olly limping

Advice please .. approx. 3 months ago olly started to limp holding up front leg, always after exercise (luvs a ball )I rested him n only had lead walks .. after walks it cums back . took him to vets (ortho specialist) who took x rays and said his knee joint looked odd?? nothing specific .. more rest n 5 minute lead walks .limp started again . so Friday b4 xmas he was taken in and had steroid injected into joint .. he was rested till 2 weeks ago and has had few walks on lead since but today still limping .it had stopped all the time he dosnt go out. im kinda confused as he said x ray didn't show to much . said hmmm operation is difficult expensive and painful .. also he has very sensitive tummy concerning food and tablets so have to be careful .. hes only 3 years old .. just kinda wondering if anyone has any ideas

welcome i would take him back to the vet and if he wont do anything to improve your dogs leg would get a 2nd opinion from a different vet. If the knee joint looks odd an operation may be the only way forward