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.