This specification describes technologies relating to an intervertebral disc prosthesis used to strengthen and stabilize the spine. Implementations of the technology described herein comprise a surgical device that is implanted through a small surgical incision into a portion of a human intervertebral disc, various support tools used to insert such a surgical device, and a method by which the device is used to strengthen and stabilize the spine.

An implantable prosthesis component for a joint prosthesis includes a flexible wall, a proximal side comprising a rigid portion for connecting to a first bone at a joint; and a distal side comprising a rigid portion for connecting to a second bone at the joint. The flexible wall has an inverted spherical shape and defines an inner cavity of the implantable prosthesis component. The inner cavity is filled with a fluid. The flexible wall is deformable such that relative movement between the first and second bone causes deformation of the implantable prosthesis component.