A nerve root decompression position identified by 3D CT scan: the modified reversed contralateral axial rotation position for patients with lumbar disc prolapse

Abstract

Background: Nerve root compression in the lumbar intervertebral foramen (LIVF) is a consistent feature of radicular syndrome. There is debate about movements and positions that may reduce compression for possible use in conservative treatment.

Purpose: To investigate real-time effects of specific 3 dimensional positioning of the trunk on the cross sectional area (CSA) of the LIVF in patients with lumbar disc prolapse and radiculopathy using 3D-CT scan imaging.

Methods: Ninety males aged between 20 and 40 years with unilateral lumbar disc prolapse and radiculopathy were separated into three equal groups based on the level of disc prolapse. Group (A): L3/L4, group (B): L4/L5, and group (C): L5/S1. All underwent three separate imaging sessions; first in the supine position to establish baseline data (Baseline-Image 1), followed by a modified reversed contralateral axial rotation position (Image 2), and finally the same position as Image 2 but after 48 h of using the position as a therapeutic intervention (Image 3). The CSA of LIVF at L3/L4, L4/L5, and L5/S1 levels and the angles of straight leg raising (SLR) test were measured following each imaging session.

Results: Two-way mixed MANOVA analysis revealed that the mean values of the CSA of LIVF and the angle of SLR test were significantly increased in Image 2 compared with Baseline-Image 1 across all tested groups (P = 0.001). Moreover, the measured outcome variables were significantly increased in Image 3 compared with Image 2 and Baseline-Image 1 across all tested groups (P = 0.001).

Conclusion: The modified reversed contralateral axial rotation position of the trunk had a real-time decompression effect on the impinged nerve roots in patients with unilateral lumbar disc prolapse and radiculopathy.

Keywords: Lumbar disc prolapse; Lumbar intervertebral foramen; Modified reversed contralateral axial rotation position; Nerve root decompression position; Radiculopathy.

Fig. 1

Body positions during 3D-CT scan imaging of asymptomatic individuals: (A) Conventional neutral supine position. (B) Lumbar side bending toward the pain-free side. (C) Modified reversed contralateral axial rotation (MRCAR) position; lumbar side bending and rotation toward the pain-free side

Fig. 2

Modified reversed contralateral axial rotation (MRCAR) position; sagittal view on right and transverse view on left

Fig. 3

Lumbar 3D-CT scan images; right images from the modified reversed contralateral axial rotation (MRCAR) position and left images from the supine position

Fig. 4

3D-CT scan images of the CSA of the LIVF at L5/S1 level

Fig. 5

Mean values of the CSA of the LIVF (cm²) at the three 3D-CT scan images different tested groups

Fig. 6

Mean values of the angle of SLR test (degrees) after the three 3D-CT scan images at different tested groups

Fig. 7

(A) Classic reverse rotation strain position involves lumbar axial rotation in the transverse plane. (B) Modified reversed contralateral axial rotation (MRCAR) position combines lumbar axial rotation, side bending, and flexion in the transverse, frontal, and sagittal planes, respectively

Fig. 8

Schematic model illustrates that the modified reversed contralateral axial rotation (MRCAR) position effectively opens the foramen by incorporating lumbar axial rotation, side bending, and flexion in the transverse, frontal, and sagittal planes, simultaneously

Fig. 9

Schematic model of LIVF dimensional changes during the modified reversed contralateral axial rotation (MRCAR) and supine positions

Fig. 10

Lumbar MRI images, showing the LIVF at L5/S1. The right image depicts the modified reversed contralateral axial rotation (MRCAR) position, whereas the left depicts the supine position

Fig. 11

Schematic model of LIVF dimensional and SLR testing angle changes after releasing the nerve root compression