Can bone mineral density affect intra-operative blood loss of mini-invasive posterior lumbar interbody fusion?

Objective Many factors affect intraoperative blood loss (BL) in mini-invasive posterior lumbar interbody fusion (PLIF) procedures, but only few has examined. Specifically, the impact of bone mineral density (BMD) levels on intraoperative BL. This study aims to examine the correlation between these two factors. Methods Retrospective review of 120 patients with low back disorders who were scheduled to undergo mini-invasive PLIF from October 2018 to October 2019 was performed. Patients were divided into two groups based on BMD of the lumbar spine: normal group and abnormal group (osteoporosis and osteopenia). Comparison of age, gender, BMD, BL, BMI, prothrombin time, activated partial thromboplastin time, haemoglobin concentration, intraoperative mean arterial pressure, platelet count, and operative time (OT) between the two groups, and correlation analysis of BMD and BL were conducted. Results The mean BL of patients in the abnormal group was remarkably higher than that in the normal group: 357.22 ± 152.55 ml and 259.37 ± 125.90 ml respectively (p < 0.001). The partial correlation coefficient between BL and BMD was −0.45 (p < 0.001). The results of univariate regression analysis demonstrated that only BMD, gender, and OT were related to BL (BMD, r = −0.427, p < 0.001; gender, r = −0.211, p = 0.024; OT, r = 0.318, p = 0.001). While multivariate linear regression analysis demonstrated that patients with lower BMD and longer OT had a higher amount of intraoperative BL (p < 0.001). Conclusions BMD is an important factor influencing intraoperative BL in mini-invasive PLIF. It should be assessed routinely as a part of the preoperative examination to improve preoperative assessment and ensure patient safety.