You have not mentioned your age as osteoartheritis of knee is very common after 40.
If you have any history of knee injury
then it may give this type of pain and there is early osteo artheritic changes in the joint.
As you get pain in inside area of the knee,there is chances of having median meniscus
and median ligament injury
Do not bent your joint much,avoid squatting position
Do patellar exercise.
ok and bye.