Rotating, locking intervertebral disk stabilizer and applicator

• US 5,893,890 A
• Filed: 07/25/1997
• Issued: 04/13/1999
• Est. Priority Date: 03/18/1994
• Status: Expired due to Fees

• Current Assignee: Perumala Corporation
• Original Assignee: Perumala Corporation
• Inventors: Pisharodi, Madhavan
• Primary Examiner(s): Prebilic, Paul B.
• Application Number:
  US08/900,174
• Time in Patent Office: 627 Days
• Field of Search: 623/17, 623/66, 606/53, 606/60, 606/61, 606/62, 606/63, 606/66, 606/73
• US Class Current: 623/17.16
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• CPC Class Codes: A61F 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30169 Pi-shaped
• CPC Class Codes: A61F 2002/30214 having tapered sections of different conicities
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30253 ellipsoidal or ovoid
• CPC Class Codes: A61F 2002/30286 barrel-shaped
• CPC Class Codes: A61F 2002/3037 Translation along the common longitudinal axis, e.g. piston
• CPC Class Codes: A61F 2002/30398 Sliding
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30426 Bayonet coupling
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30594 : slotted, e.g. radial or meridian slot ending in a polar aperture, non-polar slots, horizontal or arcuate slots
• CPC Class Codes: A61F 2002/30777 : Oblong apertures
• CPC Class Codes: A61F 2002/30797 : internally-threaded
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30873 : Threadings machined on non-cylindrical external surfaces
• CPC Class Codes: A61F 2002/30879 : Ribs
• CPC Class Codes: A61F 2002/4627 : with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2002/4629 : connected to the endoprosthesis or implant via a threaded connection
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2230/0047 : Pi-shaped
• CPC Class Codes: A61F 2230/0063 : Three-dimensional shapes
• CPC Class Codes: A61F 2230/0067 : conical
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0076 : ellipsoidal or ovoid
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys

Abstract

A middle expanded, removable disk implant for stabilizing adjacent vertebrae. The implant is substantially rectangular in cross-sectional shape with a minimal height and a width greater than the height. The implant is detachably mounted to an applicator for insertion into the anatomical region between two adjacent vertebrae from which a portion of the intervertebral disk has been removed. Once inserted, the implant is positioned by anterior-posterior movement in the disk space to the position in which both the expanded, larger width middle portion and the smaller diameter end portions of the implant engage the bodies of the adjacent vertebrae and the implant is then rotated to bring the sides of the rectangularly-shaped implant defining the width of the implant, with its larger dimension, into engagement with the bodies of the adjacent vertebrae. A lock is then secured to the implant to prevent further rotation thereof.

Claims

1. A stabilizer for implanting in the disk space between adjacent vertebrae of a patient to stabilize the vertebrae comprising:

an elongate implant having a substantially rectangular cross-sectional shape with a minimal height defined by first and second sides and a maximal width defined by third and forth sides, the third and fourth sides being arched from one end of the implant to the other;

a lock means detachably mounted to one end of said implant having a bearing surface thereon for bearing against the adjacent vertebrae to prevent rotation of the implant in the disk space when the implant is inserted into the disk space and rotated so that the third and fourth sides of the implant and the bearing surface of said lock means contact the adjacent vertebrae;

a key formed on the lock means; and

a keyway formed on said implant for receiving said key therein, said keyway having a mouth wider than the width of said key facilitating insertion of said key therein.

2. The stabilizer of claim 1 wherein said keyway is provided with a funnel-shaped portion behind the mouth, the width of the funnel-shaped portion decreasing to the width of said keyway.

3. The stabilizer of claim 1 wherein both the first and second sides of the implant are provided with said keyways.

4. The stabilizer of claim 3 wherein said keyways are provided with funnel-shaped portions behind their respective mouths, the width of the funnel-shaped portions decreasing to the width of said keyways.

7. The stabilizer of claim 1 additionally comprising a bolt for mounting said lock to the implant.

8. The stabilizer of claim 7 additionally comprising a lock nut for preventing the loosening of said lock nut.

5. A spinal stabilizer and applicator comprising:

an elongate implant having a substantially rectangular cross-sectional shape with a minimal height defined by first and second sides and a maximal width defined by third and fourth sides, the third and fourth sides being arched from one end of the implant to the other;

a lock detachably mounted on said implant having a bearing surface formed thereon for bearing against the adjacent vertebrae;

a bore for receiving a bolt therein for mounting said lock to one end of the implant to prevent rotation of the implant in the disk space when the implant is inserted into the disk space and rotated so that the third and fourth sides of the implant and the bearing surface of said lock contact the adjacent vertebrae;

a key formed on the lock;

a keyway formed on the first and second sides of said implant for receiving said key therein, said keyway having a mouth wider than the width of said key and funnel-shaped portions the width of which decreases from the width of the mouth of said keyways to the width of said keyways; and

an applicator detachably mounted to said implant comprised of an elongate handle and a head, said head having prongs formed thereon shaped to fit into the funnel-shaped portions of said keyways.

6. The stabilizer of claim 5 wherein the prongs of the head of said applicator are flush with the surfaces of the first and second sides of the implant when the prongs are engaged to the funnel-shaped portions of said keyways.