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The Classic: The Surgery of the Osteo-Arthritic Hip

2003; Lippincott Williams & Wilkins; Volume: 417; Linguagem: Inglês

10.1097/01.blo.0000096822.67494.2d

1528-1132

Philip Wiles,

Orthopaedic implants and arthroplasty

Phillip Wiles (Fig 1), born on August 18, 1899, was the son of a wealthy corn merchant and Privy Councilor, in the City of London. He attended the famous Rugby School and served 3 years in the army in France during World War I. He could have looked forward to a life of respectable comfort but chose to study medicine. After the necessary years of preparation, he joined the senior staff at the Middlesex Hospital in London where he did his life’s work, practicing and teaching orthopaedic surgery. His publications document a great versatility and innovation, such as a radical interinnomino-abdominal amputation for lower limb sarcoma in 1934, hemivertebra resection for correction of congenital scoliosis in the 1950s, and the world’s first total hip replacement in 1938.Fig 1: Dr. Philip Wiles (Reprinted with permission from J Bone Joint Surg 49B:580, 1967.)He also published a definitive orthopaedic textbook, which went through four editions and multiple reprintings from 1949 to 1965. He also served as president of the British Orthopaedic Association. As treasurer, he provided critically important service to the British Journal of Bone and Joint surgery during its early years. During World War II, he served in India and the Middle East, and he rose to the rank of Brigadier. When he was 60 years, he resigned from Middlesex Hospital and moved to Jamaica. He involved himself in the development of the new medical school on the island, and he became chairman of the Scientific Research Council of Jamaica. He died there at the age of 67, years. Henry H. Sherk, MD The hip-joints became of increasing importance as man assumed an upright posture and adopted the mode of bipedal terrestrial progression. They were then called upon not only to adapt themselves to this major change in posture, but they had also to transmit the entire body-weight, and they became necessary for the natural performance of nearly every movement. The economy in design of the hip is striking. It is a straightforward ball-and-socket joint, the simplest way of providing for movement in every plane whilst giving strength and stability. This arrangement does, however, render the joint particularly liable to mechanical derangement, and once the bones composing it have become distorted, the interference with function is necessarily severe. At one time it was thought that the structure of the joint, together with the hard work it is called upon to perform, explained the high frequency of degenerative changes. The present tendency, however, is to incriminate the arrangements for nourishing the articular cartilage. Whatever the reason, degenerative arthritis is only too common, and being a painful complaint it interferes gravely with the life of the unfortunate victim. The methods available for the treatment of the painful hip are those applying to most orthopaedic problems—move it, keep it still, or cut it out. In the very early stages it may be possible to delay the progress of the degenerative process by reducing the patient’s weight to decrease the pressure on the joint, and by giving deliberate exercises to maintain as full a range of movements as possible. When the symptoms have become severe, conservative measures are of little real value. Physiotherapy, manipulation, radiotherapy, and intra-articular injections are often prescribed, but more to assure the patient that an attempt is being made to help him than in the hope of giving lasting relief. The more conservative operations such as denervation and excision of the joint capsule give only temporary benefit. It is sad and depressing that there are virtually no half-measures in treatment. The patient has to grin and bear it, adapting his life as best he can, until such time as the symptoms become intolerable. Major surgery must be postponed until there is a strong probability that it will make the condition better and not worse. The choice is then between attempting to give a movable joint by some form of arthroplasty or an osteotomy, keeping it still by arthrodesis, and cutting out the head of the femur. ARTHROPLASTY The advantages of movement at the hip are clearly so great that surgeons have been striving since the dawn of modern surgery to find a way of retaining or restoring movement when the hip is diseased. Progress has been made, many methods have been tried, but none has stood the test of time, and although there are many brilliant exceptions, there is as yet no procedure that can be relied upon to give a good and lasting result. The earliest arthroplasties were performed with the intention of mobilizing ankylosed joints. The joint surfaces were refashioned and then neighbouring soft tissue or some sort of foreign substance was interposed to prevent their fusing