Relevance research of blood loss in orthomorphia of adolescent idiopathic scoliosis and menstrual cycle

Objective To investigate the relevance between blood loss in orthomorphia of adolescent idiopathic scoliosis(AIS) and menstrual cycle.Methods April 2010 to December 2012,200 female AIS patients who underwent posterior orthomorphia operation were reviewed,and 60 cases were choosed to be sorted into 3 groups.To compare each 2 groups by matched t-test.And then,the days from the end of menstrual cycle to the day of operation,operative time,Cobb's angle of chief scoliosis,ages,weight,number of fused vertebrae,number of implant,blood loss,Risser and Lenke classification were collected and employed as independent variances.Multiple regression analysis was performed to ascertain the relevance between blood loss and the days from the end of menstrual cycle to the day of operation,and continuing to perfect the multiple linear regression model of blood loss.Results Average number of fused vertebrae was 9.5 ± 3.8.Average number of implant was 14.2 ± 2.2.Average estimated blood loss was(931 ± 251) mL.Average operative time was(180 ± 21) min.Average days from the end of menstrual cycle to the day of operation was(11.1 ± 5.3) d.Multiple regression analysis showed that operative time,number of fused vertebrae,number of implant and the days from the end of menstrual cycle to the day of operation has significant influence to the blood loss(P 0.01).Conclusion Operative time,number of fused vertebrae,number of implant and the days from the end of menstrual cycle to the day of operation are significant influencing factors of blood loss.