Tibial Insufficiency Fracture with Characteristics of an Atypical Fracture: A Rare Case and Literature Review.

: Osteoporosis is becoming more prevalent with the rise in the aging population, leading to the increased use of bisphosphonates for treatment. While these medications are effective in preventing osteoporotic fractures, long-term use has been associated with atypical insufficiency fractures, primarily in the femur. However, atypical fractures in other weight-bearing bones, such as the tibia, have rarely been reported. This study aims to present a case of an atypical insufficiency fracture of the tibia in an elderly female who has been on long-term bisphosphonate therapy and to review treatment outcomes within the context of the current literature. : A 76-year-old female presented with pain in the proximal right tibia, developing two months prior without trauma. She had been receiving long-term bisphosphonate therapy for osteoporosis, initially taking sodium risedronate orally for 4 years, followed by intravenous ibandronate for 10 years. Physical examination revealed localized tenderness, and radiographs showed cortical thickening and a horizontal fracture line in the proximal right tibia. MRI confirmed these findings, along with surrounding edema. The laboratory results were mostly normal, but the bone formation marker osteocalcin was significantly reduced. The patient had a history of insufficiency fractures in the ipsilateral tibia and contralateral femur, previously treated conservatively with teriparatide. A similar conservative approach was attempted but failed, leading to surgical intervention with intramedullary nailing and supplementary plating. At the 8-month follow-up, the patient showed successful fracture union and resolution of symptoms. Long-term use of bisphosphonates, though effective for osteoporosis, can lead to atypical insufficiency fractures, primarily in the femur but also occasionally in the tibia. Clinicians should consider this possibility when patients present with pain in weight-bearing bones without a history of trauma. Prompt diagnosis through thorough history-taking, physical examination, and appropriate imaging is essential to ensure timely management.