Data-Driven Preoperative Hemoglobin Strata Predict Blood Transfusion and Surgical Complication Risk Following Total Shoulder Arthroplasty.

INTRODUCTION: Preoperative anemia is associated with postoperative surgical complications and blood transfusions following total shoulder arthroplasty (TSA). However, hemoglobin thresholds have not been well identified. This study aimed to create data-driven preoperative hemoglobin levels that characterize the risk of blood transfusion and other medical and surgical complications.

METHODS: Patients who underwent TSA with a hemoglobin value recorded one month before surgery were identified from the TriNetX database. Stratum-specific likelihood ratio (SSLR) analysis defined preoperative hemoglobin cut-offs associated with increased 90-day postoperative blood transfusions for men and women. Additional outcomes included 90-day medical complications such as blood transfusion, major complications, wound infection, or dehiscence and 2-year surgical outcomes including all-cause revision, periprosthetic joint infection (PJI), and mechanical loosening.

RESULTS: The SSLR analysis identified four hemoglobin strata with increased 90-day blood transfusion for men (<12, 12-13, 13-14.5, >14.5 g/dL) and five hemoglobin strata for women (<10, 10-11, 11-12, 12-13, >13 g/dL). When comparing against the highest-value strata, there were sequential, significant increases in risk for 2-year PJI, 90-day major complications, and 90-day infection/wound disruption, progressing down the hemoglobin strata for both cohorts.

CONCLUSION: SSLR analysis characterized the likelihood of 90-day blood transfusions associated with hemoglobin strata, ranging from 0.24 to 4.65 for men and 0.23 to 8.11 for females, where intermediate strata had a LR close to 1, thus minimally changing the likelihood of transfusion. After matching, we observed a progressive increase in 90-day major medical complications (up to 1.84 and 2.2 times for men and women, respectively), 90-day infection/wound disruption (up to 3.14 and 3.71 times), and 2-year PJI (up to 2.36 and 4.94 times). These findings indicate that progressively lower preoperative hemoglobin is associated with a step-wise increase in postoperative TSA complication risk.

LEVEL OF EVIDENCE: Level III, Retrospective Cohort Comparison using Large Database, Prognosis Study.