Changes in the Superior Zygapophyseal Joints in the Lower Thoracic and Upper Lumbar Vertebrae in Babylon Population

Abstract

Background: The articular processes of the vertebral column play a role in weight transmission as well as in governing the range and direction of movement between two vertebrae. The pattern of changes of orientation of these particular processes from thoracic to lumbar type was seldom mentioned in anatomical textbooks.
Objective: to study the pattern of changes of zygapophyseal joints in local citizen in Babylon Province.
Methodology: 140 persons (80 female and 60 male) aged 20-66 years (mean 46.84± 14.438) attending to radiology department in Marjan Teaching Hospital, Babylon, Iraq, were participated in this study, they were investigated to be free from any congenital anomaly or pathological change. Using computed tomography with axial sections, the lower four thoracic and upper lumbar vertebrae. The zygapophyseal joints were carefully observed to detect the site of changes in orientation from thoracic to lumbar type.
Results:
The present study revealed that there were two types of change in the orientation of zygapophyseal joint were observed; gradual and sudden.
21.42% of subjects showed gradual changes in orientation of zygapophyseal from thoracic type to lumbar type, with female ratio higher than male. The transition started mainly at T11-L2, some subjects showed transition at T12-L2.
While 78.58% of subjects showed sudden changes; mainly at T12-L1, and to a lesser extent at T11-T12.
Conclusions:
In the group of people who were studied it was clear that the change of the superior zygapophyseal joint from flat, posterolaterally oriented which is thoracic type to curved, posteromedially oriented which is lumbar type is more likely to occur as sudden change rather than the gradual change which observed in about one-fifth of the population.