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.