Analysis On Quality Of Life Before And After Kyphoscoliosis Correction In Ankylosing Spondylitis And Predictors Of Massive Blood Loss In Pedicle Subtraction Osteotomy

Objective:1. To evaluate the quality of life and capacity for action in AS patients with kyphoscoliosis before and after orthopedic. To discuss the operation method of AS patients with kyphoscoliosis.2. To investigate the predictors of massive blood loss (MBL) in pedicle subtraction osteotomy (PSO) in the treatment of spinal kyphosis caused by ankylosing spondylitis (AS).Methods:1. Collect 38 AS patients with kyphoscoliosis classified into 2 groups according to spine malformation types:Group A, patients with kyphoscoliosis, Group B, patients with kyphosis. Patients in group A underwent asymmetric PSO surgery. The BASFI and SRS-22 were completed to compare quality of life and capacity for action of two groups preoperative; Analyze the relation between the imbalanced degree of coronal plane and patients’ quality of life, capacity for action; Compare quality of life, capacity for action of patients in group A pre-and postoperation.2. A total of 106 patients with spinal kyphosis caused by AS underwent PSO. All cases were divided into two groups. In group A (n=69) the intraoperative blood loss was more than or equal to 30% of the estimated blood volume, and in group B (n=37) the intraoperative blood loss less than 30% of the estimated blood volume. The preoperative date were compared between the 2 groups, and univariate analysis was undertaken to distinguish all the possible predictors of MBL. And a binary logistic regression analysis was used to determine the independent risk factors of MBL. The relationship between the incidence of MBL and the cumulative amount of PSO by spine surgeons was analyzed with the Pearson correlation test.Results:1. The score of BASFI and SRS-22 of AS patients with kyphoscoliosis are worse than patients only with kyphosis. Patients with larger imbalanced degree of coronal plane has worse score of BASFI and SRS-22. Global kyphosis(GK) decreased from 77.1 ° to 18.7°, Cobb angle of coronal plane decreased from 29.9° to 6.5° after the surgery.2. There were more cases of double-segment osteotomy in group A (65%) than in group B (35%),with the global kyphosis (GK)≥70° (p<0.05) and the number of fixation segments≥9. Logistic regression analysis showed that more than or equal to 9 fixation segments and double-segment osteotomy were independent risk factors for MBL. The Pearson correlation test showed that the incidence of MBL was decreased with the increase of the cumulative amount of PSO by spine surgeons in certain range and a linear correlation was found between them.Conclusion:1. The quality of life and capacity for action of AS patients with kyphoscoliosis are worse than patients only with kyphosis. The imbalanced degree of coronal plane has bad influence on the quality of life and capacity for action. Asymmetric PSO surgery is appropriate for AS patients with kyphoscoliosis.2. When PSO is performed in the treatment of spinal kyphosis caused by AS, the incidence of MBL is 65%.The predictors of MBL included the preoperative Cobb’s angle ≥70°, double-segment PSO osteotomy and number of fixation segments≥9, and the last two predictors are independent. In certain range, with the increase of cumulative amount of PSO by spine surgeons, the incidence of MBL will be decreased.