Clinical outcomes and complication analysis of two kinds of osteotomy for severe thoracolumbar kyphosis seondary to ankylosing spondylitis

CHEN Zhi-ming; MA Hua-song; WANG Xiao-ping; TAN Rong; YUAN Wei; ZHAO Fu-jiang; XU Qi-ming

doi:10.3969/j.issn.2095-252X.2014.10.005

Abstract：Objective To compare the clinical outcomes and perioperative complications between 2 kinds of osteotomy in the treatment of severe thoracolumbar kyphosis ( TLK ) secondary to ankylosing spondylitis ( AS ). Methods From May 2009 to December 2013, 33 AS patients with severe TLK of more than 70° were divided into 2 groups because of the different osteotomy methods. A total of 18 male patients underwent double-segment pedicle subtraction osteotomy ( PSO ) in group 1, whose average age was ( 34.8±10.6 ) years old ( range: 19-47 years ). The global kyphosis ( GK ) angle was ( 82.6±17.5 ) ° ( range: 70°-108° ), and the chin-brow vertical angle was ( 67.2±21.9 ) ° ( range: 43°-130° ). The sagittal vertical axis ( SVA ) from the C7 plumb line to the posterior superior corner of the sacrum was ( 18.3±14.8 ) cm ( range: 11-35 cm ). The patients underwent mono-segment closing-opening wedge osteotomy ( COWO ) in group 2. There were 13 males and 2 females, with an average age of ( 31.2±8.5 ) years old ( range: 22-43 years ). The GK angle, chin-brow vertical angle and SVA was ( 76.3±11.2 ) ° ( range: 73°-98° ), ( 63.5±15.6 ) ° ( range: 47°-86° ) and ( 16.7±7.3 ) cm ( ragne: 10-26 cm ) respectively. The clinical outcomes and perioperative complications were compared between the 2 groups.Results In group 1, the correction rates of the GK angle, chin-brow vertical angle and SVA were ( 74.2±8.3 ) %, ( 86.2±9.5 ) % and ( 83.6±10.2 ) % respectively. In group 2, the correction rates of the GK angle, chin-brow vertical angle and SVA was ( 70.2±6.5 ) %, ( 86.6±8.3 ) %and ( 88.0±8.7 ) % respectively. As to all the parameters, there were no statistically signiifcant differences between the 2 groups (P>0.05 ). But there were statistically signiifcant differences between the 2 groups with regard to the operation time and blood loss (P<0.05 ). The patients in group 1 had longer operation time and more bleeding volume. The incidence rate of perioperative complications in group 2 was signiifcant higher than that in group 1 (P<0.05 ), especially the incidence rate of pedicle screw loosening and sagittal translation of the vertebral column.Conclusions The clincial outcomes by mono-segment COWO is similar to that by double-segment PSO in the treatment of AS patients with severe TLK. Shorter operation time and less blood loss can be achieved by mono-segment COWO, but with higher peripoerative complications.