LLU&MC Scope Autumn 2000

Professor receives $112,000 for orthopaedic surgery research study

A $112,000 hip-joint contract was awarded in April, 2000, to Ian C. Clarke, PhD, research professor of orthopaedic surgery, School of Medicine.

"These funds will support a year-long study of ceramic hip joints in the Howard and Irene Peterson Tribology Laboratory," Dr. Clarke says.

This is the largest contract awarded in the tribology laboratory's four-year history. Tribology is the study of friction, lubrication, and wear in bearings, and at LLUMC, this is currently applied to the hip and knee joint implants used by orthopaedic surgeons.

Ceramic balls and cups have been used in artificial hip joints since 1970 due to their exceptionally high wear-resistance. Pierre Boutin in France was the first surgeon to innovate this ceramic concept for implants. He was followed in 1973 by surgeons in Germany and Austria.

Today, such ceramic hip experiences extend over 30 years in Europe and over 23 years in Japan. In the early 1980s, the Food and Drug Administration (FDA) gave limited approval for the German Mittelmeier hip implants to be used in selected American universities.

However, these restricted clinical studies revealed several implant deficiencies and the Mittelmeier ceramic implants were abandoned by the mid 1980s.

"Our tribology laboratory has now studied ceramic wear-rates for hip implants made by three of the top ceramic corporations in the world; Kyocera in Japan, Norton in France, and CeramTec in Germany."

Christopher M. Jobe, MD, professor of orthopaedic surgery, and acting chair, department of orthopaedic surgery, noted that this contract from Ceraver in France means that now the world's top four ceramic corporations have come to LLUMC to have their implants evaluated.

Dr. Clarke pointed out that not only do these ceramic contracts highlight the type of world-class tribology laboratory located at LLUMC, but it also fulfills the tribology laboratory's mission statement, "to benefit patients worldwide by providing orthopaedic surgeons with scientific research information of direct clinical relevance to their practice of implant surgery."

The Food and Drug Administration has not yet approved the latest designs of all-ceramic implants for use in the United States. LLUMC is participating in one of the current FDA studies of ceramic hip implants.

The standard polyethylene cups in use since 1962 have shown relatively poor wear-resistance and could not stand up to such rigorous, athletic performance. Once the FDA gives marketing approval to all-ceramic implants, then LLUMC surgeons will be able to select the implant to match the patient's activity level and projected life-span.

[Scope, Autumn 2000]