Impingement on the tendinous portion of the rotator cuff by the coraco-acromial ligament and the anterior third of the acromion is responsible for a characteristic syndrome of disability of the shoulder. A characteristic proliferative spur and ridge has been noted on the anterior lip and undersurface of the anterior process of the acromion and this area may also show erosion and eburnation. The treatment of the impingement is to remove the anterior edge and undersurface of the anterior part of the acromion with the attached coraco-acromial ligament. The impingement may also involve the tendon of the long head of the biceps and if it does, it is best to decompress the tendon and remove any osteophytes which may be in its groove, but to avoid transplanting the biceps tendon if possible. Hypertrophic lipping at the acromio-clavicular joint may impinge on the supraspinatus tendon when the arm is in abduction and, if the lip is prominent, this joint should be resected. These are the principles of anterior acromioplasty.

Fifty shoulders in forty-six patients have been subjected to anterior acromioplasty during the past five years. Nineteen had proliferative bursitis and tendinitis or partial tears of the supraspinatus, without roentgenographic evidence of calcium deposits, and twenty had complete tears of the supraspinatus and the results in these thirty-nine patients from one to five years following surgery were good. Eleven patients with residual impingement following partial lateral acromionectomy were improved but their results were impaired by pre-existent deltoid weakness and scar. Anterior acromioplasty may offer better relief of chronic pain in carefully selected patients with mechanical impingement, while it provides better exposure for repairing tears of the supraspinatus, and may prevent further impingement and wear at the critical area without loss of deltoid power.