When I ripped my bicep off the orthopedic surgeon said he wanted to do the operation in under 5 days of the injury. He said the greatest success is to have it done quickly. That way the tendon doesn't start dying and the anchor point where it was ripped off is fresh. He sewed it to two metal anchors that held it to where it was ripped off. I think it reattached in the months following the operation. Long rehab. It took 6 months to regain the strength in the arm. My biceps were completely detached and my biceps rolled up to my delt. He told me if I waited the only way he could fix it would be with using a cadaver tendon and the success odds would be low and it wouldn't be for athletic function but for every day use. My bicep doesn't look the same but close. I can do a full bicep workout with it as well as deadlift with the repaired arm.