Experimental Study Of The Rap-style Bone Stress Stimulator On Accelerating Fracture Healing

Background: Fracture healing is regulated by the local mechanical environmen, and can be significantly promoted by proper stress. A rap-style bone stress stimulator had been developed based on this principle by our group, and had obtained the national invention patent.Objective: To explore the effect of the rap-style bone stress stimulator on accelerating fracture healing.Methods:Ten male grey goats of the same species were randomly collected. All the goats were performed with bilateral tibial transverse osteotomy and plate fixation, the right tibias undewent stress stimulation as the experimental group, the left didn't as the self-control group. Study factor treatment was started at the first day post operation and persevered for 12 weeks. Radiographs were taken for each tibia at the first day and the end of every four weeks after surgery. All animals were killed at the 12th weekend, bilateral complete tibias were obtained for three-point bending mechanical test and torsion test, the data was processed by SPSS V13.0. After the biomechanical tests, histological sections of the callus tissue were stained by HE and Masson method to assess the level of maturity.Results: All the animals had healed, and no reaction had been seen. The quality and quantity of callus of the experimental group was better than that of the control group by observing X-ray at the same time point. The results of Biomechanical tests suggested that three-point bending static rigidity, maximum load and torsional static rigidity of callus of the experimental group were significantly higher than that of the control group(P=0.000). The histomorphometry tests pointed out that the callus of the experimental group was more mature than that of the control group.Conclusion: Fracture healing should be promoted significantly by the rap-style bone stress stimulator, and the basis for the next clinical trials could be provided by this study.