Intraosseous vs. intravenous vancomycin administration in total shoulder arthroplasty: comparable tissue concentrations with better control

Background: Total shoulder arthroplasty (TSA) is a common and increasingly utilized surgical procedure. Due to many factors, achieving optional timing for intravenous (IV) administration of antibiotics is challenging, and improper timing has been linked to increased patient risk. IO regional administration (IORA) of vancomycin (VANC) has shown to be an effective route for surgical prophylaxis in total knee and hip arthroplasty. IORA has not been described for TSA. This study aims to evaluate the efficacy of IORA VANC compared to the traditional IV route in TSA. The primary purpose of this study is to determine if IORA VANC produces the same tissue concentrations as IV during TSA. A secondary outcome was to compare 30-day and 90-day postoperative complication infection rates between these 2 groups. Methods: Thirty-three patients undergoing TSA were randomized into 2 groups. The control group received IV cefazolin and IV VANC (15 mg/kg) preoperatively while the interventional group received IV cefazolin and IO (intraosseous) VANC (500 mg). The IO injection was performed through the incision into the proximal humerus. Tissue samples from bone, soft tissue, and serum were collected and analyzed for VANC concentrations throughout the surgery. Postoperative 30- and 90-day complications were also compared between the groups. Results: There were 15 in the interventional group and 18 in the control group. No patients were lost to follow-up, and data from 32 patients was analyzed. The systemic VANC levels were significantly lower in the IO group at the start of the case (IO 0.0 μG/mL vs. IV 17.8 μG/mL; P < .001) and at the end of the case (IO 9.8 μG/mL vs. IV 22.9 μG/mL; P = .006). There was a significant difference in total VANC provided between the 2 groups. Tissue concentrations showed no significant differences between any of the 7 samples. Initial deltoid (P < .798), biceps tendon (P < .090), humeral head or neck (P < .790), synovium (P < .622), labrum (P < .116), glenoid (P < .968), and final deltoid (P < .562). Only 1 unrelated complication was reported within 30 days postsurgery which was in the IV group. Conclusions: IORA VANC is a safe and effective method for antibiotic prophylaxis in TSA, achieving comparable local tissue concentrations with significantly lower systemic levels and total VANC provided to the patient compared to IV administration. This method may reduce the risk of systemic side effects and may eliminate logistical challenges associated with timing and rate of administration of IV VANC.