The association between cervical spine curvature and neck pain

Abstract

Degenerative changes of the cervical spine are commonly accompanied by a reduction or loss of the segmental or global lordosis, and are often considered to be a cause of neck pain. Nonetheless, such changes may also remain clinically silent. The aim of this study was to examine the correlation between the presence of neck pain and alterations of the normal cervical lordosis in people aged over 45 years. One hundred and seven volunteers, who were otherwise undergoing treatment for lower extremity problems in our hospital, took part. Sagittal radiographs of the cervical spine were taken and a questionnaire was completed, enquiring about neck pain and disability in the last 12 months. Based on the latter, subjects were divided into a group with neck pain (N = 54) and a group without neck pain (N = 53). The global curvature of the cervical spine (C2-C7) and each segmental angle were measured from the radiographs, using the posterior tangent method, and examined in relation to neck complaints. No significant difference between the two groups could be found in relation to the global curvature, the segmental angles, or the incidence of straight-spine or kyphotic deformity (P > 0.05). Twenty-three per cent of the people with neck pain and 17% of those without neck pain showed a segmental kyphosis deformity of more than 4 degrees in at least one segment--most frequently at C4/5, closely followed by C5/6 and C3/4. The average segmental angle at the kyphotic level was 6.5 degrees in the pain group and 6.3 degrees in the group without pain, with a range of 5-10 degrees in each group. In the group with neck pain, there was no association between any of the clinical characteristics (duration, frequency, intensity of pain; radiating pain; sensory/motor disturbances; disability; healthcare utilisation) and either global cervical curvature or segmental angles. The presence of such structural abnormalities in the patient with neck pain must be considered coincidental, i.e. not necessarily indicative of the cause of pain. This should be given due consideration in the differential diagnosis of patients with neck pain.

Fig. 1

Degenerative segmental kyphosis at C3/4

Fig. 2

Degenerative global kyphosis

Fig. 3

Setup for the lateral cervical radiograph: a wire is stretched at 20° on an adjustable height pole and the shadow of this is projected onto the head, enabling standardisation of the head position in all participants

Fig. 4

a Schematic diagram of the posterior tangent method of Harrison et al. [23]; btangent lines at the posterior vertebral body margins (here of C2 and C7) are drawn and the angle of these intersecting lines is measured

Fig. 5

Mean (SD) segmental angles in the PAIN and NO PAIN groups. No significant differences at any level