Rigid fusion after cloward operation for cervical disc disease using autograft, allograft, or xenograft - A randomized study with radiostereometric and clinical follow-up assessment

Study Design. In this study, 43 patients scheduled for a single-level cervi cal Cloward procedure for disc disease were randomized prospectively to fus ion with autograft, allograft, or xenograft. Objective. To outline any differences in fusion over time in terms of final mobility and clinical outcome between the three bone grafts. Summary of Background Data. Fusion is used to relieve pain from a spinal se gment. The bovine xenograft gives a fibrous fusion in contrast to the solid bone fusion obtained with autograft from the iliac crest, but no definite differences in clinical outcome have been shown previously after surgery at a single level. Methods. By use of radiostereometric analysis, 33 patients were observed af ter 6, 12, and 24 to 50 (mean, 37) months. All 43 patients underwent clinic al examination, which involved pain rating before and after surgery, with a final follow-up assessment by an unbiased observer. Results. Mobility could be demonstrated in 9 patients after 1 year and in 6 patients at the final follow-up assessment, without pain, and with no diff erence between bone grafts, The patients who received autograft experienced a greater reduction of pain than the patients treated with xenograft. Conclusions. Most of the patients healed with a rigid fusion no matter whic h graft was used, but the healing process look longer than expected. The cl inical results were not influenced by whether mobility could be demonstrate d. There was a tendency toward better clinical results in the patients trea ted with autograft.