How to Calculate the Exact Angle for Two-level Osteotomy in Ankylosing Spondylitis?

作者：Zheng, Guoquan; Song, Kai; Yao, Ziming; Zhang, Yonggang; Tang, Xiangyu; Wang, Zheng; Zhang, Xuesong; Mao, Keya; Cui, Geng; Wang, Yan^*

来源：Spine, 2016, 41(17): E1046-E1052.

DOI：10.1097/BRS.0000000000001610

• ankylosing spondylitis
• hilus pulmonis
• sagittal balance
• spinal osteotomy

Study Design.A prospective case series study.Objective.To describe and assess a two-level osteotomy method for the management of severe thoracolumbar kyphosis (TLK) in patients with ankylosing spondylitis (AS).Summary of Background Data.To achieve better postoperative outcomes in these patients, a sophisticated preoperative surgical plan is required. Most deformities are managed using a one-level osteotomy and a two-level osteotomy is seldomly reported. Till date, no study has described a two-level osteotomy for these cases.Methods.From January 2011 to December 2012, 10 consecutive patients with ankylosing spondylitis who underwent two-level spinal osteotomy were studied. Pre- and postoperative full-length free-standing radiographs, including the whole spine and pelvis, were available for all patients. Pre- and postoperative radiological parameters, including T5-S1 Cobb angles, TLK, lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope, and sagittal vertical axis were measured. Health related quality of life , including Oswestry Disability Index and Scoliosis Research Society-22 surveys were administered before surgery and at 1-year follow up.Results.The preoperative and postoperative T5-S1 Cobb angles was 51.3 degrees and -7.1 degrees, respectively (P<0.001). All patients demonstrated changes in postoperative radiographic parameters including decreased pelvic tilt (from 37.1 degrees to 14.3 degrees, P<0.001), TLK (from 36.9 degrees to 12.6 degrees, P<0.001), and sagittal vertical axis (from 21.4cm to 7.1cm, P<0.001), increased lumbar lordosis (from -5.1 degrees to -47.1 degrees, P<0.001), sacral slope (from 13.4 degrees to 37.7 degrees, P<0.001), but no significant change in pelvic incidence. Health related quality of life scores at 1-year follow up were significantly improved compared to those before surgery.Conclusion.This calculation of two-level osteotomy provides an accurate and reproducible method for ankylosing spondylitis correction. By which, we can obtain satisfactory radiological parameters and clinical outcomes.Level of Evidence: 4

• 出版日期2016-9-1