Middle-column preserved pedicle subtractionclosing-opening wedge osteotomy to treat thoracolumbar kyphosis deformity in ankylosing spondylitis / 中华骨科杂志

ABSTRACT

Objective To investigate the effectiveness and safety of middle-column preserved pedicle subtraction closingopening wedge osteotomy for the treatment of ankylosing spondylitis (AS)-related thoracolumbar kyphosis.Methods From January 2010 to December 2016,eleven patients (9 males and 2 females) who underwent one-level middle-column preserved pedicle subtraction osteotomy with an average age of 40.8 years (21-68 years) were reviewed.The average thoracolumbar kyphosis angle (TLK) was 50.5°±9.6° and the average lumbar lordosis angle was-2.5°±24.1°.The thoracolumbar kyphosis,sagittal vertical axis (SVA),lumbar lordosis,pelvic tilt,sacral slope,thoracic kyphosis,Scoliosis Research Society (SIRS) 22,Oswestry disability index (ODI) score,the length of anterior column and posterior column at the pre-and post-operation,operation time,perioperative blood loss and complications were recorded.Results The osteotomy sites of 11 cases included 7 in L2,2 in L3 and 2 in T12.Theaverage operation time was 156.8 min (120-220 min).The average blood loss was 604.5 ml (350-900 ml).The average time of followup was 24 months (12-42 months).Complications were encountered in 2 patients.There were 1 casewith transient neurological deficits,another case with incision infection.No serious neurological or vascular complications occurred in all cases.The thoracolumbar kyphosis (TLK),lumbar lordosis,pelvic tilt,sacral slope,thoracic kyphosis,SRS 22 and ODI score were improved significantly.The preoperative TLK cobb was 50.5° (36°-66°),which improved to 5.1 ° (1 °-11°) at the final follow-up with a mean correction rate of 89.9％.Sagittal migrationwas improved from 184.6 mm preoperatively to 79.2 mm atthe final follow-up with an average correctionrate of 49.3％.The differences of the length of posterior column of osteotomy site after operation showed no statistical significance.All patients had solid fusion at osteotomy site and no instrumentational failure and loosening were found over the follow up.Conclusion Middle-column preserved pedicle subtraction closing-openingwedge osteotomy is safe and effective for correction of the thoracolumbar kyphosis deformity occurring in ankylosing spondylitis,resulting in satisfactory out comes with acceptable complications.