What is the medical term for exposed metal wire from a previous hip replacement protruding through the skin that requires removal?

Medical Term for Exposed Metal Wire from Hip Replacement

The medical term for exposed metal wire from a previous hip replacement protruding through the skin that requires removal is "hardware protrusion" or "implant extrusion." This represents a serious complication that requires prompt surgical intervention to prevent infection and further tissue damage.

Understanding Hardware Protrusion in Hip Replacements

• Hardware protrusion occurs when components of a hip implant (such as wires, screws, or other metallic components) penetrate through soft tissue and skin, creating a direct communication between the external environment and the implant 1
• This condition may be associated with metallosis, which is characterized by visible staining, necrosis, and fibrosis of periprosthetic soft tissues due to metal debris deposition 2
• When metal components become exposed through the skin, they create a pathway for bacteria to enter, significantly increasing infection risk 1

Causes and Risk Factors

• Component migration or loosening can lead to hardware protrusion, particularly in cases of aseptic loosening (15.8% of THA revision causes) 1
• Infection and inflammatory reactions (19.3% of THA revision causes) may contribute to soft tissue breakdown and subsequent hardware exposure 1
• Metal-on-metal implants have higher risk of complications including metallosis and tissue damage that may lead to hardware exposure 2, 3
• Inadequate soft tissue coverage over prominent hardware components, particularly in thin patients 1

Diagnostic Approach

• Radiographs are typically the first imaging modality used to assess component position, migration, and potential loosening 1
• CT scanning with metal artifact reduction (MAR) techniques may be necessary to accurately assess component position and the extent of hardware complications 1
• Ultrasound can be valuable for assessing soft tissues adjacent to hip arthroplasties without being affected by prosthetic artifacts 1
• Metal Artifact Reduction Sequences (MARS)-MRI enables evaluation of soft tissues around the prosthetic hip, including the pseudocapsule and surrounding structures 1

Management Approach

• Prompt surgical intervention is required when hardware becomes exposed through the skin 1
• Complete removal of the exposed hardware is necessary, as partial removal or retention of exposed components carries high risk of infection 1
• Any foreign body or device that may potentially be the source of infection should be removed 1
• Debridement of all non-viable tissue should be performed, including muscle, fascial layers, subcutaneous tissue, and compromised skin 1
• Revision surgery often involves replacement with non-metal-on-metal bearing components to prevent recurrence of metallosis and related complications 4, 3

Complications and Outcomes

• Hardware protrusion with associated infection can lead to significant morbidity and potentially mortality if not addressed promptly 1
• Revision surgery for exposed hardware has high complication rates, with studies showing up to 45% of patients experiencing complications after metal-on-metal hip replacement revisions 3
• Long-term outcomes depend on the extent of tissue damage, presence of infection, and whether complete hardware removal and appropriate revision was performed 3

Prevention and Monitoring

• Regular radiographic follow-up is important to identify any component positioning issues before they progress to hardware protrusion 1
• Periodic assessment of implant position is recommended to ensure maintenance of proper positioning 5
• Early intervention for signs of implant loosening or migration may prevent progression to hardware protrusion 1