Analysis of pedicle screw misplacement in the thoracolumbar spine of 19 cases / 中国组织工程研究

ABSTRACT

OBJECTIVE: To analyze the causes for misplacement of pedicle screw in thoracolumbar spine.METHODS: From January 2002 to January 2008, 19 patients with misplacement in thoracolumbar spine were treated in Department of Orthopedics, Wuxi Affiliated Hospital of Nanjing University of Chinese Medicine, including 12 males and 7 females with an average age of 52.5 years (range 23-68 years). The diagnoses were thoracolumbar fracture in 5 cases, lumbar spondylolisthesis in 8 and degenerative lumbar disease in 6. The fixation systems were Steffee used in 4 cases, DRFS in 3, RF in 6, AF in 4 and GSS in 2. X-ray and CT scanning were used to observe pedicle screw location, including screw,pedicle and membranous sac and great vessels.RESULTS: The time of misplacement of pedicle screw was 5-69 days with an average time of 18.5 days, including 7 cases of screw penetrating into lateral cortex, 4 of screw penetrating into medial cortex, 2 of screw penetrating into pedicle cortex, 2 of overplacement, 2 of intervertebral foremen placement and 2 of intervertebral space placement.CONCLUSION: The causes for screw misplacement were anatomic variation and poor surgical skills, and the key factors in precise insertion of pedicle screw are fine surgical skills, carefully study of preoperative image and the intra-operative monitoring.