Chronic pain? mri, scarring of the deep layer of the deltoid subcortical bony oedema at the fib attach of the pos talo ligament, synovitis ankle joint

Prolotherapy: I suggest a good hands-on osteopathic examination to determine whether the MRI findings exactly match your source of pain. If clinically correlated, one of the best treatments i know to resolve chronic synovitis is prolotherapy aka regenerative injection therapy or stimulated ligament reconstruction. It's non-surgical, an injection, & highly effective in many such cases.

Possibly arthritis: Possibly underlying arthritis such as reactive arthritis. Rheumatology evaluation should be helpful.

Many possibilities: You could have arthritis but if chronic i would see a foot and ankle specialist and bring your mri.