Study design: After determining the normal reference values for the length of the transverse processes of the seventh cervical vertebra, the association between the presence of cervical rib and sacralization was investigated.
Objective: To determine the length of cervical rib and search for any association between cervical rib and sacralization.
Summary of background data: Both cervical ribs and sacralization have been noted in some patients in the authors' clinical practice.
Methods: The cervical rib is a supernumerary rib arising from a cervical vertebra, or it might be simply an elongation of the transverse process of the seventh cervical vertebra. However, there is no consensus about a specified length of this process. For reference values, anteroposterior cervical radiographs of 210 normal individuals (112 male, 98 female, mean age 33.9 +/- 10.1 years, range 19-61 years) were taken, and elongation of the transverse processes beyond 2 standard deviations (30 mm) was considered as cervical rib. In the guide of the reference values, 324 outpatients (165 male, 159 female, mean age 42.0 +/- 14.6 years, range 17-85 years), having cervical ribs or sacralization detected by plain radiographs, were taken as the study group. As control 729 volunteers (364 male, 365 female, mean age 41.7 +/- 14.3 years, range 15-76 years) were studied.
Results: In 1053 patients, of 471 patients having cervical ribs, 345 (73.2%) had also sacralization; of 536 patients with sacralization, 345 (64.4%) also had cervical ribs. Significant associations were found between cervical rib with or without articulation and sacralization [chi2 = 52.284, P < 0.001, odds ratio 5.097 (3.156-8.234); chi2 = 139.473, P < 0.001, odds ratio 5.204 (3.922-6.905), respectively].
Conclusion: Presence of cervical rib might be a clue to the existence of sacralization or vice versa. In patients with cervical or lumbar pain, this association may be helpful for differential diagnosis before applying sophisticated diagnostic techniques.