What Causes Recurring Ankle Pain?

Hi Doc, I have this ankle pain for the past 5 months.MRI and x-ray did not show anything other than some inflammation .Took anti-inflammtory,was immobilised for 3 weeks,2 steroid shots ( pain aggravated after 1 shot.I have pain on alternate days sometimes.Sharp pain of level 3 in sinus tarsi.I live in US, so am just wondering about whats going on.Even rest does not control the pain.In a pattern it pains on and off.Could you give your suggestions?