again. Until a few years ago nearly every effort was directed towards finding a suitable material to place between the bones. The idea was pioneered at the end of the last century by Ollier, who interposed the periarticular soft tissues. Within a few years experiments, usually but not always in animals, had been made with a great variety of materials ranging from pig’s bladder to rubber sheeting, zinc foil, and collodion. In 1902 Robert Jones successfully reconstructed a hip using gold foil, and in the same year Murphy obtained a good result by interposing a flap of fat and fascia. A little later Whitman described a reconstructive procedure in which the head and neck of the femur were excised and the greater trochanter was transplanted to a lower level. Until the second world war, the few surgeons bold enough to advise arthroplasty of the hip used either the Whitman procedure, or the Murphy technique as developed by Vittorio Putti, Willis Campbell, and others. Attempts to find a better method were, however, unremitting, but the search always was for a better way of refashioning the joint and a better substance to interpose. The author was comparatively late in the field. His first attempt, using the cat as an experimental animal, was to spray metal on to the denuded joint surfaces. It failed, if only because the metals that can be melted quickly enough in an oxy-acetylene flame are unsuitable to leave permanently in the body. Next, in 1938, he tried inserting a pre-formed acetabulum and femoral head made of stainless steel with the two parts ground to fit accurately. The acetabulum was prevented from rotating by a couple of screws, and the femoral head was secured by a bolt passing through the neck of the femur. The animal experiments were promising, and the operation was performed six times on patients severely crippled by Still’s disease. There was a measure of success in that those who were previously bed-ridden were thereby enabled just to walk. All these patients are now believed to be dead of other causes; the radiographs of their hips were destroyed during the war not by enemy action but deliberately by those responsible for the care of hospital records. One patient who had both hips operated upon in 1938 was alive in 1951, thirteen years later, but she can no longer be traced. She then had some 20° of active flexion at each hip and, although many other joints were stiff, she could walk a little and operate a mechanically propelled chair. The acetabular portions of the prostheses were disintegrating (Fig 557), but there was no pain. Fig. 557: A ball-and-cup arthroplasty performed in 1938. Radiograph thirteen years later. The lug and screws retaining the metal acetabulum have disintegrated, much of the neck of the femur has been absorbed, and the bolt has broken away from the head.Mould Arthroplasty The credit for putting arthroplasty of the hip firmly on the surgical map goes to Smith-Petersen, of Boston. He described the anterior approach to the hip which goes by his name in 1917 whilst he was still a resident, and in 1923 he performed his first arthroplasties. He began by interposing a glass mould between the refashioned joint surfaces, but sometimes it broke during use. Not deterred, he tried a variety of other substances such as pyrex and bakelite until in the end he settled on vitallium. The technique gradually developed in his hands and he designed a number of instruments specially contrived to combine accurate work with the least possible tissue damage. The operation reached its final form in 1938, and by 1947 he had operated upon more than 500 hips in 420 patients. A surgeon of great skill, an enthusiast, and a man of endearing personality, he nursed back the function of each hip; and he retained the confidence of his patients so that when further trouble arose, as sometimes happened, he was still able to encourage them and help them, even on occasion by ‘revision’ of the arthroplasty. The mould arthroplasty made it possible for the first time to give the sufferer from a painful hip at any rate the hope of losing his pain without sacrificing movement and stability. The operation was adopted with enthusiasm by surgeons throughout the world, but it was soon apparent that every problem had not been solved. A few patients had no relief from pain; the re-fashioned bone, especially if it were previously diseased, did not always tolerate the new stresses placed upon it and gradually became absorbed; osteophytes grew on the neck of the femur and prevented movement of the head within the mould; the new joint capsule composed of scar tissue became painful. So it happened that the pain, even though relieved at first, not infrequently returned after a few years (Fig 558). Many of Smith-Petersen’s early patients still have painless hips (Aufrank, 1957), but other surgeons, perhaps because their discipline was less meticulous, or because they magnified the imperfections of their results, soon found themselves impelled to resume the search for yet a better