Correlates of axial gout: a cross-sectional study

A cross-sectional study was undertaken to determine the prevalence of axial gout in patients with established gouty arthritis and to analyze clinical, laboratory, and radiological correlations.

Forty-eight subjects with a history of gouty arthritis (American College of Rheumatology criteria) for ≥ 3 years under poor control were included. Subjects underwent history, physical examination, laboratory testing, and imaging studies, including radiographs of the hands and feet and computerized tomography (CT) of the cervical and lumbar spines and sacroiliac joints (SIJ). Patients with characteristic erosions and/or tophi in the spine or SIJ were considered to have axial or spinal gout.

Seventeen patients (35%) had CT evidence of spinal erosions and/or tophi, with tophi identified in 7 of the 48 subjects (15%). The spinal location of axial gout was cervical in 7 patients (15%), lumbar in 16 (94%), SIJ in 1 (6%), and more than 1 location in 14 (82%). Duration of gout, presence of back pain, and serum uric acid levels did not correlate with axial gout. Extremity radiographs characteristic of gouty arthropathy found in 21 patients (45%) were strongly correlated with CT evidence of axial gout (p < 0.001). All patients with tophi in the spine had abnormal hand or feet radiographs (p = 0.005).

Axial gout may be a common feature of chronic gouty arthritis. The lack of correlation with back pain, the infrequent use of CT imaging in patients with back pain, and the lack of recognition of the problem of spinal involvement in gouty arthritis suggest that this diagnosis is often missed.