My 26 year old Morgan was injected with only one (usually there are two injections) Tildren shot for bone spavin (hock arthritis) in Oct 2006. He had been in retirement with light riding only prior to that. Within 2 weeks, he was out of retirement.. and we just had new Xrays taken last week and the bones in the hock and fetlock are remodeling due to the Tildren, and some of the arthritis is GONE. He is a totally different horse!
Have you tried the Search facility for this - there have been several threads on Tildren lately.
My experience was negative - my then 14yo Arab was diagnosed with navicular in 2004. Tried Tildren after Navilox failed - as Tildren was unlicensed in the UK it was sourced in France and he got it as part of a clinical trial. It had absolutely no effect and the vet hosp advised against a second dose. At the time the manufacturers were claiming a 60% success rate so maybe we were unlucky.