method. This time, however, the inquiry was in a different direction and the emphasis changed from re-fashioning the joint to replacing it.Fig. 558: A mould arthroplasty after 5 years. The neck of the femur has been absorbed, the mould is in contact with the trochanters thus preventing movement, and pain has returned.Replacement Arthroplasty The era of ‘replacement’ or ‘prosthetic’ arthroplasty was ushered in by the brothers Jean and Robert Judet, of Paris, in the late nineteen-forties. These surgeons removed the femoral head and replaced it with a new one made of acrylic resin. The operation was attractively easy to perform and the early results were brilliant, but, alas, pain returned only too quickly. The shape of the prosthesis has since been modified, and it has been copied in steel, vitallium, and other materials, but the procedure, at any rate in the hands of British surgeons, has not given lasting results and now is seldom practised. There are at least three reasons for the frequent failure of this type of prosthesis. Firstly, the bone, unable to withstand the stresses placed on it, is absorbed and the prosthesis becomes loose (Fig. 559). Secondly, the acetabulum cannot be shaped to fit the prosthesis really accurately and the spaces that remain are filled with fibrous tissue which may become painful, particularly after damage by some unusual strain. And thirdly, it is difficult to design a strong enough prosthesis; those made of acrylic resin rub flat surfaces on themselves, or they fragment or break (Fig. 560), and those made of steel sometimes become fatigued and break.Fig. 559: A Judet type arthroplasty after 3 years. The bone of the neck, unable to withstand the stresses placed on it, has been absorbed and the pain has returned.Fig. 560: A judet type arthroplasty after 2 years. The stem of the prosthesis has broken.The author, in an attempt to overcome these difficulties, revived his earlier apparatus in a modified form (Fig. 561). It was designed to transfer the stress from the cancellous bone of the head of the femur to the dense cortical bone of the shaft. The stainless-steel acetabulum and femoral head fitted accurately. The acetabulum had a flange around it to discourage encroachment by scar tissue, and it was prevented from rotating by three pins projecting from the rim. The head of the prosthesis was hollowed to replace the amount of bone removed, and it had a cutting edge to ensure a close fit with the bone. The stem was 4-flanged to increase its strength, and it fitted into a round hole in the plate so that it could slide outwards should the bone absorb.Fig. 561: A ball-and-cup arthroplasty after 1 year. The stem is sliding outwards showing that the neck is being absorbed. (A posterolateral approach was used with a staple to re-attach the smaller gluteal muscles.)The apparatus was used eight times, but the results were not encouraging. Stability was good in all cases, but there was reasonable movement only in 6; in the other 2 movement was prevented by a great mass of new bone which encircled the joint. In 3 patients the bone absorbed slowly, allowing the stem to slide laterally and project beneath the skin. The results could be regarded as tolerably satisfactory in 2 patients only. Even were the known difficulties overcome, it would still be doubtful if the steel and the bone to which it is attached could withstand for many years the great stresses and strains placed on them. The failed replacement arthroplasty has created a formidable surgical problem, and one that now is only too common. The number of prostheses actually in use cannot be calculated but some idea is given by a survey conducted on behalf of the American Academy of Orthopaedic Surgeons (Lambert, 1956). It was found that 8384 prostheses of thirty varieties had been inserted during the two years October, 1952, to October, 1954, by the 58 per cent of the members of the Academy who answered the questionnaire. The number by now inserted in the whole world may well be over 50,000. The surgical problem arises partly because the head of the femur—Smith-Petersen called it “the working stock”—has been removed and this makes even an arthrodesis exceptionally difficult. Perhaps the most hopeful attempt at solution, at any rate in elderly patients, is to replace the prosthesis with another of the Austin Moore or Frederick Thompson type (Fig. 562). The stresses set up by these appliances are such that both the bone and the metal may be expected to withstand them for quite a long time. They are now in common use not only in attempts at salvage after other kinds of prostheses have failed, but also as a primary operation for the relief of pain in osteo-arthritis. It is said that one manufacturer alone had sold more than 10,000 by the end of 1956.Fig. 562: A Thompson prosthesis inserted in an attempt to salve a failed Judet type arthroplasty.Every surgeon can produce the brilliant results of arthroplasty, but occasional, or even frequent, success is not enough. The operation is