preoperative variables predicting massive blood loss during surgical management of adolescent idiopathic scoliosis

background: massive blood loss is one of the most important concerns in scoliosis surgery. there are some factors suggested to predict the massive blood loss in patients with adolescent idiopathic scoliosis (ais), however, their predictive value remained unclear.objectives: the current study aimed to investigate whether preoperative variables can predict perioperative massive blood loss in patients with ais.patients and methods: there were 60 patients with ais who underwent surgical treatment in the current retrospective study. posterior spinal fusion (psf) was performed on 36 patients and psf and anterior spinal fusion (asf) for the other 24. estimated blood loss (ebl) was calculated intraoperative. the correlation between preoperative radiographic and demographic variables with ebl was investigated.results: among the variables, only avb-r ratio positively correlated with the amount of intraoperative blood transfusion (r = 0.28; p = 0.03). also, preoperative lateral rib hump positively correlated with blood loss in the psf group (r = 0.39; p < 0.05). also, the classification of the scoliosis did not affect the amount of blood loss and the number of transfused units.conclusions: the preoperative lateral rib hump is an important factor positively correlated with the ebl.