Pediatric Rheumatology Online Journal → August 2003 → Bone → Abstract #145

DECREASED BONE STRENGTH IN CHILDREN WITH GROWING PAINS (GP) AS MEASURED BY QUANTITATIVE ULTRASOUND

Y. Uziel,¹ O. Friedland,¹ L. Jaber,² A. Cohen,³ A. Eliakim,¹ B. Wolach,¹ P. J. Hashkes.⁴

¹Pediatrics, Meir Hospital, Kfar Saba, Israel; ²Child Health Center, Taibe, Israel; ³Child Health Center, Petah Tikva, Israel; ⁴Pediatrics, Sieff and Poriya Hospitals, Zafed and Tiberias, Israel

BACKGROUND: "Growing pains" (GP), are the most common cause of recurrent childhood musculoskeletal pain. The etiology and pathogenesis are unknown. GP is diagnosed on the basis of typical clinical characteristics. Pain appears late in day or is nocturnal. Quantitative ultrasound (QUS) measurement of bone speed of sound (SOS) was recently developed for diagnosis of osteoporosis. SOS measurements also reflect bone architecture, thickness, and elasticity. Since GP occur most frequently late during the day, often after physical exersion, GP may represent an overuse syndrome. We therefore hypothesized that children with GP have decreased bone strength, which may contribute to their pain.
OBJECTIVE: To investigate whether GP are associated with bone strength changes in painful tibial region.
PATIENTS AND METHODS: We studied 39 children with GP, 15 female (mean age 8.5 ± 3.2 yrs) and 24 male (mean age 7.9± 2.1). Diagnosis was confirmed by a pediatric rheumatologist. Bone SOS was measured by QUS in mid-tibial and radial bones. Unpaired Student t-test was used to compare patients and norms of healthy controls. Pearson and Spearman correlations were used to evaluate relationship between bone SOS and physical activity, calcium intake, and clinical chracteristics of the GP.
RESULTS: Tibial SOS was significantly reduced in children with GP as compared to healthy controls (Z score = -0.55 for males and -0.89 for females, P 0.004, 0.001, respectively). Radial SOS was significantly reduced only in females with GP (Z score = -0.69, P 0.02). No correlation was found between the patient's bone SOS and demographic data, body mass index, calcium intake, physical activity, and GP clinical characteristics.
CONCLUSION: Bone SOS was significantly reduced in children with GP. These results suggest that decreased bone strength may be a contributing factor in the pathogenesis of GP and support the notion that GP may represent an overuse syndrome.