Atypical periprosthetic acetabular fracture in long-term alendronate therapy

Bisphosphonates have been commonly used in the treatment of osteoporosis, demonstrating its efficacy in fracture risk reduction. However, even if are generally safe and well tolerated, concerns have emerged about atypical fractures related to its prolonged use. Although atypical femoral fracture are more common, case reports demonstrated that even other skeletal areas can be involved by unusual pattern of fracture. We report a atypical acetabular periprosthetic fracture in a 83-year-old female patient after prolonged alendronate treatment for osteoporosis and isolated acetabular revision surgery. The patient underwent to clinical, bioumoral and radiological evaluation and all the history cases were fully reported. We believe this periprosthetic fracture, according to the available data, may have similar underlying pathology to atypical femoral fractures. Awareness of symptoms, in addition to a regular radiographic survey may facilitate early diagnosis and possible prevention of spontaneous periprosthetic fractures, in patients receiving bisphosphonate therapy beyond 5 years. The treatment of this atypical periprosthetic fracture should include both surgical than pharmacological therapy to obtained bone healing.