Fracture risk in children with a forearm injury is associated with volumetric bone density and cortical area (by peripheral QCT) and areal bone density (by DXA)
- First Online:
- 266 Downloads
Children who sustain a forearm fracture when injured have lower bone density throughout their skeleton, and have a smaller cortical area and a lower strength index in their radius. Odds ratios per SD decrease in bone characteristics measured by peripheral quantitative computed tomography (pQCT) and dual-energy X-ray absorptiometry (DXA) were similar (1.28 to 1.41).
Forearm fractures are common in children. Bone strength is affected by bone mineral density (BMD) and bone geometry, including cross-sectional dimensions and distribution of mineral. Our objective was to identify bone characteristics that differed between children who sustained a forearm fracture compared to those who did not fracture when injured.
Children (5–16 years) with a forearm fracture (cases, n = 224) and injured controls without fracture (n = 200) were enrolled 28 ± 8 days following injury. Peripheral QCT scans of the radius (4% and 20% sites) were obtained to measure volumetric BMD (vBMD) of total, trabecular and cortical bone compartments, and bone geometry (area, cortical thickness, and strength strain index [SSI]). DXA scans (forearm, spine, and hip) were obtained to measure areal BMD (aBMD) and bone area. Receiver operating characteristic (ROC) analyses were used to assess screening performance of bone measurements.
At the 4% pQCT site, total vBMD, but not trabecular vBMD or bone area, was lower (−3.4%; p = 0.02) in cases than controls. At the 20% site, cases had lower cortical vBMD (−0.9%), cortical area (−2.8%), and SSI (−4.6%) (p < 0.05). aBMD, but not bone area, at the 1/3 radius, spine, and hip were 2.7–3.3% lower for cases (p < 0.01). Odds ratios per 1 SD decrease in bone measures (1.28–1.41) and areas under the ROC curves (0.56–0.59) were similar for all bone measures.
Low vBMD, aBMD, cortical area, and SSI of the distal radius were associated with an increased fracture risk. Interventions to increase these characteristics are needed to help reduce forearm fracture occurrence.
KeywordsBone densitometry Epidemiology Fracture Orthopedics Pediatrics QCT
- 20.Landin LA (1983) Fracture patterns in children. Acta Orthop Scand Suppl 54:1–109Google Scholar
- 22.Ogden CL, Kuczmarski RJ, Flegal KM, Mei Z, Guo S, Wei R, Grummer-Strawn LM, Curtin LR, Roche AF, Johnson CL (2002) Centers for Disease Control and Prevention 2000 growth charts for the United States: improvements to the 1977 National Center for Health Statistics version. Pediatrics 109:45–60CrossRefPubMedGoogle Scholar
- 23.Tanner JM (1962) Growth at adolescence. Blackwell Scientific, OxfordGoogle Scholar
- 35.Johnell O, Kanis JA, Oden A, Johansson H, De Laet C, Delmas P, Eisman JA, Fujiwara S, Kroger H, Mellstrom D, Meunier PJ, Melton LJ 3rd, O’Neill T, Pols H, Reeve J, Silman A, Tenenhouse A (2005) Predictive value of BMD for hip and other fractures. J Bone Miner Res 20:1185–1194CrossRefPubMedGoogle Scholar