The healing rate for ligament repair is slow since ligaments are poorly vascularized(few blood vessels). The minimum time for the ligament to sustain ~80% of it's prior load is 17 weeks to 1 year. So having your son refrain from stressing the elbow will allow it to heal. The healing does occur by scaring, but keeping the joint flexed will result in scar tissue aligning with the original colligen fibril direction and give it max. flexibility and strength.
How would viamin E affect this?
By the way, thank you for your input.