Patent ID: 7942910

Claim:
A spinal fixation system for orthopedic rod implantation, comprising: a bone screw having a threaded shank portion and a substantially spherical head portion; a rod base member having a pair of upright spaced apart arms defining a U-shaped channel, said rod base member having an upper pass through aperture and a lower pass through aperture and an internal cavity extending between said upper pass through aperture and said lower pass through aperture, said internal cavity including a threaded surface that extends the length of said internal cavity from said upper pass through aperture to said lower pass through aperture to allow said threaded shank portion to pass through said internal cavity while retaining said spherical head portion; a monolithic cap member positioned along an end of said spherical head portion, said cap member providing a spherical seating surface for an upper surface of said spherical head and a support base for a stabilizing rod placed within said U-shaped channel, wherein the cap member includes annular ridges on the cylindrical wall of the cap member at the top and bottom thereof; and a set screw threadably engageable along said threaded surface of said internal cavity for engaging said stabilizing rod against said cap member wherein said cap member secures said rod base member in a fixed position by frictional engagement with said spherical head portion of said bone screw.