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

Aims To assess calcaneal ultrasonometry in Charcot osteoarthropathy (CO) and to compare it with densitometry measured by dual energy X-ray absorptiometry (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- and age-matched control subjects. Both calcaneal quantitative ultrasound (QUS) parameter stiffness and bone mineral density (BMD) measured in lumbar spine and femoral neck by DEXA were compared. Collagen type I cross-linked C-telopeptides (ICTP) were used for assessment of bone resorption. Results Patients with acute CO had significantly lower stiffness of the calcaneus in the Charcot and non-Charcot foot (both P < 0.001) and significantly 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 compared 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 significant 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 significant correlation was demonstrated between ICTP and the T-score of stiffness (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 BMD in the lumbar spine and femoral neck, and its association with increased bone resorption indicate that calcaneal ultrasonometry may be useful in diagnosing the acute stage of CO and in assessing the risk of foot fracture.