Two strengthening pedicle screw techniques and bone cement in lumbar internal fixation / 中国组织工程研究

ABSTRACT

BACKGROUND:Screw loosening and shedding may occur after osteoporosis associated with lumbar degenerative disease treated with pedicle screw fixation. Application of pedicle screw enhanced with cured materials can improve the therapeutic effect. OBJECTIVE:To compare the clinical effect of pedicle screws enhanced with poly(methyl methacrylate) and injectable calcium sulfate cement in the lumbar internal fixation of osteoporosis. METHODS:Sixty-one patients diagnosed with osteoporosis combined with lumbar spondylolisthesis, lumbar spinal instability, and severe lumbar spinal stenosis were col ected. Al patients were divided into two groups according to the treatment method:poly(methyl methacrylate) bone cement enhanced pedicle screw group and calcium sulfate bone cement enhanced pedicle screw group. RESULTS AND CONCLUSION:There were no significant differences in the operation time, blood loss, preoperative and postoperative visual analog scale score, Japanese Orthopedic Association scores and the Japanese Orthopedic Association score improvement rate between two groups (P>0.05). The results showed that two patients had bone cement leakage in poly(methyl methacrylate) group which had no neurological symptoms caused by new symptoms during fol ow-up period. The bone mineral density was not improved gradual y in poly(methyl methacrylate) group with fol ow-up time prolonging;however, in calcium sulfate group, the bone mineral density was increased significantly after treatment, and the change of bone mineral density was linearly related with Japanese Orthopaedic Association score improvement rate in calcium sulfate group. No screw loosening, pul ing out or neurological dysfunction occurred in both groups. The results indicate that like poly(methyl methacrylate), balcium sulfate bone cement can increase the stability of pedicle screws.