WO2015009935A1

WO2015009935A1 - Surgical implant and method of use thereof

Info

Publication number: WO2015009935A1
Application number: PCT/US2014/047037
Authority: WO
Inventors: Brett OWENS
Original assignee: Brett Owens
Priority date: 2013-07-19
Filing date: 2014-07-17
Publication date: 2015-01-22

Abstract

A surgical implant (10) for use in anterior cruciate ligament (ACL) reconstruction of the soft tissue (52) of the knee joint, comprising an elongated body with a through hole (18) defined by the body, the center of the through hole being located midway between the sides of the body and offset toward and end of the body. The offset position of the through hole facilitates rotation of the body and an interference fit of the body in a bone tunnel (48) during use. The surgical implant described herein enables suspensory fixation to a bone tunnel and direct attachment of the soft tissue to the surgical implant without the need of attachment to a suture or external fixation devices.

Description

SURGICAL IMPLANT AND METHOD OF USE THEREOF

BACKGROUND

The invention described herein relates generally to medical instruments and, more particularly, to surgical implants for attaching tissue to bone.

Anterior cruciate ligament (ACL) reconstruction is a surgical tissue graft replacement of the anterior cruciate ligament, located in the knee, to restore its function after injury. The torn ligament is removed from the knee before a graft (often a piece of tendon from the knee, leg, or another part of the body) is inserted. The surgery is performed as an arthroscopic surgery, a minimally- invasive surgical procedure.

In order to effectively and efficiently attach the tissue graft to the bone during ACL reconstruction, a surgical implant is needed. A common practice is to use a suture anchor to attach a suture to the bone and thereafter tie the tendon to the suture in order to effect attachment of the tendon to the bone. However, this approach creates unnecessary risks of failure. For example, the suture may become detached from the anchor, or the process of suturing the tendon to the anchor may actually weaken the strength of the tendon or cause it to tear. A better technique would involve a direct attachment of the tendon itself to the surgical implant which would be secured within the bone.

Another common practice is to use suspension fixation buttons that are hinged on the outer femoral cortex (that is, the denser, outer shell of bone), or interference screws that are placed at the aperture, or opening into the knee joint. However, it has been hypothesized that femoral notching weakens the cortex of the femur, which can predispose a patient to femoral fractures in the early postoperative period. Furthermore, such devices may be overly complex to insert, and may require multiple steps or parts.

Accordingly, there is a need for a simple device that would directly attach a tendon to a surgical implant secured within a bone, with minimum drilling into the femoral cortex and elimination of external fixation devices. SUMMARY

The invention described herein is a surgical implant for use in ACL reconstruction of the soft tissue of the knee joint. The surgical implant described herein enables direct attachment of the soft tissue (such as a tendon) to the surgical implant without the need of attachment to a suture. The surgical instrument described herein can also be suspended within a bone by an interference fit, with minimal drilling, and without the need for external fixation devices.

In one example, the surgical implant described herein comprises an elongated body, the elongated body comprising a proximal end, a distal end, and a longitudinal axis extending between the proximal and distal ends, the elongated body being curved along the longitudinal axis; a first lateral edge at the proximal end, the first lateral edge being orthogonal to the longitudinal axis and having a first length; a second lateral edge at the distal end, the second lateral edge being orthogonal to the longitudinal axis and having a second length that is longer than the first length, the second lateral edge having at least one tapered surface; a first side and an opposing second side extending between the first and second lateral edges; a through hole defined by the elongated body for receiving a tissue graft and a suture, the through hole having a center located midway between the first and second sides and being offset towards the proximal end of the body; wherein the first and second lateral edges engage a bone tunnel when the elongated body is rotated from an undeployed position with the longitudinal axis of the body substantially parallel to a long axis of the bone tunnel to a deployed position with the longitudinal axis of the body substantially perpendicular to the long axis of the bone tunnel.

As further described in the examples herein, the first lateral edge of the surgical implant comprises at least one outward projection. The angle of the curve of the elongated body is selected to facilitate rotation of the elongated body within the bone tunnel. The height of the first and second sides is less than a distance between the first lateral edge and the second lateral edge. The through hole is substantially oval and the at least one tapered surface is substantially trapezoidal. The elongated body is constructed from any one of plastic, metal, biocomposite/bioresorbable materials, and combinations thereof. The second length of the second lateral edge is selected based on the width of the bone tunnel is between about 8mm and 10mm. The distance between the first lateral edge and the second lateral edge along the longitudinal axis is at least 15mm, and preferably between about 20mm to 22mm. The height or thickness of the first and second sides is between about 1.5mm and 2.0mm.

