Atrophy reversal using SEO's / injectables

I've had two shoulder surgeries on the same arm. After my second surgery I experienced noticeable atrophy of the deltoids, biceps and triceps on that side.

6 years later and the area has still not caught up. It looks better, but just won't put on that extra size.

I'm looking into injectable options to possibly fill in the area that bothers me the most - the medial and posterior delts. I've researched non permanent injectables and it seems like Synthol could be an option. I am however worried about risks like eventual fibrosis, embolism, etc, but would like to get opinions from vets about what they think of the safety of it when 'properly' used.
If not Synthol, are there any other injectables or treatments you think might help my case?




P.S. After surgery I also now have real weight limits and durability issues with that arm - I get above a certain weight and I'm causing structural damage and risking a complete blowout (anterior dislocation). So 'put in the hard work and lift big' will not and has not worked for me. It's a disability - but I'd at least like it to not look as bad as it is.