RADIOLOGICAL EVIDENCE OF FUSION MASS IN POSTERIO-LATERAL LUMBAR SPINE FUSIONS USING DEMINERALISED BONE MATRIX (DBM).

Abstract

The purpose of the study and background. Advances in biotechnology have led to the development of demineralised bone matrix (DBM). This is a soup of cellular molecules extracted from cadaveric bone material, from which the minerals of the donor bone have been removed. The resulting material is described as having both osteoinductive and osteoconductive properties. Clinically this material is attractive as it could provide a framework to allow fusion between suitably prepared bones, thereby potentially avoiding the morbidity associated with autologous bone grafts.

There is published evidence of the efficacy of DBM in animal spine models, but at present there is scanty evaluation of its use in the human spine in routine clinical practice.

The purpose of our pilot study has been to observe the radiological evidence of fusion rates in lumbar spine transverse process fusions, using DBM.

Methods A retrospective pilot study of 21 patients who underwent posterolateral lumbar spinal fusions using DBM. AP L spine radiographs were graded according to degree of fusion mass seen.

Results We analysed radiographs from a range of 13 – 28 weeks post op (average 4.5 months post op), and found that 50% of our study population did not have any radiological evidence of fusion mass, 45% had scanty evidence of fusion mass and only 5% had clear fusion mass.

Conclusion These early results suggest that the use of expensive DBM may not be cost effective, as we would have expected more radiological evidence of fusion mass forming.

This findings of this study have led us to design a randomised prospective study which will compare using stringent experimental design the use of DBM with using the more traditional autologous graft.