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Osteonecrosis after lung transplantation: cystic fibrosis as a potential risk factor.

BACKGROUND
Osteonecrosis is a known complication after transplantation of solid organs. The incidence of osteonecrosis after lung transplantation is not well documented.


METHODS
We investigated the incidence of symptomatic osteonecrosis in lung transplant recipients, transplanted between November 1992 and June 1998 at our institution. For the detection of osteonecrosis, all patients complaining of musculoskeletal pain underwent magnetic resonance imaging. Demographic characteristics, time after transplantation, etiology of underlying lung disease, and the number of steroid pulses for rejection episodes were compared for patients with and without osteonecrosis.


RESULTS
Of 63 transplant recipients, all 49 with a follow-up of >3 months were included for analysis. Of seven symptomatic transplant recipients, five cases of osteonecrosis (10%) were detected at a median duration of 216 days (range 44-600) after transplantation. Patients with osteonecrosis have been treated with the same immunosuppressive regimen and with an equal number of steroid pulses for acute rejection episodes (1.4+/-1.1 vs. 1.4+/-1.5, P=0.69), but were younger (26+/-8 vs. 40+/-11 years, P<0.01) than other transplant recipients. Symptomatic osteonecrosis was detected in four of 14 patients (29%) with cystic fibrosis (CF), compared with one osteonecrosis among 35 patients (3%) with other underlying diseases (P<0.02). Within the group of CF patients, specific clinical and demographic characteristics correlating with the risk for subsequent osteonecrosis could not be found.


CONCLUSION
In lung transplant recipients, CF may be a risk factor for the development of symptomatic osteonecrosis.