Preliminary Report of Temporary Posterior Instrumentation in Stable Thoracolumbar Burst Fractures

Abstract

‐ Abstract ‐ Study Design : A prospective study of posterior instrumentation without fusion for the stable thoracolumbar fracture. Objectives : To confirm vertebral body collapse by roentgenograp hy and computerized tomography after removing posterior instrumentation at 6 months postoperatively in stable thoracolumbar burst fractures. Summary of literature review : Many authors have reported that vertebral body collapse occurs after instrumentation removal. Materials & Method : Sixty patients admitted between March 1999 and March 2001 with thoracolumbar junction fractures were included. Patients were divided into 3 groups: Group I - the Conservative management group (20 patients), Group II Reduction and posterior fixation with fusion group (20 patients), Group III - Reduction and temporary posterior fixation group (20 patients). The patients were aged between 21 and 49 years (mean 38), and the follow-up period exceeded 1 year (mean 13.3 months). We studied vertebral height, kyphotic angle, disc height and facet hypertrophy by roentgenography, and the continuity of the anterior cortical connection, cavity formation, sclerotic bone formation and new bone formation by CT. Results : The loss of vertebral height was 7.9% (from 21.5 to 29.4%) in Group I, 3.7% in Group II (preop 35%, postop 12.7%, postop 1Yr. 16.4%), and 3.5% in Group III (preop. 35.2%, postop 5.6%, postop 1Yr. 9.1%). Loss of angulation was 4.2。(from 9.6。to 13.8。 ) in Group I, 3.0。in Group II (preop 15.3。 , postop 7.2。 , postop. 1Yr. 10.2。 ), and 3.0。in Group III (preop 14.6。 , postop. 5.9。 , postop 1Yr. 8.9。 ). Loss of disc height was not statistically different for the 3 groups. Degenerative changes of the posterior facet were seen 3 patients of Group I, 11 patients of Group II, and in 5 patients of group III. On CT scan of Group III, all cases showed cavity formation and sclerosis ,and continuity of the anterior cortical connection and of new bone formation into the cavity were seen in 18 cases. Conclusions : Vertebral body collapse were not observed by roentgenography by computerized tomography after removing the posterior instrumentation at 6 months postoperatively in stable thoracolumbar burst fractures.