Subacromial Bursitis: Clinical and Roentgen Observations

Abstract

In the average clinic and hospital, painful shoulders constitute an appreciable percentage of ailments treated. In the past five years this percentage has been increasing, and the condition is now encountered almost daily by the general clinician. A source of wonder to the author is the high incidence of cases of long standing, some of which are not only distressing but incapacitating, preventing the patient almost completely from performing his daily work. Whether the patient has failed to visit his doctor in the early days of distress or the physician has failed to take advantage of a complete study need not enter into consideration. The average case is readily recognizable and, with competent procedure, the diagnosis may be made with little or no difficulty. To refrain from a roentgen study of the shoulder joint in this condition is comparable to the omission of a blood sugar test in the care of a diabetic. Injuries of the shoulder joint are relatively frequent. Our attention is drawn chiefly to fractures and dislocations because of their more common occurrence. Subacromial or subdeltoid bursitis is a traumatic lesion having a lower incidence, but, while its clinical manifestations are at times less dramatic, the condition is crippling and may result in a major disability. The writer has been frequently impressed with these injuries in and about the shoulder joint and has attempted to record the variations in anatomy and surface structures in subacromial bursitis. While such variations occur, certain salient points have been observed in clinical cases which can be considered as an average pattern. On the roentgenogram are recorded changes in contour of the greater tuberosity of the humerus and variations in outline of the trabeculae. These, with a clinical picture of painful abduction and outward rotation, suggest a lesion of the subacromial bursa. Formerly attention was paid only to the bursa in which calcium deposits were visualized in the soft tissues, either beneath the acromion process or adjacent to the greater tuberosity of the humerus. It is now believed that roughening, excavation, and localized thickening of the periosteum or cortex on the greater tuberosity, indicate, in the greater number of instances, underlying involvement of the subacromial bursal sac (Fig. 3). That portion of the bursal sac lying between the deep surface of the deltoid muscle and the outer surface of the capsule of the shoulder joint is called the subdeltoid bursa. A delicate membrane may divide this from the subacromial bursa, interposed between the tendon of the supraspinatus, which forms its floor, and the acromion and the deltoid muscle which form its roof. Because of the frequent communication between these bursae, they may be considered as one; together they form a flat, translucent sac, almost invisible when the normal joint is opened, about the size of the palm of the hand (1).