Abstract
The subdeltoid bursa lies primarily under the acromion and extends laterally between the deltoid muscle and the joint capsule under the deltoid muscle. It may exist as a single bursal sac or, in some patients, as a multisegmented series of loculated sacs. The subdeltoid bursa is vulnerable to injury from both acute trauma and repeated microtrauma. Acute injuries frequently take the form of direct trauma to the shoulder when playing sports or falling off a bicycle. Repeated strain from throwing, bowling, carrying a heavy briefcase, working with the arm raised across the body, rotator cuff injuries, or repetitive motion associated with assembly-line work may result in inflammation of the subdeltoid bursa. If the inflammation becomes chronic, calcification of the bursa may occur.
Patients suffering from subdeltoid bursitis frequently complain of pain with any movement of the shoulder, but especially with abduction. The pain is localized to the subdeltoid area, with referred pain often noted at the insertion of the deltoid at the deltoid tuberosity on the upper third of the humerus. Patients are often unable to sleep on the affected shoulder and may complain of a sharp, catching sensation when abducting the shoulder, especially on first awakening.
Keywords
subdeltoid bursitis, shoulder pain, septic bursitis, Rice bodies, subdeltoid bursa injection, ballotment test, ultrasound guided injection
ICD-10 CODE M75.50
The Clinical Syndrome
The subdeltoid bursa lies primarily under the acromion and extends laterally between the deltoid muscle and the joint capsule under the deltoid muscle ( Fig. 27.1 ). It may exist as a single bursal sac or, in some patients, as a multisegmented series of loculated sacs. The subdeltoid bursa is vulnerable to injury from both acute trauma and repeated microtrauma. Acute injuries frequently take the form of direct trauma to the shoulder when playing sports or falling off a bicycle. Repeated strain from throwing, bowling, carrying a heavy briefcase, working with the arm raised across the body, rotator cuff injuries, or repetitive motion associated with assembly-line work may result in inflammation of the subdeltoid bursa. If the inflammation becomes chronic, calcification of the bursa may occur.
Patients suffering from subdeltoid bursitis frequently complain of pain with any movement of the shoulder, but especially with abduction ( Fig. 27.2 ). The pain is localized to the subdeltoid area, with referred pain often noted at the insertion of the deltoid at the deltoid tuberosity on the upper third of the humerus. Patients are often unable to sleep on the affected shoulder and may complain of a sharp, catching sensation when abducting the shoulder, especially on first awakening.
Signs and Symptoms
Physical examination may reveal point tenderness over the acromion; occasionally, swelling of the bursa gives the affected deltoid muscle an edematous feel. Passive elevation and medial rotation of the affected shoulder reproduce the pain, as do resisted abduction and lateral rotation. Sudden release of resistance during this maneuver markedly increases the pain. Rotator cuff tear may mimic or coexist with subdeltoid bursitis and may confuse the diagnosis (see “ Differential Diagnosis ”).
Testing
Plain radiographs of the shoulder may reveal calcification of the bursa and associated structures, consistent with chronic inflammation. Magnetic resonance imaging is indicated if tendinitis, partial disruption of the ligaments, or rotator cuff tear is being considered ( Fig. 27.3 ). Ultrasound imaging may further delineate the cause of the patient’s pain ( Figs. 27.4 and 27.5 ) Based on the patient’s clinical presentation, additional testing may be indicated, including a complete blood count, erythrocyte sedimentation rate, and antinuclear antibody testing. Radionuclide bone scanning is indicated if metastatic disease or primary tumor involving the shoulder is a possibility. The injection technique described later serves as both a diagnostic and a therapeutic maneuver.
