There’s no doubt that replacing the cartilage in hip or knee joints that’s been worn away by osteoarthritis with an artificial joint has transformed the life of many older people who would otherwise be confined to a wheelchair.
Hip replacement is now thought to be the most common form of surgery in the UK. However, there’s a catch – and it’s not just the long waiting lists for the procedure on the NHS. You might not think such a commonly performed operation could turn into a walking time-bomb, but varying surgical standards and the use of unproven materials are being blamed for hip replacements wearing out, and a wide range of life-threatening side effects – from chronic infection to cancer and thrombosis.
Advancements in surgical diagnosis, such as arthroscopy, whereby a fibre optic lens is inserted into a joint to help diagnose the damage and assist doctors in making recommendations, are far less invasive than the old-style ‘let’s cut you open and see’ approach. Even so, having surgery is certainly not a choice for anyone to make lightly. A 2013 study conducted as part of the series ‘When Health Care Makes You Sick’ by USA Today found that unnecessary surgeries might account for 10 to 20 per cent of all operations – especially in the medical specialities.
Arthroscopic surgery is the most common surgical procedure orthopaedic surgeons use to visualize, diagnose and treat problems inside a joint. It’s most frequently performed on the knee and shoulder joints, less commonly on the hip, wrist, elbow and ankle. The reason the knee and shoulder are the most usually arthroscoped joints is that they are large enough for surgeons to manoeuvre the instruments around, and thus are more accessible to arthroscopic treatment.
In an arthroscopic examination, an orthopaedic surgeon makes a small incision and inserts a small camera lens and fibre-optic lighting system inside the joint to magnify and illuminate the cartilage and ligaments and other structures, displaying them for the doctor on a TV or computer monitor.
Even if the doctor does nothing but an exploration, after this type of surgery it takes several weeks for the joint to recover fully. A specific activity and rehabilitation programme may be suggested to speed recovery and protect future joint function.
A synovectomy commonly accompanies arthroscopy. This is performed to partially or completely remove the synovial membrane of a joint, with the aim of reducing the pain and swelling of rheumatoid arthritis and slowing the destruction of joints. However, this is usually a temporary measure: the synovium often grows back several years after surgery and the problem can happen again.
In mild cases, shoulder (glenohumeral) arthritis may be treated with arthroscopy. During the procedure the inside of the joint is debrided (cleaned out). But again, further surgery is often required.
Arthroscopic joint debridement is a minimally invasive surgery to the lining of joints, including the ankle joint (an area commonly affected by arthritis), where areas of loose, ‘mechanically redundant’ cartilage and inflamed tissue (synovitis) are removed from the joint. Loose fragments of bone within the joint and even bone ‘spurs’ (osteophytes) at the front of the joint can also be removed. Usually this procedure is useful only for patients with mild-to-moderate arthritis where the symptoms are not too severe and sufficient joint space shows up on X-rays.
Arthroscopic surgery is carried out around 650,000 times a year in the USA alone, and is the last option before knee replacement surgery for osteoarthritis sufferers. Around half the patients say they feel a big improvement in pain levels and movement afterwards,1 although there’s never been evidence to suggest the procedure either cures or arrests the osteoarthritic process. In fact, in a study of 180 patients, researchers discovered that surgery is no better than a placebo. In other words, patients who underwent ‘dummy’ surgery, during which nothing was done to them, reported the same benefits as those who’d received the full arthroscopic treatment.2
Joint replacement, or ‘arthroplasty’ as doctors term it, is justifiably regarded as miracle surgery. In the case of a hip replacement, the ball-and-socket joint of the hip, worn away by osteoarthritis, is replaced with an artificial joint made of a mix of metal and polyethylene (plastic).
During surgery, the surgeon removes the top of the femur (thigh bone) and replaces it with a metal ball attached to a long metal stem that is inserted into the hollow middle of the thigh bone. He then replaces the worn cup-like socket (acetabulum) of the pelvic bone – into which the rounded head of the femur fits, making up the hip joint – with a plastic or metal cup with a plastic lining.
