India is in many ways is the ARTHRITIS CAPITAL OF THE WORLD. More people needing knee replacement here than anywhere else in the world. For people considering knee replacement surgery, it’s something they want — and need — to know.
When Joint Replacement surgeries were first performed in the early 1970s, it was thought that the average artificial joint would last approximately 10 years. Most current data suggests that knee replacements have an annual failure rate between 0.5-1.0%. This means that if you have your total joint replaced today, you have a 90-95% chance that your joint will last 10 years. 80-85% that it will last 20 years and beyond. With improvements in technology, these numbers may improve. Improvements in surgical technique and artificial joint materials should make these implants last even longer.
There’s no knee replacement guarantee
Unfortunately, no one can be sure that a knee replacement will be the last operation needed on that joint. No operation is 100% successful, and nothing lasts forever. In addition, a number of factors, including surgical technique, type of implant and surgeon and patient factors (including age, weight and activity level) can all have powerful effects on how long a replaced joint lasts.
Considering average age of patients coming forward for having their knees and hips replaced is decreasing, more active patients are seeking this as a treatment for their joint pains. With these patients, the stress and demands placed on a joint replaced are higher, and there is more of a chance of further surgery being necessary. Same implant in an older person will generally be subjected to less load or aggressive activity, hence will last longer.
Three factors play the largest role in knee implant longevity
Weight, activity, and implant type have the most significant impact on how long a knee replacement will last. There is significant controversy about what activities should be performed by patients who have a knee replacement. It is known that some strenuous activities, including impact sports, skiing, and any activity requiring running and jumping. These can create stress on the implants that may lead to early failure of the implanted joint. While many patients do these activities, there is some good evidence that this may lead to faster wearing on the implanted knee joint. Low impact activities like treadmill, walking, bicycling, elliptical or swimming, on the other hand, are fine.
The chances of needing another operation is greater if you’re overweight and/or involved in heavy manual work
Setting reasonable expectations
“We tell patients to expect 20 to 25 years on their new knee,” provided best implant biomaterials and alignment are achieved. We may have more time if activity level doesn’t put demands on the implant. For patients who are at least 60 years of age, a knee replacement will probably last for a lifetime. Unfortunately, not every implant lasts a patient’s lifetime, and a second surgery called Revision Joint Replacement can be needed subsequently.
30 year wear performance
One of the most important aspects of ensuring an artificial joint will last as long as possible is a precise, accurate surgery. Having a properly aligned joint replacement is critical to the long-term functioning of the implant.
A good analogy is to think of the tires on your car. It does not matter what brand of tyres you put on the car, if the wheels are not properly aligned, they’re not going to last.
This knee replacement wear performance more than 30 years is a concept which is beyond just purely an implant (ceramic/verilast/gold). It’s biomaterials, accuracy, alignment, sizing, technology and conglomeration of all these is the answer for a joint replacement which is biological, gives wear performance around 30 years.
While these newer implants may be better, it is also important to understand that long-term data on how well these implants will function over time is also needed.