A Case of Nonunion with Ballooning Deformity after Periprosthetic Humeral Fracture

INTRODUCTION: We report a very rare case of nonunion with ballooning deformity of the humeral bone after a periprosthetic humeral fracture nonunion. CASE REPORT: A 79-year-old woman underwent hemiarthroplasty 19 years ago for her proximal humerus fracture. She injured her right humeral diaphysis (stem distal end fracture) 6 years ago. She underwent revision hemiarthroplasty with long stem, but bony union was not obtained, and her right upper limb function was subsequently abolished due to extreme instability and pain in her right upper arm. She was then referred to our hospital for further treatment. X-ray showed nonunion in the humeral diaphysis and a severe ballooning deformity in the distal humeral bone fragment. Due to the advanced age and low activity of the patient, we chose total humerus replacement surgery instead of osteosynthesis. After the surgery, her upper arm pain and instability immediately improved. Three years after the last surgery, there have been no implant failures, and the upper arm is stable and painless. CONCLUSION: Although there are some reports of total humerus replacement as surgical treatment for humeral tumor and severe periprosthetic fracture, we found no reports of such ballooning deformity around the nonunion site. Total humerus replacement can be one of the treatment options in cases where nonunion surgery is extremely difficult, depending on the patient’s age and activities of daily living.