December 6th, 2011 , Orthopedics

Bisphosphonate fractures as a cause of painful total hip arthroplasty

Osteoporotic fractures pose a significant health concern for postmenopausal women. Bisphosphonate therapy has been shown to decrease the risk of these fractures. The bisphosphonate alendronate was approved by the US Food and Drug Administration for use in the United States in 1995, but questions have recently arisen concerning low-energy subtrochanteric femur fractures sustained by chronic users. Although no definitive association or causality between bisphosphonates and these fractures has been established, numerous cautionary reports exist concerning the duration of use and safety of alendronate in osteoporotic patients. This article reports 3 occurrences of bisphosphonate-associated atypical femur fractures as an etiology of periprosthetic hip pain in the total hip arthroplasty (THA) patient. These fractures are particularly concerning because these patients are often not advised to protect their weight bearing simply due to a painful THA and may sustain a catastrophic failure if not followed closely. Several theories have been suggested concerning the pathophysiology of atypical low-energy subtrochanteric fractures following bisphosphonate use. Each patient described in this article carried a diagnosis of rheumatoid arthritis and underwent chronic medical therapy; each patient experienced a delay in the diagnosis and onset of therapy due to low suspicion for bisphosphonate-associated fracture. This problem may become more common in the clinical setting; therefore, one must be vigilant and aware of this etiology of periprosthetic hip pain.