Systemic and local TGF-ß1 concentration in patients with aseptic loosening of hip prostheses

Background: The bone quality may have an influence on prostheses survival. TGF-ß1 is one of the most important factors that determine regeneration and adaptive capacity of the bone. We hypothesized that the patients with failed hip implant without osteolysis may have an altered TGF- profile in comparison to the patients with prostheses loosening who develop osteolysis due to the wear of polyethylene or the patients with stable prosthesis. Material and methods: To assess the hypothesis four patient populations were studied: patients who had a hip revision surgery for failed uncemented implants without osteolysis (group A, n=32), patients who had a hip revision surgery for osteolysis around the failed cemented implant (group B, n=49), patients who have been using a well functioning total hip prostheses for a minimum of 10 years (group K1, n=27) and patients with hip osteoarthritis (group K2, n=25). Peripheral blood and periprosthetic fluid samples were collected to measure TGF-ß1 concentration. Results: The mean local TGF-ß1 concentration in periprosthetic synovial fluid was significantly lower than in the serum in both groups of patients (A and B) with failed prostheses (p<0,001). The mean systemic serum concentration of TGF-ß1 was significantly lower in the patients with mechanical prosthesis failure without osteolysis (group A) in comparison to the patients with failed prostheses due to osteolysis (p<0,005), to the patients with stable implants (p< 0,001) and to the patients with hip osteoarthritis (p<0,015). Conclusion: The low systemic and local TGF-ß1 concentration may contribute to the loosening of total uncemented hip prostheses with no substantial wear or osteolysis.