# Patent

## Title
Chondral defect repair

## Abstract

A tissue repair device. The tissue repair device includes a tubular shaft having a longitudinal bore for delivering biological material to a soft tissue defect, and an awl having a distal end configured for microfracturing bone underlying the defect. The tubular shaft and the awl are movable relative to one another such that the awl is at least partially positioned within the longitudinal bore of the tubular shaft.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 11/504,882 filed on Aug. 16, 2006.
This application is related to U.S. patent application Ser. No. 11/739,768 filed on Apr. 25, 2007.
This application is related to U.S. patent application Ser. No. 11/740,035 filed on Apr. 25, 2007.
The disclosures of the above applications are incorporated herein by reference.


INTRODUCTION
Articular cartilage can be damaged by trauma or degenerative diseases. Articular cartilage has limited capacity for regeneration, and cartilage defects can penetrate to subchondral bone. Known treatments for cartilage defects depend on the extent of the chondral defect and can include any of the following and their combinations: removing the damaged cartilage; microfracturing the underlying bone; cell or tissue transplantation; and injection of biological materials or therapeutic agents to facilitate repair or regeneration.
The present teaching generally provide an instrument and associated method for repairing chondral defects.
SUMMARY
The present teachings provide a tissue repair device. In one aspect, the tissue repair device includes a tubular shaft having a longitudinal bore for delivering biological material to a soft tissue defect, and an awl having a distal end configured for microfracturing bone underlying the defect. The tubular shaft and the awl are movable relative to one another such that the awl is at least partially positioned within the longitudinal bore of the tubular shaft.
In another aspect, the tissue repair device can include a handle having a slider, a delivery shaft having a proximal end a distal end and defining longitudinal bore for delivering biological material, the proximal end of the delivery shaft coupled to the handle, and an awl received in the longitudinal bore in the delivery shaft, the awl having a distal tip configured for microfracturing. The awl can move by the slider between a first retracted position in which distal tip of the awl is inside the delivery shaft and a second extended position in which the distal tip of the awl is extended out of the distal end of the delivery shaft.
The present teachings provide a method of repairing a chondral defect. In one aspect, the method includes engaging a distal end of a delivery tube to the defect, positioning a distal tip of an awl outside the distal end of the delivery tube, microfracturing the bone with the distal tip of the awl, positioning the distal tip of the awl into the delivery tube, and delivering biological material through the delivery tube into the defect.
In another aspect, the method includes making an arthroscopic incision to the joint bone, exposing a chondral defect, anchoring a distal tip of a delivery tube of a tissue repair device to the defect, exposing a distal tip of an awl coupled to the tissue repair device outside the distal tip of the delivery tube and into the joint bone, and microfracturing the bone underlying the defect. The method further includes enclosing the distal tip of the awl into the delivery tube, delivering biological material through the delivery tube to the defect, removing the delivery shaft from the incision, and closing the incision.
Further areas of applicability of the present invention will become apparent from the description provided hereinafter. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the invention.



BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is an environment isometric view of a tissue repair device according to the present teachings;
FIG. 1A is an isometric view of the proximal portion of the repair of FIG. 1;
FIG. 1B is a cross-sectional view of through a delivery shaft of a tissue repair device according to the present teachings;
FIG. 1C is a cross-sectional view of through a delivery shaft of a tissue repair device according to the present teachings;
FIG. 1D is a cross-sectional view of through a delivery shaft of a tissue repair device according to the present teachings;
FIG. 1E is a cross-sectional view of through a delivery shaft of a tissue repair device according to the present teachings;
FIG. 1F is a cross-sectional view of through a delivery shaft of a tissue repair device according to the present teachings;
FIG. 2 is an isometric view of the repair of FIG. 1, shown in a position with a retracted tip;
FIG. 3 is an isometric view of the repair of FIG. 1, shown in a position with an extended tip; and
FIG. 4 is an environment isometric view of a tissue repair device according to the present teachings;



