Without any doubt, total hip arthroplasty represents one of the most important and impressive technological developments in the history of orthopedics and one that still attracts the attention of the orthopedist. Orthopedists had tried for hundreds of years to surgically relieve the pain and disability that accompany the arthritic hip joint with nothing more than occasional clinical successes. With the advent of anesthesia and later more sophisticated metallurgical advances, major progress began to take place.

Having witnessed the birth of a number of innovations which were initially heralded as the final solution to the replacement of the arthritic hip, but soon to be found wanting and then replaced by either improved or new techniques or implants, were lessons of great importance. To ignore the continuous evolution of hip surgery and to assume that we have finally found a permanent solution is not only wrong but rather naïve. It will be a long time before perfection is attained. This is why, I have structured this book in a manner that identifies the likely reasons for the failures of so many different approaches to the “hip problem” hoping that our enthusiasm with “new” techniques will be tempered by the lessons of history.

The encouraging results obtained with the use of a Vitallium cup, designed by Smith-Petersen from Boston, the acrylic cement prosthesis of Judet from Paris, and similar ventures into the field early in the twentieth century gave impetus to further experimentation. These two implants gained great popularity, but within less than a couple of decades their usage was discontinued–the Smith-Petersen because of failure to provide long-lasting relief of pain and loss of motion; and the Judet implant because of mechanical failure of the material and boring of the head into the acetabulum.

Austin Moore and Fred Thompson's endopros theses developed in the 1940s suggested that effective replacement of the hip joint had become a realty. Their implants, however, failed to provide consistent good results since complete and permanent relief of pain became elusive. Over time, the prosthetic heads often bored into the acetabulum producing pain and disability. Their use in the care of femoral neck fractures found wider applications.

It was not until the late 1950s and early 1960s that it became evident that more successful replacement of the arthritic hip was within sight. The pioneer work of McKee and Farrar from England, was a major break-through. They used opposing metallic surfaces to replace the arthritic cartilage of the acetabulum and femoral head. Peter Ring, from England, several years later, attempted to improve the McKee-Farrar concept by developing an implant that replaced the acetabulum with a screw-in cup, and the femoral component with an Austin Moore endoprosthesis. Neither the McKee-Farrar nor the Ring implants survived, since either loosening of the components or wear of the articulating metallic surfaces became frequent complications.8

Charnley, in the 1960s, used Teflon, a plastic material, to replace the socket and a metal ball made of stainless steel to replace the femoral head. Although surgeons, like Habush from New York and Leon Wiltsi, from California, had done some work with acrylic cement, it was John Charnley from England, the first one to successfully use it to stabilize the parts. Charnley's initial spectacular success with Teflon was short lived. The massive bone lysis around the prosthetic components that developed in virtually all of his patients necessitated removal of the prostheses, leaving the patients with flail, disabling joints. The Teflon material, under in vivo weight-bearing conditions, underwent significant wear. The particles of debris traveled into the medullary canal and all areas around the femur and acetabulum created havoc.

Charnley readily recognized that Teflon, though heralded as the ideal material to tolerate weight-bearing stresses, did not do well in the human body. Undeterred by the major tragedy and professional failure, he proceeded to search for a better material. He found it: high-density polyethylene; a material that 50 years later is still felt by many to be the preferred material to oppose the metallic head. Recent work with improved cross-linked polyethylene, metallic designs and ceramics has raised questions regarding the permanent acceptance of the traditional polyethylene as the preferred bearing surface. Within the next few years, we may have an answer to this.

As soon as the word spread out that Charnley's results with the new material were very good, the world's orthopedic community embraced the concept. People from all over the world traveled to England to learn about the new procedure. I personally made my pilgrimage to John Charnley's Mecca and spent three months observing his operation and learning about his overall philosophy of hip disease.

Some orthopedists, desirous to make additional contributions to the field, or blinded by the sight of possible overnight fame, modified the design of Charnley's implant even before they had an opportunity to learn and appreciate Charnley's teachings. One of them, after spending a few days at Charnley's Hip Center, designed upon his return to the United States, his own prosthesis, made minor modifications to the original design and attached his name to the new implant. He, however, chose the wrong material and his implant was promptly discredited.

Industry saw enormous market opportunities and began, with the aid of physicians, to further modify the Charnley's prosthesis since his design was protected with a patent. By the mid-seventies there, were dozens of different total hip prostheses available in the market. They differed in length, width, shape, texture and every conceivable geometric variety. Some had grooves, others notches; some were longer, others shorter. Larger and smaller collars were designed and some prostheses not even had a mark where the old collars once existed. Some advocated matted surfaces while others claimed that polished surfaces were better. Some implants had larger heads in millimeters increments. The sockets were also modified. Some were reinforced with metal-backed shells or had projections to better make the column of cement equal in thickness. Modularity was introduced in order to best accomplish gains during leg length equalization. In some instances, these modifications resulted in improvements, but in other instances, retarded progress. The excessive commercialization of orthopedics has done harm to the profession and patients as well.

