Change in Angular Alignment Is Associated With Early Dysphagia After Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective analysis of a prospective cohort.

OBJECTIVE

Change in cervical angular alignment may be associated with dysphagia.

SUMMARY OF BACKGROUND DATA

Bony deformities of the cervical spine may be associated with secondary contractures of soft tissues in the neck. Acute surgical deformity correction causes in changes in soft tissue tension in the anterior neck, resulting in dysphagia.

METHODS

The study population included patients undergoing 1 and 2 level elective anterior cervical discectomy and fusion for cervical myelopathy or radiculopathy. Preoperative and postoperative radiographs at 2 weeks were measured by a blinded observer for C2-C7 endplate angle, C2-C7 posterior vertebral body length, and occipital condyle plumb line distance on upright lateral radiographs at 2, 6, and 12 weeks postoperatively. Patients were prospectively queried about dysphagia incidence and severity using a numeric rating scale. Multiple linear regression analysis was used to determine the effect of change in radiographic parameters controlling for demographic characteristics.

RESULTS

The study population included 25 patients with complete radiographs. The mean change in C2-C7 angle was -0.6 degrees (SD 9), the mean change in C2-C7 length was 1.7 mm (SD 26), the mean change in occipital condyle plumb line distance was 2.3 mm (SD 20).Multiple linear regression analysis was performed including operative time, age, sex, number of levels, and change in radiographic parameters as independent variables and using dysphagia score as the dependent variable. The change in C2-C7 angle and operative time were the only statistically significant predictors of change in dysphagia at 2 and 6 weeks postoperatively.

CONCLUSIONS

These results indicate that lordotic change in spinal alignment and longer operative times are associated with increased postoperative dysphagia. Surgeons should counsel patients in whom a large angular correction is expected about the possibility for postoperative dysphagia. Furthermore, future studies on dysphagia incidence should include radiographic alignment as an independent predictor of dysphagia.

What is the incidence of dysphagia after posterior cervical surgery?

STUDY DESIGN

Prospective comparative study.

OBJECTIVE

To determine whether dysphagia is a unique complication of anterior neck dissection or whether it occurs after any cervical surgery.

SUMMARY OF BACKGROUND DATA

Dysphagia is a common complication after anterior cervical discectomy and fusion. However, current literature is scarce whether dysphagia occurs as a direct result of the anterior approach (dissection or instrumentation) or because of cervical spine surgery itself.

METHODS

Patients undergoing posterior cervical surgery were prospectively evaluated for dysphagia up to 6 months after surgery. Patients were evaluated for dysphagia preoperatively, at 2 weeks and 6 weeks postoperatively using the dysphagia numeric rating scale. The data was compared with a previously published cohort of anterior cervical and lumbar surgical procedures from the same institution. Statistical significance was evaluated using the Fisher exact test.

RESULTS

Eighty-five patients were included who underwent posterior cervical surgery. Baseline dysphagia was present in 11% (10/85) of patients. The incidence of new dysphagia was 10 of 85 (11%) at 2 weeks, 8 of 85 (8%) at 6 weeks, 13 of 85 (13%) at 12 weeks, and 5 of 85 (6%) at 24 weeks. The incidence of new dysphagia was significantly less than that of anterior cervical surgery at 2 weeks (posterior [P] 11% vs. anterior [A] 61.5%, P = 0.0001), 6 weeks (P 8% vs. A 44%, P = 0.0001), but not 12 weeks (P 13% vs. A 11%, P = 1). The incidence of dysphagia after posterior cervical surgery was significantly increased compared with that of lumbar surgery at 2 weeks (P 11% vs. lumbar surgery [L] 9%, P = 0.78), 6 weeks (P 8% vs. L 0%, P = 0.02), and 12 weeks (P 13% vs. L 0%, P = 0.007). At 12 weeks postoperatively, there was a statistically significant increase in postoperative neck pain (P = 0.008), tightness (P = 0.032), and peripheral pain/numbness (P = 0.032) in patients with dysphagia.

CONCLUSION

Both anterior and posterior cervical surgery may result in long-term dysphagia in a small number of patients, perhaps due to loss of motion or postoperative pain. Surgeons should counsel their patients about possibility for dysphagia prior to all cervical spine surgery.