Whe Can I Bend The Knee After The Treatment For Hematoma?

I met with an accident and hert my nee on 17Th of February 2011, there was hematoma in the nee, the blood was aspirated with a syringe without any Anastasia.All the outer wounds are healed, but still I cant bent my nee completely my doctor as prescribed me CHYMORAL TABLETS how long will it take the nee to bend completely.I am 72 years of age.5'-3" with good health except high blood pressure which is under control with medicine