I can only tell you what my orthopedist told me when I blew out my Achilles last year. Basically he told me that steroid injections cut down on the swelling, which reduces the pain, but slows the healing at the same time, so you feel better, but the tendon isn't really getting better. I had a partial Achilles rupture right at the heelbone, calcification down near the distal end of the tendon, and two heel spurs, one at the top, the other at the back. I had two options.
First, I could keep my foot booted until enough scar tissue formed around the point of the rupture to allow me to walk again(about 6 weeks). That would allow the tendon to restore a bit of mobility back, but the flexibility issues I had with the foot would still be there, and there was a 30%+ chance that I would have a full rupture sometime in the future.
The option I went with was to go the surgical route. All the calcification was be removed from my Achilles, the tendon was detached, the bones spurs removed, and then anchored back into the heelbone, and the FHL tendon from my big toe was removed at the toe end, and attached into my heelbone to give the Achilles a bit more support. All the flexibility was restored, and then some, but the recovery time was much, much longer. I am still recovering my strength in the calf muscle almost 10mos after surgery, but I have no pain in the ankle at all, and the flexibility is actually better than the good leg.
I'm not sure what an orthopedist would do with the knee, but if you haven't ruptured the tendon, I doubt they'd want go in and do surgery unless you actually had a rupture.