Object: This study details long-term clinical and radiographic outcomes following single-level posterior cervical foraminotomy for degenerative disc or osteophyte disease.
Methods: The authors conducted a retrospective review of 162 cases involving patients treated by a single surgeon using a posterior cervical foraminotomy. Inclusion criteria were a minimum of 5 years' clinical and radiographic follow-up and unilateral single-level posterior cervical foraminotomy for degenerative disease between C-3 and C-7. Patients who had undergone previous operations, those who underwent bilateral procedures, and those who underwent foraminotomy as part of a larger laminectomy were excluded. The Neck Disability Index (NDI) was used for clinical follow-up, and radiographic follow-up was performed using static and dynamic lateral radiographs to compare focal and segmental alignment and changes in disc-space height.
Results: The mean presenting NDI score was 18 (range 2-39). The most common presenting symptoms were radiculopathy (110 patients [68%]), neck pain (85 patients [52%]), and subjective weakness (91 patients [56%]). The mean preoperative focal angulation at the surgically treated level was 4.2 degrees (median 4.1 degrees , range 7.3-15.3 degrees ), and the mean preoperative segmental curvature between C-2 and C-7 was 18.0 degrees (median 19.3 degrees , range -22.1 to 39.3 degrees ). The mean postoperative NDI score was 8 (range 0-39). Improvement in NDI scores was seen in 150 patients (93%). Resolution of radiculopathy was experienced by 104 patients (95% of patients with radiculopathy). The mean radiographic follow-up was 77.3 months (range 60-177 months). No statistically significant changes in focal or segmental kyphosis or disc-space height were seen among the overall cohort with time (Cox proportional hazards analysis and Student t-test, p > 0.05). The mean postoperative focal angulation was 4.1 degrees (median 3.9 degrees , range -9.9 degrees to 15.1 degrees ) and mean postoperative segmental angulation was 17.6 degrees (median 15.4 degrees , range -40.2 to 35.3 degrees ). Postoperative instability on dynamic imaging was present in 8 patients (4.9%); 7 of these patients were clinically asymptomatic and were treated conservatively, and 1 required cervical fusion. Postoperative loss of lordosis (defined as segmental Cobb angle < 10 degrees ) was seen in 30 patients (20%), 9 of whom had clinical symptoms and 4 of whom required further surgical correction. Factors associated with worsening sagittal alignment (Cox proportional hazards analysis, p < 0.05) included age > 60 at initial surgery, the presence of preoperative cervical lordosis of < 10 degrees , and the need for posterior surgery after the initial foraminotomy.
Conclusions: The posterior cervical foraminotomy is highly effective in treating patients with cervical radiculopathy and results in long-lasting pain relief and improved quality-of-life outcomes in most patients. Long-term radiographic follow-up shows no significant trend toward kyphosis, although select patient subsets (patients older than 60 years, patients who had previous posterior surgery, and patients with < 10 degrees of lordosis preoperatively) appear to be at higher risk and require closer follow-up.