Bone status assessment in Japanese subjects using speed of sound along the tibia.

Objectives: To explore the potential use of ultrasound measurement (SoundScan 2000 Compact, Myriad Ultrasound Systems Ltd., Rehovot, Israel), and to assess both quantitative and qualitative properties of bone.

Methods: The speed of sound waves (SOS; m/s) propagating along the cortical bone was determined at the tibial shaft. The performance, reliability, validity, and clinical application of this system were evaluated in Japanese subjects.

Results: In phantom experiments, validity of this system was 0.04 (%), coefficient variation (CV: %) in same-day tests was 0.12, in five-separate-day tests was 0.13, and in independent operators was 0.11, respectively. In experiments with Japanese subjects, CV in same-day tests was 0.38, in five-separate-day tests was 0.99, and in independent operators was 0.90, respectively. In addition, cortical bone status of 1176 Japanese subjects (372 males, 804 females) was clinically evaluated by SoundScan 2000 Compact. SOS was negatively correlated with body fat percentage (%), body fat (kg) and waist hip ratio in females and subjects with higher weight bearing index (leg strength/body weight; WBI) have higher SOS in females under the age of forty.

Conclusions: These findings indicate that the SoundScan 2000 Compact is a highly reliable and valid method for determining cortical bone status and body composition and WBI are closely related to cortical bone status in Japanese females.