The number of years that an artificial hip is expected to last varies depending on a number of factors, including the material being used and the amount of stress being placed on the new hip.
Joint replacement surgeons began using newer plastic materials in the year 2000, so right now we only have around 16 years worth of data to look at. What we are seeing is that newer hip replacements have a very long lifespan and most patients can expect that their artificial hips are not going to wear out in their lifetimes.
The latest research, presented at the orthopaedic academy meeting this year, indicates that average wear rates for hip replacements are as low as .1 millimeter per year. Current survival rates, barring any post-surgical complications, are greater than 95% at 15 years, which puts us on track for a 20 to 30 year lifespan for most modern hip replacements. The average person undergoing total hip replacement surgery is 65 years old, and they can expect to get 20 years or longer out of their artificial hips.
The weak link in hip replacement is the plastic liner inside of the cup, which we expect to wear out with time. Just like the miles on a car, the more miles patients put on their artificial hips the quicker they will wear out.
Patients play an important role in helping to extend the lifespan of their artificial hips. One thing I always talk to patients about in the office—and this is something I have also written about in my book, Life After Hip Replacement: A Complete Guide to Recovery & Rehabilitation—is the advertised “30-Year Hip.”
The concept of the “30-Year Hip” is based on laboratory studies with 45 million simulated walking cycles. Over these 45 million simulated cycles, the plastic and mechanics of the artificial hip were maintained reliably, which led researchers to qualify that as the “30-Year Hip.”
My concern is that we don’t all take the same number of steps each day. If you average 45 million walking cycles out over 30 years, that leaves you with approximately 4,250 steps per day. In the FitBit era, where the American Heart Association recommends 10,000 steps per day, 45 million cycles lasts just over 12 years. So again, how long your artificial hips will last is directly correlated with how much wear is placed on them.
To make artificial hips last longer, most orthopaedic surgeons now recommend following a series of defined protocols. Specifically, patients who have undergone hip replacement surgery are advised to avoid repetitive, high-impact activities. They should also be mindful of the types of exercises they do. I recommend sticking to low-impact exercises, such as bicycling, swimming, elliptical machines, and long walks.
I plan to discuss this topic in further detail at the hip and knee pain seminar hosted by Shasta Orthopaedics on Wednesday, May 11th. You can click here to learn more information about the seminar, along with a link to reserve your seat. I hope to see you there.