Horizontal fixation of the L3 vertebra with a tilt of less than 5° can prevent the long-term curve progression of unfused adult scoliosis: ten-year follow-up study of concave PLIF at the wedged disc below the caudal end vertebra.

Abstract

Prospective consecutive series. The objective of this 10-year follow-up study was to assess the efficacy of concave PLIF for lumbosacral hemicurve in treating patients with adult scoliosis. Long-term results and clinical significance of PLIF for allowing L3 vertebra to become horizontal in adult scoliosis have not yet been reported. Fourteen patients (53-72 yr) were operatively treated and prospectively studied. The surgical procedure was, after decompression of the affected nerve root, to correct the wedged disc below the caudal end vertebra, L3 or L4, which allowed for the end vertebra to become horizontal by way of concave PLIF. The follow-up period was 10 years. Mean visual analogue scale (100 mm) score was 78 before surgery, 20 at 2 years after surgery, and 17 at the final follow-up in leg pain, 67, 25, and 28, respectively, in low back pain, and 13, 7, and 7, respectively, in the disability score (Rolland-Morris). The mean Cobb angles were 24°, 16°, and 17°, respectively, in scoliosis, 17°, 9°, and 10°, respectively, in L3 vertebral tilt, and 21°, 28°, and 26°, respectively, in lumbar lordosis. In 7 patients with postoperative L3 vertebral tilt of less than 5°, the Cobb angle of the unfused main curve improved over time. The results of this study suggest that horizontal fixation of the L3 vertebra can prevent the long-term development of unfused adult scoliosis. 4.