CASE REPORT - Bilateral fractures of the femur diaphysis in a patient with RA on long-term alendronate (Fosamax)

[Guest guest]

J Bone Miner Res. 2009 Oct;24(10):1736-40.

Bilateral fractures of the femur diaphysis in a patient with

rheumatoid arthritis on long-term treatment with alendronate: clues to

the mechanism of increased bone fragility.

Somford MP, Draijer FW, sen BJ, Chavassieux PM, Boivin G, Papapoulos SE.

Department of Orthopaedics, Maasland Hospital, Sittard, The Netherlands.

Unusual fractures of the femur diaphysis have been reported in

patients treated with alendronate and, although no causal relationship

has been established, excessive suppression of bone turnover and

length of treatment with alendronate have been implicated in their

pathogenesis. We report here clinical, biochemical, and radiological

findings of a patient with rheumatoid arthritis and multiple risk

factors for fractures who was treated with alendronate for 8 yr and

developed spontaneous bilateral subtrochanteric/diaphyseal fractures.

Bone biopsies obtained form the iliac crest and the femur showed

decreased bone formation with histomorphometric evidence of markedly

increased bone resorption at the femur. These results show for the

first time that an imbalance between bone resorption and bone

formation at the affected bone is associated with the occurrence of

these atypical femur fractures. The cause of this imbalance is

currently unknown, and further studies of the epidemiology and

pathogenesis of diaphyseal femur fractures are warranted.

PMID: 19419297

http://www.ncbi.nlm.nih.gov/pubmed/19419297

Not an MD