I have downward sloping acromion from shoulder injury if it aches in the cold is it the sign of arthritis ?as mri never stated that

Not arthritis: In general, at age 37 it would be fairly uncommon to have shoulder arthritis. The MRI would have picked up arthritis in your shoulder or in the collar bone joint (AC joint). A downward sloping acromion has been traditionally associated with increased risk of rotator cuff tendonitis/bursitis (impingement). If your only symptom is aches in the cold, you may have mild bursitis, no rotator cuff tear