Arm and leg length discrepancy is the difference in size between the length of both arms or both legs, which can occur in the upper and lower parts of either limb. This length difference can be from a few millimeters to a few centimeters. The causes of limb length inconsistency are usually divided into three categories:
1. Congenital causes. A baby may be born with an underlying skeletal disease that affects bone development, and this difference is visible at birth and often becomes more apparent as the child grows. Developmental Dysplasia of the Hip, abbreviated as DDH, is common among infants and young children. The onset of this disease is from the fetal period or during the first year of life and may not be recognized at birth. Some types of bone dysplasia (abnormal bone tissue) can also lead to length differences.
2. Fracture and damage to the growing bone can lead to a difference in the length of the same organ. Fractures that involve the growth center can cause abnormal bone growth. In this case, some types of fractures can cause excessive bone growth, which is mostly seen in femur fractures.
3. Infection or tumor. The presence of a bone infection or bone tumor in a child's developing skeleton can interfere with the growth of his organs. The growth of part of the bone may stop or slow down compared to the related organ.