What Does This MRI Report Indicate?

Question :
About a week 1/2 ago I was squatting close to the ground and when I stood up I felt a tear in my knee and my knee locked. Eventually I was able to move it. I have had intermittent pain,limited movement and swelling since. I just got my MRI report and it says:

There is a large osteochondral defect seen over the mid to posterior aspect of the medial femoral condyle, mid to laterally positioned. The defect measures 3cm in AP dimension x 2 cm in transverse dimension x 1 cm in depth. Within the defect, there is a fragments body that is hypointense on T1 and T2-weighted imaging, appearing fractured. This body in total measures 2cm in length x 5mm in height. Fluid fills the defect and surrounds this body, which is concerning for a loose fragment. There suprapatellar effusion. The larger focus measures 11mm in diameter and the smaller focus measures 8mm in diameter. The marrow signal adjacent to the defect is normal. There is a moderate effusion.

The menisci are normal. The anterior and posterior cruciate ligaments are normal. The extensor mechanism and collateral limits are normal. The popliteus tendon is normal.

There is mild condromalacia involving the medial patellar facet. The trochlear cartilage is normal. Lateral compartment articular cartilage is normal.


I forgot to add that the report said. "there is a necrotic fragmented loose body within the defect" Why is there a necrotic body?

Is surgery a must and how soon do they usually do it?

Will I have to worry about it happening to my other knee too? Because I have problems with that knee as well. What kind of diseases can cause this?

Is there anything I should be doing until I see my ortho doctor? I use crutches sometimes because my knee locks up or is really painful to bend or stand. I don't know if I made it worse at work because I am on my feet 10 hours a day. Should I just push through the pain and continue walking or is that making it worse?