Perioperative Complications In Spinal Osteotomy For Thoracolumbar Kyphosis Caused By Ankylosing Spondylitis:Incidence And Risk Factors

Part one: Perioperative complications in spinal osteotomy for thoracolumbar kyphosis caused by ankylosing spondylitis:incidence and risk factorsObjectives: To describe the incidence of perioperative complications in spinal osteotomy for thoracolumbar kyphosis caused by ankylosing spondylitis(AS)and to investigate the risk factors for these complications.Methods: From April 2000 to July 2017,342 consecutive AS patients undergoing spinal osteotomy were enrolled.Patients with perioperative complications were identified.Demographic,radiological and surgical data were compared between patients with and without perioperative complications.Perioperative complications were classified into intraoperative and early postoperative complications.Results: A total of 309 consecutive pedicle subtraction osteotomy(PSO)and 37 multiple Smith-Petersen osteotomies(SPOs)procedures were performed in 342 patients.Overall,forty-six complications were identified in 46 patients(13.5%),including 31 intraoperative complications and 15 early postoperative complications.Patients with perioperative complications were older than those without(P=0.005).A significant difference was observed in preoperative global kyphosis(GK),lumbar lordosis(LL),sagittal vertical axis(SVA)and the correction of these radiographic parameters between patients with and without perioperative complications(P<0.05).Two-level PSO(P=0.012)and an increased number of instrumented vertebra(P=0.039)were significantly associated with an increased risk of perioperative complications.Conclusions: The overall incidence of perioperative complications was 13.5%.Age;preoperative GK,LL and SVA;the correction of GK,LL and SVA;two-level PSO;and number of instrumented vertebra were risk factors.Therefore,the potential risk of extensive surgeries with large correction and long fusion in older AS patients with severe GK should be seriously considered in surgical decision-making.Part two: Quality of life and correlation with clinical and radiographic variables in patients with ankylosing spondylitis: a retrospective case series studyObjectives: To evaluate quality of life(QoL)and correlation with clinical and radiographic variables in ankylosing spondylitis(AS)patients,especially to figure out the relationship about the pain-specific disability measured by Oswestry Disability Index(ODI),global kyphosis(GK)and QoL.Methods: From January 2008 to November 2015,two hundred and forty-five consecutive patients with an average age of 36.2 ±10.9 years(range,17-66 years)satisfying the Modified New York Criteria for AS from a single institution were enrolled.Bath Ankylosing Spondylitis Disease Activity Index(BASDAI),Bath Ankylosing Spondylitis Functional Index(BASFI),Bath Ankylosing Spondylitis Metrology Index(BASMI)and Bath Ankylosing Spondylitis Global score(BAS-G)were applied to assess the disease activity,functional status,spinal mobility and overall feeling of AS patients,respectively.ODI was recorded to evaluate low back pain-related disability.Qo L was evaluated by the Short Form-36(SF-36).According to global kyphosis(GK)measured on standing lateral full-spine radiographs,the patients were divided into two groups: mild kyphotic group(GK<70°,n=176)and severe kyphotic group(GK?70°,n=69).Results: The scores of BASDAI,BASFI,BASMI and ODI had significant negative correlations with all SF-36 subscale scores(P<0.01).BASFI and BASMI scores of severe kyphotic group were much higher than those of mild kyphotic group,respectively(P=0.005 and P=0.001,respectively)and the score of physical function(PF)subscale in severe kyphotic group was significantly higher than that in mild kyphotic group(P=0.046)as well.Notably,the scores of ODI,BASFI and BASMI were the major predictors of PF subscale score of SF-36.Conclusions: Poor Qo L is significantly correlated with high disease activity,poor functional status and decreased spinal mobility in AS.GK is significantly associated with functional status,spinal mobility and Qo L in AS patients.ODI,BASFI and BASMI are the major predictors of PF subscale of SF-36.