"Skeletally immature" refers to a stage in skeletal development where the growth plates (epiphyseal plates) have not yet fused, indicating that the bones are still growing. This status is clinically significant as it affects treatment decisions in paediatric orthopaedics, particularly in fractures, where the risk of malunion or growth disturbances must be considered. An example is the increased risk of limb length discrepancies in children with fractures before skeletal maturity is reached.