Outcome analysis of noninstrumented anterior cervical discectomy and interbody fusion in 348 patients

Twenty-one outcome and outcome-relevant variables (fusion and patient satisfaction) were evaluated in a subset of 348 of 514 patients operated on by one surgeon during a 22-year period, using Cloward's anterior cervical discectomy and dowel interbody fusion. Minimum patient follow-up was 2 years; average length of follow-up was 5.2 years. This retrospective analysis is accompanied by a comprehensive review of the literature (1975-1996) of noninstrumented anterior cervical fusions, excluding fibular grafts alone in the interbody space. To provide data on outcome (with regard to patient satisfaction and radiologically supported fusion) and risks of noninstrumented anterior cervical discectomy and fusion for intractable cervical nerve root and spinal cord compression symptoms at single or multiple levels, using the results from a single surgeon. Three experienced spine radiologists determined fusion rates in one to five levels in 348 patients on the basis of the results of plain film analysis. Patient self-assessment was used to determine degree of patient satisfaction and other related variables. From a comprehensive review of the literature, 43 clinical reports meeting requirements for comparison of findings with those in the current study were selected from more than 1600 reports. The mean fusion rate for 348 patients in the current study ranged from 75% (multilevel) to 88% (one level; n = 202). The overall fusion rate was 83%. The persistent complication rate was 0.1%, and patient self-assessments showed that 78% were satisfied with the outcome and that 83% returned to work. The overall fusion rate for 2037 patients evaluated in the comprehensive literature review is 92%. Results of this study indicate that better outcome in noninstrumented anterior cervical discectomy and fusion is associated with solid fusion, fewer fused levels, nonsmoking patients, higher education levels, and absence of secondary economic gain. There was no correlation between fusion status and bone graft source or use of cervical collar.