A variety of innovations were made in the technique of cement injection: plugging, water picking, rasping and pressurizing. These variations became known as the second generation of cementing techniques. The cement itself was then offered with different speeds of polymerization. Some were more viscous than others.

The osteotomy of the trochanter, essential component of Charnley's original operation, began to loose popularity and, within a few years, virtually disappeared from the scene. I, for one, referred to it as an unnecessary “masochistic ritual”.

New materials were introduced and efforts were made to discredit stainless steel after occasional stem fractures were reported. Cobalt-Chrome alloys replaced stainless steel implants. I personally became involved in the frenzy of improvement and thought that a material with a lower modulus of elasticity would eliminate the stress shielding of the proximal femur that the stiffer stainless steel and Cobalt-Chrome alloys seemed to have created. I designed the first Titanium prosthesis used in the United States, anticipating improvement in the radiological and clinical results. My expectation was not fulfilled in spite of initial encouraging results.

In the early 1980s, after thousands of orthopedic surgeons throughout the world had performed millions of hip arthroplasties, reports of complications with the operation began to flood the medical journals. Loosening of the components was the main problem. Acrylic cement was blamed for those complications and “cement disease” became a familiar term among orthopedic surgeons.9

Efforts made to eliminate the “evil cement” from the surgical procedure, gave birth to the noncemented prosthesis. To the best of my knowledge, the first such implant was conceptualized by Emmet Lunceford from Columbia, South Carolina. He had been a fellow-resident of mine and later an associate of Austin Moore. He named the experimental implant as AML (Austin Moore-Lunceford). Lunceford died tragically a few years later and never had the opportunity to observe the clinical results with his prosthesis. With alacrity and without waiting for good documentation of the superior qualities of the noncemented implant, the use of the new technique became an epidemic. It was heralded as the answer to all the problems created by the cement. The noncemented prostheses had porous surfaces into which the bone would grow.

It did not take very long, however, for the orthopedic community to find itself disappointed by the lack of consistent good results. Thigh pain appeared to be a very frequent sequella that either did not be spontaneously disappear or persisted for a long period of time. Furthermore, and more disturbing, was the appearance of lysis, both in the pelvis as well as in the femur.

Postmortem examinations demonstrated that bone ingrowth did not occur in all instances or throughout the entire porous surface. Even in patients who had remained asymptomatic during their lives, only small areas of bone ingrowth were found. Femoral osteopenia around the implant, sometimes of worrisome degrees, was encountered in some instances.

Hoping to eliminate complications, the extent of porosity on the surface of the metallic components was modified. Arguments were advanced in favor and against the degree to which the stem should be covered with porous material, and soon we witnessed the manufacturing of prostheses with porous surfaces throughout their entire length; others only to mid-level or proximal third, and even just over a small area below the collar of the femoral implant.

Surgeons found themselves having serious difficulties removing porous implants, which though well-fixed in the medullary canal or acetabulum needed to be revised for a variety of reasons such as recurrent dislocation, disabling pain, infection, and fractures of the components of the femur. Bone had grown into the pores making their removal difficult if not impossible.

Wear of the polyethylene socket continued to be a concern with both cemented and noncemented arthroplasties. Wear was originally found to be higher with the noncemented ones for reasons, which are not yet clear. It is believed that one reason for the higher wear observed with uncemented implants was the increased number of foreign body elements arising either from motion between the stem and the surrounding bone, from the outer surface of the acetabular cup, the plastic-metal articulation, the Morse taper head fixation, or from other modular components. These phenomena occurred more frequently with titanium alloy implants because the material is softer and, therefore, has a propensity to scratching.

The initial dissatisfaction with the cementless implants prompted a solution: the use of a noncemented acetabulum and a cemented femoral component. This modification was allegedly inspired by the finding that cementless acetabula had experienced a very low failure rate, while the femur had not performed as well. Although this “hybrid” model is still popular at this point, I have doubts about its future. I have personally documented a higher incidence of radiological complications in patients who had “hybrid” titanium prostheses than comparable cohorts of totally cemented titanium arthroplasties.

