Intervertebral implant

An intervertebral implant is provided comprising a single piece hollow body with an upper wall configured to engage a first vertebral end plate and a lower wall configured to engage a second vertebral end plate, with two opposite sidewalls connecting the upper wall and the lower wall, respectively, and with a load transmitting part configured to transmit load between the upper wall and the lower wall; wherein the body is configured to assume a compressed condition in which a distance between the upper wall and the lower wall defines a first height (h₁) of the implant and an expanded condition in which the distance between the upper wall and the lower wall defines a second height (h₂) of the implant that is greater than the first height (h₁); and wherein the implant is made of a material that exhibits shape memory properties.