Abstract
In cases of sero-negative rheumatoid arthritis (RA), no abnormal findings are observed on blood tests and its clinical course is favorable, compared to sero-positive RA. In the acute phase of sero-negative RA, infiltration of neutrophils may be the only pathologic finding on frozen section biopsy. Thus, it might be misdiagnosed as pyogenic arthritis. We report on a case of acute sero-negative RA misdiagnosed as pyogenic arthritis during hip surgery with review of the literature.
Figures and Tables
Fig. 1
Preoperative radiographs of the hip joint showing sclerotic change of both femoral head, subchondral bone cysts & fracture, joint destructive change. (A) AP view, (B) Frogleg view.
![hp-24-328-g001](/upload/SynapseData/ArticleImage/1147hp/hp-24-328-g001.jpg)
Fig. 2
MRI view showing joint fluid collection, synovial hypertrophy, subchondral bone cyst & fracture. (A) T1 weighted coronal view (B) T2 weighted coronal view.
![hp-24-328-g002](/upload/SynapseData/ArticleImage/1147hp/hp-24-328-g002.jpg)
Fig. 3
Postoperative radiographs showing antibiotics pregnated cement spacer insertion of the right hip joint.
![hp-24-328-g003](/upload/SynapseData/ArticleImage/1147hp/hp-24-328-g003.jpg)
Fig. 4
(A) Histologic examination of hematoxyline and eosin stained specimen showed of neutrophils infiltration in the tissues around the hip joint and did not show the lymphoid follicle (×100). (B) The same findings above figure (×400), (C) Small pannus (dark arrow) formation ingrowing cartilage (×100).
![hp-24-328-g004](/upload/SynapseData/ArticleImage/1147hp/hp-24-328-g004.jpg)
References
1. Rozin AP, Hasin T, Toledano K, Guralnik L, Balbir-Gurman A. Seronegative polyarthritis as severe systemic disease. Neth J Med. 2010. 68:236–241.
2. Bullough PG. Orthopaedic pathology. 2004. 4th ed. Edinburgh: Mosby;286–297.
3. Arnett FC, Edworthy SM, Bloch DA, et al. The American Rheumatism Association 1987 revised criteria for the classification of rheumatoid arthritis. Arthritis Rheum. 1988. 31:315–324.
![crossref](/image/icon/bnr_ref_cross.gif)
![crossref](/image/icon/bnr_ref_cross.gif)
4. Cascão R, Rosário HS, Souto-Carneiro MM, Fonseca JE. Neurtophils in rheumatoid arthritis: More than simple final effectors. Autoimmun Rev. 2010. 9:531–535.
5. Morel J, Combe B. How to predict prognosis in early rheumatoid arthritis. Best Pract Res Clin Rheumatol. 2005. 19:137–146.
![crossref](/image/icon/bnr_ref_cross.gif)
![crossref](/image/icon/bnr_ref_cross.gif)