Background: Total joint arthroplasty (TJA) is a common procedure with demand for arthroplasties expected to increase exponentially. Incidence of acute kidney injury (AKI) following TJA is reportedly low, with most studies finding an incidence of <2%, increasing to 9% when emergency orthopaedic patients are included.
Methods: Retrospective medical record review of consecutive primary, elective TJA procedures was undertaken at a large tertiary hospital (Alfred). Demographic, peri-operative and post-operative data were recorded. Factors associated with AKI (based on RIFLE criteria) were determined using multiple logistic regression.
Results: Between January 2011 and June 2013, 425 patients underwent TJA; 252 total knee replacements (TKR) and 173 total hip replacements (THR). Sixty-seven patients (14.8%) developed AKI, including 51 TKR. Factors associated with AKI (adjusting for known confounders) include increasing body mass index [adjusted odds ratio (AOR) 1.14; 95% CI: 1.07, 1.21], older age (AOR 1.07; 95% CI 1.02, 1.13) and lower pre-operative glomerular filtration rate (AOR 0.97; 95% CI 0.96, 0.99) and taking angiotensin-converting enzyme inhibitors (AOR 2.70; 95% CI 1.12, 6.48) and angiotensin-II receptor blockers (AOR 2.64; 95% CI 1.18, 5.93). In most patients, AKI resolved by discharge, however, only 62% of patients had renal function tests after discharge.
Conclusions: This study showed a rate of AKI of nearly 15% in our TJA population, substantially higher than previously reported. Given that AKI and long-term complications are associated, prospective research is needed to further understand the associated factors and predict those at risk of AKI. There may be opportunities to maximize the pre-operative medical management and mitigate risk.
Keywords: acute kidney injury; elective surgery; orthopaedics.