Background: Endoscopic surgery in lumbosacral spine has been a procedure for spine surgeons since 1999. The most common position for patients in prone position, but in some situation, it is impossible to proceed, such as in overweight patients or patients with associated injury. It is necessary to compare the anatomy of nerve roots in different positions such as supine, prone, and lateral decubitus position. Therefore, the magnetic radiography imaging is a proper tool for evaluating nerve roots.

Material and Methods: The authors designed a study where 14 patients would engage in the magnetic resonance imaging (MRI) process in three different positions. The first group, control group, would get the MRI at supine position while the second and the third group would proceed with MRI at prone and lateral decubitus position, respectively. Then, the authors would measure the values by drawing the line between upper border of the exiting nerves and the lateral border of traversing nerves. Hence, if the nerve root angle was different from the control group by more than 10 degrees, it would be clinically significant because of changes in the Kambin’s triangle.

Results: The demographic data were not statistically significant for all population in the three groups. All of nerve roots direction, at the L3-L5 level, were not similar in supine, prone, and lateral decubitus positions.

Conclusion: The present study will help orthopedic surgeon be aware that the position of patients affected nerve roots direction. Pre-operative MRI must be done, and pathological level should be specified despite the above and below part. Even though the result showed no statistical difference, the angle of more than 10 degrees affected the increased area of Kambin’s triangle. However, it would be favorable for the expansion of Kambin’s area in prone and lateral decubitus.

Keywords: Position of MRI; Nerve roots direction in lumbar spine; Kambin’s triangle and position

DOI: 10.35755/jmedassocthai.2022.07.13375

Received 4 April 2022 | Revised 13 May 2022 | Accepted 19 May 2022