Development of a per-operative procedure for concentrated bone marrow adjunction in postero-lateral lumbar fusion: radiological, biological and clinical assessment.

Purpose: Addition of bone marrow to the bone graft in the postero-lateral lumbar arthrodesis is a widely used technique. Bone marrow brings stem cells and growth factors contained in the platelets, favorable for bone growth. Adjunction of concentrated bone marrow should create better conditions and may increase bone growth.

Methods: Simple blind randomized clinical, prospective, monocentric trial was conducted. Fifteen patients underwent lumbar arthrodesis. During surgery, a fraction of the bone marrow harvested was centrifuged. One side received this concentrate with autologous bone and ceramics; the other side received the same graft with unconcentrated bone marrow. A quantitative study, realised with a volume calculating software on CT-scan images, determined the cortical bone volume in the graft post-operatively and at 3 months. The osteoprogenitor cells, nucleated cells and platelet concentrations were determined.

Results: The biological study found an average concentration of six times for the nucleated cells, 3.5 times for the platelets and 2.2 times for the osteoprogenitor cells. The comparison of the mean cortical bone volumes post-operatively and at 3 months was not significantly different.

Conclusions: Despite the concentration obtained, there was no increase of bone growth by adding concentrated bone marrow. However, the number of stem cells in bone marrow was low and maybe a stronger concentration is needed to obtain a difference. The 3D reconstruction of the graft and the analysis of the graft's volume using a novel software was efficient according to the similarity of the graft's volume post-operatively in all patients.