Osteolysis: medical and surgical approaches.

Osteolysis is defined as the process of progressive destruction of periprosthetic bony tissue, characterized on serial radiographs as progressive radiolucent lines and/or cavitation at the implant-bone or cement-bone interface. Without proper treatment, osteolysis may progress to aseptic loosening and catastrophic failure of the implant. Osteolysis is a multifactorial process stemming from host, prosthesis, and surgical factors. Billions of submicron wear particles are generated at material interfaces that cause osteolysis. Wear particles are dispersed along the effective joint space, into bone, and throughout the adjacent soft tissues. Initially, patients may have no clinical symptoms despite radiographic evidence of osteolysis and can remain completely asymptomatic, even in the presence of substantial bone loss. Symptoms usually do not occur until the bone loss has reached the point of causing implant loosening, implant failure (fracture), or periprosthetic fracture. Radiographic images and standard examination provide limited information and almost always underestimate the amount of bone loss. Three-dimensional computed tomography is more sensitive and can monitor the volume of the lesion, however the trade-offs are its high cost and radiation exposure. The timing for treatment of periprosthetic osteolysis is controversial and the medical decision-making is debatable. Medical treatment seems to be attractive but there is no proven or approved drug therapy to prevent or inhibit periprosthetic osteolysis. We reviewed the medical and surgical options that are available for treatment of periprosthetic osteolysis.