These days, surgeons often use cementless metal balls in the thigh bone, relying instead on the porous metal titanium to adhere to the bone, and manufacturers are also experimenting with metal-on-metal components (a mix of cobalt–chromium and molybdenum alloys) to avoid the wear and tear seen with plastic components in the hope that these types of replacement hips will last longer and so be of use in younger patients.
The operation has become routine for most orthopaedic surgeons, who boast success rates of 98 per cent. Indeed, the age at which patients are recommended for such a hip op is spiralling downward: in one recent study, the median patient’s age was 48.
Total hip replacement, invented in 1962 by English country orthopaedic surgeon John Charnley, has gone on to become one of the great surgical feats of the last century. It’s now estimated that 10 per cent of people over 65 have a hip replacement, making it the most common form of surgery in the UK.
However, that 98 per cent success rate refers to the number of patients who are wheeled out of surgery alive with the new hip intact. It doesn’t cover the casualties that occur subsequently, which can range from death to a permanent abnormal gait or lifelong illness. Particularly if you’re young, you should know about these possible side effects before you agree to the operation.
If an operation goes wrong, you could:
Die within a few months: According to one study, the death rate after just one month was 0.29 per cent, or 290 deaths out of every 100,000 operations. A review of the Norwegian Arthroplasty Register found a mortality rate of around 15 per cent (6,201 deaths out of 39,543 patients); of those deaths, 323 (about 5 per cent) occurred within the first 60 days after surgery. Overall, there was a 39 per cent greater mortality than expected in the general population.3
Develop venous thrombosis: This is a major risk after hip and knee surgery. Non-fatal venous thrombo-embolism after surgery – when a clot dislodges from a leg or lung vein and causes blockage in another part of the circulation, often an artery going to your lungs – occurs in one in 32 patients; fatal pulmonary embolism befalls around one in 100 patients. Those having knee replacement surgery had double the risk of deep vein thrombosis in the week following surgery than those undergoing hip replacement.4
Suffer from chip-off debris, resulting in autoimmune disease: The friction caused by the metal ball rubbing against the polyethylene socket lining causes small plastic or metal particles to flake off.
The body’s immune system sees these particles as foreign invaders and attacks them – and because the particles typically settle near the implant, the immune system will also attack the surrounding bone (osteolysis). As bone loss occurs, the hip implant loosens and begins to function improperly. Osteolysis is considered the number one reason for implant failure and the need for a repeat operation.
A group of researchers called the Bristol Wear Debris Analysis Team discovered that in some cases particles of metals like nickel, chrome, titanium and cobalt, and even the bone cement (which contains hard ceramic particles of barium sulphate or zirconia), had worked their way from the hip joint to the liver, spleen, lymph nodes and bone marrow.
The greatest particle migrations were seen in those whose joint replacements were loose and worn, where the main problem was the matte coating used in the joint. In one patient, the level of cobalt found in the bone marrow was several thousands of times higher than normal.5 In the case of a Frenchman complaining of weight loss and fatigue, wear debris had travelled into his spleen and liver eight years after surgery.6
Have the hip dislocate: This can happen either immediately or later, requiring repeat surgery.
End up with one leg appreciably shorter than the other: If the joint surface needs to be fused, as happens after some failed operations, you can end up with one leg as much as two to three inches shorter than the other.7 This may happen in any case as many surgeons, to stabilize the hip so that it won’t dislocate, deliberately make one leg a bit longer or shorter.
Eventually need a replacement: In other words, have the artificial hip replaced with a new one. After 10–15 years, the hip will be worn and in need of ‘revision’ – a replacement hip joint. This is a far more formidable operation, requiring the removal of more bone and tissue, and has a far lower success rate. If you’re under 60, you face having to undergo several more revision operations in your lifetime.
Suffer damage to the sciatic nerve: This is the large nerve that runs down your leg. Repair neurosurgery has a poor success rate.
