The challenges of accurately estimating time of long bone injury in children

• “Bone injury” can be defined and diagnosed in different ways.
• Radiologic features of bone healing are a marker of injury.
• Processes within and between individuals effect injury and healing.
• Force, mechanism, and anatomical location of injury affect healing rate.
• Bone growth is superimposed upon childhood injury patterns and healing processes.

The ability to determine the time an injury occurred can be of crucial significance in forensic medicine and holds special relevance to the investigation of child abuse. However, dating paediatric long bone injury, including fractures, is nuanced by complexities specific to the paediatric population. These challenges include the ability to identify bone injury in a growing or only partially-calcified skeleton, different injury patterns seen within the spectrum of the paediatric population, the effects of bone growth on healing as a separate entity from injury, differential healing rates seen at different ages, and the relative scarcity of information regarding healing rates in children, especially the very young. The challenges posed by these factors are compounded by a lack of consistency in defining and categorizing healing parameters.This paper sets out the primary limitations of existing knowledge regarding estimating timing of paediatric bone injury. Consideration and understanding of the multitude of factors affecting bone injury and healing in children will assist those providing opinion in the medical-legal forum.