DEVELOPMENT OF A PEDIATRIC FOREARM FINITE ELEMENT MODEL FOR CHARACTERIZING MECHANICAL RESPONSES OF BACKWARD FALL

摘要

Distal radius and carpal fractures in children and adolescent account for approximately 25% of all pediatric fractures. For the age distribution, 5 to 14 years olds group comprised largest proportion (26%) of all hand and forearm fractures than other age groups. Radius and/or ulna fractures took up the largest proportion of fractures (32.9%) in age group 5 to 14 years old. A population-based study revealed that the incidence rate of forearm fractures in boys and girls aged 5 to 14 years increased dramatically. In particular, the age group 10 to 14 has the highest increase in the period from 1997 to 2009. The pediatric musculoskeletal system is distinctly different from that of adult. Although these differences decrease with age, they present unique injury patterns and challenges in the diagnosis and treatment of pediatric orthopedic problems. Pediatric bone is highly cellular and porous, and it contains a great number of collagen and cartilage compared with adult bone. The abundance of collagen leads to a reduction of tensile strength and prevents the propagation of fractures, whereas the large amount of cartilage enhance resilience. The wrist bones consist of eight irregular shape bones: scaphoid, lunate, pisiform, triquetrum, trapezium, trapezoid, capitate and hamte. The pisiform does not appear on radiographs until 9 or 10 years of age. Pediatric forearm fractures has been described in several studies, but the proportion of fractures in these studies are controversial. For example, Katrina et al. indicated that scaphoid fractures are most common in the age 15 to 30 years and are rare under the age of 10, whereas Carson et al. pointed out that as in adults, the scaphoid fracture is the most commonly fracture in children.