Total Hip Arthroplasty in a Patient With a Large Proximal Femur Aneurysmal Bone Cyst: A Case Report and Literature Review.

Aneurysmal bone cysts (ABCs) are rare benign bone lesions with a predilection for the metaphysis of long bones. They are often cystic, expansive, and osteolytic and may result in bony deformity. In general, there remains debate about optimal treatment for ABCs; however, the mainstay typically consists of a combination of curettage, bone grafting, and considering the need for internal fixation and osteotomies. The goals of treatment include preserving bony anatomy while eliminating the lesion. There is sparse literature regarding the treatment of osteoarthritis adjacent to benign bony tumors. If total hip arthroplasty is chosen as a treatment option, diligent preoperative planning is required, and the surgeon must assess the patient's bone stock, account for bony deformity, and utilize specific implants and techniques based on the patient's characteristics. We present a case of an adult patient with proximal femur ABC and symptomatic adjacent hip osteoarthritis who underwent treatment with total hip arthroplasty.