Evaluation of crystal-related arthritis in patients with knee effusion: insights from ultrasonography, microscopy and radiography


Ogun H., TERLEMEZ R., PALAMAR KADIOĞLU D., AKGÜN K., Saridogan F. M.

Clinical Rheumatology, cilt.45, sa.4, ss.2319-2327, 2026 (SCI-Expanded, Scopus) identifier identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 45 Sayı: 4
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1007/s10067-026-07977-4
  • Dergi Adı: Clinical Rheumatology
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, EMBASE, MEDLINE
  • Sayfa Sayıları: ss.2319-2327
  • Anahtar Kelimeler: Calcium pyrophosphate dehydrate deposition disease, Microscopic analysis, Ultrasound
  • İstanbul Üniversitesi-Cerrahpaşa Adresli: Evet

Özet

Objectives: This study aimed to investigate the prevalence of crystal arthritis in patients with unilateral knee effusion and to evaluate the diagnostic performance of US in comparison with radiography. Methods: Patients above 18 years of age presenting with symptomatic unilateral knee effusion were included. Ultrasound of involved knees were performed. Hyperechoic bands within the femoral hyaline cartilage, hyperechoic foci in meniscal fibrocartilage, hyperechoic foci in the effusion and tendon calcifications were recorded as findings of calcium pyrophosphate dehydrate deposition(CPPD) disease and radiographic evaluations were done for searching chondrocalcinosis. SF aspiration was performed for searching crystals microscopically. Microscopic analysis accepted as the gold standard for CPPD, the sensitivity and specificity of US and radiography were assessed. Results: Eighty-five patients with a mean age of 60.98 ± 11.95 years were included. None of them had uric acid crystals. CPPD was diagnosed with detecting CPP crystals in SF analysis in 15 of 85 patients. Two of these patients had coexisting rheumatoid arthritis (RA), 1 spondyloarthritis and 12 osteoarthritis. Of the remaining 70 patients, 1 was considered as spondyloarthritis, 4 as RA and 65 as exacerbation of osteoarthritis. The sensitivity and specificity of US were 93.33% and 80%, while radiography demonstrated values of 46.67% and 98.57%, respectively. Inter- and intra-rater agreement for US were 93.3% and 96.67%, respectively. Conclusion: A notable 17.6% CPPD prevalence in patients with knee effusion suggests that this condition may be underestimated in practice due to diagnostic challenges. Ultrasound showed higher sensitivity than radiography, and specificity increased in parallel with the number of positive findings.