The methods of using the current invention include the steps of: (a) drilling a femur pilot hole through the femur of a patient; (b) overdrilling the femur pilot hole part way through the femur to form a bone tunnel, the bone tunnel having a long axis; (c) providing a surgical implant having an elongated body, the elongated body comprising a proximal end, a distal end, a longitudinal axis extending between the proximal and distal ends, a through hole defined by the body, a first lateral edge at the proximal end and a second lateral edge at the distal end; (d) passing an end of a suture through the through hole of the elongated body; (e) passing an end of a tissue graft through the through hole of the elongated body; (f) passing the end of the suture and an opposite end of the suture through the bone tunnel and out of the femur pilot hole; (g) pulling the ends of the suture in the direction of the femur, causing the surgical implant to enter the bone tunnel in an undeployed position, the longitudinal axis of the elongated body being substantially parallel to the long axis of the bone tunnel; and (h) pulling the end of the tissue graft in the direction of the tibia, causing the surgical implant to rotate to a deployed position, the longitudinal axis of the elongated body being substantially perpendicular to the long axis of the bone tunnel, and the first and second lateral edges engages the bone tunnel. The steps optionally include, prior to step (b): (al) drilling a tibia pilot hole through a tibia adjacent to the femur of the patient; and (a2) overdrilling the tibia pilot hole through the tibia to form a portion of the bone tunnel or, after step (h), removing the suture from the surgical implant through the femur pilot hole.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of the examples, as illustrated in the accompanying drawings, in which:

FIG. 1 is a perspective illustration of a surgical implant of the current invention;

FIG. 2 is a perspective illustration of the method of using the current invention; FIG. 3 is a further illustration of the methods of using the current invention; and FIGs. 4a-b are further illustrations of the methods of using the current invention.

DETAILED DESCRIPTION

In the description that follows, like components have been given the same reference numerals, regardless of whether they are shown in different examples. To illustrate an example(s) of the present invention in a clear and concise manner, the drawings may not necessarily be to scale and certain features may be shown in somewhat schematic form.

Features that are described and/or illustrated with respect to one example may be used in the same way or in a similar way in one or more other examples and/or in combination with or instead of the features of the other examples.

As used in the specification and in the claims, the singular form of "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

As used in the specification and in the claims, for the purposes of describing and defining the invention, the terms "about" and "substantially" are used represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The terms "about" and "substantially" are also used herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.

Referring now to FIG. 1, an example of the surgical implant 10 for attaching tissue to bone is shown. The surgical implant 10 comprises an elongated body 12 with a proximal end 14 and a distal end 16. The elongated body can be comprised of plastic, metal, biocomposite/ bioresorbable or other suitable materials, and combinations thereof. The surface of the elongated body 12 is shown as being curved along the longitudinal axis 20. The angle of the curve may also vary, but is selected to facilitate rotation of the elongated body 12 when a force (tension) is applied to the distal end 16. The proximal end 14 of the elongated body 12 comprises a first lateral edge 22 and the distal end 16 comprises a second lateral edge 24. Both first and second lateral edges 22, 24 are orthogonal to the longitudinal axis 20. As shown in FIG. 1, the first lateral edge 22 may contain at least one outward projection 26. The length of the first lateral edge 22 is variable but is less than the length of the second lateral edge 24. The second lateral edge 24 comprises at least one tapered surface 32. Each tapered surface 32 can be substantially trapezoidal. The length of the second lateral edge 24 is selected based on the width of a standard surgical bone tunnel, and may be between about 8mm and 10mm. The distance between the first lateral edge 22 and the second lateral edge 24 is selected to provide an adequate amount of tissue graft to obtain graft healing within a bone tunnel and to provide resistance to dislodging by an interference fit against the walls of a bone tunnel. The distance may be at least 15mm but more preferably is between about 20mm to 22mm.

As also shown in FIG. 1, the elongated body 12 further comprises a first side 23 and an opposing second side 25 extending between the first and second lateral edges 22, 24. The height of the first and second sides 23, 25 is shown as less than a distance between the first and second lateral edges 22, 24, although the height (thickness) of the first and second sides 23, 25 can vary but may be between about 1.5mm and 2.0mm.

FIG. 1 also shows a through hole 18 defined by the elongated body 12, with its center located midway between the first and second sides 23, 25 and offset towards the proximal end of the elongated body 12. The offset center of the through hole 18 also facilitates rotation of the elongated body 12 during use. The through hole 18 is shown as substantially oval, but other shapes are possible. The size of the through hole 18 can also vary but is selected to receive both a tissue graft and a draw suture without damage to either and without

compromising the structural integrity of the elongated body 12.

FIG. 2 shows a basic illustration of a typical knee joint 40 between a tibia 44 and a femur 46 of a patient. When a surgeon performs an ACL reconstruction, the surgeon may start by drilling a femur pilot hole 42 beginning in an area adjacent to the tibia 44 and through the femur 46 of a patient. Next, the surgeon may overdrill the femur pilot hole 42 part way through the femur to form a bone tunnel 48. In addition, as an optional step, the surgeon may also drill a tibia pilot hole 43 through the tibia 44 adjacent to the femur 46 and then overdrill the tibia pilot hole 43 through the tibia 44 to form a portion of the bone tunnel 48. Referring now to FIG. 3, one end of the tissue draft 52 is shown as passing through the through hole 18 of surgical implant 10. An end of the draw suture 50 is also passed through the through hole 18 as shown.

