Subacromial impingement

Abstract

Since the middle of the last century, many studies have been performed with the aim to identify factors predisposing to cuff tendon tear. Since it was known that the acromion could have different shapes and different degrees of inclination, it has been simple to attribute these acromion features the responsibility of a pathological narrowness of the subacromial space. In fact, studies conducted between 1943 and 1969 [1-8] concluded that cuff tendon impingement against the antero-inferior margin of the acromion was the determining cause of tendon injury. Despite the fact that this belief was almost universal, the proposed treatments were discordant; Armstrong [3], Watson-Jones [4], Hammond [5], and Diamonds [6, 7] suggested performing total acromionectomy in case of symptomatic rotator cuff tear; Smith-Petersen et al. [1] and McLaughlin [2] suggested the removal of the lateral margin of the acromion because they believed that cuff tendons could rub only against this acromial portion.