Spinal gout in gouty polyarthropathy.

Gout is a crystal arthropathy and is the most common inflammatory arthritis in adults. Spinal involvement is observed in 17% of gout patients and may still be under-recognized. MRI is sensitive, but not specific, in identifying spinal gout, mainly due to varying signal characteristics of tophi and mimicking findings with infectious spondylodiscitis. In patients with a history of spinal surgery, distinguishing between spondylodiscitis and spinal gout on MRI becomes even more challenging. Dual-energy computed tomography (DECT) can help differentiate crystal arthropathies from infectious spondylodiscitis and regular degenerative osteoarthritis with high sensitivity and specificity by detecting monosodium urate crystals. This paper reports the case of an 80-year-old patient with lumbar back pain and a history of lumbar spine surgery. MRI revealed alterations suggestive of spondylodiscitis. Surgical biopsy results were negative for infection, but inconclusive for gout. The diagnosis of spinal gout was ultimately established using DECT in the context of polyarthropathy.