Study Design. Retrospective cohort study.
Objective. To investigate the fate of sclerosis and anterior osteophytes in the fused segments after instrumented lumbar fusion for degenerative lumbar disorders.
Summary of Background Data. Sclerosis and osteophytosis are well-known radiographical findings, but little is known of their significance with regard to spontaneous resorption after spine fusion.
Methods. Thirty patients (9 males, 21 females; 60 vertebra; mean age of 66.9 yr [45–86 yr]) were divided into a posterolateral fusion group (n = 14, 28 vertebrae) and a posterior lumbar interbody fusion group (n = 16, 32 vertebrae). Using serial radiographs obtained preoperatively; postoperatively at 3, 6, 12, and 24 months; and last follow-up, sclerotic areas of each involved vertebra were mapped and osteophyte lengths were measured.
Results. Sclerosis and osteophytes decreased with time for the instrumented fusion. The decrease in sclerotic areas and osteophytes length was observed as early as 3 months postoperatively, and the significant changes between each time point were noted in initial 3- and 6-month intervals. In terms of the type of surgery, similar changes were noted in the posterolateral fusion and posterior lumbar interbody fusion groups.
Conclusion. Resorption of osteophytes and sclerosis after instrumented spine fusion were observed. Significant resorption was noted at 3 and 6 months postoperatively. As well, most graft bone would be incorporated in postoperative 6 months. Resorption of osteophytes and sclerosis after instrumented spine fusion could be helpful to confirm the successful union.
Level of Evidence: 4