Herniated Intervertebral Cervical Discs
In contrast to studies of patients with neck pain as a syndrome, a herniated cervical disc is a specific diagnosis. The only published study that provides an incidence rate was done by Kondo and colleagues. They analyzed residents of Rochester, Minn, from 1950 to 1974 and found an annual herniated disc incidence of 5.5/100,000 people. The most frequent level involved was C5-6, followed by C4-5 and C6-7. In reviews of surgically-treated patients, these are also the most frequent levels involved.
Kelsey and associates reported on 88 people with cervical disc protrusions living in New Haven and Hartford, Conn. Forty were surgically treated after the diagnosis of herniated cervical disc was made. Based on their clinical appearance, 20 were listed as probable and 28 as possible disc protrusions. Fifty-two patients were men and 36 were women, and most patients were in their 40s and 50s. The researchers compared cervical disc protrusion patients with age- and sex-matched controls. A strong association was found between protrusion and recurrent lifting of heavy objects on the job, cigarette smoking, and frequent diving from a board. Driving vibrating equipment and time spent in motor vehicles were weakly associated. Frequent twisting of the neck on the job and sitting on the job were not associated with the clinical diagnosis of herniated disc.
The association of lifting heavy objects and driving vibrating equipment with prolapsed disc is not surprising, but the relationship with smoking is not as easily explained. Cigarette smoking has been implicated in impeding bone metabolism and in interfering with fracture repair, in nonunions in fractures, in arthrodesing procedures, and in increasing the rate of postoperative wound infections. A number of studies have identified smoking as a risk factor for low-back pain, and although several explanations have been proposed, the mechanism has not been elucidated.
Cite this: The Epidemiology of Neck Pain - Medscape - Sep 01, 1998.