Use of ALBC implants may lead to kidney injury

Aminoglycoside-loaded bone cement (ALBC) implants, frequently used in orthopedic surgery, may result in systemic effects that raise aminoglycoside serum concentrations and lead to acute kidney injury (AKI), according to a study published July 3 in The Annals of Pharmacotherapy.

According to the multidisciplinary group of researchers from the University of Iowa Hospitals and Clinics who conducted the single-center study, monitoring of aminoglycoside serum concentrations after orthopedic implantation is not common practice, partly due to the belief that the aminoglycoside loaded in the cement will not achieve notable systemic concentrations or lead to kidney injury. However, they note that cases of AKI associated with the use of ALBC in total hip arthroplasty have been described in the literature.

The researchers, from the Department of Pharmaceutical Care, Department of Internal Medicine, and Department of Orthopaedic Surgery and Rehabilitation, conducted the performance improvement project to evaluate the association between ALBC implantation and aminoglycoside serum levels.

“Our intent for this performance improvement project was to assess whether aminoglycoside serum concentrations are detectable following implantation of ALBC and to assess the potential for development of systemic toxicity, primarily AKI, as indicated by increases in serum creatinine, following implantation of ALBC,” the authors wrote.

From January through April 2010, the researchers identified 17 patients between the ages of 50 and 84 years who were receiving an ALBC implant for hip or knee arthroplasty revision or resection. The patients were categorized into two groups: group 1 had a preoperative diagnosis of infection and received high-dose ALBC (>2 g aminoglycoside per 40 g bone cement) for treatment and group 2 had a preoperative diagnosis of osteoarthritis and received low-dose ALBC (≤2 g aminoglycoside per 40 g bone cement) as infection prophylaxis. Aminoglycoside serum concentrations and serum creatinine levels were measured for each patient during the early postoperative period, before hospital discharge, and at follow-up visits, when possible.

The researchers noted seven patients in group 1 and one patient in group 2 with detectable aminoglycoside serum concentrations (mean 0.42 μg/mL; range 0.3 to 2.0). Of three patients whose postdischarge aminoglycoside serum concentrations were measured, one patient had a concentration of 0.9 μg/mL at 38 days post-op. Among patients in both groups, those 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.

“This report raises a potential concern for the safety of high-dose ALBC implants,” the authors wrote. “We recommend measuring aminoglycoside serum concentrations in the early postoperative period to identify patients in need of further monitoring.”