Avascular Necrosis and Risk Factors in Kidney Transplant Recipients: A Single-Center Experience

Objectives: Renal osteodystrophy, osteoporosis, bone fractures, and avascular necrosis (AVN) are prevalent complications observed in the posttransplant period among kidney transplant recipients (KTRs).Despite notable advancements, AVN remains a significant and devastating complication following kidney transplantation (KT). Materials and Methods:The study included all patients who underwent KT at our transplantation unit and had at least one year of routine followup (n=343).Cases of symptomatic AVN were diagnosed by X-radiation, radioisotope bone scan, or magnetic resonance imaging.We evaluated the baseline characteristics, laboratories, and immunosuppressive treatments of KTRs.Results: The frequency of AVN in our KTRs was 7.9% during the follow-up period, with a median diagnosis time of 15.2 (10.2-34.9)months.In KTRs with AVN, the leading cause of end-stage renal disease was glomerulonephritis (GN) (52% vs. 20%, p<0.001), and more rejection episodes occurred at follow-up (33% vs. 15%, p=0.01).In univariate analysis, GN [odds ratio (OR): 4.325, 95% confidence interval (CI), 1.936-9.661],cumulative steroid dosage at the post-transplant first year (OR: 1.001, 95% CI, 1.000-1.002),and rejection episodes (OR: 2.792, 95% CI, 1.185-6.578)detected as possible risk factors for AVN.Upon multivariate analysis, GN was identified as an independent risk factor for the development of AVN (OR: 4.373, 95% CI, 1.935-9.880,p<0.001).Conclusion: Our study found GN to be associated with an increased risk of AVN.A higher prevalence of AVN may attributed to long-term pretransplant steroid therapy in this group.In KTRs with a history of GN, greater awareness should be paid to cumulative steroid dosages, and early discontinuation of steroids may be considered.