Mid-term follow-up outcomes of single-level cervical total disc replacement versus anterior cervical discectomy and fusion for the treatment of cervical disc degenerative disease

BACKGROUND: To evaluate the clinical and radiographic results of cervical total disc replacement (CTDR) and anterior cervical discectomy and fusion (ACDF) in the treatment of single-level cervical disc degenerative disease with a mid-term follow-up period. METHODS: Seventy-two patients with C5/6 single-level cervical degenerative disc disease refractory to conservative interventions were randomly assigned to two groups: ACDF and CTDR. Clinical outcomes were assessed by using the Japanese Orthopedic Association (JOA) score and the Neck Disability Index (NDI). Radiographic evaluations included range of motion (ROM), Cobb angles, heterotopic ossification (HO) and adjacent segment degeneration during follow-up. RESULTS: Sixty-nine patients (35 CTDR and 34 ACDF) were followed up over 4 years (mean 50.3 months). At 1 month postoperation, the NDI scores in CTDR patients were significantly higher than those in ACDF patients, especially in the work, driving and recreation aspects. There was significant improvement in global ROM in CTDR patients than in ACDF patients. The postoperative ROM of the C4/5 segment in ACDF patients increased significantly, and no significant difference was shown in other adjacent segments. The occurrence of HO was 42.9% (15/35) in the CTDR group at the last followup, with Grade I in 3 cases, Grade II in 11 cases and Grade III in 1 case. CONCLUSIONS: CTDR is an effective method in the treatment of single-level cervical disc degenerative disease. Compared to ACDF, CTDR is superior in the early improvement of quality of life, and restoration of segmental motion despite radiographic evidence of HO during a mid-term follow-up period.