intended to relieve pain, not to save life, and the failures are of equal importance. A failed arthroplasty may mean worse pain, greater disability, and perhaps a succession of major operations. Margaret Shepherd (1954), on behalf of the British Orthopaedic Association, made a careful personal examination of a considerable number of patients who had undergone mould and acrylic replacement arthroplasties several centres in Great Britain. She found that, amongst the mould arthroplasties which had been performed 1, 2, 3, and 4 years before, the number of poor results was nearly constant at 30 per cent; amongst those which had been done for 5 years or more, there were over 50 per cent of poor results. Acrylic replacement arthroplasties showed 25 per cent of poor results at 1 year, 30 per cent at 2 years, and 38 per cent at 3 years. The findings in a further survey of these same patients that is now in progress are awaited with great interest. There is a fundamental difference between the Smith-Petersen mould arthroplasty and the replacement procedures. The mould floats freely between the re-fashioned bony surfaces, the intention being to hold them apart whilst they become re-covered with fibrous or cartilaginous tissues. Its function has been regarded as physiological rather than mechanical, but whether this is so or not, it is now clear that the reaction of the body, perhaps not so much to the pressure of the mould as to the somewhat crude attempts of the surgeon to fashion a new joint, is such that the result is not durable. The prosthesis, on the other hand, has a mechanical rather than a physiological function. It is intended to replace a part of the bone that has been excised; it is attached to bone and must remain securely attached for the rest of the patient’s life. But bone is not an inert substance, it is living; it reacts to the new stresses placed upon it and it continues to react for as long as they are present. Like a house built without foundations, a prosthesis fastened to bone must fall in time. A replacement arthroplasty is therefore hard to justify except in the elderly. In younger people, should it be necessary to re-fashion the joint, a mould arthroplasty is still the best operation available. The inevitable difficulties and uncertainties of arthroplasty have increased the popularity, at any rate in Great Britain, of two older procedures-McMurray’s intertrochanteric osteotomy, and excision of the head and neck of the femur as advocated by the late G.R. Girdlestone. INTERTROCHANTERIC (DISPLACEMENT) OSTEOTOMY A few surgeons have remained faithful to this operation since its introduction, but it has only recently come into general use. Interest was stimulated by a paper by Osborne and Fahrni (1950), who re-examined 75 patients operated upon by the late T.P. McMurray and his colleagues from one to twelve years earlier. They found that 80 per cent were nearly or completely relieved of pain and in only a few was movement markedly reduced. Pain had not returned with the passing of time. The operation as originally performed consisted in an osteotomy of the femur sloping obliquely upwards and inwards at an angle of about 40° and terminating just above the lesser trochanter. The lower fragment was displaced inwards so that its inner point lay below the acetabulum, thus restricting adduction. McMurray immobilized the patient in a plaster-of-Paris spica whilst the osteotomy was uniting, but the common practice now is to rely upon some form of internal fixation. The reason why osteotomy should so often give relief from pain, apparently for very many years, has not been satisfactorily explained. Amongst the suggestions are:— The head of the femur gradually rotates to the position in which the capsule is most relaxed thus relieving tension—but success also follows internal fixation of the osteotomy when gradual rotation is prevented. The changed position of the femoral head re-alines the stresses within the bone—but then the pain should return when the bone has become adapted to the changed conditions. The inner angle of the lower fragment abuts against the acetabulum and prevents adduction—but relief often follows osteotomy with little or no displacement. Interruption of the medullary blood-supply to the head of the femur arrests or slows the progress of the arthritis. Whatever the explanation, subsequent series have shown a comparable number of successes. A fair assessment of the results is that half the patients lose nearly all their pain, and a third lose much of it. Those not relieved of pain apparently are made no worse. The operation seems to be so entirely irrational that surgeons have been slow in accepting it, but now that many good and lasting results have been reported it is being used more and more. EXCISION OF THE HEAD AND NECK OF THE FEMUR Excision of the head and neck of the femur was advocated by the late G.R. Girdlestone, but, although he had learnt it from Robert Jones and had practised, it on occasion for many years, his views