Calcaneal ultrasonometry in patients with Charcot osteoarthropathy and itsrelationship with densitometry in the lumbar spine and femoral neck and with markers of bone turnover

Aims To assess calcaneal ultrasonometry in Charcot osteoarthropathy (CO) an d to compare it with densitometry measured by dual energy X-ray absorptiome try (DEXA) and with bone remodelling markers. Patients and methods A group of 16 diabetic patients in the acute stage of CO with a mean age (+/- sd) of 51 +/- 13 years was compared with 26 sex- an d age-matched control subjects. Both calcaneal quantitative ultrasound (QUS ) parameter stiffness and bone mineral density (BMD) measured in lumbar spi ne and femoral neck by DEXA were compared. Collagen type I cross-linked C-t elopeptides (ICTP) were used for assessment of bone resorption. Results Patients with acute CO had significantly lower stiffness of the cal caneus in the Charcot and non-Charcot foot (both P < 0.001) and significant ly lower femoral neck BMD (P < 0.05) in comparison with the control group. The T-score of stiffness was significantly lower in the Charcot foot compar ed with the non-Charcot foot (-3.00 +/- 1.39 vs. -2.36 +/- 1.12; P < 0.01) and significantly lower than the mean T-score of BMD in the lumbar spine (- 0.57 +/- 1.28; P < 0.001) and femoral neck (-1.58 +/- 1.24; P < 0.05). A si gnificant difference in ICTP (8.49 +/- 4.37 vs. 3.92 +/- 2.55 ng/ml; P < 0. 001) between patients with CO and the control group was found, and a signif icant correlation was demonstrated between ICTP and the T-score of stiffnes s (r = -0.73; P < 0.01). Conclusion The lower calcaneal QUS parameter stiffness in the Charcot foot in comparison with the control group, with the non-Charcot foot and with BM D in the lumbar spine and femoral neck, and its association with increased bone resorption indicate that calcaneal ultrasonometry may be useful in dia gnosing the acute stage of CO and in assessing the risk of foot fracture.