I have a horse that has a club like right front as well. He has always been a little short strided on that right front. HE started going off in May. He is also huge 18.2 hands. I say that because the size of him works against him.
Our first vet visit was also a bone scan. The scan showed a bone bruise on his right front. We started treating that with Hand walking and rest. * weeks later I started bringing him back, within 5 days he was off again. I took him back for an MRI. They determined he had degenerative joint disease. My heart sank and I thought this might be the end for this horses career. Again the pure size of him works against him.
I have started him on Adequen we are in the loading dose now. But one thing I have done which I am amazed about is I started doing laser therapy on him. I am amazed at the results. The trick I found is on the right front besides using the laser on the pastern and coffin bone joints we started doing his shoulders and back. I have seen incredible results. My horse is totally sound. If you can find someone in you area that has this machine its called Pegasus Therapy Laser. Its a very high powered laser that works miracles. We even used it on my dog that was having a hard time getting up and he is now up and running around again. The machine works on a cellular level. Here is the website for it http://www.pegasuslaser.com and litecure.com. If you are in Southern California area let me know. I know two ladies that do this at a VERY reasonable price. My insurance covers it as well.
Good luck!!! I hope this has helped you and given you some hope!!