Radiographic Progression of Degenerative Lumbar Scoliosis after Short Segment Decompression and Fusion

STUDY DESIGN A retrospective study. PURPOSE To assess the radiographic progression of degenerative lumbar scoliosis after short segment decompression and fusion without deformity correction. OVERVIEW OF LITERATURE The aims of surgery in degenerative lumbar scoliosis are the relief of low back and leg pain along with a correction of the deformity. Short segment decompression and fusion can be performed to decrease the level of low back and leg pain provided the patient is not indicated for a deformity correction due to medical problems. In such circumstance, the patients and surgeon should be concerned with whether the scoliotic angle increases postoperatively. METHODS Forty-seven patients who had undergone short segment decompression and fusion were evaluated. The average follow-up period was more than 3 years. The preoperative scoliotic angle and number of fusion segments was 13.6+/-3.9 degrees and 2.3+/-0.5, respectively. The preoperative, postoperative and last follow-up scoliotic angles were compared and the time of progression of scoliotic angle was determined. RESULTS The postoperative and last follow-up scoliotic angle was 10.4+/-2.3 degrees and 12.1+/-3.6 degrees , respectively. In eight patients, conversion to long segment fusion was required due to the rapid progression of the scoliotic angle that accelerated from 6 to 9 months after the primary surgery. The postoperative scoliosis aggravated rapidly when the preoperative scoliotic angle was larger and the fusion was extended to the apical vertebra. CONCLUSIONS The scoliotic angle after short segment decompression and fusion was not deteriorated seriously in degenerative lumbar scoliosis. A larger scoliotic angle and fusion to the apical vertebra are significant risk factors for the acceleration of degenerative lumbar scoliosis.