Long vs. short fusions for adult lumbar degenerative scoliosis: does balance matters?

Purpose: Surgery of adult scoliosis was based upon coronal plane radiographical analysis using Cobb angle measurements, but recently it has been demonstrated that sagittal spinopelvic alignment plays a critical role in determining the final outcome. The aim of this paper is to compare the clinical and radiological results of 81 patients affected by adult scoliosis, treated with short or long fusions, and followed for 2–5 year follow-up. Materials and methods: 81 patients affected by degenerative lumbar scoliosis managed by posterior-only surgery were retrospectively evaluated. Fifty-seven patients underwent to a short fusion procedure, while 24 had a long fusion. Clinical and radiographic coronal and sagittal spinopelvic parameters were compared between the two groups. Results: Coronal Cobb angle was 24° preoperatively and passed to 12° in the short fusion group, while changed from 45° to 10° in the long fusion group. Lumbar lordosis was 45° preoperatively and 60° at final follow-up in the short fusion group passed from 24° to 55° in the long fusion group. Sacral slope passed from 25° to 45° in the short fusion group, while from 10° to 40° in the long fusion group. Pelvic tilt passed from 24° to 13° in the short fusion group, and from 28° to 23° in the long fusion group. Conclusion: Surgical treatment of degenerative lumbar scoliosis improved balance and alignment of the spine, and also the coronal plane in terms of Cobb angle. These results were associated to a consistent clinical improvement and an acceptable rate of complications.