Positive predictive factors and subgroup analysis of clinically relevant improvement after anterior cervical decompression and fusion for cervical disc disease: a 10- to 13-year follow-up of a prospective randomized study

Abstract

Object The main purpose of this 10- to 13-year follow-up of a prospective randomized study was to identify preoperative factors that predicted good long-term outcome after anterior cervical decompression and fusion (ACDF) with the Cloward procedure or the cervical intervertebral fusion cage. A second purpose was to investigate subgroup differences at the 10-year follow-up between patients with and without clinically relevant improvement (CRI) and between men and women. Methods To evaluate clinically meaningful outcomes, good outcome was defined as CRI in neck-related pain intensity (≥ 30-mm improvement on a visual analog scale), and CRI in neck-specific disability (≥ 20% improvement in the neck disability index [NDI]) from preoperative measurements to the 10-year follow-up. A total of 73 patients (77% of the original study sample) completed questionnaires at least 10 years after ACDF. Results High preoperative neck-related pain intensity and preoperative nonsmoking status were predictors of CRI in neck-related pain intensity, and male sex was a predictor of CRI in neck-specific disability; however, no additional predictive factors were identified for good outcome after ACDF. The surgical procedure, number of operated levels, and radiological factors such as healing status did not influence the prediction models. Individuals without CRI in neck-specific disability (75%) and pain intensity (43%) reported a worse outcome for several psychosocial outcome variables compared with those with CRI. At the 10-year follow-up, women reported significantly greater neck- and arm-related pain intensity than men, and women also reported more disability and worse psychosocial status. Women reported CRI on the NDI less frequently than men (p = 0.01). Conclusions Preoperative predictive factors of good outcome 10–13 years after ACDF included initial high neck-related pain intensity, nonsmoking status at the time of surgery, and male sex. There were greater improvements in pain intensity than in neck-specific disability, and the latter showed a greater association with psychosocial factors. These results suggest the need for multimodal postoperative rehabilitation for patients who do not have a satisfactory outcome after ACDF.