Trabecular edema of the bone marrow of the femur

Female 37 years.
RF St. Petersburg

Dear doctors, good afternoon.
June 14, was injured. Dislocation of the patella. The joint was fixed and cast. An X-ray control shot showed the correctness of the tapped joint. Puncture in the hospital was done three times. On the 18th day after the injury, she made an MRI. Result:
On a series of MR tomograms weighted by T1 and T2 in three projections with fat suppression is determined:
The patella is laterally displaced. The medial retinaculum is pronounced thinned, a non-uniform MR signal by T2 VI. Trabecular edema of the marrow of the external condyle and metadiaphysis of the femur and the medial parts of the patella are described.
Capsule of the joint is thin. In the joint cavity, an increased amount of effusion is determined. The joint slit is uniform. Menisci not changed. An increased MR signal from the fibers of the anterior cruciate and outer collateral ligaments is determined, the ligaments are thinned. The integrity of the posterior cruciate and inner collateral ligaments is preserved. Patellar ligament without features. The signal of the cartilage component of the joint is preserved, the articular hyaline cartilage of usual thickness, uniform. The intensity of the signal from Goff's fiber is uncommon. Popliteal fossa unchanged. There are no osteophytes. Surrounding soft tissues with signs of edema.
Conclusion: MR pattern of subluxation of the patella laterally. Damage to the medial retinaculum, anterior cruciate and internal collateral ligament. Trabecular edema of the marrow of the external condyle and metadiaphysis of the femur and medial patella (contusion changes). Synovitis.
Could the patella be displaced due to ligament injury within 18 days after the injury, or was it initially poorly fixed and this can be done now.
Prompt, please, at such conclusionwhether surgical treatment is inevitable. If so, is there an opportunity for immediate treatment or is it necessary to do this after the inflammation is removed. How much surgery is needed? What is the rehabilitation period and the possible consequences later on in the joint.
Thank you in advance.