It might be painful to have an injection into a small joint and you'll find recommended limitations to the number of injections into a joint to not more than 3 to 4 a year. Tendon fix: The surgeon would make an incision within the skin to expose the destroyed tendon https://www.theorthopaedicandpainpractice.com/why-cant-i-straighten-the-tip-of-my-finger/