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° 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° and 12.1±3.6°, 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.