Unveiling A Rare Complication In Post-Implant Orthopedic Surgeries: Two Cases Of Metallosis

Abstract

Background: Metallosis is an uncommon but clinically significant complication of orthopedic implantation, characterized by the local and systemic deposition of metallic debris within soft tissues and bone. It typically arises from wear or corrosion of metallic prosthetic components, leading to an inflammatory cascade, osteolysis, and pseudotumor formation. Although its estimated incidence is around 5%, the use of non-metallic and hybrid implants has reduced its occurrence.

Case Presentation: We report two cases of metallosis following orthopedic interventions, confirmed through imaging and histopathological evaluation.

Case 1: A 27-year-old male presented with pain and swelling at the site of a previous open reduction and internal fixation (ORIF) for a distal femur fracture, performed 15 months earlier. Radiographs showed healed fracture changes, and histopathology revealed acute on chronic inflammation with foreign body giant cell reaction and metallic particulate deposition, consistent with metallosis.

Case 2: A 40-year-old male developed progressive wrist pain and ulceration following external fixation for a distal radius and ulna fracture. Imaging revealed a comminuted distal radius fracture with callus formation. Histopathological findings demonstrated granulation tissue with hemosiderin-laden macrophages, foreign body-type giant cells, and granulomatous inflammation, confirming metallosis.

Conclusion: While metallosis is well-documented in prosthetic wear-related arthroplasty, its occurrence following retained metallic fragments or non-prosthetic hardware remains rare. These cases highlight both acute and chronic inflammatory responses to metal debris, addressing a gap in existing literature. Early clinical suspicion, imaging, and histopathological confirmation are vital for timely diagnosis and management to prevent progressive tissue destruction and morbidity.