Same-segment and adjacent-segment disease following posterior cervical foraminotomy

Object. The cervical foraminotomy was pioneered in the 1940s to address radicular symptoms via a posterior approach, but the long-term outcome has not been adequately studied. Methods. The authors retrospectively analyzed data obtained from 303 patients (188 male and 115 female, mean age 49.2 years) who had consecutively undergone a single-level posterior foraminotomy for cervical radiculopathy between 1972 and 1992. The median follow-up duration was 7.1 years. The major end point studied was the development of symptomatic adjacent- or same-segment disease. Incidence rates per 1000 person-years were calculated, and the natural history of the disease was predicted using Kaplan-Meier survivorship analysis. In 15 (4.9%) of 303 patients, symptomatic adjacent-segment disease developed, yielding a rate of 6.4/1000 personyears at risk. This included nine (2.9%) of 303 patients requiring reoperation, yielding a rate of 3.8/1000 person-years. Kaplan-Meier survivorship analysis suggested a relatively stable annual 0.7% rate for developing adjacent-segment disease, with a 10-year rate of 6.7%. Ten patients developed same-segment disease, yielding a risk rate of 3.9/1000 person-years. Kaplan-Meier survivorship analysis demonstrated a 5- and 10-year risk rate of developing same-segment disease of 3.2 and 5.0%, respectively. Conclusions. Although additional study is needed, analysis of the present data suggests that posterior foraminotomy is associated with a low rate of same- and adjacent-segment disease.