Cervical Radiculopathy : Studies on Pain Analysis and Treatment

Abstract: Background: Knowledge about how to interpret pain-analyzing tools such as the pain drawing test and the visual analog scale (VAS) in cervical spine patients are sparse; hence, they have never been validated for this subgroup of patients. The method of artificial disc replacement (ADR) has been developed as an alternative treatment to fusion surgery after decompression for cervical degenerative disc disease (DDD) with radiculopathy. Preserved motion of ADR devices aims to prevent immobilization side effects such as stiffness, dysphagia and adjacent segment pathology. Long-term follow-ups of these devices compared with the gold standard treatment are needed to create future guidelines.Objectives: This thesis aims at (1) validating the pain drawing as an investigational tool for the cervical spine, (2) validating the VAS for the cervical spine regarding the measurement noise and the minimum clinically important difference (MCID), (3) comparing ADR with fusion surgery at 5-years of follow-up regarding outcome and complications in a randomized controlled trial (RCT) as well as in the Swedish spine (Swespine) registry, and (4) investigating possible predictors to outcome after surgical treatment of cervical radiculopathy.Methods: An RCT with 153 patients undergoing surgery for cervical radiculopathy was performed. Baseline data, the Neck disability index (NDI), two sets of VAS-neck and VAS-arm scores, the EQ-5D, Hospital anxiety and depression scale (HADS), Dysphagia short questionnaire and a pain drawing test were gathered preoperatively and after 5 years. Radiographs in flexion/extension and MRIs were done preoperatively and at follow-up. All patients registered in Swespine since January 1st, 2006 with cervical DDD and radiculopathy treated with ADR or fusion surgery, were included. Baseline data, the NDI, EQ-5D, and VAS-neck and VAS-arm scores were analyzed at 1, 2, 5 and 10-years of follow-up as well as the information regarding secondary surgeries.Results: Pain drawings interpreted with the simple body region method showed good inter-rater reliability in cervical spine patients. Markings in the upper arm region on the pain drawing predicted surgical treatment outcome and markings in the head region predicted depression. The measurement noise was ~10 mm and the MCID was ~20 mm on a 100 mm pain VAS. In both the RCT and Swespine register the outcome after ADR surgery were comparable with fusion at 5 years of follow-up, except for an elevated risk regarding secondary surgery on the index level in the ADR group. Fifty percent of the patients in the RCT, allocated to ADR surgery had preserved motion of less than 5°, at the 5-year follow-up, and 25%, mostly men were spontaneously fused. Preserved motion did not prevent adjacent segment pathology. High values of preoperative HADS scores were negative predictors of outcome.Conclusions: In patients with cervical DDD and radiculopathy both the pain drawing test and the VAS are validated tools to interpret the patients’ pain. Preoperative mental distress affects long-term outcome much more than the allocated treatment, ADR or fusion surgery in patients with cervical radiculopathy.Clinical Trial Registration: ISRCTN, registration number: 44347115.