Quantitative changes in the cervical neural foramen resulting from axial traction: in vivo imaging study.

Abstract Background context Cervical traction has a long history as a method of conservative treatment for cervical spine diseases. However, information on quantitative changes in the cervical neural foramen resulting from axial traction in vivo is lacking. Purpose To quantitatively evaluate the changes in the neural foramen of the cervical spine during axial traction in vivo. Study design A prospective radiographic analysis of the cervical neural foramen of adult volunteers. Patient sample Fifteen healthy volunteers (10 men, 5 women) without any history of cervical spine disease. Outcome measures The changes in cervical cross-sectional foraminal areas and heights were measured. Methods Cervical magnetic resonance (MR) images of the volunteers were taken at the neutral position and were reconstructed in the oblique plane perpendicular to the long axis of each neural foramen from the C2–3 to the C6–7 level. The changes in the neural foraminal dimensions at incremental axial traction forces (0, 5, 10, and 15kg) were analyzed. Results After each 5-kg incremental increase in traction weight, there was a significant (p value less than .05) increase in area and height of the intervertebral foramen compared with the position in which no weight was applied. There was an average increase of 5.81%, 16.56%, and 18.9% in the foraminal area and an average increase of 3.75%, 8.67%, and 10.43% in foraminal height compared with the position with no weight at traction of 5, 10, and 15kg, respectively. There was no statistically significant difference for the increase in foraminal area and height from 10 to 15kg of traction (p value greater than .05). Conclusions There was a significant increase in intervertebral foraminal area and height after each 5-kg increment in traction weight compared with the position in which no weight was applied. From 10 to 15kg of traction, there was no significant change in the foraminal area and height.