There's arthritis, and then there's arthritis. Anyone who complains to an orthopedist about pain risks hearing the dreaded, "It's age appropriate." Point is, after a certain age we all have some arthritis symptoms. Some much worse than others. In most cases it shouldn't prevent cycling. Take the medicine you need and can tolerate. Make the adjustments you have to such as more relaxed position. Invoke any other tricks you can like looser shoes, etc. But don't, I repeat, don't stop riding until it is the last resort. Have fun!