Bone filling mesh container repairs vertebral compression fractures：biomechanical changes / 中国组织工程研究

ABSTRACT

BACKGROUND:Percutaneous vertebroplasty and percutaneous kyphoplasty have become the mainstream clinical methods for the treatment of vertebral compression fractures. However, both of them have several shortcomings such as bone cement leakage, spinal stenosis, nerve compression, pulmonary embolism and other issues. OBJECTIVE:To verify the possibility of bone filing mesh container prepared by polyethylene terephthalate for the treatment of vertebral compression fractures. METHODS:The biological properties of bone filing mesh container were examined according to GB/T16886. After sample aging test, the tensile properties of the aged samples and the fresh prepared samples were compared. The expansion and bone cement leakage were evaluated by injecting bone cement into the bone filing mesh container and measuring the pressure. The initial strength and stiffness of the fresh pig vertebrae with calcium phosphate cement injection or with bone filing mesh container filed with calcium phosphate cement were compared. The in vivo bone tissue growth was periodicaly observed after the lumbar vertebra of 4-month-old pigs was implanted with the bone filing mesh container that was then ful of bone cement. RESULTS AND CONCLUSION: The bone filing mesh container had good biocompatibility. Bone filing mesh containers after 2-year storage had the same tensile strength to the fresh bone filing mesh containers. At ambient conditions, after bone cement injection, bone filing mesh containers could be expanded at 5-10 atm and therefore could play the role of uplift; at 7-10 atm, bone cement could leak out from the bone filing mesh container and enter into the interspace between surrounding bone tissues, thus playing the role of adhesion and fixation. The vertebrae after bone cement injection with or without bone filing mesh containers had the same initial strength and stiffness and exhibited bigger initial strength and stiffness than untreated vertebrae. Thein vivo animal experiments proved that bone filing mesh container had no obvious effect on the vertebrae. These findings indicate that the bone filing mesh container can be used to restore the height and strength of the fractured vertebrae. Moreover, it may eliminate bone cement leakage and therefore increase the surgery safety.