The Frequency of Axial Deposition in Korean Patients With Gout at a Tertiary Spine Center

Abstract

Objectives: This study aimed to describe the frequency of axial deposition (axial gout) and determine the associated factors in patients with gout who presented to a spine clinic in Korea. Methods: We enrolled 95 Korean patients who visited our spine center from March 2012 to February 2016 and who had been previously diagnosed with gout and had available computed tomography (CT) images of the vertebral columns. Axial gout was defined as the presence of erosions or tophi in the vertebral endplate or facet joint. The clinical and laboratory data of these patients were retrieved from medical records. Results: Out of 95 patients, 15 [15.8%; 95% confidence interval (CI), 9.4-25.0%] had a conventional CT evidence suggestive of axial gout. In these 15 patients, 12 (80%) had lumbar spine involvement (95% CI, 51.4-94.7%). Fifteen patients had erosions of the vertebral column, and two presented with tophi that exhibited erosive changes of the facet joints. The presence of axial gout was not associated with the patients' age, duration of gout, laboratory findings, inflammatory back pain symptoms, identification of monosodium urate crystals in the peripheral joints, current use of urate-lowering drugs, hypertension, and end-stage renal disease; however, there was a significant association with the presence of diabetes (P = 0.008). Conclusions: The frequency of axial deposition in Korean patients with gout and spinal symptoms was 15.8%, with the lumbar region being the most commonly involved section of the spine. In addition, diabetes was associated with evidence of axial gout on imaging.

Keywords: computed tomography; gout; monosodium urate deposit; spine; tophi.

Figure 1

Computed tomography suggestive of axial gout. (A) Erosive changes with sclerotic margins in the vertebral body (white arrow) and facet joints (white hollow arrows). (B) Tophi in the facet joints (white arrows).

Figure 2

Lumbar spine magnetic resonance imaging and computed tomography (CT) in axial gout. (A) Increased signal intensity on T2WI of L4-5 and L5-S1 intervertebral disc and erosive changes on the posterior cortices and endplates of L4-L5-S1 vertebra. (B) Enhancement of epidural space on T1WI. (C) Erosive changes in L4-5 and L5-S1 endplates on conventional CT. (D) Monosodium urate deposits (green) in the erosive foci of endplate on dual-energy CT.