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 cervical Cloward procedure for disc disease were randomized prospectively to fusion 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 segment. 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 after 6, 12, and 24 to 50 (mean, 37) months. All 43 patients underwent clinical 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 difference 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 which graft was used, but the healing process took longer than expected. The clinical results were not influenced by whether mobility could be demonstrated. There was a tendency toward better clinical results in the patients treated with autograft.