Micrometer-Sized Titanium Particles Induce Aseptic Loosening in Rabbit Knee

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Immunology

Background:

• Aseptic loosening, often caused by wear debris, is the primary reason for total knee arthroplasty (TKA) failure.
• Understanding the mechanisms of aseptic loosening is critical for developing effective prevention and treatment strategies.

Purpose of the Study:

• To establish a simplified and efficient rabbit model for studying wear debris-induced aseptic loosening in TKA.
• To investigate the role of micrometer-sized titanium particles in inducing osteolysis and aseptic loosening.

Main Methods:

• A TKA surgery was performed on 20 New Zealand white rabbits, with the study group (n=10) receiving a titanium rod prosthesis coated with titanium particles, and the control group (n=10) receiving an uncoated prosthesis.
• After 12 weeks, analyses including X-ray, histological staining (H&E, Goldner Masson trichrome, Von Kossa), PCR, and Western blotting were conducted on interface membrane tissues.

Main Results:

• Titanium particle implantation induced osteolysis and aseptic loosening around the prosthesis.
• Macrophages stimulated by titanium particles produced inflammatory factors that activated osteoclast differentiation via the OPG/RANKL/RANK pathway.
• Osteoblast function was suppressed, and bone ingrowth was reduced.

Conclusions:

• The established rabbit model effectively simulates the process of artificial prosthesis implantation and loosening.
• This model serves as an ideal etiological tool for studying aseptic prosthetic loosening, particularly the inflammatory mechanisms involved.