Loma Linda University School of Medicine News
May 4, 2000
Orthopaedic surgery professor receives $112,000 for year-long 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 to be awarded to the tribology laboratory's four-year history. Tribology is the study of friction, lubrication, and wear in bearings, and at Loma Linda University Medical Center, 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 (see photo on page 3). 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 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 the 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.
"This represents a significant statement of confidence in our tribology lab because measuring the wear in ceramic implants is a very demanding task."
Dr. Clarke pointed out that not only do these ceramic contracts highlight the type of world-class tribology laboratory located at Loma Linda University Medical Center, 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 (FDA) 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.
Allen Gustafson, MD, assistant professor of orthopaedic surgery, points out that his patients have to qualify for inclusion in his FDA-controlled studies.
Dr. Gustafson also noted that under the current FDA study-design, the patient may receive either a 'ceramic-polyethylene' or a Ôceramic-ceramic' hip set.
By the FDA's definition, the former is considered the standard or "control" implant, the latter is considered the "experimental" implant.
Assignment of implant type is done on a randomized basis, i.e., neither Dr. Gustafson nor his patient can pre-select the actual implant in such an FDA study.
Ceramic implants became a household word in January, 1999, when Jack Nicklaus had one implanted in his left hip and then went back into training for his competitive golf schedule (Golf Digest, March, 1999).
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 the LLUMC surgeons will be able to select the implant to match the patient's activity level and projected life-span.
The earliest that the FDA approval could be given for all-ceramic implants would be year-end 2000, but Dr. Gustafson said it is more likely to be in the year 2001.
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