Hardware Protrusion in Hip Replacements

Definition and Diagnosis

The American College of Radiology defines hardware protrusion as components of a hip implant penetrating through soft tissue and skin, creating a direct communication between the external environment and the implant 1, 2
Radiographs are typically the first imaging modality used to assess component position, migration, and potential loosening 5
The American College of Radiology recommends CT scanning with metal artifact reduction (MAR) techniques to accurately assess component position and the extent of hardware complications 6
Ultrasound can be valuable for assessing soft tissues adjacent to hip arthroplasties without being affected by prosthetic artifacts, as suggested by the American College of Radiology 1

Component migration or loosening can lead to hardware protrusion, particularly in cases of aseptic loosening (15.8% of THA revision causes), according to the American College of Radiology 1, 4
Infection and inflammatory reactions (19.3% of THA revision causes) may contribute to soft tissue breakdown and subsequent hardware exposure, as reported by the American College of Radiology 4
Inadequate soft tissue coverage over prominent hardware components, particularly in thin patients, is a risk factor for hardware protrusion, as noted by the American College of Radiology 2, 4

Prompt surgical intervention is required when hardware becomes exposed through the skin, as recommended by the World Journal of Emergency Surgery and Intensive Care Medicine 3, 7
Complete removal of the exposed hardware is necessary, as partial removal or retention of exposed components carries high risk of infection, according to the World Journal of Emergency Surgery 7
Debridement of all non-viable tissue should be performed, including muscle, fascial layers, subcutaneous tissue, and compromised skin, as suggested by the World Journal of Emergency Surgery 7

Regular radiographic follow-up is important to identify any component positioning issues before they progress to hardware protrusion, as recommended by the American College of Radiology 5
Early intervention for signs of implant loosening or migration may prevent progression to hardware protrusion, according to the American College of Radiology 4, 5