PURPOSE:

Analysis of a β-tricalcium phosphate (β-TCP) bone graft soaked with bone marrow aspirate explanted during revision surgery after 28 months.

METHODS:

A 41-year-old female patient undergoing scoliosis correction Th4-L5 in 2007 was revised due to screw loosening in 2008. During revision surgery, a β-TCP bone graft (chronOS^® chips) soaked with bone marrow aspirate was applied. Due to implant failure, the patient was revised again 2011. The bone graft was removed and taken to the laboratory for histological analysis. The biomaterial samples were stained with DAPI and analyzed under a fluorescence microscope. Five biomaterial chips were maintained in tissue culture to evaluate outgrowing cells. The remaining samples were embedded in paraffin, sectioned into 7 μm sections and stained with Hemalaun/eosin.

RESULTS:

The morphology and rigidity of the β-TCP bone graft were comparable to the original. The pores were not filled with tissue and could be clearly identified. Only single vital cells were detected on the graft. The outgrowth culture yielded only erythrocytes-no cells of the osteoblastic lineage cells could be harvested. Histological analysis demonstrated a failure of resorption and the absence of new bone formation.

CONCLUSION:

Histological analysis of bone grafts is rare after implantation in humans due to ethical and clinical limitations of sample harvest. In this study, implantation of a β-TCP bone graft did not result in bone formation after 28 months in vivo.