Diagnosis and Treatment of Osteolysis

Total hip replacement arthroplasty (THRA) is widely performed, and is a successful orthopedic treatment method. Osteolysis, which often happens after THRA, causes a chronic inflammation stage due to wear debris in the artificial articular surface, leading to bone loss or loosening of implants. Osteolysis eventually results in shortening the lifespan of the joint. Afterwards, many researchers reported on the basis of experiments with tissue cultivation that due to the influence of wear particles, the surrounding tissues of the implants as obtained during replacement and the surrounding cells of the implants are secreting enzymes, prostaglandin, cytokine, and the like that stimulate the formation of fibrous tissues or bone resorption by osteoclasts. At this time, THRA was a main cement fixation method, so researchers thought that the loose particles of cement were the cause of osteolysis and aseptic loosening, and so they named these symptoms "cement disease". However, despite the advancement of cement techniques and the use of cement-free implants, the osteolysis problem continued to rise, leading to polyethylene wear particles being regarded as the main cause of osteolysis, and naming these symptoms "particle disease". In this way attention was drawn to new wear particles, now that it is revealed that ultra-high-molecular-weight- polyethylene (UHMWPE) or metal particles constitute the main cause. However, because no symptoms arise until serious bone defects or loosening occurs, it is difficult to diagnose or treat the disease early on. Thus, based on updated hypotheses and theories, this study examines the pathophysiology of osteolysis following THRA, as well as the diagnosis and treatment of osteolysis in the acetabular and femoral regions.