Abstract
The objective of this study was to evaluate the sensitivity and specificity of ultrasound (US) and conventional radiography (CR) for the detection of calcium pyrophosphate (CPP) crystals in patients with knee effusion. Consecutive patients ≥50 years old with knee effusion were included. All patients underwent arthrocentesis with aspiration of synovial fluid (SF) and subsequent analysis of CPP crystals using plain light and polarizing light microscopy. US and CR of the involved knee were performed immediately after arthrocentesis. CR results were read by an experienced rheumatologist, searching for chondrocalcinosis. US examinations were carried out by an experienced rheumatologist blinded to all clinical and imaging data. The following US abnormal findings were considered indicative of CPP crystals deposition (CPPD): (1) hyperechoic bands within the femoral hyaline cartilage layer, and (2) hyperechoic sparkling spots in meniscal fibrocartilage. A total of 75 knees were evaluated in the same number of patients. Analysis of SF revealed CPP crystals in 15 out of 75 (20 %) knees: all (10) patients with previous diagnosis of CPPD, 3 patients with previous diagnosis of primary knee osteoarthritis (OA) and 2 patients without previous definitive diagnosis of a rheumatic condition. Using SF analysis as reference method, sensitivity and specificity for US findings was 60 and 96.7 %, respectively, while CR showed a sensitivity of 40 % and a specificity of 83.3 %. US results showed high specificity with acceptable sensitivity to detect CPP crystals in patients with knee effusion. Compared with CR, US results had better specificity and sensitivity. US may be used in daily rheumatologic practice when CPPD is suspected.
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Fam AG, Topp JR, Stein HB, Little AH (1981) Clinical and roentgenographic aspects of pseudogout: a study of 50 cases and a review. Can Med Assoc J 124(5):545–51
Gordon TP, Smith M, Ebert B, McCredie M, Brooks PM (1984) Articular chondrocalcinosis in a hospital population: an Australian experience. Aust N Z J Med 14(5):655–9
Salaffi F, De Angelis R, Grassi W (2005) Prevalence of musculoskeletal conditions in an Italian population sample: results of a regional community-based study. I. The MAPPING study. Clin Exp Rheumatol 23(6):819–28
Doherty M, Dieppe P (1986) Crystal deposition disease in the elderly. Clin Rheum Dis 12(1):97–116
Richette P, Bardin T, Doherty M (2009) An update on the epidemiology of calcium pyrophosphate dihydrate crystal deposition disease. Rheumatology (Oxford) 48(7):711–5
Zhang W, Doherty M, Bardin T, Barskova V, Guerne PA, Jansen TL et al (2011) European league against rheumatism recommendations for calcium pyrophosphate deposition. Part I: terminology and diagnosis. Ann Rheum Dis 70(4):563–70
Filippucci E, Di Geso L, Girolimetti R, Grassi W (2014) Ultrasound in crystal-related arthritis. Clin Exp Rheumatol 32(1 Suppl 80):S42–7
Ciapetti A, Filippucci E, Gutierrez M, Grassi W (2009) Calcium pyrophosphate dihydrate crystal deposition disease: sonographic findings. Clin Rheumatol 28(3):271–6
Grassi W, Meenagh G, Pascual E, Filippucci E (2006) “Crystal clear”-sonographic assessment of gout and calcium pyrophosphate deposition disease. Semin Arthritis Rheum 36(3):197–202
Dalbeth N, McQueen FM (2009) Use of imaging to evaluate gout and other crystal deposition disorders. Curr Opin Rheumatol 21(2):124–31
Fodor D, Albu A, Gherman C (2008) Crystal-associated synovitis–ultrasonographic feature and clinical correlation. Ortop Traumatol Rehabil 10(2):99–110
Delle Sedie A, Riente L, Iagnocco A, Filippucci E, Meenagh G, Grassi W et al (2007) Ultrasound imaging for the rheumatologist X. Ultrasound imaging in crystal-related arthropathies. Clin Exp Rheumatol 25(4):513–7
Filippucci E, Riveros MG, Georgescu D, Salaffi F, Grassi W (2009) Hyaline cartilage involvement in patients with gout and calcium pyrophosphate deposition disease. An ultrasound study. Osteoarthr Cartil 17(2):178–81
Filippou G, Frediani B, Gallo A, Menza L, Falsetti P, Baldi F et al (2007) A “new” technique for the diagnosis of chondrocalcinosis of the knee: sensitivity and specificity of high-frequency ultrasonography. Ann Rheum Dis 66(8):1126–8
Thiele RG, Schlesinger N (2007) Diagnosis of gout by ultrasound. Rheumatology (Oxford) 46(7):1116–21
Doherty M, Dieppe P, Watt I (1993) Pyrophosphate arthropathy: a prospective study. Br J Rheumatol 32(3):189–96
Backhaus M, Burmester GR, Gerber T, Grassi W, Machold KP, Swen WA et al (2001) Guidelines for musculoskeletal ultrasound in rheumatology. Ann Rheum Dis 60(7):641–9
Sivera F, Andres M, Carmona L, Kydd AS, Moi J, Seth R et al (2014) Multinational evidence-based recommendations for the diagnosis and management of gout: integrating systematic literature review and expert opinion of a broad panel of rheumatologists in the 3e initiative. Ann Rheum Dis 73(2):328–35
Grassi W, Okano T, Filippucci E (2015) Use of ultrasound for diagnosis and monitoring of outcomes in crystal arthropathies. Curr Opin Rheumatol 27(2):147–55
Ellabban AS, Kamel SR, Omar HA, El-Sherif AM, Abdel-Magied RA (2012) Ultrasonographic diagnosis of articular chondrocalcinosis. Rheumatol Int 32(12):3863–8
Ottaviani S, Juge PA, Aubrun A, Palazzo E, Dieude P (2015) Sensitivity and reproducibility of ultrasonography in calcium pyrophosphate crystal deposition in knee cartilage: a cross-sectional study. J Rheumatol 42(8):1511–3
Barskova VG, Kudaeva FM, Bozhieva LA, Smirnov AV, Volkov AV, Nasonov EL (2013) Comparison of three imaging techniques in diagnosis of chondrocalcinosis of the knees in calcium pyrophosphate deposition disease. Rheumatology (Oxford) 52(6):1090–4
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The study was conducted according to the Declaration of Helsinki and local regulations. Ethical approval for the study was obtained from the Hospital local Ethics Committee and informed consent was obtained from all patients.
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Ruta, S., Catay, E., Marin, J. et al. Knee effusion: ultrasound as a useful tool for the detection of calcium pyrophosphate crystals. Clin Rheumatol 35, 1087–1091 (2016). https://doi.org/10.1007/s10067-015-3100-1
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DOI: https://doi.org/10.1007/s10067-015-3100-1