Develop cancer near the implant site: One study found associations between cancer of the lymph nodes and leukaemia, and hip replacement.8 In a recent survey of 116,727 hip-replacement patients in Sweden, there was evidence of increased risks of melanoma (skin cancer), prostate cancer, multiple myeloma (bone marrow cancer) and bladder cancer.9
Do whatever you can to avoid surgery by treating your osteoarthritis holistically (see Chapters 7–10). Think twice about going under the knife, especially if you are under 60: if you do have surgery below this age, it’s extremely likely that you’ll need a revision in your lifetime. But if you must have joint replacement surgery:
Use the cementless variety of ball-and-socket replacement if your bones are strong.
Insist on a hospital and a surgeon with a long and successful track record in performing this particular operation.
Opt for tried-and-tested materials. At the last count, there were more than 60 brands of artificial hips. In a 1998 health technology assessment of all research on the various hip brands, the lowest revision rates were seen with the Exeter, Lubinus and Charnley prostheses. In fact, in one study, two-thirds of Charnley prostheses, among the oldest and best-tested models, were still operational after 25 years.10 Another good performer is the Stanmore.11 More recently, metal-on-metal stemmed prostheses had higher failure rates than other types, and using them in combination with large head sizes led to particularly high rates of revision surgery in men and women up to 6 per cent of the time. The metal-on-polyethylene devices with 28mm head sizes had the lowest revision rates for women (1.6 per cent at five years), while the ceramic-on-ceramic with larger (40mm) head sizes proved the best option for men over 60 (with revision rates of 2 per cent at five years).12
Among the cementless varieties, the AML Total Hip Replacement is the most widely used model in the world. The lowest wear rate, as of the year 2000, was with metal-on-metal (alumina-on-alumina).13 More recent research suggests that devices using highly cross-linked polyethylene cup liners are the most durable and cost-effective for most patients.14
Avoid these products: hip prostheses made from zirconia ceramic, hydroxyapatite(HA)-coated total hip replacements with a thin polyethylene inlay, and the W Hex Loc cementless hip socket.15
Besides hips, other joints such as the knees, shoulders, elbows, ankles and knuckles may also be replaced. Like hip replacement surgery, knee replacement surgery is the last resort when pain and immobility have become too great, and, like hip replacement, is performed under a general anaesthesia. In the operation, the surgeon removes the damaged cartilage (the soft lining of the joint), plus a small amount of bone. An artificial joint made of metal and polyethylene is cemented into place. A patient with no complications usually spends around five days in hospital, and a month recuperating at home, returning to normal activity over the course of two to three months.
The medical research paints a glowing picture of knee replacement, claiming that 95 per cent of knee operations using cement are successful (that is, have no complications) for at least a decade. According to a review of 130 studies,16 89 per cent of knee replacements have a good outcome over an average follow-up period of more than four years, and the majority of knee replacements remain functional for at least 10 years.
However, that sterling track record refers simply to knee replacements that ‘take’, and omits all the problems that could occur. The above-mentioned review came up with an overall complication rate of 18 per cent among those studies that reported on complications, including superficial infections, deep infections, pulmonary embolism (a blockage in a vein in the lung), deep venous thrombosis (blood clot in a vein) and nerve damage to a limb.
There are also admittedly small risks of other nerve or artery injury, permanent foot injury or, the worst-case scenario, loss of the limb. Complications can mean the patient is in hospital for a longer period of time and can even be subject to repeated operations.
Since the 1980s, medical technology firms have been trying to fix artificial knees biologically to bone via little metal beads or mesh.
But these ‘uncemented porous-coated knee replacements’ haven’t been as successful as the cemented joints. According to one of many studies demonstrating this in the prestigious Journal of Bone and Joint Surgery (July 1991), out of 96 patients undergoing 108 replacements, about a fifth had failed owing to problems with the lower leg component. After seven years, more than half of these replacements were recommended for revision.17
As with hip replacements, it’s important to understand that the knee will never be as good as new. Although such an operation may (though it may not) end chronic pain and enable you to move, doctors recognize that nothing artificial can match the versatility of a human joint. As with hip replacements, you need to hold off such an operation for as long as you can, because an artificial knee will only last about a decade before becoming fatigued; and at that point, you’ll have to replace the knee replacement – a more formidable operation, with far more bone loss, removal of scarred tissue and a far lower success rate.
