HISTORY OF TOTAL JOINT REPLACEMENT
HIPS
Due to the crippling nature of arthritis, surgeons have been trying for well over a century to successfully treat this debilitating disease. It was clear that many people required surgery to relieve the terrible pain and keep their joints mobile. Initial attempts to treat arthritic hips included arthrodesis (fusion), osteotomy, nerve division, and joint debridements. The goal of these early debridements was to remove arthritic spurs, calcium deposits, and irregular cartilage in an attempt to smooth the surfaces of the joint. Indeed, there was a great search for some material which could be utilized to resurface or even replace the hip. Several proposals and trials were made including the use of muscles, fat, chromatized pig bladder, gold, magnesium and zinc. All met with failure. Surgeons and scientists were unable to find a material which was biocompatible with the body, and yet strong enough to withstand the tremendous forces placed on the hip joint.
In 1925, a surgeon in Boston, Massachusetts, M.N. Smith-Petersen, M.D., molded a piece of glass into the shape of a hollow hemisphere which could fit over the ball of the hip joint and provide a new smooth surface for movement. While proving biocompatible, the glass could not withstand the stress of walking and quickly failed. Undaunted, he pursued other materials for his "mold arthroplasty" including plastic and stainless steel. The shipping industry first used stainless steel to resist the corrosion of ocean going vessels. Its application to surgery, where it might well resist corrosion by bodily fluids, seemed natural. During the 1940's, mold arthroplasty was "state of the art."
A dramatic improvement was made in 1936 when scientists manufactured a cobalt-chromium alloy which was almost immediately applied to orthopaedics. This new alloy was both very strong and resistant to corrosion, and has continued to be employed in various prostheses since that time. While this new metal proved to be a great success, the actual resurfacing technique was found to be less than adequate. It became clear that pain relief was not as predictable as hoped, and hip movement remained limited for many patients. Mold arthroplasty also did not allow surgeons to treat the numerous and varied arthritic deformities of the hip. The search for different types of prostheses continued.
Frederick R. Thompson of New York, and Austin T. Moore of South Carolina, separately developed replacements for the entire ball of the hip. These could be used to treat hip fractures and also certain arthritis cases. This type of hip replacement, called hemiarthroplasty, only addressed the problem of the arthritic femoral head (the ball). The diseased acetabulum (hip socket) was not replaced. The prosthesis consisted of a metal stem which was placed into the marrow cavity of the femur, connected in one piece with a metal ball which fit into the hip socket. While very popular in the 1950's, results remained unpredictable and arthritic destruction of the socket persisted. In addition, there was no truly effective method of securing the component to the bone. Large numbers of patients developed pain because of this loosening of the implant. The desired result was still not achieved.
As early as 1938, Dr. Jean Judet and his brother, Dr. Robert Judet, of Paris, attempted to use an acrylic material to replace arthritic hip surfaces. This acrylic provided a smooth surface, but unfortunately tended to come loose. The idea did lead Dr. Edwarc J. Haboush from the Hospital for Joint Diseases in New York City to utilize a "fast setting dental acrylic" to actually glue the prothesis to the bone. A new era in fixation techniques had begun.
In England, a very innovative surgeon, John Charnley, was also attempting to solve these ongoing problems. Some of his ideas were so bold and creative that he was seriously questioned by many of his colleagues. He was relegated or banished to an isolated tuberculosis sanatorium that had been converted to a makeshift hospital. This center at Wrightington, Manchester, England, became a well-spring of knowledge for the surgical treatment of arthritis. Charnley aggressively pursued effective methods of replacing both the femoral head and acetabulum of the hip. In 1958, he addressed the eroded arthritic socket by replacing it with a Teflon implant. He hoped this would allow for a smooth joint surface to articulate with the metal ball component. When the Teflon did not achieve this goal, he went on to try polyethylene. This worked wonderfully well. In order to obtain fixation of this polyethylene socket as well as the femoral implant to the bone, Charnley borrowed polymehtylmethacrylate from the dentists. this substance, known as bone cement, was mixed during the operation then used as a strong grouting agent to firmly secure the artificial joint to the bone. Truly this was the birth of "total hip replacement."
