Lumbar spinal fusion in postmenopausal women with a history of hormone replacement therapy.

Introduction: Recent re-evaluation of the Women's Health Initiative Hormone Therapy Trials has established that hormone replacement therapy (HRT) can be beneficial for patients, if begun shortly after menopause. This study investigates the impact of a history of postmenopausal HRT on patient demographics and perioperative complications in women undergoing lumbar spinal fusion. Methods: The National Inpatient Sample was queried from 2016 to 2020 for postmenopausal women (>55 years old or applicable diagnosis) undergoing lumbar spinal fusion for degenerative etiologies, using International Classification of Disease Tenth Revision diagnostic and procedural codes. Patient characteristics and perioperative complications were evaluated for history of HRT versus non-HRT patients undergoing lumbar spinal fusion surgery. Results: Of the 202,945 postmenopausal patients undergoing lumbar spinal fusion, 2645 (1.3 %) had a history of receiving HRT. Analysis demonstrated that HRT was a negative predictor of acute kidney injury (OR: 0.672; p = 0.006), pneumonia (OR: 0.320; p = 0.010), and anemia (OR: 0.887; p = 0.020). It was a positive predictor of bowel/bladder dysfunction (OR: 1.371; p < 0.001). Conclusions: The findings of this study highlight the unique demographics, comorbidities, and perioperative complications of postmenopausal women with a history of HRT undergoing lumbar spinal fusion surgery. While HRT history was associated with a favorable inpatient course, including reduced risk of acute kidney injury, pneumonia, deep venous thrombosis and myocardial infarction, these findings should be interpreted with caution due to limitations in coding accuracy and lack of long-term follow-up. HRT status may reflect broader differences in baseline health and healthcare access.