Stubborn rear foot and heel pain following ankle surgery (Read 23 times)

There is a lot of back story here, but I will try my best to keep things brief.
30ish years ago, when I was in jr high, I had implants placed in my subtalar joint to "correct" flat feet. I was never told that the implants should have come out when I finished growing. Fast forward to more or less present day and the left implant decided to launch an attack - essentially a foreign body response. I ended up having the implant removed and required a bone graft to repair the damage. I had the same procedure on my right ankle (thought the damage was not nearly as extensive) as soon as I could bear weight on my left to create one long recovery period. Surgeries were in late October (left) and mid December (right). The good news is I am walking on two feet and my right ankle is doing quite well. The bad news is my left is struggling. The pain is not in the joint (which is reassuring) but rather along either side of the achilles (not the tendon itself) and down into the heel. It's quite a sharp pain and is really limiting my progress. And it's KILLING me mentally. It's worse when I wear shoes, less when I don't. We have determined that it's not plantar fasciitis. Also, I cannot do a single leg calf raise. Like at all. No matter how hard I think about it, the leg won't even budge in that direction. I can do double calf raise and can do single if I take a fair amount of the weight burden with my arms. So I know the motion can happen and there is some muscle strength there.

I should also note that the left ankle was in a brace for about 5 months prior to surgery. 
Any orthos or PTs out there have thoughts on what may be going on? Or ideas on what to try or focus on?
TYIA