: Comparison of mean anterior height of the vertebral body in typical thoracic vertebrae
Table 4: Comparison of mean posterior height of the vertebral body in typical thoracic vertebrae
The mean posterior height of the vertebral body in the present study is greater than that of the other studies. Singh R2 et al found that the anterior height of the vertebral body was less as compared with the posterior height of the body at all levels of the thoracic spine. They noted this as an explanation for the normal physiological kyphosis present in the thoracic region. The present study found a similar observation.
CONCLUSION The current increased interest in vertebral body implants and spinal implants call for a detailed knowledge of its anatomy. Direct measurements on specimens is the best method for extracting morphometric data from anatomical structures. The present study has focused on a comprehensive data set which provides quantitative anatomy of vertebral body of typical thoracic vertebrae. The differences in the result of the present study and those of the previous studies with respect to some of the parameters may be due to differences in race, ethnicity as well as methods used for the studies. The quantitative findings from the present study can hopefully provide more accurate information in the design of vertebral implants for the population studied.
REFERENCES
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