Asymmetrical pedicle subtraction osteotomy for rigid degenerative lumbar kyphoscoliosis.

Study Design. A prospectively study. Objective. Our objective was to clarify the safety and efficacy of asymmetrical pedicle subtraction osteotomy (PSO) in the treatment of severe adult lumbar deformities prospectively. Summary of Background Data. Vertebral wedge osteotomy provides good correction of kyphosis but has rarely been applied to degenerative lumbar kyphoscoliosis. Methods. A total of 14 patients who had undergone corrective osteotomy were enrolled. The average age at PSO was 67 years (range, 45-76 yr). The minimum follow-up was 2 years. Patient questionnaires were administered prospectively. Radiographical parameters including sagittal and coronal balance were analyzed. Results. Average operative time was 310 minutes (range, 254-375 min). Average blood loss was 1090 mL (range, 700-2900 mL). Mean preoperative lumbar lordosis improved from -3 degrees to 42 degrees at the final follow-up, and sagittal balance improved from 12 to 3 cm, respectively. Mean lumbar scoliosis improved from 40 degrees to 12 degrees, and coronal offset improved from 3 to 1 cm, respectively. There was also statistically significant improvement from preoperative to final evaluation in all clinical domains. There were 4 complications: 1 dural tear, 2 hook dislodgements at the cephalad side requiring revision instrumentation, and 1 rod breakage not requiring surgical intervention. Overall, all 14 patients were satisfied with their surgical management and would choose to repeat the procedure. Conclusion. Our data suggest that the surgical procedure of asymmetrical PSO is to correct the scoliosis, to restore the lumbar lordosis by way of convex-sided posterolateral wedge osteotomy, and may go a long way toward solving the problems of rigid lumbar degenerative kyphoscoliosis.