DESCRIPTION OF VARIOUS ASPECTS
The following description is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. For example, although the present teachings are illustrated for repairing chondral defects in knee surgery, the present teachings can be used to repair and facilitate healing or regeneration of any injured tissue.
The present teachings provide a tissue repair device 100 that combines in a single instrument an awl 106 for microfracturing bone under a tissue repair site or defect 82, and a delivery shaft 108 for delivering biological material to the repair site. The awl 106 and the delivery shaft 108 can be coupled to a handle 102, such that the awl 106 and the delivery shaft 108 can move relative to one another. In one aspect, illustrated in FIGS. 1 and 2, the awl 106 is retractably coupled to the handle 102, while the delivery shaft 108 is fixed relative to the handle 102. In another aspect, illustrated in FIG. 4, the delivery shaft 108 is retractably coupled to the handle 102, while the awl 106 is fixed relative to the handle 102. In each aspect, the relative motion between the awl 106 and the delivery shaft 108 operates to present a first configuration in which a distal tip 112 of the awl 106 is exposed and positioned outside the delivery shaft 108 and a second configuration in which the distal tip 112 of the awl 106 is covered and positioned inside the delivery shaft 108.
Referring to FIGS. 1-3, an exemplary tissue repair device 100 is illustrated. The tissue repair device 100 can include a gripping handle 102, a slider 104 that can be linearly moved to operate a retractable awl 106, and an access port 110 that communicates with a tubular delivery shaft 108. The delivery shaft 108 can be in the form of a hypodermic tube or a cannula or surgical needle, for example. The retractable awl 106 can be a solid shaft and can have an outer diameter D1 and a sharp or piercing distal tip 112 configured for microfracturing bone. The delivery shaft 108 can define an inner longitudinal bore 114 communicating with the access port 110 and having an inner diameter D.
In one aspect, the inner diameter D of the inner bore 114 can be sufficiently larger than the outer diameter or other outer dimension D1 of the awl 106, such that an annular passage 130 is formed between the inner bore 114 and surrounding the awl 106 for allowing unobstructed flow of biological material, as shown in FIG. 1B. In another aspect, the awl 106 can be solid shaft having a D-shaped cross-section and received in the inner bore 114, such that a one-sided passage 130 is defined between the inner bore 114 and the awl 106 for passage of biological material, as shown in FIG. 1C. In another aspect, the awl 106 can have an external longitudinal channel, groove or slot 132 defining the passage 130, as shown in FIG. 1D. It will be appreciated that the cross-section of the awl 106 can be of other shapes, such as triangular, oval, polygonal, partly concave, etc., such that one or more passages 130 can be defined between the inner bore 114 and the outer surface of the awl 106. A seal 134 can placed on the awl 106 between the access port 110 and the opening into the cavity 136 of the handle 102 to prevent biological material for flowing into the handle 102, as shown in FIG. 3. The seal 134 can be made of rubber silicone or other sealing material. In another aspect, the awl 106 can be retracted completely into the handle 102 behind the access port 110, such that biological material can flow through the entire volume of the inner bore 114 of the delivery shaft 108.
In another aspect, the inner bore 114 can have an external longitudinal channel, groove or slot 132 defining the passage 130 for the flow of biological material, as shown in FIG. 1E. The outer dimension D1 of the awl 106 can be substantially equal to the diameter D of the inner bore 114, except around the passage 130, where the inner bore 114 can have an inner dimension D′, which is locally is greater than the outer dimension D1 of the awl 106.
Referring to FIG. 1F, the outer dimension D1 of the awl 106 can be substantially equal to the diameter D of the inner bore 114. The passage 130 can be defined by a longitudinal hole or opening 132 defined longitudinally inside and along the wall of the delivery shaft 108. The opening 132 does not communicate with the inner bore 114 in this aspect.
The delivery shaft 108 can include a distal tip 116 configured for anchoring or biting onto tissue and preventing sliding of the delivery shaft 108. The distal tip 116 can be a sharp or toothed tip 116 or can have other features for engaging tissue and preventing sliding. The access port 110 can be in the form of a luer lock or can include a luer lock 118 for quick connection with a delivery device 120, such as a syringe or cannula or pumping device. The access port 110 can be used to deliver nutrients or other biological materials through the delivery shaft 108 to a chondral defect 82 associated with a joint surface 80.
