Background: A 54-year-old woman presented with myalgia and arthralgia predominantly in the knees and small joints of the hands and feet with morning stiffness lasting for at least 2 h. The patient had received a wrought titanium 6-aluminium 4-vanadium alloy C cage implant 1.5 years previously, following a severe disc prolapse. No signs of rheumatic disease were evident before the C cage was implanted.
Investigations: Physical examination, radiography, skin and muscle biopsies, serology tests, white blood cell count, HLA genotyping, tumor necrosis factor release assay, skin patch test, lymphocyte transformation test.
Diagnosis: Implant-related inflammatory arthritis.
Management: Combination therapy with corticosteroids, disease-modifying antirheumatic drugs and nonsteroidal anti-inflammatory drugs, and replacement of the titanium cage with a polyetherketone cage.