Pedicle Subtraction Osteotomy with a Cage Prevents Sagittal Translation in the Correction of Kyphosis in Ankylosing Spondylitis

摘要

Background:Sagittal translation (ST) is an accidental event that surgeons commonly encounter during a spinal osteotomy in the correction of kyphosis in ankylosing spondylitis (AS).However,there is a paucity of effective techniques to prevent ST.The purpose of this study was to propose a pedicle subtraction osteotomy (PSO) with a cage as a method to prevent ST and to explore the efficacy and feasibility of this method in the treatment of kyphosis in AS.Methods:We retrospectively reviewed 89 consecutive patients with AS kyphosis who underwent a PSO (Group B,46 patients) or a PSO with a cage (Group A,43 patients) from February 2009 to December 2013.Pre-and post-operative radiographic results were reviewed.ST and complications were analyzed in both groups.Clinical assessment was performed using the Scoliosis Research Society-22 (SRS-22) outcomes metric.The patients were followed up for at least 2 years.Results:Group A achieved the same re-alignment of the kyphotic spine as Group B.Two (4.7％) of the 43 patients in Group A and 14 (30.4％) of the 46 patients in Group B had intraoperative ST (x2 =10.020,P =0.002).Significant differences were identified between the two groups in the height change of the osteotomized column.SRS-22 scores improved significantly in both groups.Seven patients experienced neurologic complications (1 in Group A and 6 in Group B).Eight patients had cerebrospinal fluid leakage (2 in Group A and 6 in Group B).Conclusion:PSO with a cage significantly avoided ST during the osteotomy procedure and might represent a new,safe,and feasible choice for treating patients with AS kyphosis.