The slider 104 of the tissue repair device 100 can be operated to move the retractable awl 106 between a retracted position illustrated in FIG. 2 and an extended position illustrated in FIG. 3. In the extended position, the distal tip 112 of the awl 106 can be used to microfracture the area of the bone 80 underlying the defect 82. After microfracturing, the awl 106 can be moved to the retracted position into the delivery shaft 108, and nutrients can be delivered from the access port 110 through the space between the inner bore 114 of the delivery shaft 108 and the awl 106 and into the defect 82. The handle 102 of the repair device 100 can incorporate a double click or other sound mechanism to alert the operating surgeon that a proper depth into tissue has been achieved for microfracturing.
Referring to FIGS. 1-1A, an exemplary procedure for repairing a chondral defect 82 is illustrated. With the knee in flexion, an arthroscopic incision can be made and held open to expose the defect 82. The defect 82 or a portion of the defect 82 and or other tissue may be optionally removed. In an illustrative procedure, the distal tip 116 of the delivery shaft 108 of the tissue repair device 100 can be supported on the site of the defect 82. The slider 104 can be operated to move the awl 106 from a first retracted position to a second extended position for microfracturing. The distal tip 112 of the awl 106 can pierce the bone under the defect 82 at several points to cause localized bleeding from the underlying bone 80 into the area of the defect 82. The blood from the underlying bone 80 can generally contain whole blood and various blood components, including bone marrow and the accompanying stem cells. The induced bleeding can form a blood clot that releases cartilage building cells. It can be beneficial to sufficiently shape the surrounding cartilage such that the microfracture blood containing the chondrocytes can integrate into healthy tissue. Microfracture can be particularly useful for cartilage injuries, arthritis, lesions, chondral lesions, and traumatic injuries.
In an alternate aspect, and referring to FIG. 4, the awl 106 can be fixed relative to the handle 102, and the delivery shaft 108 can be moved relative to the awl 106. The delivery shaft 108 can be coupled to the slider 104, such that moving the slider 104 forward, i.e., toward the distal tip 116 of the delivery shaft 108, moves the delivery shaft 108 to a position in which the entire awl 106, including the distal tip 112 of the awl 106, is inside the bore 114 of the delivery shaft 114. Moving the slider 104 in an opposite direction moves the delivery shaft 108 away from the distal tip 112 of the awl 106, thereby exposing the distal tip 112 of the awl 106.
The distal tip 112 of the awl 106 can be substantially straight, as shown in FIG. 1, or angled and/or curved, as shown in FIG. 4. When an angled distal tip 112 is used with the movable delivery shaft 108 of FIG. 4, the awl 106 or at least a portion of the awl 106 that includes the distal tip 112 can be made of shape memory material, such as nitinol, and trained to take an angled or curved shape when not constrained within a substantially rigid delivery shaft 108. Thus, the distal tip 112 can assume a straight configuration inside the bore 114 of the delivery shaft 108, and revert to the angled configuration when exposed outside the delivery shaft 108.
In another aspect, the delivery shaft 108 can be made of elastically deformable material, such as rubber, such that the delivery shaft 108 can deform sufficiently to accommodate the curved or angled distal tip 112 of the awl 106, which does not change to straight configuration inside the delivery shaft 108.
Biological material can be delivered from a delivery device 120 through the access port 110 into the delivery shaft 108 into the defect 82. The biological materials can be in the form of autologous material harvested from the patient, allogenic, xenograft or recombinant cells and factors derived from blood, bone marrow aspirate, or adipose tissue, and can contain various growth factors, stem cells, and activators with or without adhesive properties. Various other biological materials that can be used are described in co-pending and commonly assigned U.S. patent application Ser. No. 11/739,768 and Ser. No. 11/740,035, both filed on Apr. 25, 2007, and incorporated by reference herein.
Accordingly, the repair device 100 is an integrated instrument that can be used for both microfracturing and delivering biological materials at a defect site in a single operation and without having to remove the distal tip 116 from the defect site 82. Using an integrated instrument can save the surgeon valuable operating time and simplify the surgical procedure.
Further, it will be appreciated from the above description that the repair device 100 can be used for many applications requiring microfracturing and/or delivery of biological materials or nutrients to tissue.
The foregoing discussion discloses and describes merely exemplary arrangements of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.

