Acute neck pain caused by septic arthritis of the lateral atlantoaxial joint with subluxation: a case report

INTRODUCTION Crystal-induced arthritis of the lateral atlantoaxial joint may be intimately involved in acute neck pain in the elderly. Patients typically have a good prognosis, and symptoms usually subside within a few weeks. On the other hand, septic arthritis of the lateral atlantoaxial joint requires early diagnosis and antibiotic treatment. Diagnostic delay is a risk factor for an unfavorable outcome of vertebral osteomyelitis. Even though septic arthritis of the lateral atlantoaxial joint is a very rare clinical entity, it is important to differentiate septic arthritis from crystal-induced arthritis. CASE PRESENTATION A 53-year-old Japanese man presented with neck pain, stiffness, and loss of power of his left upper extremity which started 20 days before his visit to our hospital. A physical examination revealed a limited range of motion of his neck, with rotation being especially very restricted. Atlantoaxial subluxation was seen on plain radiography of his cervical spine. During puncture of the lateral atlantoaxial joint, clear yellow fluid was collected. Cultures later grew methicillin-sensitive Staphylococcus aureus. He was diagnosed with septic arthritis of the lateral atlantoaxial joint with atlantoaxial subluxation. After diagnosis, intravenous administration of antibiotics was begun. The atlantoaxial region was stabilized with the Brooks procedure. Plain radiography showed complete bone union 8 months after operation. At a follow-up evaluation 7 years after initial onset, he had complete relief of neck pain, and there were no neurological abnormalities. CONCLUSIONS A patient with septic arthritis of the lateral atlantoaxial joint with subluxation presenting with acute neck pain was successfully treated with antibiotics and fusion surgery. In patients with persistent neck pain, septic arthritis of the lateral atlantoaxial joint should be considered and further examinations performed.