Fusion device

1. A device for positioning between two bone regions, the device comprising:

a body extending along a longitudinal axis between two opposing device ends, a first device end configured to be positioned in use at or adjacent a first bone region and a second device end configured to be positioned in use at or adjacent a second bone region;

a side wall defined by an outer surface and an inner surface extending between the first device end and the second device end, the side wall defining an interior cavity;

at least a first stabilising arrangement extending into the interior cavity from the inner surface of the side wall and located proximal the first device end, the first stabilising arrangement comprising a first plurality of protrusions, each protrusion having two opposing and laterally extending planar surfaces extending to a protrusion end, the protrusion end located within the interior cavity and distal from the inner surface, the planar surfaces comprising a first planar surface facing toward the first device end and a second planar surface facing toward the second device end, the second planar surface forming a shoulder with the protrusion end;

at least a second stabilising arrangement extending from the inner surface of the side wall and located proximal the second device end, the second stabilising arrangement comprising a second plurality of protrusions, each protrusion having two opposing and laterally extending planar surfaces extending to a protrusion end, the protrusion end located within the interior cavity and distal from the inner surface, the planar surfaces comprising a first planar surface facing toward the first device end and a second planar surface facing toward the second device end, the first planar surface forming a shoulder with the protrusion end;

wherein the second surface of the first stabilising arrangement is positioned in a facing arrangement with the first surface of the second stabilising arrangement, at least a portion of each of the laterally extending surfaces extending from the side wall of the body and part way across the inner cavity, the protrusions and the laterally extending surfaces being shaped and spaced apart such that bone growing from one bone region toward the other grows around the stabilising arrangements and mechanically engages the shoulders of the stabilising arrangements to secure the bone with respect to the device and stabilise the bone regions with respect to the device,

wherein the protrusions of the first plurality of protrusions and the protrusions of the second plurality of protrusions are each spaced apart laterally around an interior circumference of the interior cavity such that in a lateral plane plane the protrusions are separated by the inner surface, and

wherein, in a longitudinal plane, the first plurality of protrusions and the second plurality of protrusions are spaced apart from each other along the inner surface of the interior cavity.

2. The device as defined in claim 1 , wherein the protrusion end of each protrusion extends parallel to the inner surface.

3. The device as defined in claim 1 , wherein, for each protrusion, the laterally extending planar surfaces and the protrusion end are perpendicular to one another.

4. The device as defined in claim 1 , wherein the protrusion end of each protrusion comprises a planar surface having both lateral width and longitudinal height.

5. A device as defined in claim 1 , wherein each of the protrusions of the first stabilising arrangement is aligned with a protrusion in the second stabilising arrangement in a longitudinal direction.