Give a f***x wrote:
A tendon doesn't sublux. It rolls over the malleolus. It's not an injury. Cool.
The peroneal tendons can, indeed, experience subluxation when the superior peroneal retinaculum (the tissue keeping the two tendons in place behind the malleolus) has weakened/torn. I suffered from this, as well as a longitudinal split torn peroneus brevis tendon. Reconstructive surgery was required for me, which included repairing the torn tendon, drilling behind my fibular to make the retromalleolar groove deeper, and repairing the retinaculum. I was non-weightbearing for over two months on that leg (splint followed by cast followed by boot). Here's one article (of many out there) from the Journal of Bone & Joint Surgery:
http://jbjs.org/content/90/2/404Having said that, if you don't have pain, you might have caught it early and a proactive boot/cast situation might keep you from needing surgery. Some people have subluxating tendons their whole lives and never have a real issue with it. I was having pain, as well as major compensation issues elsewhere. Kept me from running at all. The good news, is that after a lengthy rehab, I'm back to 100%.
Good luck!