By 1961, Charnley was performing the surgery regularly with good results. He further improved the techniques and component designs. Thousands of people were successfully relieved of their hip pain and the long term results became very predictable. The Queen of England knighted him for his immense contributions. He is now known as Sir John Charnley.
Since that time, many skilled surgeons have improved upon the concepts which started in central England. Methods of fixation and actual cementing techniques are significantly better. Refinements in the design of the prothesis have evolved to more clearly mirror the normal hip joint. Today over 100,000 hip replacements are performed annually in the United States using the principles of a low friction arthroplasty with a polyethylene socket and metal femoral prosthesis.
In the last ten years there has been considerable effort and research in trying to yet improve the methods of fixation. Occasionally it has been found that cement fixation breaks down over time. If a living type of bond could be created, this would theoretically be longer lasting and possible stronger. To this end, implants with textured surfaces which allow bone to grow into them have been developed. These have been used experimentally in animals and are now being used in humans. The results of these cementless joints look very promising when utilized in the correct circumstances.
Dr. Bertin has helped design and develop new total hip implants and instruments to use in surgery. These new innovations improved patient recovery, function and long term results. Some of these improvements have been patented and are used by many other surgeons in the United States and around the world.
KNEES
A parallel line of development occurred with total knees that was occurring with total hips. The first attempt at total knee arthroplasty was a prosthesis which was really a hinge fixed to the bones with stems into the medullary canals (the hollow marrow cavity). These hinges provided good short term pain relief but function was not always great due to the limitations of motion. After a few short years, this prosthesis showed severe problems with loosening and infection and was abandoned. During this same period of time, some surgeons were trying to treat arthritis of the knee with a metal spacer which was placed between the bones of the knee to eliminate the rubbing of irregular surfaces on each other. These implants, the McKeever (1957) and MacIntosh (1958, 1964), achieved some success but were not predictable, and many patients continued with significant symptoms. Next, surgeons at Massachusetts General Hospital made a prosthesis in the shape of the femoral half of the knee joint. This mold type arthroplasty helped in relieving symptoms but was not predictable nor were the results always lasting. These "primitive" replacements evolved from 1940 to 1965.
During the late 1960's, a Canadian orthopaedist, Frank Gunston, from Sir John Charnley's Hip Center, developed a metal on plastic knee replacement secured to the bone with cement. This was really the first metal and plastic knee and the first with cement fixation (1968). The era of total knee arthroplasty had begun. In 1972 another Englishman living in New York City, John Insall, M.D., designed what has become the prototype for current total knee replacements. This was a prosthesis made of three components which would resurface all three surfaces of the knee - the femur, tibia and patella (kneecap). They were each fixed with bone cement and the results were outstanding. This was the first total knee complete with specific instrumentation to help with accurate bone cutting and implantation. Since then, by reviewing the cases of patients who have had total knee replacements, further significant improvements have been introduced. Today with metal backing of the plastic components, an increased inventory of appropriate sizes of implants, and markedly better instruments to perform the procedure, knee replacement results have equalled or surpassed those of hip replacement. This is a noticeable change from 1975 to 1980 when knee replacements were much inferior to hip replacements. Approximately 150,000 knee replacements are performed annually in the United States.
Current research with total knee replacement is directed at refining the design to improve patient function. The desire to achieve greater knee motion and strength motivates researchers to further enhance knee replacements so as to be equal to normal knees. Cementless fixation using a prosthesis with a textured, porous surface into which bone can grow may provide biologic fixation. That is, the bone grows into the prosthesis and holds it in place. This may be more durable than cement used in the past. Cementless total knee arthroplasty is currently being used in patients, and the results look very promising.
Dr. Bertin has helped develop a total knee prosthesis which is used widely around the world. This research, in conjunction with other orthopaedic surgeons and engineers, has resulted in excelled pain relief and improved function for thousands of patients. Additionally, he developed new concepts and designed modern instruments which have been patented. Thus, the entire total knee procedure is performed more accurately and reproductively in each patient.