were not published until 1945. The procedure certainly removes the actual cause of pain, but it does so at the price of stability. Batchelor (1948), in an attempt to improve stability, recommended that an abduction osteotomy of the femur below the lesser trochanter should be performed as well. This modification increases both the severity of the operation and the subsequent period of immobilization; its advantages do not strikingly outweigh its disadvantages. A simple excision of this type is practised not infrequently after a prosthesis has failed, and also to obtain movement when there is bilateral ankylosis of the hips as in Still’s disease and ankylosing spondylitis. A weight-relieving calliper may be necessary at first, but the new scar tissue forming around the pseudo-arthrosis usually becomes strong enough within three to six months to enable it to be dispensed with. A usual result is a comparatively painless and movable hip which permits sitting in comfort and walking a fair distance, but with a Trendelenburg gait and the aid of one stick. ARTHRODESIS The most certain way of getting rid of pain at a joint is to fuse it, because when there is no movement whatsoever there can no longer be pain. The price that must be paid for a stiff hip can be discussed in terms of function and this varies with the age of the patient, his occupation, and the condition of other joints, particularly those of the spine and the knees. The major functions of the hip are:—MATH Walking: The movements of the hips when walking are subtly adjusted in such a way as to ensure that the path followed by the centre of gravity of the body is as straight as possible, and any divergence from this path increases the expenditure of energy (Saunders, Inman, and Eberhart, 1953). Walking on level ground involves not only the major movements of flexion and extension of the hips, but also internal and external rotation, adduction, and abduction at every step. Loss of flexion and extension can be compensated almost completely by movement at the opposite hip, loss of abduction or adduction can be adjusted by flexing one or other knee, but loss of rotation cannot be compensated. A person with a stiff hip therefore walks with only a very slight limp, but he uses rather more energy. Climbing: Walking up a gentle incline is not difficult, but, since the glutei are no longer available to help lift the body, the work has to be done by the quadriceps alone. Going up a steep hill or going upstairs in the ordinary way may be impossible, although it can be accomplished by leading with the sound leg at each step. Sitting: Loss of flexion cannot be compensated at the opposite hip, but it can be to a considerable extent at the lumbar spine, provided the spine is normal. A supple spine permits nearly 90° of flexion; this enables a reasonable sitting posture to be adopted, although at the price of some strain on the intervertebral joints and ligaments. Older people usually have a smaller range of movements at the spine and after arthrodesis sitting upright is correspondingly difficult, but it can be managed by sitting at the edge of the chair. The disability is really grave only for those races who customarily squat on the heels, and for those people whose religious observances call for ritual prostration. Riding, perhaps less important than it was at one time, is possible if only one hip is stiff, but it does mean rather an ugly saddle with a long stirrup on the affected side. Bicycling is usually impossible. Sexual intercourse and parturition, also functions that commonly involve abduction of the hips, are sometimes said to be interfered with, but many women with a stiff hip have both conceived and borne children in the natural way. Bending or stooping to the ground is ordinarily carried out by a combination of movements at the knees, the hips, and the spine. A young person with a flexible spine and one hip fixed in 20° of flexion can usually bend forwards to do up his own shoelaces. Gardeners, even elderly ones, manage to work with their hands at ground level by flexing the opposite knee and hip whilst the affected leg sticks out behind. Regulation of Posture: The curve of the lumbar spine when standing erect depends upon the inclination of the pelvis and this is determined by the position of the hip-joints. A fixed deformity of the hip modifies the position of the pelvis, but this can be compensated within wide limits by a supple spine. A stiff spine is, however, unable to do so and then, if the deformity of the hip is severe, standing and walking are difficult. It is clear that those actions involving progression are interfered with less seriously than those which are comparatively static. A stiff hip therefore tends to be a smaller handicap to the young than to the old because the elderly spend more time sitting (but the occasion of this special number of the Journal calls for notice of a pertinent exception to this generalization!). A young person with a painful hip is usually pleased to exchange