but the sentence prior says "it restores protective processes to diseased joints and enables the regeneration of affected tissues." I don't understand how it does if it's just blocking pain signals.

I don’t know about this case, but in general, the body’s reaction to pain sometimes makes things worse, so relieving pain can be part of encouraging recovery.

Degenerative diseases don’t de-pathologise when you remove their pain

Pathways that remove pain can be due to healing though, it's a mildly positive indicator.

This is at best a fallacy with occasional exceptions and in this particular case, just plain incorrect.

If it works by 'blocking a compound that supports nerve cells in transmitting pain' it isn't doing anything to correct the pathology. You are, in the truest sense of the way that people naively talk in derogatory terms around modern medicine, 'treating the result, not the cause'

It's definitely not a fallacy that things that relieve pain can also help heal or prevent damage, NSAIDs are a great example. It mentions it may do more than just blocking the signal in the article.