Denosumab prevents periprosthetic bone mineral density loss in the tibial metaphysis in total knee arthroplasty

Periprosthetic bone quality is one of the most important factors preventing early prosthesis migration and long-term failure. Although denosumab, which binds to the receptor activator of nuclear factor kappa-B ligand (RANKL), has been linked with periprosthetic bone mineral density (BMD), the effectiveness of denosumab against bone loss remains unclear. We hypothesized that denosumab treatment after total knee arthroplasty (TKA) could prevent periprosthetic bone resorption. In this prospective cohort study, 28 patients with primary knee osteoarthritis were divided into two groups: denosumab (denosumab and vitamin D) and control (vitamin D only) groups. All patients underwent TKA with the same implant model and received medication after surgery. We used dual-energy X-ray absorptiometry to measure periprosthetic BMD after TKA. In the control group, the BMD of the proximal medial tibia decreased drastically at 12 months after TKA (−19.7%). Denosumab treatment significantly preserved this BMD loss (0.7%). The linear regression analysis revealed that denosumab intervention had the highest significantly positive relationship with BMD. Our results indicate that denosumab treatment significantly reduces periprosthetic BMD loss, even at the early stages after TKA. This therapeutic strategy may facilitate early stable fixation of the prosthesis which, in turn, may help to prevent early implant migration and reduce the need for revision surgery.