Revisiting the clinical predictors of avascular necrosis after kidney transplantation

Avascular necrosis (AVN) is a debilitating bone complication that may occur after kidney transplantation (KT), often associated with corticosteroid use. This study aimed to evaluate the prevalence of AVN, identify its risk factors, assess associations with immunosuppressive agents, determine lateralization relative to the allograft, and review treatment methods.

Demographic and clinical data, including donor type, primary kidney disease, immunosuppressive therapies, and details on AVN were evaluated.

This study retrospectively analyzed 421 KTs. The overall AVN prevalence was 8.3% (n = 35), with the femoral head being the most commonly affected site (85.7%). The prevalence of AVN significantly declined from 21.2% before 2000 to 7.2% after 2000 (p = 0.005). Cumulative steroid doses at post-transplant months 3 and 12 were significantly higher in the AVN group (p = 0.002 and p = 0.003, respectively). Cox regression revealed that glomerulonephritis as primary kidney disease (Hazard Ratio [HR]: 3.12; 95% Confidence Interval [CI]: 1.46-6.69; p = 0.003), acute rejection (HR: 6.59; 95% CI: 1.6-27.01; p = 0.009), and azathioprine (AZA) use (HR: 2.49; 95% CI: 1.14-5.46; p = 0.022) were independent risk factors for AVN development.

Glomerulonephritis, acute rejection, and AZA use, largely linked to corticosteroid exposure, are significant contributors to AVN after KT. The introduction of tacrolimus post-2000 was associated with a notable reduction in AVN prevalence, reinforcing the importance of optimized immunosuppressive protocols.