Stiffness after fracture

Question from a member of the community:

I had fracture below knee , stayed bedrest for two months .Now its 8months doc says ur bone is alright but I feel stiffness of my knee sometime pain too after sitting on chair or bed too , after standing for sometime the stiffness releases &able to walk for 1km at a streach .Please advice how to get well as due to this stiffness my other left knee also pains .I 'm 58yrs old healthy body .l would be grateful to u for ur advice .