Spontaneous Incomplete transverse subtrochanteric femoral fracture with cortical thickening possibly secondary to risedronate use: a case report

Abstract

IntroductionOsteoporosis is an asymptomatic disease characterized by bone weakening and predisposition to fragility (insufficiency) fractures and can have devastating effects on individual life and great financial impact on the economy. Bisphosphonates are used worldwide for the primary and secondary prevention of osteoporotic fractures. However, increasing evidence raises concern that bisphosphonates can be associated with atypical fractures.Case presentationA 65-year-old Caucasian woman on long-term steroid treatment for polymyalgia rheumatica was admitted with severe and constant pain in the right hip, radiating to the right knee. She had a history of steroid-induced osteoporosis, for which she was started on risedronate four years earlier. She had no history of trauma. Her blood results were unremarkable. Her X-rays confirmed that she had an incomplete right subtrochanteric femoral fracture. A bone scan confirmed the diagnosis and also ruled out any other associated fractures. Our patient successfully underwent internal nail fixation of the fracture. She was reviewed by a rheumatology team, which stopped the risedronate. She was started on treatment with denosumab injection.ConclusionsPrevious case series have reported that long-term bisphosphonate use is associated with atypical fractures of the femur, and certain criteria have been established to help identify such rare fractures. Delayed union or non-union is expected in such fractures following definitive orthopedic treatment because of the long half life of bisphosphonates. In this case report, we try to raise questions related to this important subject, like the duration and safety of bisphosphonate use and the alternative medications used in osteoporosis in this rare condition. We consider this case report not only interesting but also important and unusual because it is about a patient who developed a potentially rare and serious side effect of long-term bisphosphonate use, estimated to affect 2.3 in every 10,000 patients, and who presented with a pelvic X-ray that showed the characteristic features of atypical fractures secondary to risedronate use. In addition, most of the documented cases have been associated with many years of bisphosphonate use whereas our patient had been on risedronate for only four years.

No effect of risedronate on femoral periprosthetic bone loss following total hip arthroplasty

“…Now, with the 4-year results at hand, we no longer believe this. With the reported occasional occurrence of atypical subtrochanteric or diaphyseal femoral fracture in patients with long-term use of alendronate ( Sellmeyer 2010 ) and risedronate ( Alfahad et al 2012 ), the risk outweighs the merits of treatment in our opinion.…”

Low Positive Predictive Value of Bone Scan to Predict Impending Complete Fracture among Incomplete Atypical Femoral Fracture

“…Many studies have reported that 99m Tc-HDP bone scans are useful for the detection of stress fracture, 16 17 18 19 and several studies used bone scans to diagnose AFF. 20 21 22 23 AFFs have a characteristic appearance and can be detected on bone scan. 22 Some focal thickenings of the femoral cortex, which are seen on plain radiographs, might be inactive scars after a stress reaction.…”

Laboratory methods and biomarkers in the evaluation of bisphosphonate effects on body tissues: a literature review

“…Atypical non‐traumatic femoral fractures have also been recognized as an important side effect of bisphosphonate use . These fractures affect the diaphyseal (subtrochanteric or shaft) part of the femur and, although involving a very small number, they are indeed associated with bisphosphonate use and have shown increased incidence over a 12‐year period , which is directly related to the longer duration of the drug therapy .…”