Aseptic necrosis of the femoral head following renal transplantation

Japanese Orthopaedic Association 2019 Guidelines for osteonecrosis of the femoral head

PURPOSE

The Clinical Practice Guidelines for Osteonecrosis of the Femoral Head (ONFH) 2019 Edition, written by the working group for ONFH guidelines of the Japanese Investigation Committee (JIC) for ONFH under the auspices of the Japanese Ministry of Health, Labour, and Welfare and endorsed by the Japanese Orthopaedic Association, were published in Japanese in October 2019. The objective of this guideline is to provide a support tool for decision-making between doctors and patients.

METHODS

Procedures for developing this guideline were based on the Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014, which proposed an appropriate method for preparing clinical guidelines in Japan.

RESULTS

This clinical practice guideline consists of 7 chapters: epidemiology; pathology; diagnosis; conservative therapy; surgical treatment: bone transplantation/cell therapy; surgical treatment: osteotomy; and surgical treatment: hip replacement. Twelve background questions and 13 clinical questions were determined to define the basic features of the disease and to be addressed when deciding treatment in daily practice, respectively.

CONCLUSIONS

The clinical practice guidelines for the ONFH 2019 edition will be useful for physicians, investigators, and medical staff in clinical practice, as well as for patients, during the decision-making process when defining how to treat ONFH.

Risk factors for nontraumatic osteonecrosis of the femoral head after renal transplantation

We investigated risk factors for osteonecrosis of the femoral head (ONF) in renal transplant recipients, who are susceptible to the disease. Among 287 renal transplant recipients, 18 ONF patients with enough data were included, and 18 age- and sex-matched recipients without ONF were nominated as reference cases. Risk factors were analyzed using a conditional logistic regression method. There were no differences between the ONF patients and the reference cases regarding the types of immunosuppressant or the donor (living or cadaveric, father or mother, matching blood type and human leukocyte antigens). The daily oral steroid dosage (prednisolone 25.0 mg/day or more) and blood urea nitrogen level 2 months after transplantation were the only factors with relevance to the occurrence of ONF. We propose that oral steroid dosages should be low or reduced after renal transplantation, and acute rejection should be controlled with pulsed therapy.

Metabolism of prednisone in kidney transplanted patients with necrosis of the femoral head

Interindividual variation of the metabolism of prednisolone and of the susceptibility to glucocorticoids might be possible factors contributing to the development of osteonecrosis after renal allotransplantation. As this aspect has not been properly investigated previously, we compared, in the present study, the metabolism of total and free prednisolone in 6 renal allotransplanted patients who subsequently developed osteonecrosis of the femoral head and the metabolism of 6 matched controls, who did not develop osteonecrosis. There was no difference in age, bodyweight, total serum protein or albumin, or in liver or renal function. The baseline cortisol was 54 +/- 23 micrograms in patients with necrosis, and 102 +/- 53 micrograms/l in patients without necrosis (n.s.). Likewise there was no difference in the peak concentration of prednisolone (420 +/- 43 vs. 394 +/- 42 micrograms/l, n.s.), the bioavailability (0.57 +/- 0.09 vs. 0.61 +/- 0.05, n.s.) or in the apparent volume of distribution at steady state (Vdss, 0.37 +/- 0.09 vs. 0.37 +/- 0.04 l/kg, n.s.). The clearance of prednisolone in patients with osteonecrosis was 33% lower (0.79 +/- 0.11 vs. 1.18 +/- 0.13 ml/min./kg b.wt., P < 0.05) and t1/2 was correspondingly 33% longer (246 +/- 18 min. vs. 184 +/- 15 min., P < 0.05) than in patients without osteonecrosis. However, there was no difference in the apparent volume of distribution of free prednisolone (2.07 +/- 0.36 vs. 1.69 +/- 0.28 l/kg, n.s.), in the t1/2 (152 +/- 30 vs. 107 +/- 20 min., n.s.), or in the clearance (7.33 +/- 2.12 vs. 7.82 +/- 1.18 ml/min./kg) between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Necrosis of the femoral head after renal transplantation

The cumulated risk of developing necrosis of the femoral head following renal transplantation was 42/374 in patients treated with steroids and azathioprine, and 4/124 in patients treated with cyclosporine-A and a reduced dose of steroids. 29 of the osteonecrosis cases were bilateral, with the time lapse between the two sides rarely exceeding 6 months. The reduction in the rate of osteonecrosis paralleled a reduction in the number of rejection episodes during the first month after transplantation and in the cumulated dose of steroids 1 month and 1 year after transplantation. We concluded that the risk of femoral head necrosis following renal transplantation is reduced by using cyclosporin-A for immunosuppression, which caused less rejection episodes and consequently a reduction in steroid medication.