[Blitzzz (RIP)]

I did Physical Therapy for over 17 years the last 4 at FT Campbell, where there were many Ankle, Foot, Knees, and the occasional Hip surgeries. Hips are hard to regain full strength at full ranges, knees are easiest and Feet are tough to ever get back. All of this is because of the different amounts of use and number of movement directions.

Use because we walk/run all the time.
The hip joints have 4 planar motions (single joint, but Internal rotation,external rotation, flexion, and extension)
The knee also a single joint has only has 2 planar movements (flexion and extension)
THE FOOT ankle complex has many, many joints and planar movements. The Ankle alone has at least 6. (Plantar flexion, extension, eversion, inversion, internal and external rotations.
I don't know who did or how good your Physical Therapy was, But I am always more prone to exercising the specific muscles often overlooked. As you may know I am a great proponent of high rep low resisted exercises for neuro and muscular rehab.
Really strengthening the Muscles surrounding Ankle movement should better align the lower foot joints.

I would recommend highly a very specific working of those muscles before ever getting surgery. Simply because less time to recover a better fix. Surgery will require you much down time without the promise of a real fix, plus all surgical scaring will require rehab as well.
Imobilization will cause more muscle weakness. for any thing further PM me with a question and I may give you my phone number and we can talk Dave Boltz