A radially compressed xerogel spinal nucleus implant is manufactured and utilized for implantation into an intervertebral disc space. The implant has an optimized cross-sectional ellipsoid configuration which facilitates insertion of the implant through a minimal incision in the annulus. Radial compression is achieved by exerting substantially equilateral circumferential compression on an object contained within a radially collapsible member for exerting substantially equilateral circumferential compression on the object. Radial compression may also be achieved by exerting substantially equilateral circumferential compression force on a spinal nucleus implant via gas pressure in a sealed chamber.