title: Intraoperative blood loss in female patients with adolescent idiopathic scoliosis during different phases of the menstrual cycle.
abstract: BACKGROUND
  The vast majority of AIS patients who require surgical intervention are women. Blood loss is a major concern during the operation.
  
  
  METHODS
  The medical records of all female AIS patients who underwent posterior correction and fusion operations using the all-pedicle screw system from January 2012 to January 2014 were reviewed. Patients with irregular menstruation; underwent osteotomy; use coagulants were excluded from the study. The remaining patients were divided into 4 groups according to the operation date in the menstrual cycle (A: premenstrual group, 24-30 d; B: follicle group, 6-11 d; C: ovulatory group, 12-17 d; D: luteal group, 18-23 d). The information of patients from the 4 groups was reviewed. The data was analyzed using analysis of variance, the Student-Newman-Keels test and Kruskal-Wallis Test.
  
  
  RESULTS
  A total of 161 patients were included in this study. There were 40 patients included in group A, 38 patients in group B, 41 patients in group C and 42 patients in group D. The 4 groups were matched in age (P = 0.238), body height (P = 0.291), body weight (P = 0.756), Risser sign (P = 0.576), mean curve Cobb angle (P = 0.520), and bending flexibility index (P = 0.547), the number of levels fused (P = 0.397). The activated partial thromboplastin time (P = 0.235) and prothrombin time (P = 0.074) tended to be higher in group A, but the difference was not statistically significant. The fibrinogen level was lower in group B than the other 3 groups (P = 0.039). Blood loss and normalized intraoperative blood loss (NBL) was significantly higher in group A than the other 3 groups (P<0.01).
  
  
  CONCLUSIONS
  The hemostatic function tended to be lower in the premenstrual phase. The fibrinogen level was lowest in the mid-follicle phase. Female AIS patients tended to endure more intraoperative blood loss when the operation was performed in the premenstrual phase during the menstrual cycle.
authors.affiliation: Department of Spine Surgery, Changhai Hospital, the Second Military Medical University, Shanghai, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Orthopedics, Changhai Hospital, the Second Military Medical University, Shanghai, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Department of Spine Surgery, Changhai Hospital, the Second Military Medical University, Shanghai, China.
authors.forename: Zhikun
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Spine Surgery, Changhai Hospital, the Second Military Medical University, Shanghai, China.
authors.forename: Mingyuan
authors.initials: M
authors.lastname: Yang
authors.affiliation: Department of Spine Surgery, Changhai Hospital, the Second Military Medical University, Shanghai, China.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Sun
authors.affiliation: Department of Spine Surgery, Changhai Hospital, the Second Military Medical University, Shanghai, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Fan
authors.affiliation: Department of Spine Surgery, Changhai Hospital, the Second Military Medical University, Shanghai, China.
authors.forename: Honglei Yi Xiaodong
authors.initials: HY
authors.lastname: Zhu
authors.affiliation: Department of Orthopedics, Changhai Hospital, the Second Military Medical University, Shanghai, China.
authors.forename: Chuanfeng
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Spine Surgery, Changhai Hospital, the Second Military Medical University, Shanghai, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
mesh_terms: D000293:Adolescent; D016063:Blood Loss, Surgical / Q000503:physiopathology* / Q000517:prevention & control; D005260:Female; D005340:Fibrinogen / Q000032:analysis; D006801:Humans; D008597:Menstrual Cycle / Q000097:blood*; D019637:Orthopedic Procedures / Q000009:adverse effects; D012600:Scoliosis / Q000601:surgery*
chemical_list: D005340:Fibrinogen