US 5,055,104 A · Surgically implanting threaded fusion cages between adjacent low-back vertebrae by an anterior approach

Abstract

When an intervertebral fusion is required, and the disc space is unusualy large, that disc space can be preserved by surgically implanting a pair of relatively large male-thread fusion cages 20, 20A with their threads 13 overlapping. Because of their large size, such fusion cages 20, 20A should be implanted by an anterior approach to the lower back. When each of the cages is made of a shape-retaining helix 22 of wire that is hollow within the helix 22 and has openings 23 between adjacent turns, the cages 20, 20A can be removed after the adjacent vertebrae have become fused together and without disrupting that fusion, thus guarding against possible rejection of the cages 20, 20A by the patient's body. The anterior approach and scaled-down fusion cages 20, 20A may be used in cervical spine fusions.

Claims20

Dependent claims

A fusion cage system for being implanted in and promoting fusion with respect to one of more bone structures, said fusion cage system for containing bone-growth-inducing substance packed therein for accelerating bone fusion, said fusion cage system comprising:

a first fusion cage which has a first outside dimension and a first internal cavity means for being packed with the bone-growth-induction substance;
a second fusion cage which has a second outside dimension and a second internal cavity means for being packed with the bone-growth-inducing substance;
at least one of the first fusion cage and the second fusion cage including means for allowing said first and second fusion cages to be positioned adjacent each other such that an outside dimension of the combination of the first fusion cage positioned adjacent the second fusion cage is less than the sum of the first outside dimension and the second outside dimension.

A fusion cage system for being implanted in and promote fusion with respect to one or more bone structures, said fusion cage system for containing bone-growth-inducing substance packed therein for accelerating bone fusion, said fusion cage system comprising:

a first fusion cage which is comprised of a first helical structure having a first inner surface which defines a first internal cavity, which first helical structure including a plurality of spaced apart first turns, said first helical structure having a first outer diameter;
a second fusion cage which is comprised of a second helical structure having a second inner surface which defines a second internal cavity, said second helical structure including a plurality of spaced apart second turns, said second helical structure having a second outer diameter;
wherein the spacing of the first turns and the spacing of the second turns is such that the first turns can intermesh with the second turns when the first fusion cage is implanted beside the second fusion cage with respect to the one or more bone structures, with the overall dimension of the first fusion cage intermeshed with the second fusion cage being less than the sum of the first outer diameter and the second outer diameter.

Dependencies are inferred from the claim text.

Surgically implanting threaded fusion cages between adjacent low-back vertebrae by an anterior approach

Life of this patent

Surgically implanting threaded fusion cages between adjacent low-back vertebrae by an anterior approach

Life of this patent

Abstract

Claims20