Tension device for anchoring ligament grafts

• US 5,562,668 A
• Filed: 04/28/1995
• Issued: 10/08/1996
• Est. Priority Date: 07/31/1990
• Status: Expired due to Fees

• Current Assignee: David P. Johnson
• Original Assignee: David P. Johnson
• Inventors: Johnson, David P.
• Primary Examiner(s): Tucker, Guy V.
• Application Number:
  US08/430,293
• Time in Patent Office: 529 Days
• Field of Search: 606/65, 606/66, 606/73, 606/86, 606/53, 606/72, 606/105, 606/99, 606/90, 623/13, 623/16, 623/20
• US Class Current: 623/13.13
• CPC Class Codes: A61F 2/08 Muscles; Tendons; Ligaments sutures A61B17/04
• CPC Class Codes: A61F 2/0811 Fixation devices for tendons or ligaments
• CPC Class Codes: A61F 2002/0829 without deformation of anchor parts, e.g. fixation screws on bone surface, extending barbs, cams, butterflies, spring-loaded pins
• CPC Class Codes: A61F 2002/0852 Fixation of a loop or U-turn, e.g. eyelets, anchor having multiple holes
• CPC Class Codes: A61F 2002/0882 Anchor in or on top of a bone tunnel, i.e. a hole running through the entire bone

Abstract

A screw tensioning device is proposed for holding at least one end of a ligament graft. The device has a thimble (1) which locates in the mouth of a drilling through bone, a nut (2) captively seated in the thimble, and an anchorage element (3) with a screw threaded stud (12) which can engage the nut. Different forms of anchorage elements are provided for different grafts, but each is adapted to securely hold one end of a ligament graft. The anchorage element (3) with a ligament attached is drawn through the drilling from the opposite side to the thimble (1) until the stud (12) engages the nut (2). The nut is then turned by a tool (19) until the required tension is achieved.

Claims

1. A tensioning device for ligament grafts, the device comprising:

a bone engaging thimble;

a generally cylindrical anchorage element having a cylindrical wall, a central longitudinal axis, a first end wall facing the thimble, and a second end wall facing away from the thimble;

screw means cooperating coaxially with said first end wall of the anchorage element for drawing said anchorage element and said thimble together;

a lateral recess formed in a first portion of the cylindrical wall of the anchorage elements, the recess extending from an external surface of the cylindrical wall to the central longitudinal axis of the anchorage element, to accept and retain, in use, an end of a ligament graft;

a second portion of said cylindrical wall dividing said lateral recess from said second end wall of the anchorage element;

a hole extending through said second end wall substantially along said central longitudinal axis from an external end surface of said second end wall to communicate with said lateral recess; and

a slot formed in said second portion of the cylindrical wall and in a radial outer edge of said second end wall, said slot being open at both ends and extending longitudinally from said recess to said external end surface of said second end wall and radially inwards from a radial outer edge of said second portion of the cylindrical wall and the radial outer edge of the second end wall to communicate with said hole, thereby permitting, in use, a portion of a ligament graft adjacent the lateral recess to be passed laterally inwards through the slot to lie within the hole so as to align substantially co-axially with said longitudinal axis of said anchorage element, and wherein the hole and the slot form an opening in the second end wall having a transverse cross-sectional area smaller than a transverse cross-sectional area of said recess.

2. A device as claimed in claim 1, wherein said bone engaging thimble is of hollow cylindrical form having an external flange at one end and an internal shoulder at the other end, the flange being for abutment of bone around the mouth of a drilling in which the remainder of the device is received, and the shoulder being for location and retention of the screw means, which has an external projection for engagement of said shoulder.

3. A device as claimed in claim 2, wherein the flange is at a slant with respect to an axis of the thimble.

4. A device as claimed in claim 2 or 3, wherein the screw means has a detent in one end for turning by a tool entered through the thimble.

5. A device as claimed in claim 1, wherein the screw means is a nut engageable on a threaded portion of said anchorage element.

6. A device as claimed in claim 1, wherein said second portion of the cylindrical wall in which the slot is formed provides a surface facing toward said thimble for abutting a bone fragment at the end of a harvested tendon.

7. A device as claimed in claim 1, further comprising a bollard fixed within the recess to said anchorage element within a substantially cylindrical envelope of said cylindrical wall of the anchorage element for the retention, in use, of an end of a prosthetic anterior cruciate graft.

8. A tensioning device for ligament grafts, the device comprising:

a bone-engaging thimble;

a generally cylindrical anchorage element having a cylindrical wall, a central longitudinal axis, a first end wall facing the thimble, and a second end wall facing away from the thimble;

screw means cooperating with said first end wall of the anchorage element for drawing said anchorage element and said thimble together;

a recess formed in the cylindrical wall of the anchorage element, the recess extending from the external surface of the cylindrical wall to the central longitudinal axis of the anchorage element, to accept and retain, in use, an end of a ligament graft;

a hole extending through said second end wall of the anchorage element substantially along said central longitudinal axis from an external end surface of said second end wall to communicate with said recess for the passage through said hole, in use, of the ligament graft; and

a slot linking the recess to the hole, said slot being open at both ends and extending longitudinally from said recess to said external end surface of said second end wall and radially inwards from a radial outer edge of said cylindrical wall and a radial outer edge of the second end wall to communicate with said hole to allow passage of the ligament graft or insertion of the ligament graft laterally inwards into said anchorage element, and wherein the hole and the slot form an opening in the second end wall having a transverse cross-sectional area smaller than a transverse cross-sectional area of said recess.