Decreased bone speed of sound in children with growing pains measured by quantitative ultrasound.

OBJECTIVE: The most common cause of recurring childhood musculoskeletal pain is termed growing pains (GP). We hypothesized that GP may represent a local overuse syndrome and therefore may be associated with decreased bone speed of sound (SOS) measured by quantitative ultrasound (US). METHODS: We studied 39 children with GP. Bone SOS was measured by US in both mid-tibial and radius bones according to a validated protocol. Unpaired Student t test was used to compare patients and norms of healthy controls. RESULTS: Tibial SOS was significantly reduced in children with GP compared to controls (Z score -0.546 for boys and -0.891 for girls; p = 0.004, p < 0.001, respectively). Radius SOS was significantly reduced only in girls with GP (Z score -0.692, p = 0.006). No correlation was found between bone SOS and various demographic and clinical factors besides the child's ethnicity and body mass index. CONCLUSION: Bone SOS was significantly reduced in children with GP, especially in painful tibial regions. GP may represent a local overuse syndrome.