I have studied your case.
As per your age and history there is possibility of soft tissue injury
Most commonly meniscus
As per your symptoms you need to do physiotherapy
and knee exercises to improve range of motion .
If pain persist then you may need to do MRI
again to see for any functional defect.
Small meniscus tear can be managed conservatively with physiotherapy with USG andTENS.
Due to so long history there can be possibility of RSD associated with it.
Hope this answers your query. If you have additional questions or follow up queries then please do not hesitate in writing to us. I will be happy to answer your queries.
Wishing you good health.