The effusion can be relieved with the help of medicines but the strength of the muscle decreases with the time and creates pain during movement and the damage persists. you should consult a physiotherapist.
Next Steps
go for physitherapy..ultrasonic therapy for healing,IFT for muscle relaxation and wax therfapy for reducing inflammation may required . take rest. then the exercises(STRENGTHENING+CO-ORDINATION EX) are to be done and very much important.
Health Tips
at home: give rest to the knee,avoid full weight bearing to the painful or knee weak knee and hot water fomentation and some painkiller gel are temporarily helpful.