it for a painless but stiff one. A girl of 20 who had had several previous operations on her hip, including a mould arthroplasty, wrote, a year after it had been fixed by arthrodesis: “For the first time in my life I am able to lead a normal life like other young people.” Since reasonable function is assured for as long as other joints remain supple, it is not surprising that arthrodesis received early attention from surgeons. The first arthrodeses were performed to stabilize flail joints resulting from infantile paralysis. The scope of the operation was later extended to the treatment of tuberculous disease, the idea being to place the joint at rest without the necessity for prolonged recumbency. Arthrodesis of the hip, to avoid interfering with the diseased area, was by means of an extra-articular, iliofemoral graft. This could not correct deformity, and the graft often failed to fuse at the lower end because the femur was pulled away by the predominating power of the adductors and the adducting force of bearing weight. For the treatment of osteo-arthritis, intra-articular methods were developed. These for the most part consisted in removing the articular cartilage and eburnated bone from both surfaces of the joint followed by prolonged immobilization in a double plaster-of-Paris spica. It was a formidable procedure, and as recently as 1929 Robert Jones, in the standard text-book of the day, relegated the opoeration to small type and described it as “a fairly severe test of endurance of the patient”. Very many different types of arthrodesis have since been described, some intra-articular and some extra-articular. Most of them, for example those of Albee, of Ghormley, and of Hibbs (Fig. 565), made use of iliofemoral grafts; they often failed because of the tendency of the hip to adduct. Brittain (1942) overcame this difficulty by adapting Trumble’s ischiofemoral arthrodesis in such a way that adduction compressed the graft and therefore assisted fusion. However, this operation like the others, was necessarily followed by prolonged recumbency in a plaster spica.Fig. 565: Types of arthrodesis.The next step followed naturally on the development of the technique for the internal fixation of transcervical fractures of the neck of the femur by Smith-Petersen and Sven Johannsen in the late nineteen-twenties and early thirties. The obvious thing was to drive a trifin nail across the joint into the iliuM in the hope that it would resist the adducting forces acting on the joint. The first occasion on which the author attempted this, after excising the joint, was in 1933, and he has used the method, or a modification of it, ever since. The operation was developed independently by Burns (1936), and also by Watson-Jones (1938), who had an extra long and strong trifin nail made especially for the purpose. The advantage of internal fixation is that it facilitates fusion by preventing adduction and nearly abolishing all other movement between the raw bony surfaces. The bone, however, reacts in the ordinary way to the presence of metal under stress and undergoes absorption. A trifin nail is therefore unable to fix a joint indefinitely, but it does immobilize it for long enough to enable cancellous bony surfaces to fuse. The author’s operation is intended firstly to promote fusion by bringing large areas of cancellous bone into close apposition, secondly to incorporate a graft including cortical bone which quickly thickens to give strength, and thirdly to prevent movement by means of internal fixation whilst fusion is taking place (Fig. 566). To this end the articular cartilage and cortical bone are removed from the head of the femur and acetabulum, preferably after dislocating the hip, but if necessary without doing so. A graft is cut from the outer table of the concavity of the ilium where the curve allows it to be moved downwards to overlap the neck of the femur. This both increases the area of cancellous bone in opposition and provides cortical bone. Internal fixation is by means of a Watson-Jones trifin nail driven through the neck of the femur into the ilium. The nail prevents abduction and adduction until union has occurred. It does not, however, give any good protection against flexion because the outer, cortical surface of the shaft of the femur is splintered when the nail is introduced, the almost hollow neck gives it no support, and there is only the cancellous and possibly cystic head to prevent the femur rotating around the long axis of the nail. A short plaster-of-Paris spica is therefore applied for additional security in most cases. The spica need not, as a rule, extend below the knee, hence it does not cause stiffness of that joint, nor does it prevent the patient from being lifted into a chair soon after operation, or from walking after a few weeks.Fig. 566: Wiles’s arthrodesis.The details of the operation are varied according to the age and general condition of the patient, and the condition of the bone. Very few people are too frail to be subjected