In these days of angst about health care and its costs, I am reminded of a medical school professor who told his students that all surgery was optional. Without surgery, he said, some people would die prematurely and some would have miserable lives, but the human race would survive.  He was right. Surgery benefits individuals, not populations, and all surgery falls into one of two categories – those procedures, like appendectomies and C-sections, which rescue individuals from premature death, or those like joint replacements, which improve individual quality of life.

Artificial joints

The forerunners of joint replacements were wooden legs – the crude mechanical approximations of limbs torn asunder by accidents and war.  Fast forward a few hundred years, through remarkable developments in materials science, anesthesia and infection control, and we have slick titanium or ceramic implants that replace joints worn down by modern life. Hip and knee replacements, procedures which began in earnest in the 1960s, are safe and effective. Currently it is estimated that over 300,000 hips are replaced in the United states alone each year. In most people, even the very elderly, they return mobility and help maintain independence.

Costly and difficult substitutes for nature

As good as these artificial parts are, they are still less than perfect substitutes for your native joints.  Joint replacement is irreversible, initially painful, and potentially risky.  Good results require serious commitment to rehabilitation – more exercise than some people have ever engaged in.  Already major consumers of the health care dollar, hip and knee replacements are set to explode budgets as our obese population ages and wears out weight bearing joints.  Between 1997 and 2004, private insurance layouts climbed from $1.1 billion to $3 billion for new hips and from $1.46 billion to $4.64 billion for new knees. These figures don’t include Medicare expenditures, which are the principle source of payment, and constitute over 20% of Medicare outlays.  Limits may be imposed by available surgeons trained to do these procedures, a number already in decline and not expected to increase over the next decade. If you are in possession of good joints, try to hang on to them for as long as possible. Maintain normal weight, don’t smoke, and work on strength and flexibility of trunk and limbs.

Deciding to replace a joint

The decision to replace a hip or knee usually comes after years of declining physical activity and escalating anti-inflammatory and pain medication use. At times a decision is forced on a patient as treatment for a hip fracture, but ideally the surgery is an elective procedure decided upon by a patient, along with a doctor who knows him well and understands all his other medical problems. Time spent researching surgeons and hospitals and settling upon those with good results is worthwhile. Sometimes a decision can be delayed by opting for steroid injections, but they weaken connective tissue and cannot be repeated indefinitely. Delaying too long, however, might influence results. Some studies show worse functional outcomes after knee or hip replacements in more debilitated patients.

On the replacement road

Whatever way it happens, once the road to hip or knee replacement is undertaken, the orthopedic team and patient travel as close companions. Careful adherence by the patient to all instructions and advice insures the best possible outcome, and good communication from the doctors, nurses and therapists encourages patient cooperation. Work starts well before the surgery. Painful knees and hips are often housed in bodies that are overweight and out of shape. The difficult job of getting a new joint moving is easier if muscles have been in training pre-operatively.  And the more weight that can be shed ahead of time, the less the strain on bone and muscle as they attempt to hold a new joint in place.

Immediately after surgery, mobilization begins. First comes sitting up, getting out of bed, and walking with assistance – as soon as tolerable and with whatever restrictions needed to protect the new joint. Supervised therapy sessions, starting within the first few days, aim at moving the new joint through larger ranges of motion without endangering its stability. Every encouragement to move and every caution about how one moves (such as the prohibition against leg crossing) is important.

Potential problems

The push to get patients moving and the precautions about how they move are important for preventing two of the biggest complications of lower extremity joint replacement: blood clots in the legs (with potentially catastrophic migration to the lungs) and dislocation of the hip (slipping of the ball of the new hip out of the socket).  The most feared complication, infection, prompts meticulous wound care and surveillance for other infections. A brief stay in a transitional care facility, if recommended, is beneficial. Therapy occurs in well-equipped spaces several times a day and gets the long-term recovery off to a good start, and medical supervision is close at hand. Most people will also need home help for a month or more, as well as continued outpatient physical therapy.

The long run

If joint replacements are so advanced and helpful, why suffer with bad knees and hips at all? There are many joint replacements being done at younger and younger ages, but the fact remains that artificial joints have a limited  – though quite long – life span,  in the range of 15-20 years, though as advances are made, these figures may stretch out. Some people are still walking well on their first new joints at the 25 year mark.  But artificial materials  will eventually suffer wear, and there is an additional problem of the prosthesis loosening in the bone, a process that is not entirely understood. Replace a joint at age 65 and it may well last until life’s end. Replace one at 45 and you may be looking at a second period of disabling pain followed by a redo of the replacement, but this time in an older bone already altered by the first procedure. Opting for a new knee or hip is a decision that warrants careful, educated and open-eyed assessment of short and long-term risks and benefits, but as quality of life surgery goes, these procedures are among the most useful.