gms | German Medical Science

Objective: In the last years, PEEK- or titanium-cages have become a standard for lumbar interbody fusion. However, there is no scientific evidence which proves the advantage of artificial implants compared to autologous bone. This retrospective analysis was performed to investigate whether lumbar interbody fusion using artificial cages was superior to autologous bone chips after posterior instrumentation.

Method: 66 patients with degenerative lumbar stenosis and spondylolisthesis were included. Patients had decompressive surgery and nucleotomy followed by posterior instrumentation and interbody fusion. Materials inserted to induce interbody ossification were – by surgeons’ choice – either a bone-filled TLIF-cage or chips of spongious bone, removed during decompression. The clinical and radiological course was followed for at least 18 months assessing pain (VAS), functional outcome (ODI), osseous fusion rate and loosening of screws (CT).

Results: In 41 patients, a bone-filled PEEK-cage was implanted (group 1), in 25 patients, spongious bone chips were used (group 2). Clinical outcome was comparable in both groups with a similar improvement of pain and functional outcome. After the observation period, fusion rate was 75% in group 1 and 90% in group 2. Loosening of screws was observed in 12 of 41 patients in group 1 and in 3 of 25 patients in group 2. Spondylodiscitis occurred in 1 patient of group 2.

Conclusions: The results of this retrospective analysis are, by trend, in favor of the implantation of spongious bone chips for lumbar interbody fusion in lumbar degenerative spondylolisthesis. The results suggest a randomized two-arm study which prospectively compares the two methods of interbody fusion.