A 26-year-old Irish white man with a known history of intravenous drug abuse, hepatitis C, and lower limb deep venous thrombosis (DVT) presented to the accident and emergency department with a 2-day history of anterior chest wall, shoulder, neck, and left arm discomfort. This was associated with an increasingly tender, hot, spreading erythematous area around the sternoclavicular joint. The patient reported he was unable to move his left arm, holding it in an adducted position by his side.
On physical examination, the sternoclavicular joint and overlying skin was red, hot, nonfluctuant, and extremely tender with associated periarticular swelling (Fig. 1). Left shoulder range of motion was limited to 15-degree forward flexion, 20-degree abduction, and extension, and 10-degree internal and 20-degree external rotation. A temperature of 38.2°C and a tachycardia of 123 beats per minute were recorded.
Laboratory investigations revealed a raised leukocyte count, 16.5 × 109/L; erythrocyte sedimentation rate, 91 mm/h; and C-reactive protein, 97.8 mg/L. Cardiac enzymes, creatinine kinase, troponin I, arterial blood gas, and D-dimers were all within normal limits. No abnormalities were seen in his chest radiograph and transthoracic echocardiogram. It was noted that the patient had a recent history of lower limb DVT, receiving daily therapeutic tinzaparin (Innohep). Upper limb venous Doppler studies were obtained, but no evidence of DVT was found. Blood cultures were taken, and high-dose intravenous flucloxacillin and benzylpenicillin were started. The cellulitis worsened over the next 2 days to include a large surface area over the anterior chest wall with no significant improvement in pain score. Further investigations obtained to confirm the diagnosis included whole-body bone scan, ultrasound, and sternoclavicular joint plain films. After the fifth day of high-dose antibiotics, the swelling and erythema began to resolve with concomitant reduction in pain severity, the patient eventually making a full recovery with continued intravenous antibiotics and analgesia. No long-term complications have been reported by the patient on outpatient review.
What is your diagnosis?
Diagnosis: Sternoclavicular joint septic arthritis.
Given the patient's known history of intravenous drug abuse and hepatitis C, together with clinical evidence of left sternoclavicular joint pain, localized swelling, and pyrexia, a primary differential diagnosis of sternoclavicular joint septic arthritis was made. Septic arthritis of the sternoclavicular joint is rare, accounting for approximately 0.5% to 1% of all joint infections.1 Contributing causes include diabetes, renal disease, HIV, intravenous drug abuse, fractures of the clavicle, or catheterization of the subclavian vein.2 Despite its rarity, septic arthritis of the sternoclavicular joint is commonly reported in intravenous drug abusers especially in male patients of middle age.3,4
A review of 180 cases found that sternoclavicular arthritis accounts for 1% of septic arthritis in the general population, but 17% in intravenous drug users, most likely attributable to translocation of bacteria after injection of contaminated drugs into the upper extremity.1 Intravenous drug abusers often present with monoarticular involvement at time of presentation,3 and serious complications such as chest wall abscess, osteomyelitis, and mediastinitis may develop1 unless prompt diagnosis and aggressive management are instigated. Staphylococcus aureus is the most common pathogen found, followed by Pseudomonas.1,5 Sternoclavicular joint septic arthritis often develops insidiously before symptoms of shoulder and anterior chest wall pain, joint swelling, or fever become apparent. Less commonly, it may present acutely with fever (30%-60%) and septic shock, which develop secondary to seeding of the subclavian vein and rapid bacteremia.6 Another common cause of tenderness and swelling of the sternoclavicular joint region, which also has to be excluded, is degenerative osteoarthritis with osteophyte formation (Tietze syndrome). However, this condition is benign and settles spontaneously, frequently not requiring specific treatment. Needle aspiration of the sternoclavicular joint may be necessary if a definite joint effusion is demonstrated, but successfully obtaining fluid may be technically difficult and nondiagnostic in many cases.7 Therefore, reliance on noninvasive techniques such as computed tomography and magnetic resonance imaging may be necessary. They are useful in assessing the presence of any joint damage and guiding surgical treatment if required. Other important corollary investigations include ultrasound, bone scans, and plain films.
Conservative treatment, as in our case, is advocated in the early stages of the disease when no abscesses exist and the infection has not extended into the mediastinum. In cases of osteomyelitis/soft tissue abscess, thorough debridement can be obtained only by excision of the proximal one third of the clavicle and part of the manubrium together with the sternal part of the first rib. The remaining defect of the chest wall that leaves uncovered major vessels can be obliterated either by the advancement of a pectoralis major flap or by use of a split pectoralis major rotational muscle flap.4,5 In this case report, the patient exhibited many of these early warning symptoms and signs including ipsilateral joint swelling and severe pain. However, sternoclavicular joint septic arthritis may be difficult to differentiate from simple cellulitis and cutaneous/subcutaneous abscesses or may be confused with pseudoaneurysms, hematoma, phlegmon, or thrombosed vein especially in intravenous drug abusers. Therefore, any patient presenting with significant risk factors (intravenous drug abuse, hepatitis) and demonstrating clinical symptoms and signs of potential sternoclavicular joint arthritis requires full investigation, prompt diagnosis, and aggressive management, particularly given the potential for development of serious life-threatening complications.
1. Ross JJ, Shamsuddin H. Sternoclavicular septic arthritis: review of 180 cases. Medicine
2. Chen WS, Wan YL, Lui CC, et al. Extrapleural abscess secondary to infection of the sternoclavicular joint. J Bone Joint Surg Am
3. Akkasilpa S, Osiri M, Ukritchon S, et al. Clinical features of septic arthritis of sternoclavicular joint. J Med Assoc Thai
4. Mikroulis DA, Verettas DA, Xarchas KC, et al. Sternoclavicular joint septic arthritis and mediastinitis. A case report and review of literature. Arch Orthop Trauma Surg
5. Lowy FD. Medical progress: Staphylococcus aureus
infections. N Engl J Med
6. Kelly PJ, Martin WJ, Coventry MB. Bacterial suppurative arthritis in the adult. J Bone Joint Surg Am
7. Argen RJ, Wilson CH Jr, Wood P. Suppurative arthritis-clinical features of 42 cases. Arch Intern Med