There is research regarding THCV and its use for inflammation and related pain. You can do a google search for "THCV pain" and read some of the research. High THCV strains would be African sativas. Ethiopian contains decent levels of THCV.
Try Diet Durbin THCV:THC. Aprox 7% THCV, 7%THC, and 2 - 5 % CBD. I have one indoor plant growing now to test, 19 more seeds for outside.
For pain relief, arthritis in particular, I use ANY good strain. I haven't found any difference. Just infuse coconut oil and add one tablespoon of DMSO per cup of oil. Rub it on and (at lest for me) the pain is gone. Be sure to be clean before using it because DMSO can carry bacteria thru your skin just like it does the THC.
We are looking for several good uses for this strain, diabetes, pain, and not only inflammation but swelling from injuries.
Anyhow, with super good harvests the last two years we are only going to grow the Diet Durbin next year.
In short, for your arthritis pain, this is simple and it works, and I've used any available bud to make it. It just doesn't seem to matter.