This article is part of the Arthritis Archives.
Dateline: March 6, 1997
Joint Replacement Surgery
Although surgical treatment is often thought of as a last resort option, joint replacement surgery has become increasingly common in the past 25 years.
The prospect of pain relief offered by this type of surgery is very desirable to those suffering from debilitating arthritis. Artificial joints date back to the 1800's when surgeons used prostheses of various materials, one being an all metal hip with metal screws. There were problems with erosion and loosening however. In the 1960's a British orthopedic surgeon Sir John Charnley developed a prosthesis made of high density polyethylene. The prosthesis was held in place with methylmethacrylate cement.
Total Hip Replacement
Total hip replacement operations have been performed in the United States since 1973. The surgery is still based on Charnley's original design. During the surgery, the acetabular component of the hip is replaced by a cup made of polyethylene. The femoral head of the thigh bone is replaced by a metal ball attached to a stem. How the femoral stem is secured into the thigh bone is now an option for surgeons.
Cement had traditionally been used but in the 1980's a cementless design was developed. The cementless design is a porous implant. The intent is, through biologic fixation, that bone grows into and through the pores in the implant, thereby securing it.
In theory the cementless joint replacements are expected to reduce the chance of infection and loosening of the prosthesis, which are the two major complications of hip replacement surgery. Recent research, however, indicates that both the cemented and cementless joints do very well.
The problem of loosening is the focus of current research. Some researchers feel the way the bone is prepared or where the bone contacts the cement may be the problem and cause a breakdown. Other researchers believe that as cement flakes into microscopic particles it creates an inflammatory response in the body which leads to bone loss where bone meets cement. Yet another problem may involve the wearing down of the plastic liner.
In spite of potential loosening, the patient can expect many years of excellent results before a problem possibly occurs. 90% or more of patients having hip replacement surgery experience significant pain relief and improved range of motion. The surgery is considered highly successful.
Source: The Duke University Medical Center Book of Arthritis, by David S. Pisetsky, M.D., Ph.D. with Susan Flamholtz Trien
First published 3/07/1997