Diagnostic accuracy of musculoskeletal ultrasound and conventional radiography in the assessment of the wrist triangular fibrocartilage complex in patients with definite diagnosis of calcium pyrophosphate dihydrate deposition disease.

Objective To compare the diagnostic accuracy of musculoskeletal ultrasound (MSUS) and x-ray in evaluating wrist triangular fibrocartilage complex (TFCC) in patients with calcium pyrophosphate dihydrate deposition disease (CPPD) and to investigate the agreement between the extent of the calcium pyrophosphate dihydrate (CPP) crystal deposits assessed by MSUS and the radiographic findings. Methods We enrolled 84 patients: 36 patients with "definite" CPPD and 48 controls. The Ryan and McCarty diagnostic criteria were used. A rheumatologist performed bilateral MSUS examinations of the TFCC in all patients, assessing both the presence and absence of CCP crystals deposits and their extent (0-3; 0: absent; 1: 1-2 spots; 2: more than two spots covering <50% of the volume of the structure; 3: deposits covering >50% of the volume of the structure). A radiologist evaluated the presence/absence of x-ray calcifications at TFCC level in both groups. Results MSUS and x-ray sensitivity was 77.8% and 76.4%, respectively, whereas MSUS and x-ray specificity was 90.6% and 96.9%, respectively. Total agreement between MSUS and radiographic findings indicative of calcifications at TFCC level was 88.7%. Conclusion This study supports the diagnostic accuracy of MSUS and x-ray in evaluating TFCC crystal deposits in patients with CPPD. Sensitivity and specificity of MSUS and x-ray resulted comparable. The highest MSUS score of the extent of the deposits correlated better with x-ray findings.