Yes, I had a case of this many years ago. An old racehorse who was given to me as a hunter/jumper prospect off the track. He had had ankle problems in the last few years of his race career, and had been cortisoned a number of times. But his ankles themselves were not the problem, it was the calcification in the suspensory ligament that continued to plague him. We found that on xray, when the intermittant lameness got to the point that we needed to find out if he was going to be sound enough to jump. Vet panned the horse as a jumping prospect, and he went on to do some dressage for a few years, on maintenance bute. But even with that lifestyle and medication, his situation deteriorated over the next few years, and he was put down. He was a great horse, lovely mover, and had good jumping ability when I had him. There is little I can think of in terms of newer medications that may be helpful for this condition.
The stretching of the ligaments eventually results in calcium deposits in those ligaments. At that point they lose their elasticity, and do not function correctly, and pain and inflammation is chronic. Pain and inflammation management is about the only option along with modified expecations of the amount of work the horse can participate in, and when this management can no longer be effective, call it quits with the horse, and put him down. As always with a problem like this, it is a "wait and see" situation, dependant on how the horse comes along over time, and the extent and location of the problem how long the horse can be effectively managed to adequate soundness. Good luck with yours.
We have a 12 year old gelding that has significant calcification of the medial meniscus and medial collateral ligament along with SIGNIFICANT bone spurs and other arthritic changes in his right stifle. He's also got arthritic changes in his left stifle. We bought him without a vet check about 15 months ago - owner was selling him as he was dying of cancer and the horse was slowly starving. He w/t/c sound at the time and we put some significant trail miles on him over the first 10 months. When he became short strided at the trot this spring we had went through a series of lameness appointments, joint blocking and finally x-rays at the local hospital before we found the cause. He got progressively more unsound over that 2.5 months.
The damage is likely a result of an unknown (untreated?) injury that occurred a number of years ago. The vet thinks that he probably re-injured himself somehow last winter and it has aggravate the injury. He's permanently unsound and there's no treatment that can help. He will eventually require daily bute to be comfortable. When that happens, we'll likely put him down.
We've been able to keep him trail sound (walk only, short rides once a week) with supportive shoeing and bute as required this summer. The shoes and rides have made him more sound (he'd lost muscle tone because we weren't riding him while trying to find the cause of the lameness), but he definitely has good days and bad days. On bad days we give him bute and keep an eye on him. We only ride him on good days.
We're struggling with our long term plan for him as my husband would probably ride more often if he had a sound horse he could take lessons on and play at cutting and such as opposed to a trail horse that we're constantly monitoring for lameness. BUT, we've only got room/budget for 2 horses and my new gelding is too green for him to ride yet. We plan to re-evalute every 6 months how uncomfortable Whiskey is and what we think is fair to all of us. I've even starting keeping a note-book logging bad days to see if there's any trend.