Ah, I see now. External fixators on tibia/fibula fractures are, well, a tough choice for a doc. Tib/fib fractures are the ones most likely to end up with some infection. Well, tib/fib fractures have the highest rate of infection among fractures.
As for me, uhm, I highsided exiting a corner in a roadrace at 120mph. Right after the highside, I was alright....I just finished completely fracturing my right wrist which I had incompletely fractured the week before. However as I was sliding down the track at over 100 miles per, thinking how weirdly cool that was, I happened to look up to see my racebike re-entering the atmosphere. ( I did learn, though, that you know you're having a bad day when you sit up in the ambulance to give the lost medics directions and you notice your foot is facing backwards....).
At any rate. I asked the doc, after the first surgery when healing was seen to be problematic, why he didn't go for an external fixator. He said that such things are definitely not the first option since they carry a significant (although not necessarily big) risk of infection. The external fixators (of which Ilizarov splints are one type) require "damaging" the periosteum of the bone during placement, which in in turn decreases blood flow to the fractured area. Between the location of my fractures, the massive amount of swelling--even though he delayed surgery for 24 hrs to wait for swelling to reduce--and the fact that I'm a diabetic, he felt an external fixator was not worth the risk.
Believe me, though, I understand exactly what you're going through. I had a friend who went through exactly what you have (including near surgical amputation and the placement of an external fixator) with a lower leg fracture. I also went through it with a patient of mine who suffered a very similar injury to yours resulting from the same sort of accident (t-boned by a car) and same sort of injuries (multiple lower leg fractures, open, and missing bone fragments). In both cases my friend and my patient went through years of procedures before things turned around for them.
I had similar fit issues as you. One leg is now sigificantly shorter than the other (about 3/8 to 1/2" or so). I had fit issues and ended up getting video analysis done, the net result of which was 1/4" shim under cleat on the affected side. The video showed that my body had adapted such that all I needed was a 1/4". Shims larger than that caused perturbations in my cadence. 100+ mile days are no issue, now.