Ultrasonographic findings of Achilles tendon and plantar fascia in patients with calcium pyrophosphate deposition disease.

The aims of the study were to detect the frequency of involvement of the Achilles tendon and plantar fascia in patients with calcium pyrophosphate deposition disease (CPPD) by high-frequency gray-scale ultrasonography (US) and power Doppler sonography (PDS) and to correlate these findings with demographic and clinical data. Two groups of patients were enrolled: group I (38 patients with CPPD) and group II (22 patients with knee OA). US/PDS examination of the heels was performed to both groups. In the CPPD group, US/PDS examination of the Achilles tendon revealed: calcification in 57.9%, enthesophytosis in 57.9%, enthesopathy in 23.7%, vascular sign in 21%, bursitis in 13.2%, and cortical bone irregularity in 10.5%. US/PDS examination of plantar fascia in the CPPD group revealed: calcification in 15.8%, cortical bone irregularity in 78.9%, enthesophytosis in 60.5%, and planter fasciitis in 42.1%. In patients with CPPD, age was significantly correlated with enthesophytosis and deep retrocalcaneal bursitis (p = 0.01 and p = 0.04, respectively). Heel tenderness and posterior talalgia were significantly correlated with Achilles tendon enthesopathy, vascular sign, and deep retrocalcaneal bursitis (p = 0.0001 for each). Inferior talalgia was significantly correlated with plantar fasciitis (p = 0.0001). The sensitivity of ultrasonography for detection of calcifications in Achilles tendon and plantar fascia was 57.9% and 15.8%, respectively, and the specificity was 100% for both. To conclude, ultrasonographic Achilles tendon and plantar fascia calcifications are frequent findings in patients with CPPD. These calcifications have a high specificity and can be used as a useful indirect sign of CPPD.