Preventing the screw from loosening and pulling out, secondary lumbar spondylolisthesis: how to select a better therapeutic scheme for osteoporotic lumbar spondylolisthesis? / 中国组织工程研究

ABSTRACT

BACKGROUND: Expansive pedicle screws have been found to have strong resistance to rotation, prevent screw loosening and pulling out, and maintain the stability and physiological curvature of lumbar vertebrae, so it provides a secure and stable environment for long-tem intervertebral fusion.OBJECTIVE: To investigate the clinical efficacy of the expandable versus conventional pedicle screws in the treatment of osteoporotic lumbar spondylolisthesis.METHODS: A total of 67 cases of osteoporotic lumbar spondylolisthesis were randomized into three groups, and then treated with conservative treatment (n=12), expansive pedicle screws (n=20), and common pedicle screws (n=35),respectively. The Japanese Orthopaedic Association and Visual Analogue Scale scores as well as radiological data were obtained immediately and 1 week after admission, 6 and 12 months after discharge. The stability of the screw and spinal fusion were evaluated, and the spondylolisthesis was assessed according to Meyerding system.RESULTS AND CONCLUSION: (1) The improvement rate of Japanese Orthopaedic Association scores at the last follow-up showed no significant difference between expansive and common groups (P=1.00), and the improvement rate in the expansive and common groups was significantly higher than that in the conservative group (P < 0.05). (2) The Visual Analogue Scale scores in the expansive and common groups were significantly decreased, and the scores did not differ significantly between two groups (P > 0.05); the scores in the conservative group changed irregularly. (3) The reduction rate of spondylolisthesis in the expansive group was significantly higher than that in the common group (P < 0.01). (4) The spinal fusion score at 24 months postoperatively in the expansive group was significantly higher than that in the common group (P=0.035). (5) For osteoporotic patients with lumbar spondylolisthesis, the expansive pedicle screws are much better than the common pedicle screws in the spondylolisthesis reduction, fusion rate of bone graft,screw stability; therefore, it is a safer and more effective method.