Bisphosphonates enriched bone cement reduces risk of osteoporotic fractures and aseptic revisions in TKR

Osteoporosis is a problem for many patients after total knee arthroplasty (TKA). The aseptic loosening of the prosthesis is also a significant problem. Therefore, in these patients, bisphosphonates (BPs) are used that, by influencing the level of bone turnover markers, reduce the risk of osteoporotic fractures and aseptic revisions in TKA.

Anna Matuszewska et al conducted a study at Lublin, Poland to assess whether the Pamifos® present in bone cement has any effect on the level of selected bone turnover markers and cytokines in patients after total knee arthroplasty. The article has been published in "International Orthopaedics" journal.

The study group consisted of 30 women with degenerative changes of the knee joint, whose total knee prosthesis was stabilized with cement enriched with Pamifos®. The control group consisted of 30 women treated for degenerative changes of the knee joint without the use of bisphosphonate-enriched cement for prosthetic stabilization.

• In the study group, the authors found a decrease in tumour necrosis factor (TNF-α) levels 12 weeks after surgery, whereas the control group experienced an almost twofold increase in TNF-α level.

• The concentration of OPG, a natural RANKL antagonist, was highest in patients of the study group six weeks after surgery and was four times higher compared to the control group.

• Statistically significant differences were found in the RANKL level (p< 0.05).In the control group, there was a continuous increase in RANKL concentration from the first to the 12th week after surgery. The highest level of RANKL in patients of the study group was found six weeks after the surgery, and 12 weeks after knee arthroplasty, it was significantly lower.

• It was found that the concentration of osteocalcin (OC) in the study group was the lowest three weeks after the surgery, then it increased and remained at a similar level after 12 weeks.

• The concentrations of selected cytokines (IL-1β, IL-2, IL-6, IL-10, IL-17AF) also showed statistically significant differences.

Summarizing, the authors postulate that BPs, which have been widely studied experimentally and have clinical application in the treatment of osteoporosis and other bone metabolic disorders, are effective in knee arthroplasty, as it was confirmed by the results of research. The authors concluded that the use of a bisphosphonate (Pamifos®) in bone cement has an effect on bone turnover. The BP-stimulated increase in the level of OPG and the decrease in the level of RANKL, as well as the impact on the level of the analyzed interleukins in the bone microenvironment, may be an important element of the mechanisms limiting bone resorption. Therefore, the use of BP-enriched bone cement in knee arthroplasty appears to be justified, as does the use of bisphosphonates in the prevention of periprosthetic resorption of the femur after total hip arthroplasty.

Further reading:

Efect of bisphosphonates on selected markers of bone turnover in patients after total knee arthroplasty.

Anna Matuszewska, Łukasz Matuszewski et al.

International Orthopaedics (2022) 46:1529–1538

https://doi.org/10.1007/s00264-022-05407-z