An implantable device includes a body and a first mounting strip connected to a trailing end portion of the body. The body has a leading end portion, a first side surface, a second side surface, an upper surface, a lower surface and a central opening extending through the upper and lower surfaces. The central opening has an internal surface with an internal leading surface, a first internal side surface and a second internal side surface. A first depth is defined between the leading end and the internal leading surface, a first spacing is defined between the first side surface and the first internal side surface and a second spacing is defined between the second side surface and the second internal side surface. The first spacing is substantially the same as the second spacing.