Experiences with implants with ceramic heads and acetabulum, rather than metal on polyethylene appear at this time, are encouraging. The success is explained by the reduced wear of the material as documented in laboratory conditions and in mid-term clinical series. However, ceramics are brittle and fractures of the implants have been reported. It is too early to categorically state that ceramics will replace metal on polyethylene. More recent reports have indicated that wear debris from these implants may initiate osteoclastic activity leading to loosening.

Similar concerns can be extended to metal-on-metal articulations. Metal-on-metal prostheses are beginning to show metallosis increasingly in large numbers. This development should be a source of concern in light of the finding of chromosomal abnormalities found in tissues at the site of metallosis, as reported by Professor Patrick Case from Bristol. Others, in the United States and in other countries, have expressed concerns about metal debris in the body, such as Jonathan Black from Philadelphia, and Joshua Jacobs from Chicago.

While the new approaches to weight-bearing surfaces are being evaluated, significant improvements are being made on the wear performance of new cross-linked polyethylenes. It will be a while before the true superiority of the cross-linked polyethylene is definitively proven.10

The use of hydroxyapatite as a coating of the prosthetic implants, designed to further ensure bone ingrowth, has been reported to render better results. This perception is not universally shared at this time. When first recommended, a high failure rate was encountered, apparently due to the grains of the material being either too large or too small.

Recently, a great deal of enthusiasm has been generated with the concept of “minimally invasive” surgical approaches to total hip replacement. It is claimed to be a recent innovation, however, it was first introduced in Buenos Aires over 40 years ago by Dr Fermin Garcia. I visited him forty years ago and had the opportunity to observe the performance of the arthroplasty through a small incision. I returned home and tried the procedure. It was successful. However, I detected from the outset possible limitations of the system and the possibility of unexpected complications. The procedure is more difficult to perform and intraoperative complications more likely to occur.

At the time of this writing, acetabular osteotomies are being re-introduced into the armamentarium of the orthopedic surgeon, as well as concepts regarding the etiology of some types of osteoarthritis, such as the “lump” that grows on some femoral heads creating the now called “impingement syndrome”. These ideas and procedures are being marketed with a great deal of enthusiasm, but it is much too premature to declare them effective. The same applies to the use of “navigation” to facilitate the most appropriate position of the various prosthetic components. This very appealing concept is already being discredited in some quarters because of a higher incidence of complications. I suspect that within the next few years, the system may become a part of history.

Despite the progress made in hip replacement, I feel it has not been proportional to the efforts made in this regard. I suspect the slow progress we have made is due to the fact that the orthopedic community relinquished many of its responsibilities to industry. Its control is so great that I have been able to state on numerous occasions that “the education of the orthopedist is structured primarily to satisfy the marketing needs of industry”. The same can be said about research.

Two different episodes summarize eloquently the reasons for my deeply rooted concern over the extreme role the industry plays in the life of the orthopedist and the control of his education. The president of a major implant manufacturing company, whom I had known for quite some time, invited me a number of years ago to visit his factory to discuss my ideas regarding the future of total hip replacement. During the course of the visit, he said, “By the time we release a new prosthesis, we are already working on a new implant, in order to meet the competition given by their new implants.” A few years later, the vice president of another company said to me, “The philosophy behind implant development is not the making of a better one, but a different one. The orthopedists seem to believe that a different implant is always better than the one it replaced.” If these two experiences are not good eye-openers, I do not know what will it take to remove the blinders we have found so comfortable. These two episodes explain why is it that today we have on the market several hundred different total hip prostheses.

Had we retained control of our destiny, and maintained a balanced working relationship with industry, rather than accepting a subservient position, it is possible that we would have been in a better position to identify important issues and set aside ones which have only marketing value. The more recent trend of direct-to-patient marketing is making matters worse. At this moment, one can see elaborate ads on television advertising total joint prostheses using an athlete kicking a soccer ball and doing rock climbing after having his hip or knee surgically replaced. Such a marketing technique is misleading, dishonest and totally unprofessional. It should be forcefully opposed by our representative organizations. However, until now they have remained silent, much to the detriment of patients and the profession as a whole.

John Charnley warned us that wear was the biggest problem looming on the horizon and suggested that a concerted effort should be made in that direction. We ignored his words and today we find ourselves confronting problems that should have been solved long ago.

After limiting my surgical practice entirely to total hip replacement for 35 years, I stopped doing surgery and went back to teaching in outpatient clinics devoted to the indigent, where enormous deficiencies exist. Contrary to expectations, I did not find it difficult at all to stop doing hip surgery. Five years have gone by and have not once regretted my decision. I do, however, miss seeing patients and observing the unfolding of clinical events. This lack of enthusiasm for surgery was precipitated by the gradual realization that the operation was no longer challenging. It had become a routine where the appropriate use of techniques was the “name 11of the game”. I compared this reaction with the continued challenges that traumatic conditions of the skeleton still make the subject so fascinating.

