Introduction and Background
A healthy vertebral column of humans consists of 5 cervical, 12 thoracic, 5 lumbar vertebrae and one sacrum made of 5 vertebrae.
Lumbosacral transitional vertebrae are congenital anomalies of the lumbosacral region, which include sacralization of fifth lumbar vertebrae. This phenomenon was observed first time by Bertolotti. 2 This condition occurs due to defect in the segmentation of the lumbosacral spineduring development.1, 2
During the fourth week, sclerotome cells migrate around the spinal cord and notochord to merge with cells from the opposing somite on the other side of the neuraltube. As development continues, the sclerotome portion of each somite also undergoes a process called resegmentation. Resegmentation occurs when the caudal half of each sclerotome grows into and fuses with the cephalic half of each subjacent sclerotome.3, 4, 5 Thus, each vertebra is formed from the combination of the caudal half of one somite and the cranial half of its neighbour, if any defects occur in this fusion than it will lead into sacralization and lumbarization of vertebrae.
Thus, the present study is carried out to know the prevalence, importance and type of sacralization of the fifth lumbar vertebra, which will help the orthopaedicians, gynaecologist and anaesthetics, radiologist in there day to day work of treating patients and will help in making proper diagnosis and treatment of patients.
Materials and Methods
Source of data
All the cadaveric bones available in the Department of Human Anatomy, Prathima institute of medical sciences, karimnagar, telangana, India, after applying inclusion and exclusion criteria were included in the study.
Types of fusion were classified as follows
Complete fusion between the fifth lumbar vertebra and the first sacral vertebra.
Incomplete fusion between the fifth lumbar vertebra and the first sacral vertebra.
Bilateral sacralization consists of a bony union between the abnormal transverse process and the sacrum on both sides.
Unilateral sacralization shows a bony union between the abnormal transverse process and the sacrum either on right side or left side.
Table 1
Gender (sex)-wise distribution of sacralization of fifth lumbar vertebra (n = 100)
|
|
Male |
Female |
Total |
||||
|
|
No |
% |
No |
% |
No |
% |
|
|
|
100 |
|
66.67 |
|
50 |
|
|
|
|
|
|
33.33 |
|
150 |
|
|
|
|
|
|
|
|
100 |
|
|
|
Prevelance of |
|
|
|
|
|
|
|
|
|
15 |
|
71.43 |
|
6 |
28.57 |
|
|
Scralization of 5th Lumber Vertbrae |
|
|
|
|
|
||
Observations
Out of 21 sacralized bones, 2 bones showed bilateral sacralization and 19 bones showed unilateral sacralization (Table 2).
Out of 21 sacralized bones, 10 bones showed complete fusion between fifth lumbar vertebra and first sacral vertebra, and remaining 11 bones showed incomplete fusion between fifth lumbar vertebra and first sacral vertebra (Table 3).
Discussion
The present study shows that the incidence of sacralization of the fifth lumbar vertebra is 21, out of which 15 are male sacra and 6 are female sacra. Based on the literature, the incidence of sacralization varied by the following races. The incidence in our study was close to the races like Australian aboriginals 18%, Indians 16% reported by Mitchell and Bustami6 and much higher than the races like, Natives of Britain 8%, and Arabs 10%. The incidence of sacralization was close that reported by Steinberg 14%, Vandana Sharma 14%, and the incidence was higher than reported by Kim 1.7%, Hughes 9.2%, Hald 7.8%, Hahn 7.5%, Kubavat 11.1%, and Chithrika 5%.
