S. Becker, I. Richter, T. Fischer, G. Baroud, Wilke (Vienna, Austria)
INTRODUCTION: Recent developments focus on injectable calcium – phosphate – cements and biphasic HA / PMMA cements for different indications in orthopaedics and traumatology including spinal fractures and osteoporosis. We compared four different CPC and two different biphasic cements versus a control (pure _-TCP) regarding toxicity, cell growth and cell differentiation.
Four injectable bone cements (ChronOS inject – Synthes, Calcibone – Biomet Merck, KyphOs – Kyphon, Cerament – Bonesource) and two biphasic cements (Vertecem – Synthes, Activos – Medtronic) were compared (control Chronos cylinder). Mesenchymal stem cells from sheep were seeded for the cytotoxic test on 6-well plates (50.000 cells /well). After 3 days of cultivation, a toxicity test (trypanblue), cellproliferationtest (MTT, Absorption 550 nm) and histology was performed. After 16 days of cultivation cell growth/differentiation (2 mio cells seeded onto the sample) was performed by histology, AP synthesis, protein absorption and histology.
No significant toxic influences were found in Calcibone and ChronOS inject. KyphOs showed a 16.7% increased toxicity if compared to control. The same results were seen on cell growth, best growth in the Calcibone and ChronOS inject groups followed by 50% less growth in the KyphOs groups. After 16 days all surviving cells produced similar AP levels with again the ChronOS group showing the highest levels. No protein absorption was found in the Calcibone and Cortoss groups.
The remaining results will be presented in the talk.
DISCUSSION & CONCLUSIONS:
The tested cements show different behavior on cells according to their chemical structure. Calcibone and ChronOS inject are in our experiment superior to KyphOs. It is difficult to simulate the actual ingrowth and remodeling of bone cements as the in vivo situation with blood flow etc. are different. All cements are in clinical use; however the indications for the cement vary due to their composition and toxicity.