609 Konatalapalli, et al: Gout in the axial skeleton Personal non-commercial use only. The Journal of Rheumatology Copyright © 2009. All rights reserved. Gout in the Axial Skeleton RUKMINI M. KONATALAPALLI, PAUL J. DEMARCO, JAMES S. JELINEK, MARK MURPHEY, MICHAEL GIBSON, BRYAN JENNINGS, and ARTHUR WEINSTEIN ABSTRACT. Objective. Gout typically affects the peripheral joints of the appendicular skeleton and rarely involves the axial joints. The literature on axial gout is limited to case reports and case series. This preliminary study was conducted to identify the frequency and characteristics of axial gout. Methods. Six hundred thirty medical records with ICD codes 274.0, 274.82, and 274.9 for periph- eral gout were reviewed. Ninety-two patients had clinical or crystal-proven gout, of which 64 had prior computed tomography (CT) images of the spine performed for various medical reasons. These CT images were reviewed for features of axial gout, which include vertebral erosions mainly at the discovertebral junction and the facet joints, deposits of tophi, and erosions in the vertebral body, epidural space, ligamentum flavum and pars interarticularis. Results. Nine of the 64 patients had radiographic changes suggestive of axial gout. Lumbar verte- brae were most commonly involved, with facet joint erosions being the most common finding. Isolated involvement of the sacroiliac joints was seen in 2 patients. Axial gout had been diagnosed clinically in only one patient. Conclusion. Radiologic changes of axial gout were more common than recognized clinically, with a frequency of 14%. Since not all patients had CT images, it is possible that the frequency of axial involvement was even greater. A prospective study is needed to further define this process. (First Release Feb 1 2009; J Rheumatol 2009;36:609–13; doi:10.3899/jrheum.080374) KeyIndexingTerms: GOUT SPINE COMPUTED TOMOGRAPHY SCAN FromtheDepartmentofRheumatologyandDepartmentofRadiology, Washington Hospital Center,Washington, DC, USA. R.M. Konatalapalli, MD, Research Fellow/Rheumatology,Washington HospitalCenter;P.J.DeMarco,MD,FACP,FACR,ClinicalAssociate Professor of Medicine, Georgetown University School of Medicine, Rheumatology,Washington Hospital Center; J.S. Jelinek, MD, FACR, Chair, Section of Radiology,Washington Hospital Center; M.D. Murphey, MD, Chief, Musculoskeletal Section, Department of Radiologic Pathology, ArmedForcesInstituteofPathology,Washington,DC;B.Jennings,MD, Radiologist, Radiology Associates, Little Rock, Arkansas; M. Gibson, MD, DepartmentofRadiology,NationalNavyMedicalCenter,Bethesda, Maryland, Assistant Professor of Radiology/Radiological Sciences, F.EdwardHébertSchoolofMedicine,UniformedServicesUniversityof theHealthSciences,Bethesda,Maryland;A.Weinstein,MD,FACP,FACR, AssociateChair,DepartmentofMedicine,Director,Sectionof Rheumatology,Washington Hospital Center. AddressreprintrequeststoDr.A.Weinstein,SectionofRheumatology, Georgetown University Medical Center,Washington Hospital Center, 110 Irving Street NW, Room 2A66,Washington, DC 20010. E-mail:arthur.weinstein@medstar.net Accepted for publication October 9, 2008. Gout typically affects the peripheral joints of the appendic- ular skeleton, and has been reported to rarely involve the axial joints. The incidence of gout has increased greater than 2-fold over the last 2 decades and its prevalence in post- menopausal women approaches that of men 1,2 . With this increase in the incidence and prevalence of gout, it is reasonable to assume that the prevalence of axial gout has also increased. However, much of the information on axial gout is limited to case reports or case series. In 69 case reports on axial gout, chronic tophaceous gout was identified in 32 (46%) 3-65 . In these 69 patients, 34 (49%) had neck and/or back pain and 44 (63%) had elevated serum uric acid (SUA) concentrations. All levels of the axial skele- ton were involved by gout, 33 (48%) involving the lumbar vertebrae, 20 (29%) the cervical vertebrae, 14 (20%) the thoracic vertebrae, and 6 (8.7%) the sacroiliac joints (SIJ). The presenting features of axial gout are reported to include neck stiffness 3 , back pain 14,15 , radiculopathy 23,59 , and severe neurologic compromise 4,11,12 . Axial gout can also occur without back pain 5,6 . SIJ gout can either be asympto- matic or present as acute sacroiliitis and/or as referred pain to the back, thigh, or hip 8,66,67 . The pathology of gout involves urate deposition with resultant acute and chronic inflammation in the synovial fluid, articular cartilage, synovial membrane, and capsular and periarticular tissues 68,69 . The urate crystals penetrate into the subchondral bone, giving rise to erosions, cysts, and sclerotic appearance. In the SIJ large cystic erosions in the subchondral bone are considered to be more consistent with gout than irregularity and sclerosis of the joint margins 70 . Plain radiographs and magnetic resonance imaging (MRI) have limited use in the identification of axial gout 43,47,71,72 . In all the case reports where MRI of the spine was performed, the diagnosis was not obvious and gout was confirmed by surgery 29,36,42, 44,51,60,65,72 . On the other hand, CT imaging of the axial skeleton is the preferred modality to identify axial gouty changes. Tophaceous deposits contain- ing calcium are well identified by CT scan and appear as www.jrheum.org Downloaded on December 3, 2021 from