The first triathlete I met with a total knee in place was during the marathon portion of the 1982 Ironman. (In those days it was the Bud Light Ironman Triathlon World Championship. It was the only one on earth. There were 969 competitors in the race program, Scott Tinley wearing #1. Guess what they served at the aid stations.) Not knowing any better, I was run/walking from 13 miles on in, with two other equally spent athletes. If you've never done it, there's more time than you realize to talk with your new found friends. For some reason, the subject of my service in Vietnam came up and one of my walking mates admitted to a gun shot wound to the knee with subsequent joint replacement. I was flabbergasted! I'd been taught that joint replacement was for the bocci set at the nursing home and here's this guy next to me with one...who's probably going to beat me to the Ironman finish line! Well, maybe.
As you'd suspect, I've learned of many in our sport with artificial joints since.
So how do you and your doctor make the decision about triathlon after surgery? It's not an easy one and there's no right answer for everyone. On one hand we have...the past. Two week hospitalization after surgery, traction and sometimes a delay in weight bearing, absolutely no sports noting that the literature is rife with joint replacement in the young athlete who was too frisky failing at 10 years requiring another, more difficult, operation.
Then, we have the present. Short post operative stay, as little as over night, immediate full weight bearing, improved components and techniques, both full and half joint replacements, decades of experience on dealing with the stresses that an artificial joint sees.
Many currently feel that a strong muscular envelope around the hip or knee absorbs forces which may previously been born by the joint itself. They also may contribute to assisting the tracking and joint function helping normalizing ones gait and joint function. They go on to report that you'd try to run with normal/excellent form on forgiving surfaces with 2018 stress absorbing footwear. You still understand that in some they're risking early revision surgery but others feel that to continue the sport they love at this point in their life, it's well worth the risk.