Perhaps dazzled by the success rate, doctors are too quick to replace knees. A new study has discovered that approximately one third of knee replacements in arthritis sufferers shouldn’t have happened in the first place. And the need for such surgery was inconclusive in a further 22 per cent of cases, which suggests that potentially more than half of all total knee replacement procedures are dubious. Since approximately 600,000 knee replacements are done in the USA every year, more than 200,000 were unnecessary if these research findings are to be believed.18
Only 44 per cent of procedures were fully justified, say researchers from the Virginia Commonwealth University in the USA, after analysing 205 cases of total knee replacements.
All this suggests that anyone suffering with debilitating pain from arthritis (either rheumatoid or osteoarthritis) should consider knee replacement only if they’ve tried non-surgical approaches and failed.
Ankle fusion is called arthrodesis of the ankle: the bones of the ankle joint are fused together, fixing the ankle completely in one position. Currently considered the gold-standard surgical treatment for managing patients with advanced ankle arthritis, its main objective is to relieve pain and improve overall function.19 However, the procedure is technically complicated, often involving metal plates and screws to keep the bones in place, and the results vary widely.20 There’s also a high incidence of complications, so you’d be right to think twice before going under the knife.
One of the most common adverse consequences of ankle arthrodesis is non-union, when the bones fail to fuse, with reported fail rates as high as 40 per cent.21 However, one review claims that these rates are steadily declining with the development of more advanced techniques.22
Nevertheless, if arthrodesis fails, a further operation is usually required and, if unsuccessful, may in some cases lead to amputation.23 Another problem with arthrodesis is that, to compensate for the lack of ankle movement, the other joints have to move much more, creating excess strain on those joints and, in the long run, more pain and disability. Indeed, one arthrodesis follow-up survey concluded bleakly: ‘Although ankle arthrodesis may provide good early relief of pain, it is associated with premature deterioration of other joints of the foot and eventual arthritis, pain, and dysfunction.’24
Other studies report that ankle-fusion patients tend to develop pain and moderate to severe arthritis in the joints of the foot.25 This suggests that arthrodesis merely shifts the problem from one set of joints to another.
If this isn’t enough to put you off, there are a number of other risks from surgery to consider, including deep infection, malunion (the bones fusing in an imperfect position), delayed healing of the wound, stress fracture, neurovascular injury and deep vein thrombosis.26 You should also bear in mind that your gait will be permanently altered, and it’s likely that you’ll have to wear special footwear afterwards.27
One other surgical risk worth is noting. Early anterior cruciate ligament (ACL) surgery performed on a teenager after knee injury is being recognized as a likely cause of osteoarthritis in later life. A study has found that around 65 per cent of patients suffered from arthritis of the knee within 20 years of having the surgery.28 If your teenager injures himself or herself playing sport and ends up with a ruptured ACL, consider a stem-cell procedure (see Chapter 11) or even just exercise rehabilitation with a fully qualified physiotherapist, with experience of rehabilitating people with unreconstructed ACLs. Many physios now recognize that it is possible develop enough muscle strength to compensate for not having a functioning ACL.
The bottom line is this: surgery can help elderly people regain mobility when there’s no other alternative to a wheelchair. However, for everyone else, it makes sense to do everything possible to avoid going under the knife, because in many instances surgery is no better than a placebo.
Consider the work of Dr Bruce Moseley, a specialist in orthopaedics at the Baylor College of Medicine in Houston, who tested 180 patients with severe osteoarthritis of the knee, dividing them into three groups. One group was given arthroscopic lavage (which washes away degenerative tissue and debris with the aid of a little viewing tube). Another received another form of debridement (removal of fronds of joint material by sucking them out with a tiny vacuum system). The third group was given a sham operation: patients were surgically prepared, placed under anaesthesia and wheeled into the operating room; incisions were made in their knees, but no actual procedure was carried out.
Over the next two years, during which time none of the patients knew who’d received the real operations and who’d received the sham treatment, all three groups reported moderate improvement in pain and function. In fact, the placebo group reported better results than some who’d received the actual operation.29 The mental expectation of healing was enough to marshal the body’s healing mechanisms. The intention, brought about by the expectation of a successful operation, produced the physical improvements, not the surgery itself.