Does Day of Surgery Affect Hospital Length of Stay and Charges Following Minimally Invasive Transforaminal Lumbar Interbody Fusion?

Study Design: Retrospective Cohort. Objective: To determine if an association exists between surgery day and length of stay or hospital costs after minimally invasive transforaminal lumbar interbody fusion (MIS TLIF). Summaryof Background Data: Length of inpatient stay after orthopedic procedures has been identified as a primary cost driver, and previous research has focused on determining risk factors for prolonged length of stay. In the arthroplasty literature, surgery performed later in the week has been identified as a predictor of increased length of stay. However, no such investigation has been performed for MIS TLIF. Materials and Methods: A surgical registry of patients undergoing MIS TLIF between 2008 and 2016 was retrospectively reviewed. Patients were grouped based on day of surgery, with groups including early surgery and late surgery. Day of surgery group was tested for an association with demographics and perioperative variables using the student t test or &khgr;2 analysis. Day of surgery group was then tested for an association with direct hospital costs using multivariate linear regression. Results: In total, 438 patients were analyzed. In total, 51.8% were in the early surgery group, and 48.2% were in the late surgery group. There were no differences in demographics between groups. There were no differences between groups with regard to operative time, intraoperative blood loss, length of stay, or discharge day. Finally, there were no differences in total hospital charges between early and late surgery groups (P=0.247). Conclusions: The specific day on which a MIS TLIF procedure occurs is not associated with differences in length of inpatient stay or total hospital costs. This suggests that the postoperative course after MIS TLIF procedures is not affected by the differences in hospital staffing that occurs on the weekend compared with weekdays.