A ruptured Baker's cyst will heal on its own, if the underlying knee condition is treated, so that the cyst does not fill up again.
Baker's cysts, in adult, are essentially a ganglion cyst in the popliteal fossa of the knee (in the back of the knee). It is connected to the knee joint by a stalk, which allows the fluid in the knee to get into the cyst.
So, any condition which causes the knee to swell up, will cause the cyst to fill also. It is sort of a relief valve for the knee.
It is thus recommended that Baker's cysts be treated by determining what the condition in the knee is that is causing the swelling, and treating it.
The rupture cyst wall and the cyst contents can dissect down the back of the calf. In some cases this can be mistaken for a DVT (deep vein thrombosis), due to the swelling and discomfort. The fluid will be resorbed by the body, as will the cyst wall (if it does not fill up again).
You should see an orthopedic surgeon for a thorough evaluation of your knee.