I have the Centurion handheld Laser shower. My old hunter had one front leg with an old knee injury that left scar tissue across the front of it. Using the laser, I really noticed that it helped soften it up and decrease in size. He was always sound on it, but this made a difference in increasing the flexion. I love it! Oh and this was an old injury to boot.
Yes, on a bone cyst/lesion in the stifle, on a 2 yo.
I can't say for sure it was what did it, but all I know is after everything else (treatment wise) being the same for 30 days, then the laser starting, she started to improve, lameness going away, which eventually completely resolved.
I think it can be useful for tendon/ligament problems. But, I think your results vary greatly on the type & quality of the laser used and you obviously need to have someone with experience, who knows what they are doing.
Tom Meyers, who works on Steffen Peters' horses, uses a Respond brand laser as part of his treatments.