Is autograft the gold standard in achieving radiographic fusion in one-level anterior cervical discectomy and fusion with rigid anterior plate fixation?

STUDY DESIGN: A review of 66 consecutive patients at a single institution who underwent one-level anterior cervical discectomy and fusion (ACDF) with rigid anterior plate fixation with allograft or autograft.

OBJECTIVES: To address the efficacy of allograft to autograft with primary respect to fusion rate and secondary attention to risk factors and clinical outcome in patients undergoing one-level ACDF with rigid anterior plate fixation.

SUMMARY OF BACKGROUND DATA: Although autograft is considered the gold standard in achieving optimal fusion, when compared with allograft in noninstrumented one-level ACDF and in plated and nonplated multilevel ACDF, the efficacy of allograft to autograft in one-level ACDF with rigid anterior plate fixation is not thoroughly understood.

METHODS: Sixty-six consecutive patients (mean age, 45 years) at a single institution who underwent one-level ACDF with rigid anterior plate fixation with allograft (n = 35) or autograft (n = 31) were reviewed for radiographic fusion (mean, 12 months), risk factors, and clinical outcome (mean, 17 months). Smokers entailed 33.3% of the patients, and 45.5% of all patients presented with a work-related injury. An independent blinded observer reviewed at last follow-up lateral neutral and flexion/extension plain radiographs for radiographic fusion and instrumentation integrity. Clinical outcome was assessed on last follow-up and rated according to the Odom criteria. The threshold for statistical significance was established at P < 0.05.

RESULTS: Solid fusion was achieved in 63 patients (95.5%). Fusion was noted in 100% of the allograft patients, whereas 90.3% of the autograft cases achieved fusion. No statistically significant difference was noted between allograft to autograft with regard to fusion rate (P > 0.05). Three patients developed nonunions (1 smoker; 2 nonsmokers) and entailed Orion instrumentation. In the one patient who was a nonsmoker with a nonunion, slight screw penetration into the involved and uninvolved interbody spaces was noted. No other intraoperative, postoperative, or radiographic complication was noted. All of the nonunions occurred early in the series. Postoperatively, excellent results were reported in 19.7%, good results in 71.2%, and fair results in 9.1% of the patients. Satisfactory clinical outcome was noted in all nonunion patients. A nonstatistically significant difference was noted with regard to clinical outcome of fused and nonfused patients, demographics, and the presence of a work-related injury (P > 0.05). The impact of smoking was not a factor influencing fusion or clinical outcome in this series (P > 0.05). A statistically significant difference was noted in plate-type on fusion rate (P < 0.05).

CONCLUSION: A 100% and 90.3% radiographic fusion rate was obtained for allograft and autograft in one-level ACDF procedures with rigid anterior plate fixation, respectively. Although autograft achieved a higher incidence of nonunion than allograft, this may be attributed to the use of autograft early in the experience of plate application and fixation in this series. The effects of smoking were not found to be a significant factor influencing fusion in these plated patients. In 90.9% of the patients, excellent and good clinical outcome results were reported. The use of allograft in one-level ACDF with rigid plate fixation yields similar and high fusion rates as autograft. The use of allograft bone eliminates complications and pitfalls associated with autologous donor site harvesting. However, the use of autograft is a viable alternative to avoid the risk of infection, disease transmission, and histocompatibility differences associated with allograft. The use of allograft or autograft bone in properly selected patients for one-level ACDF with rigid anterior plate fixation can result in high fusion rates with excellent and good clinical outcomes.