The progress that has taken place in the management of the fractured hip during the last few decades has been, in my opinion, limited. Fractures of the femoral neck, which have been known for a very long time to be associated with a high frequency of nonunion and avascular necrosis continue to occur despite the development of a multitude of differently fixation devices. The same can be said about the management of idiopathic avascular necrosis, which despite better diagnostic tools and techniques, remains an unsolved problem. Efforts to revascularize the necrotic head through a variety of techniques, such as core decompression, vascularized bone grafts and osteotomies, have rendered disproportionably unsatisfactory results. Prosthetic replacement of the necrotic head is being performed with greater and greater frequency in preference to osteotomies, grafting and other techniques. Prosthetic replacement has virtually become the only reasonable approach to the condition. This trend can be justified, not only in light of the frequency of bad result from reconstructive procedures but also because the good results from primary total hip replacement arthroplasty are being obtained.

The intertrochanteric and subtrochanteric fractures have fared better. The introduction of the closed intramedullary interlocking nail has revolutionized the care of these fractures. There is still much to be learned about the place and role of this technique. Suffices to say, however, that early results are encouraging to the point that its use has become the most popular and effective method of fixation of many, if not all, intertrochanteric and subtrochanteric fractures of the femur.

My interest in hip disease began very early in my career. My first experience took place during my internship. It happened in the Radiology department at the Colombian Military Hospital in Bogota, where an elderly woman was lying on the table. She had sustained a fracture of the femoral neck the night before. The treating surgeon injected Novocain into the joint as well as over the subtrochanteric region. Once the anesthetizing was completed, he manipulated the extremity, following which an x-ray was obtained. Apparently happy with what he had seen, he picked up an instrument that held at its end what I was then told was a Smith-Petersen nail. With a single blow of a hammer, he drove the nail into the neck and head of the femur. An x-ray showed him that the placement of the nail was correct. The procedure had taken just a few minutes.

A couple of weeks, later I assisted Dr Guillermo Vargas in the reduction and nailing of a femoral neck fracture that a young soldier had suffered during a long march, shortly after his entry into the military. The experience this time was quite different. The reduction was impossible to obtain through manipulation, so an open reduction became necessary. Even though the femoral head and neck were being held reduced by the assistant surgeon, the driving of the nail into the head proved to be a major undertaking. The hard femoral head separated from the neck with every blow of the hammer. The bone seemed to be as hard as marble. I do not know what happened to the young man. I suspect, however, that his femoral head experienced avascular necrosis. These experiences prompted my desire to become an orthopedist.

Fate took me shortly afterwards to Columbia, South Carolina, where Austin T Moore, an already recognized giant in the field of hip surgery, had his practice. I became his resident and obtained from him, for a three years period, enormous love for hip surgery. His overall philosophy about patient care, his innovating ideas, and his restless and passionate commitment to the subject, did nothing but to reinforce my desire to become an active participant in the further development of the subspecialty.

Upon leaving South Carolina, I spent an additional year of residency in Orlando, Florida. The third program where I took my extended residency was at Jackson Memorial Hospital, the main teaching hospital for the University of Miami. From many of the attending surgeons, I also learned a great deal. However, Miami in the late 1950s did not have any one surgeon who could be considered a hip expert. Despite that absence, or perhaps because of the absence of such a person, I found myself deeply involved in efforts to raise the standards of care of the hip and to conduct investigative studies.

With élan and enthusiasm, and what appeared to be boundless energy, I delved into the subject of hip fractures. I performed the first Moore endoprosthetic replacement in the city. My interest in the intertrochanteric fracture led me to conduct studies in postmortem specimens and to gain insight into this very interesting fracture. I managed to arrange being notified every time a patient who had a hip fracture expired in the hospital or a nursing home in the community. I removed their hip joints and subjected them to crude testing. Eventually I published my findings and described an I-Bream nail for the treatment of those fractures. The new device, however, was 12promptly eclipsed by the sliding nail that had been developed by Kay Clawson, then chief of orthopedics in Seattle.

Suddenly, John Charnley came into my life. in the late 1960s, in the United States, very few people knew much about him. Some had read his masterful small book on fractures and had heard of his method of fusing hip joints. With skepticism, we learned of his experiences with hip arthroplasty and of his efforts to develop an implant, which contrary to the endoprosthetic replacement of Moore, would replace both sides of the joint. Our reluctance to embrace his new idea was further aggravated when it was learned that many of his patients had experienced catastrophic complications. Teflon, the plastic material that Charnley had used to replace the acetabulum, had poor wear properties. Bone lysis readily took place and massive damage to the surrounding tissues required removal of the implants.