## Claims

1. A method of repairing a chondral defect of a bone, the method comprising:
engaging a distal end of a delivery tube to the defect;
positioning only a distal tip of an awl outside the distal end of the delivery tube, the awl remaining in a longitudinal inner bore of the delivery tube;
microfracturing the bone with the distal tip of the awl;
positioning the distal tip of the awl into the delivery tube; and
delivering biological material into the defect through a longitudinal passage formed between an outer surface of the awl in the delivery tube and an inner surface of the inner bore of the delivery tube while the awl remains in the delivery tube.

2. The method of claim 1, wherein the awl has a D-shaped cross-section and the inner bore has a circular cross-section, such that the longitudinal passage is formed between the D-shaped cross-section of the awl and the circular cross-section of the inner bore of the delivery tube.

3. A method of repairing a chondral defect of a joint bone, the method comprising:
making an arthroscopic incision to the joint bone;
exposing a chondral defect;
engaging a distal tip of a delivery tube of a tissue repair device to the defect;
exposing only a distal tip of an awl coupled to the tissue repair device outside the distal tip of the delivery tube and into the joint bone with the awl remaining in an inner bore of the delivery tube;
microfracturing the bone underlying the defect with the distal tip of the awl;
enclosing the distal tip of the awl into the inner bore of the delivery tube;
delivering biological material through a longitudinal passage defined between an inner surface of the delivery tube and an outer surface of the awl with the awl in the inner bore of the delivery tube;
removing the delivery tube from the incision; and
closing the incision.

4. The method of claim 3, further comprising delivering biological material into the delivery tube through an access port communicating with the delivery tube.

5. The method of claim 3, wherein exposing the distal tip of the awl coupled to the tissue repair device outside the distal tip of the delivery tube includes moving a slider coupled to the awl in a forward position.

6. The method of claim 5, wherein enclosing the distal tip of the awl into the delivery tube includes moving a slider coupled to the awl to a rearward position and retracting the distal tip of the awl into the delivery tube.

7. The method of claim 3, wherein exposing the distal tip of the awl coupled to the tissue repair device outside the distal tip of the delivery tube includes moving a slider coupled to the delivery tube in a rearward position.

8. The method of claim 3, further comprising removing tissue from the defect.

9. The method of claim 3, further comprising harvesting autologous material from the patient.

10. The method of claim 3, wherein the awl has a D-shaped cross-section and the inner bore has a circular cross-section, such that the passage is formed between the D-shaped cross-section of the awl and the circular cross-section of the inner bore of the delivery tube.

11. A method of repairing a chondral defect of a bone, the method comprising:
exposing a chondral defect;
engaging a distal end of a delivery tube to the defect;
moving a slider coupled to an awl to extend a distal tip of the awl beyond the distal end of the delivery tube to microfracture the bone with the distal tip of the awl with the awl remaining in the delivery tube;
moving the slider to retract the distal tip of the awl into the delivery tube; and
delivering biological material to the defect through a longitudinal passage formed between an outer surface of the awl and an inner surface of the delivery tube while the awl is in the delivery tube.

12. The method of claim 11, further comprising making an arthroscopic incision to the chondral defect;
removing the delivery tube from the incision; and
closing the incision.

13. The method of claim 11, further comprising delivering biological material into the delivery tube through an access port communicating with the delivery tube.

14. The method of claim 13, further comprising coupling a delivery device to the access port to deliver the biological material.

15. The method of claim 11, wherein the passage is formed between an outer longitudinal channel defined by the awl and the inner bore of the delivery tube.

16. The method of claim 11, wherein the awl has a D-shaped cross-section and the delivery tube has a circular cross-section such that the passage is formed between the D-shaped cross-section of the awl and the circular cross-section of the inner bore of the delivery tube.

17. The method of claim 11, wherein moving the slider includes moving the slider toward the distal end of the delivery tube to extend the distal tip of the awl beyond the distal end of the delivery tube and moving the slider proximally relative to the delivery tube to retract the distal tip of the awl into the delivery tube.