Anterior cervical discectomy and fusion vs combined with cervical artificial disc replacement in bi-level cervical disc degenerative disease: a mid- and long-term follow-up study

English Keywords:Cervical spondylosis  Bi-level  Spinal fusion  Cervical artificial disc replacement  Hybrid surgery  Adjacent segment degeneration  Heterotopic ossification

English Abstract:

  【Abstract】 Objectives: To compare clinical and radiographic outcomes between anterior cervical discectomy and fusion(ACDF) and Hybrid surgery[ACDF combined cervical artificial disc replacement(C-ADR)] for bi-level cervical degenerative disease(cDDD) in the mid- and long-term follow-up. Methods: From January 2007 to March 2012, 68 patients with bi-level cDDD undergoing Hybrid surgery(n=29) and ACDF(n=39) were retrospectively reviewed. All patients were followed up for more than 60 months. The age, sex distribution, time of follow-up, surgical segments were not significantly different between the two groups. The neck disability index(NDI) scores, visual analogue scale(VAS), Japanese Orthopedic Association(JOA) scores, C2-C7 range of motion(ROM), C2-C7 lordosis, ROM of adjacent segments, and the degenerative changes of adjacent segments before surgery and at final follow-up, were recorded to assess the efficacy of the two methods. The heterotopic ossification(HO) was evaluated on lateral radiograph at final follow-up. Results: There was no statistical difference in operation time, blood loss or drainage volume between the two groups. At final follow-up, the scores of JOA scores, NDI, VAS improved significantly in all patients(P<0.05), but there was no significant difference between the two groups(P>0.05). In Odom′s scale, the excellent and good rate of the Hybrid patients was 93.1%, and that of the ACDF patients was 92.3%. The cervical lordosis(CL) was well restored in both groups, but Hybrid group had better recovery of CL than ACDF group. C2-C7 ROM decreased significantly in ACDF group. Hybrid group showed less decrease of C2-C7 ROM and less ROM of compensatory adjacent segments than ACDF group(P<0.05). No significant difference in radiographic degenerative changes at adjacent segments was found between the two groups(P>0.05). The incidence of HO in Hybrid group was 34.5%(10/29). Conclusions: The minimum five-year follow-up results show hybrid surgery can be considered an effective and safe alternative procedure compared with ACDF in bi-level cDDD. Hybrid surgery can maintain cervical ROM and lessen the ROM of compensatory adjacent segments.