Deficits of shoulder abduction (n = 50) The time of exam Grade After 6 months After 12 months No deficit (< 5%) 28 43 Mild (5% - 30%) 20 7 Moderate (30% - 50%) 2 0 Total 50 50 12 6 months post-operatively, 28 patients (56%) had no affection on muscle strength.