Why if all advice is followed can a non displaced weber b fracture with partially torn aftl & deltoid ligaments soft tissue have delayed or non union?

It Happens at times:: Generally these heal very well with non-operative treatment, but some patients despite what you do, they go onto have delayed or non-union. Maybe they haven't been fully compliant with non-weight bearing status. The combination of the ligamentous injury with a such fx, in my opinion, could be considered for surgical treatment. But in most cases with such a problem, no specific reason is found.

Medical conditions: Associated medical conditions - specifically, smoking and diabetes, among other conditions - can significantly lower healing rates.