Septic arthritis of the shoulder presenting as chronic anterior dislocation

Abstract

A lucid 83-year-old woman presented to the orthopaedic department with a painful shoul­ der. She had a three-month history of worsening pain and stiffness in her left shoulder. No history of trauma existed. Her general practitioners had treated her with two injections of cortico­ steroid and local anesthetic during the first month with no improvement. She was referred to this hospital after an x-ray examination re­ quested by her general practitioner showed an anterior dislocation of the shoulder (Figure 1). She reported pain at rest that was made worse by shoulder movement, and she had painful paresthesias in the left forearm. Asymmetry of the shoulder contour was present, and an area of cellulitis over the medial aspect of the upper arm measured 15 cm by 15 cm. No abnormal neurologic signs in the upper limb were seen. She was afebrile. No elevation of white blood cell count was seen. A diagnosis of chronic an­ terior dislocation of the shoulder was made. Closed reduction of the shoulder was impos­ sible. At arthrotomy we were surprised to find an abscess containing 50 ml pus in the gleno­ humeral joint extending anteriorly and inferiorly from the joint. The humeral head was necrotic and extremely friable. Because of these bony changes and soft-tissue contractures, reduction of the joint was not possible. Tissue specimens cultured Staphylococcus aureus sensitive to an antibiotic (f1ucloxacillin). The patient had relief of pain after antibiotic therapy. She regained good hand and elbow function, but glenohu­ meral movement has been very restricted.