Buttressing device usable in a vertebral prosthesis

• US 4,657,550 A
• Filed: 01/16/1986
• Issued: 04/14/1987
• Est. Priority Date: 12/21/1984
• Status: Expired due to Fees

• Current Assignee: Youssef H. Daher
• Original Assignee: Youssef H. Daher
• Inventors: Daher, Youssef H.
• Primary Examiner(s): FRINKS, RONALD
• Application Number:
  US06/819,353
• Time in Patent Office: 453 Days
• Field of Search: 623/17, 623/18, 128/92 YM, 128/69, 128/84 R
• US Class Current: 623/17.11
• CPC Class Codes: A61B 17/8695 Washers surrounding screw head in plate hole A61B17/8047, between bone plate and bone A61B17/8028
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30154 square
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30367 with additional means for preventing said rotation
• CPC Class Codes: A61F 2002/30411 having two threaded end parts connected by a threaded central part with opposite threads at its opposite ends, i.e. for adjusting the distance between both end parts by rotating the central part
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/3055 for adjusting length
• CPC Class Codes: A61F 2002/30601 telescopic
• CPC Class Codes: A61F 2002/30772 Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/30787 inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30892 parallel
• 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 2230/0021 square
• CPC Class Codes: A61F 2230/0069 cylindrical

Abstract

A device for maintaining the normal spacing between two vertebrae defining, in the vertebral column, the ends of a cavity resulting from the removal of at least a part of a vertebra comprises two bases each having means for anchorage in one of said end vertebrae; and adjustable buttressing means connecting said bases together.

Claims

1. A device for maintaining the normal spacing between two vertebrae defining, in the vertebral column, the ends of a cavity resulting from the removal of at least a part of a vertebra, said device comprising:

buttressing means including a connecting piece in the form of an elongated nut and a pair of threaded rods engaging said nut, each rod having a free end extending from said nut, said rods being movable with respect to each other in the connecting piece in a direction parallel to the axis of the vertebral column, and

anchorage means including a base provided with a plurality of anchorage points, said base being attached to each of said free ends for anchoring said device between said vertebrae,

at least one of said bases being removably attached to its associated free end by connecting means including a tenon on one of said free end and said associated base and a mortice on the other of said free end and said base, said mortice and said tenon having corresponding cross-sections such that said tenon fits into said mortice.

2. The device of claim 1 wherein said free end is in the form of a tenon and said base is provided with a mortice of corresponding cross-section.

3. A device in accordance with claim 2, wherein said tenon has a polygonal cross-section.

4. A device in accordance with claim 3, wherein said tenon has a cross-section which is at least substantially square.

5. A device in accordance with claim 1 further including a washer adjacent each base and fitted in said anchorage points.

6. A device in accordance with claim 1, wherein said connecting piece is provided with internal threads of opposite directions.

7. A device in accordance with claim 1, wherein means are provided at both ends of said connecting piece for locking said buttressing elements in position.

8. A device in accordance with claim 1, wherein a plurality of orifices are provided in said connecting piece adapted to receive means for rotating said connecting piece.