Is ABO blood type a risk factor for adjacent segment degeneration after lumbar spine fusion?

This study aimed to explore associations between ABO blood type and postoperative adjacent segment degeneration/disease (ASD) following lumbar spine fusion, as well as evaluate differences in spinopelvic alignment, perioperative care, postoperative complications, and patient-reported outcome measures (PROMs). An ambispective study was performed. Patients who underwent posterolateral or posterior lumbar interbody fusion were included. Demographic, perioperative and postoperative, clinical, and blood type information was recorded. Pre- and post-operative radiographic imaging was analyzed for alignment parameters and development of ASD. 445 patients were included, representing O+ (36.0%), O- (5.2%), A+ (36.2%), A- (6.3%), B+ (12.1%), B- (1.6%), and AB+ (2.7%) blood types. Most patients were female (59.1%), and had a mean age of 60.3 years and BMI of 31.1 kg/m . Postoperatively, groups did not differ in duration of the hospital (p = 0.732) or intensive care unit (p = 0.830) stay, discharge disposition (p = 0.504), reoperation rate (p = 0.192), or in-hospital complication rate (p = 0.377). Postoperative epidural hematoma was most common amongst A + patients (p = 0.024). Over a mean of 11.0 months of follow-up, all patients exhibited similar improvement in PROMs, with 132 (29.7%) patients developing radiographic evidence of ASD. B + patients were significantly more likely than A + and O + patients to develop spondylolisthesis and ASD (p 0.05). This is the first large-scale study to address and demonstrate proof-of-principle that ABO blood type, a non-modifiable risk factor, is associated with ASD following lumbar spine fusion.