[Experimental study on magnesium phosphate cement in fracture treatment]

To investigate the effect of magnesium phosphate cement (MPC) to fix fractures.

In vitro: fifty-four pairs of fresh pig femoral heads were made 1 cm2 fracture and divided into 6 groups (n=9 pairs ). MPC was used to agglutinate fracture of femoral heads at 100% humidity and at 25 degrees C, 37 degrees C respectively. At 30 minutes, 2 and 24 hours after agglutination, the biomechanical strength was measured. In vivo: the tibia plateau fracture models on both sides of 24 rabbits were made, one side was fixed with "L" shaped plate, and the other side was fixed with MPC. Then the effect of treatment was investigated by macrography, micrography, radiography and the In vitro: the adhesive ability of changes of serum electrolyte levels at 3 days, 3, 6 and 9 weeks after operation.

MPC was strong. At 24 hours after MPC agglutination, the average tensile strength was 117.16 +/- 23.29 N/cm2. In vivo: after 6 weeks of fixation, the X-ray results showed that all rabbits' tibia plateau fractures were healed without displacement, and MPC was absorbed gradually. The changes of serum electrolyte levels were very minimal. The macrography observation showed that reduction of fracture were good at 3 days after operation, partial MPC remained in fracture end at 3 weeks, fracture line disappeared at 6 weeks and good remodeling was achieved at 9 weeks after operation in the experimental group. The micrography observation showed that the interface between bone and MPC was distinct at 3 days, MPC was degraded gradually and trabeculae began to grow into MPC at 3 weeks, and almost all MPC was degraded at 6 and 9 weeks of operation.

MPC is a promising biomaterial, and might potentially be used for fracture treatment.