Avascular Necrosis in Renal Transplant Patients

Kidney transplant recipients are at increased risk for avascular necrosis due to steroid use and accompanying comorbidities. Concerning risk factors, uncertainty still exists. We evaluated the clinical characteristics and risk factors of avascular necrosis in kidney transplant recipients.

Symptomatic avascular necrosis was found by magnetic resonance imaging in 33 of 360 kidney transplant patients between 2005 and 2021. The patients' clinical characteristics, biochemical testing, and medications were evaluated.

We found the frequency of avascular necrosis to be 9.7% during the follow-up period. If the total steroid dosage used was more than 4 g in the first 3 months, the risk of developing avascular necrosis increased 4.08 times, and the presence of cytomegalovirus disease increased the risk by 4.03 times. Avascular necrosis was observed bilaterally in 60.6% of cases and at the femoral head in 66.7%. The frequency of avascular necrosis was highest in the first and second years posttransplant.

We found that avascular necrosis appears most frequently in the first 2 years after kidney transplant and the most important risk factors are cumulative steroid dose and cytomegalovirus disease. In the follow-up of kidney transplant patients, it is important to use low-dose steroid doses if possible. Of note, preventing the development of cytomegalovirus disease by screening and prophylaxis for cytomegalovirus is also important in reducing the development of avascular necrosis.