Systemic Exposure to Aminoglycosides Following Knee and Hip Arthroplasty with Aminoglycoside-Loaded Bone Cement Implants

BACKGROUND: Aminoglycoside-loaded bone cement (ALBC) implants are frequently used in orthopedic surgery. Parenteral aminoglycosides are known to cause nephrotoxicity. Reports of acute renal failure in patients receiving ALBC implants have been reported in the literature and at our hospital. OBJECTIVE: To evaluate, as part of a performance improvement project, whether patients undergoing arthroplasty procedures have detectable aminoglycoside serum concentrations following ALBC implantation and to evaluate corresponding changes in serum creatinine. METHODS: Patients undergoing hip or knee revision or resection who received an ALBC implant between January and April 2010 were included in our evaluation. In addition to baseline demographic information, we measured aminoglycoside concentrations and serum creatinine levels during the early postoperative period, prior to hospital discharge, and at the follow-up clinic visit when possible. RESULTS: Seventeen patients were evaluated: 13 women and 4 men with a mean age of 69 years (range 50-84). Eight patients had a preoperative diagnosis of infection and received high-dose ALBC implants as treatment and 9 patients received lower-dose ALBC implants for infection prophylaxis. Eight patients had detectable aminoglycoside serum concentrations (mean 0.42 mu g/mL; range 0.3 to 2.0); 1 patient had an aminoglycoside serum concentration of 0.9 mu g/mL on postoperative day 38. Patients who did not have a detectable aminoglycoside serum concentration on the first postoperative day did not have a detectable concentration in the following serum samples. Six patients had elevation of serum creatinine by greater than 0.3 mg/dL from baseline. CONCLUSIONS: The number of patients in this study is small; however, this report raises a potential concern for the safety of high-dose ALBC implants. We recommend measuring aminoglycoside serum concentrations in the early postoperative period to identify patients in need of further monitoring. Further studies are needed to determine risk factors for systemic toxicity.