...I'll have to correct one of my previous presumptions about the knee-cap. A luxation of the knee-cap is likely to be MUCH more painful for several days then what you describe. A luxated knee-cap should be treated with full immobilization for 4-6 weeks too, and very unlikely that you would be able to walk without pain as you say. And also as I said, I still can't make the features fit with the knee-cap luxating to the left. Not that it never happens, but very unlikely as a "second" trauma, especially after tearing the MCL.

The location of the swelling (above the knee-cap) still suggest some sprain of the medial patellar retinaculum/medial patellofemoral ligament and could probably also happen after a MCL tear, WITHOUT luxation of the knee-cap. So for the guessing. Full MCL tear and partial/minor sprain of the medial Wikipedia reference-linkmeniscus and/or medial patellar retinaculum and/or medial patellofemoral ligament. Prognosis is also much better for a full MCL tear alone in contrast to MCL tear combined with patellar lux. So that's good.

Apologies for the eager speculations concerning the knee-cap.

Kind regards,
Sigurd Mikkelsen