Intervertebral devices

Abstract

An anterior lumbar interbody fusion device comprising a superior component, an inferior component, and a locking mechanism. The superior component bottom side and the inferior component top side oppose each other when these are received in the intervertebral space whereby their external sides abut against the respective vertebra, thereby coupling force between the latter. The components inter-engage with each other whereby they are constrained to move in an anterior-posterior direction relative to each other and resistance is presented to movement relative to each other in each of a direction of separation and a direction orthogonal to the anterior-posterior direction and to the direction of separation. The locking mechanism allows for relative movement of the components in the anterior-posterior direction which increases an extent of their overlap and presents resistance to movement of the at least one of the component in the anterior-posterior direction which decreases an extent of their overlap, for instance with a mechanism such as protrusions shaped to engage with set of recesses and sprung cantilever beams forming a ratchet mechanism. Optionally, the fusion device may comprise or lack a core component received between said superior and inferior components.