Undeterred by the horrifying experience, Charnley continued his work. He had realized that he had made the mistake of choosing the wrong plastic, and began a desperate search for a better one. In polyethylene he found the right one. To this day, 60 years later, though not perfect, polyethylene remains the gold standard.

Upon learning of Charnley's success with the new plastic material, I issued him an invitation, on behalf of the American Academy of Orthopedic Surgeons, to attend a postgraduate course in Miami, which I, as chairman of the course, was organizing. I had asked him to participate by discussing his operation, and the results he was obtaining. His response was a dry and pithy one. “Total hip replacement should not be taught in an auditorium,” he said. Then, he added, “Only those surgeons who have been trained under me for a period of one year and commit themselves to the frequent performance of the procedure, should do this type of surgery.”

Somewhat offended by his remarks “since by that time I considered myself a fledgling hip surgeon”. I asked him if he would accept me in his hospital for a period of three months, which was the longest time I could be away from my work at the University of Miami. His response was a positive one.

The next two and one-half months proved to have been one of the most exciting periods in my entire academic life. I was absolutely overwhelmed by Charnley's personality and his knowledge of the hip joint. Upon my return to the United States, I committed myself entirely to total hip replacement. It was the only surgical procedure I was to perform during the next 35 years.

Forever, fixed in my memory was the brief conversation I had with him the day I went to his office to say good-bye and to thank him for the opportunity he had granted me. I asked him, what was the next frontier in hip replacement. Without hesitation, he responded, “This is it. The only obstacle yet to be overcome is improving the articulating surfaces to prevent the production of debris and the resulting lysis.”

I do not wish to describe his remark as hubris. However, his belief that his operation was the final word (though it could have been the case) left me a bit uncomfortable. Despite his greatness, he was human after all.

My interest and involvement in traumatic and degenerative conditions of the hip caught the attention of Dr Frank Stinchfield, the professor of orthopedics at Columbia University in the 1960s and 70s, who invited me to be among other 19 orthopedists to be a founding member of the Hip Society in 1968. In 1976, the International Hip Society was also founded by Dr Stinchfield, to which he invited me to be a founding member. I served as president of the Hip Society in 1976–1978 and have remained active in the functions of both societies. For eight years, I was the historian of the Hip Society.

Throughout the text, I based my comments primarily on my own personal experiences and conclusion, though vicariously learned in many instances. I am keenly aware many of my expressed views have been or will be proven to have been erroneous. That should not matter to the reader. No human being has had or will ever have the monopoly of knowledge. As far as I am concerned, what is important is the effort involved in seeking the truth. Not reaching that goal is not a crime; quite the contrary, the best part of the quest. It was Socrates, the immortal Athenian philosopher who said, “An unexamined life is not worth living.”

There will be some amongst the readers of the book who will readily argue the book dwells too heavily on subjects that have only historical interest, which are not worth knowing about; and that new ideas and techniques have permanently replaced the old ones. To some extent, they are correct; however, they ignore the fact that this is not the only time the orthopedic community has welcomed new ideas and expected them to become infallible, eventually realizing that those new ideas were soon replaced with “newer and better” ones. To question and investigate the reasons for their failure should help us in the charting of future ideas and the developing of newer techniques. It was Winston Churchill who said, “The longer you look back, the more you can see further.”13

I question the wisdom of those who dismiss history, and pay attention only to contemporary attitudes and trends. They are the ones who argue that it is irrelevant for the young to learn the role the ancient Indians, Chinese, Egyptians, Mesopotamians, Greeks and Romans played in the foundation of our civilization. To them, it is a waste of time to read the classics, and argue that modern ideas and literature is all that is needed to reach success in our materialistic society. Those people have been extremely successful in removing the reading of Shakespeare, Dante and Cervantes from the curriculum of so many of our colleges and universities, and have equally declared that the music of Back, Mozart or Beethoven should be replaced with the incoherent noise that currently pollutes the air.

At the risk of being criticized for listing a references composed exclusively of articles, commentaries, books and lectures I have published and/or delivered, I have choosen this route upon realizing that I have neither the talent nor the patience to quote the thousands of publications dealing with the subjects at hand. This book, therefore, is neither a scholarly written document nor a manifesto proposing a definitive plan of action. It simply is a personal attempt to bringforth personal experiences and vicarious experiences accumulated over a long professional career devoted to the study of hip diseases and traumatic conditions.