Tissue reaction to a failed Bion hip prosthesis in a dog

Area of Science:

• Biomaterials science
• Veterinary orthopedics
• Tissue engineering

Background:

• Total hip replacement (THR) systems are used to treat hip joint diseases.
• Implant failure can lead to adverse tissue reactions and complications.
• Elastomer components in THR devices require evaluation for biocompatibility and durability.

Purpose of the Study:

• To evaluate the tissue reaction in a canine model to a failed constrained total hip replacement system.
• To investigate the consequences of Bion elastomer component fracture within a THR device.

Main Methods:

• A canine subject received a constrained total hip replacement with Ti-6A1-4V alloy components and a Bion elastomer.
• The implant was explanted at necropsy following device failure.
• Histopathological analysis was performed on the surrounding tissues to assess the inflammatory response.

Main Results:

• The Bion elastomer component of the total hip replacement system was found to have fractured.
• Tissue surrounding the fractured component exhibited granulomatous inflammation with blackened regions.
• Histology revealed a severe chronic inflammatory response, characterized by giant cells and Bion-laden macrophages.

Conclusions:

• Fracture of the Bion elastomer component in a total hip replacement system can elicit a significant adverse tissue reaction.
• The observed granulomatous inflammation and presence of Bion material within macrophages indicate a foreign body response.
• This case highlights potential biocompatibility and mechanical failure issues with elastomer components in orthopedic implants.