Hi, thanks for writing to HCM.
After going through the description, I feel that it could be EFFUSION in the knee secondary to the injury
sustained. This generally indicates some form of insult/injury to the intra articular structures (soft tissues in the joint).
This cannot be bursitis
since bursae are present outiside the knee joint and will produce swelling confined to that area where bursa is present (in your case, the swelling of the knee is diffuse).
I suggest you to have a MRI
scan of the knee joint to diagnose any damage to the intra articular structures like ligaments, meniscus
, capsule etc.
Consult an orthopedic surgeon and follow his advice accordingly. Good day