How long does it take to heal synovitis of the foot after a cortisone injection?

Few weeks: Typically this resolves after 2 to 3 weeks with treatment. It can recur depending on the cause.

Synovitis: It coud take 4-6 weeks to treat a tendinitis or synovitis. You also may need multiple steroid injections.

No absolute answer: An injection is a type of treatment. Sometimes another injection may be needed in the near future. Every situation is different, depending on level of inflammation and your bodies response. Other treatments may be nedcessary as well. Could be up to several days before you begin to experience relief of symptoms.

1-5 days: Steriod injections for synovitis of the foot are used quite often. Certain steroid preparations are soluble and can work within 24 hours but their effect can be short lived. Depo forms(long acting /locally acting) can take up to 5-7 days to have their full effect since the steroid slowly dissolves or time. Wearing a brace or restricting activity of the foot can speed up the end result.