Abstract: TH-PO0722
AKI from Tobramycin-Loaded Cement Spacer: A Case Report
Session Information
- AKI: Prevention, Diagnostics, and Management
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 101 AKI: Epidemiology, Risk Factors, and Prevention
Authors
- Guyette, Michele Leigh, MaineHealth, Portland, Maine, United States
- Mahmoud, Hassan, MaineHealth, Portland, Maine, United States
Introduction
Two-stage exchange arthroplasty with antibiotic-loaded bone cement (ALBC) spacers remains the standard for periprosthetic joint infection (PJI). Aminoglycosides such as tobramycin are the most commonly incorporated agents. In the absence of standardized dosing guidelines, antibiotic concentrations in manually prepared spacers vary considerably. Systemic absorption may confer a nephrotoxic risk. Acute kidney injury (AKI) after ALBC placement for PJI occurs in roughly 14–32% of patients, with a higher risk in those with preexisting chronic kidney disease (CKD)1,2,3.
Case Description
A 61-year-old woman with a history of bilateral total knee arthroplasty and CKD stage IIIa presented with left knee swelling. Synovial fluid analysis demonstrated leukocytosis consistent with PJI. She underwent explantation with placement of a high-dose tobramycin-loaded bone cement spacer. A supratherapeutic tobramycin level on the day of implantation confirmed systemic absorption. The patient developed rising serum creatinine on post-operative day 5, peaking on postoperative day 8. Urine microscopy revealed granular casts consistent with acute tubular injury. Kidney function recovered to baseline with supportive care.
Discussion
Antibiotic selection and dosing in ALBC spacers remain unstandardized. This case highlights spacer-associated aminoglycoside nephrotoxicity as an underrecognized cause of postoperative AKI, particularly in patients with preexisting CKD. Emerging data suggest that AKI risk is influenced by higher spacer antibiotic doses, baseline CKD, comorbidity burden, and hypovolemia. Data suggests doses below 3 g per cement batch may be associated with a lower nephrotoxic risk 4. These findings emphasize the need for interdisciplinary awareness, monitoring in high-risk patients, and safe guidelines that balance effective infection eradication with kidney safety.