More commonly the tendon of the biceps brachii and/or the bursa is implicated. How has your horse been diagnosed? Do you know the cause of the injury? Sometimes, with such injuries (unless traumatic), a horse needs to be re-educated in the way of going - ie teaching it to become rear wheel drive and not just to pull itself along by the forehand.
Re how long - how long is a bit of string? Depends on severity and exact nature of injury.....bursa/tendon/muscle etc etc. Your vet will be the best person to give you an outlook.
