Intraosseous Administration of Medications in Total Knee Arthroplasty: An Opportunity for Improved Outcomes and Superior Compliance.

Background: Vancomycin is a prophylactic antibiotic with bactericidal activity against methicillin-resistant Staphylococcus aureus that is commonly used in total joint replacement surgery¹. In total knee arthroplasty (TKA), intraosseous infusions administered following tourniquet inflation have demonstrated improved local vancomycin concentrations with decreased systemic absorption^1-3. This administration method results in no adverse reactions locally, as well as equivalent or lower systemic complications compared with other vancomycin administration methods⁴. Intraosseous infusion of prophylactic surgical antibiotics has been shown to be more effective than intravenous administration, with the potential for reduction in surgical site infections⁵.

Description: After the operative extremity has been prepared and draped in the usual sterile fashion, the limb is elevated and the tourniquet is inflated to 250 mm Hg. Prior to incision, an intraosseous vascular access system (Arrow EZ IO; Teleflex) is inserted with a power driver into the tibial tubercle region. The desired volume of the medication is injected into the tibia. The device is removed and then inserted into the anterior distal femur, centrally, just proximal to the patella. Following this, the desired volume of the medication is injected into the femur. The device is then removed, and the TKA proceeds according to the surgeon's standard technique.

Alternatives: Alternative administration methods for vancomycin include other invasive methods and noninvasive delivery. Intravenous delivery is the most traditional form of medication delivery^1,2. Additional alternatives include noninvasive placement of antibiotic powder into the wound and localized soft-tissue injections of desired medications^1-3.

Rationale: Opting to administer antibiotics and other medications intraosseously (rather than intravenously) has shown improved compliance with the golden-hour rule of preoperative antibiotics (especially for vancomycin)⁴, lower incidences of acute kidney injury or adverse systemic effects⁴, and improved local tissue concentrations of all medications delivered^1-3.

Expected outcomes: Expected outcomes include improved local tissue concentrations with decreased systemic concentrations of vancomycin and with no reported local or systemic adverse reactions, as well as the potential for improved infection prevention^1-5. Literature regarding the use of intraosseous infusion during TKA has been thorough and very well received. A prospective, randomized study by Young et al. evaluated local and systemic concentrations of vancomycin following intraosseous versus intravenous administration. The authors found that low-dose intraosseous vancomycin resulted in tissue concentrations equal to or superior to those of systemic administration, also noting that the administration route reduced the infiltration time of the vancomycin without systemic complications¹. Local concentrations at the knee were found to be 5 to 9 times greater with intraosseous infusion in patients with a body mass index of >35 kg/m² as compared with the use of intravenous administration, with no adverse reactions systemically. Local concentrations in this patient population were also found to be comparable to those observed in patients with a lower body mass index². A recent study assessing the use of intraosseous vancomycin showed that local concentrations of vancomycin were maintained even if the procedure continued beyond the point of tourniquet deflation, with mean concentrations being 5 times higher locally at the end of the procedure in the intraosseous versus the intravenous group³. A separate study showed no adverse systemic reactions and no incidents of acute kidney injury among patients receiving intraosseous vancomycin. An additional study showed that intraosseous administration of vancomycin decreased the incidence of postoperative joint infections compared with traditional intravenous administration⁵. Newer studies assessing the use of intraosseous infiltration have begun to focus on the delivery of other medications, not just antibiotics. At our institution, we have examined the benefits of intraosseously administrated morphine, which has shown a significant decrease in pain and opioid consumption up to 2 weeks postoperatively.

Important tips: You may run into issues with the medication delivery due to the amount of resistance you encounter. If resistance is too great, you may first attempt to readjust the intraosseous needle depth to improve flow. If resistance is still high, you may consider downsizing to a 30-cc syringe in order to better infiltrate the medication.Note that if you downsize your syringe, you will require more time to infiltrate the desired amount of fluid. An additional way to save time is to open multiple syringes and have them prefilled with your desired medication so that they may be handed off once completed rather than needing to be refilled.A hemostat or pickup may be applied underneath the cuff of the intraosseous needle in order to help remove the needle from the bone. This step is sometimes required because the intraosseous handpieces do not have multidirectional trigger capabilities, and removing the needle can require an upward force to be applied.The use of midline locations allows the small incisions you make for intraosseous infusion to be incorporated into your larger knee incision, with no additional morbidity to the patient.Consider utilizing the medial and/or lateral femoral condyles as landmark locations for infusion if your patient is large. Alternatively, recent literature has shown nearly equivalent results with just the tibial infusion, so you may consider discontinuing the femoral intraosseous infusion if there are consistent issues with successfully initiating the medication delivery.

Acronyms and abbreviations: IO = intraosseousMRSA = methicillin-resistant Staphylococcus aureusRCT = randomized controlled trialsIV = intravenousBMI = body mass indexOR = operating room.