We hope you enjoy reading our selection of papers delivered at the November 2014 meeting of the International Hip Society in Rio de Janeiro, Brazil. This meeting brought together a group of 100 world renowned experts in hip surgery, who reflected on current and ongoing hip research.

figure 1

Michael Leunig MD

figure 2

Reinhold Ganz MD

Total hip replacement is currently one of the most successful procedures surgeons perform. While this operation works well for patients 65 years of age and older, patients under the age of 50 do not appear to do as well. Avoiding, or at least delaying, the occurrence of osteoarthritis in the younger age group could make a substantial difference in the lives of our younger patients.

During the last decades, we have dramatically improved our understanding of the causes of hip osteoarthritis. About 50 years ago, surgeons observed that childhood diseases such as Perthes disease, slipped capital femoral epiphysis, and hip dysplasia caused deformities resulting in early osteoarthritis of the hip. With the recent identification of femoroacetabular impingement (FAI) as a fundamental factor causing osteoarthritis, especially in the hips of Caucasian patients, joint-damaging factors have been described and treatment concepts have evolved—particularly in younger patients. In fact, FAI is not one kind of pathoanatomy, but several. We are beginning to understand how numerous, complex, and overlapping hip deformities may predispose some patients to later arthritis. Future research – as well as some that is in progress right now—may help us to delay or prevent arthritis in these patients.

For patients with advanced osteoarthritis, total hip replacement remains undoubtedly the most sustainable option currently available. However, it should be noted that while implant materials and design remain in continuous evolution, not all previously introduced concepts have been successful. For example, large femoral heads and hard-on-hard bearings (mainly metal-on-metal) used to address shortcomings of previous total hip replacement such as dislocation and wear, have caused new, unexpected, and even catastrophic adverse reactions not previously known (aseptic, lymphocyte-dominated vasculitis-associated lesion, taper corrosion, and fretting come to mind). Additional research may help us to diagnose and treat patients with these problems, and to design implants less likely to cause them.