Referring now to FIG. 4a, the surgeon next passes both free ends of the draw suture 50 through the bone tunnel 48 and out of the femur pilot hole 42, thus causing the surgical implant 10 to enter the bone tunnel 48 in an undeployed position, with the longitudinal axis 22 of the elongated body 12 substantially parallel to the long axis of the bone tunnel 48. As shown in FIG. 4b, the surgeon then pulls on the end of the tissue graft 52 in the direction of the tibia. Because of the offset position of the through hole 18, this causes the surgical implant 10 to rotate to a deployed position, with the longitudinal axis 22 of the elongated body 12 substantially perpendicular to the long axis of the bone tunnel 48. Due to the force of pulling, the first and second lateral edges 22, 24 engage the walls of the bone tunnel 48 and penetrate the softer cancellous bone 54. The second lateral edge 24 comes to rest on and is supported by the harder outer cortex of bone tissue 56. Once the surgical implant 10 is in place, the surgeon may remove the draw suture 50 from the surgical implant by pulling an end of the draw suture 50 through the femur pilot hole 42.

These and other features and characteristics, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of claims.

Claims

What is claimed is: CLAIMS

1. A surgical implant for attaching tissue to bone, the surgical implant comprising: an elongated body comprising a proximal end, a distal end, and a longitudinal axis extending between the proximal and distal ends, the elongated body being curved along the longitudinal axis;

a first lateral edge at the proximal end, the first lateral edge being orthogonal to the longitudinal axis and having a first length;

a second lateral edge at the distal end, the second lateral edge being orthogonal to the longitudinal axis and having a second length that is longer than the first length, the second lateral edge having at least one tapered surface;

a first side and an opposing second side extending between the first and second lateral edges;

a through hole defined by the elongated body for receiving a tissue graft and a suture, the through hole having a center located midway between the first and second sides and being offset towards the proximal end of the body; and

wherein the first and second lateral edges engage a bone tunnel when the elongated body is rotated from an undeployed position with the longitudinal axis of the body substantially parallel to a long axis of the bone tunnel to a deployed position with the longitudinal axis of the body substantially perpendicular to the long axis of the bone tunnel.

2. The surgical implant of claim 1 wherein the first lateral edge comprises at least one outward projection.

3. The surgical implant of claim 1 wherein the angle of the curve of the elongated body is selected to facilitate rotation of the elongated body within the bone tunnel.

4. The surgical implant of claim 1 wherein a height of the first and second sides is less than a distance between the first lateral edge and the second lateral edge.

5. The surgical implant of claim 1 wherein the through hole is substantially oval.

6. The surgical implant of claim 1 wherein the at least one tapered surface is

substantially trapezoidal.

7. The surgical implant of claim 1 wherein the elongated body is constructed from any one of plastic, metal, biocomposite/bioresorbable materials, and combinations thereof.

8. The surgical implant of claim 1 wherein the second length of the second lateral edge is selected based on the width of the bone tunnel.

9. The surgical implant of claim 8 wherein the second length is between about 8mm and 10mm.

10. The surgical implant of claim 1 wherein a distance between the first lateral edge and the second lateral edge along the longitudinal axis is at least 15mm.

11. The surgical implant of claim 10 wherein a distance between the first lateral edge and the second lateral edge along the longitudinal axis is between about 20mm to 22mm.

12. The surgical implant of claim 1 wherein the height or thickness of the first and second sides is between about 1.5mm and 2.0mm.

13. A method of attaching tissue to bone, the method comprising the steps of:

(a) drilling a femur pilot hole through the femur of a patient;

(b) overdrilling the femur pilot hole part way through the femur to form a bone tunnel, the bone tunnel having a long axis; (c) providing a surgical implant having an elongated body, the elongated body comprising a proximal end, a distal end, a longitudinal axis extending between the proximal and distal ends, a through hole defined by the body, a first lateral edge at the proximal end and a second lateral edge at the distal end;

(d) passing an end of a suture through the through hole of the elongated body;

(e) passing an end of a tissue graft through the through hole of the elongated body;

(f) passing the end of the suture and an opposite end of the suture through the bone tunnel and out of the femur pilot hole;

(g) pulling the ends of the suture in the direction of the femur, causing the surgical implant to enter the bone tunnel in an undeployed position, the longitudinal axis of the elongated body being substantially parallel to the long axis of the bone tunnel; and

(h) pulling the end of the tissue graft in the direction of the tibia, causing the surgical implant to rotate to a deployed position, the longitudinal axis of the elongated body being substantially perpendicular to the long axis of the bone tunnel, and the first and second lateral edges engages the bone tunnel.

14. The method of claim 13 further comprising, prior to step (b):

(al) drilling a tibia pilot hole through a tibia adjacent to the femur of the patient; and (a2) overdrilling the tibia pilot hole through the tibia to form a portion of the bone tunnel.

15. The method of claim 13 further comprising, after step (h), removing the suture from the surgical implant through the femur pilot hole.

16. The method of claim 13 wherein the first lateral edge comprises at least one outward projection.

17. The method of claim 13 wherein a distance between the first lateral edge and the second lateral edge along the longitudinal axis is at least 15mm.

18. The method of claim 17 wherein a distance between the first lateral edge and the second lateral edge along the longitudinal axis is between about 20mm to 22mm.