Increased Risk of Fracture in Patients Receiving Solid Organ Transplants

Abstract

The success of organ transplantation is related to advances in immunosuppressive therapy. These medications are associated with medical complications including bone damage. The objective of this study was to estimate and compare age, gender-specific fracture incidence between transplant recipients, and a large sample representative of the civilian noninstitutionalized United States population using the 1994 National Health Interview Survey (NHIS). This was a cohort study set in tertiary care centers. Five hundred and thirty-nine individuals who received abdominal organ and 61 heart transplants surviving at least 30 days at our institution from 1986 to 1996 were included in the study. Incident fractures were ascertained by mail, in-person interview, telephone survey, or medical record review. All fractures were verified. Organ-, age-, and gender-specific fracture numbers and rates and person-years of observation, were calculated for the transplant patients. Weighted age-and gender-specific fracture rates from the 1994 NHIS were applied to the number of person-years of observation for each organspecific age and gender category of transplant patients to generate an expected number of fractures. The ratio of observed to expected number of fractures was used to compare fracture experience of transplant patients to that of the national sample from the 1994 NHIS. Fifty-six of 600 (9.3%) patients had at least one fracture following 1221 person-years of observation. The sites of initial symptomatic fracture were as follows: foot (n = 22), arm (n = 8), leg (n = 7), ribs (n = 6), hip (n = 4), spine (n = 3), fingers (n = 3), pelvis (n = 2), and wrist (n = 1). Fracture incidence was 13 times higher than expected in male heart recipients age 45-64 years; nearly 5 times higher in male kidney recipients age 25-44 and age 45-64 years; and 18 times and 34 times higher in female kidney recipients age 25-44 years and 45-64 years compared with NHIS data. We have shown an increased incidence of fractures and estimated the magnitude of this problem in patients undergoing solid organ transplantation. Our work defines the need for a long-term prospective study of fracture risk in these patients. (J Bone Miner Res 1999;14:456-463)

Micro–MR Imaging–based Computational Biomechanics Demonstrates Reduction in Cortical and Trabecular Bone Strength after Renal Transplantation

“…Further, the data highlight that temporal changes in BMD measured at the hip and spine are not associated with detected alterations in stiffness and failure strength at the appendicular sites, which are particularly prone to fracture in renal transplant recipients (6,(8)(9)(10). Additionally, baseline values of failure strength were only weakly correlated with hip BMD while showing no correlation with spine BMD.…”

“…The risk of fracture among renal transplant recipients increases even further in the months following surgery (7). Interestingly, post-transplantation bone fractures are more frequently located in the appendicular than axial skeleton (8)(9)(10). Dual-energy x-ray absorptiometry (DXA) does not allow distinction between the effect of renal osteodystrophy on cortical and trabecular bone and provides poor fracture discrimination in patients with renal failure (8,11).…”

Bone Disease after Renal Transplantation

“…Similarly, 27 (16%) patients had either vertebral deformities or a history of a low trauma fracture after transplantation. Ramsey-Goldman et al (10) found that the most common site of fracture was the foot, and this occurred similarly in both premenopausal and postmenopausal women after transplantation.…”

Post-Transplantation Bone Disease

“…With regard to fractures, a high incidence of them (between 20% and 40% in most studies) has been documented. In heart and liver transplant recipients, the incidence of new fractures parallels the timing of the most rapid bone loss, with most fractures occurring within the first year after transplantation (Eastell R, 1991;Henderson et al, 1995;Ramsey-Goldman et al, 1999). Fractures usually affect the spine and ribs in liver, cardiac, or lung recipients, whereas long bones are more easily fractured in renal transplant recipients.…”