Tendonitis

When my calendar item on “issues” vs. “problems” was sent out recently I expected someone to challenge my spelling of “tendonitis.” The older and more technical spelling of the term is “tendinitis.” But the “O” spelling has also been around in formal medical writing since the mid-20th century.

It has the advantage of being obviously related to “tendon,” so I’ve decided to stick with it. Most dictionaries now accept both spellings.

But you shouldn’t be surprised if you see it spelled “tendinitis.”