Foerearm stability is provided by a complex interplay of the bony and osseo-ligamentous structures which constitute the forearm unit. Consequently, fractures of the radius and/or ulna with concurrent injuries to the stabilizing ligamentous structures can lead to chronic instability and dysfunction if treated incorrectly. Seen in both the adult and paediatric populations, correct diagnosis and management are essential to prevent long-term forearm pain and instability. This article covers the three main instability pattern injuries of the forearm with a focus on anatomy, biomechanics and surgical principles of acute and chronic reconstruction.