Knotless suture anchor and method of using same

A suture anchor including an outer anchor part and an inner anchor part. The outer anchor part includes a proximal end, a distal end, and an inner surface defining a center bore extending between the proximal end and the distal end. The center bore includes a tapered proximal portion. The inner anchor part includes a tapered outer surface defining a first pair of opposing apertures. Insertion of the inner anchor part into the tapered proximal portion of the outer anchor part enables a suture extending through the first pair of opposing apertures to be coupled to the suture anchor. A taper fit between the tapered proximal portion of the center bore of the outer anchor part and the tapered outer surface of the inner anchor part retains the inner anchor part within the outer anchor part.

FIELD

The present disclosure relates to a knotless suture anchor and a method of using the knotless suture anchor.

BACKGROUND

Surgeons often use suture to secure bone and tissue in place during a surgical procedure. The suture can be retained in place with a suture anchor, which is typically implanted in bone. The suture can be connected to the tissue or bone either before or after the anchor is implanted. The suture is often connected to the anchor with a knot, which can be difficult to tie during surgery. The present teachings eliminate the need for connecting the suture to the anchor with a knot by providing for a knotless suture anchor and method of using the knotless suture anchor.

SUMMARY

The present teachings provide for a suture anchor including an outer anchor part and an inner anchor part. The outer anchor part includes a proximal end, a distal end, and an inner surface defining a center bore extending between the proximal end and the distal end. The center bore includes a tapered proximal portion. The inner anchor part includes a tapered outer surface defining a first pair of opposing apertures. Insertion of the inner anchor part into the tapered proximal portion of the outer anchor part enables a suture extending through the first pair of opposing apertures to be coupled to the suture anchor. A taper fit between the tapered proximal portion of the center bore of the outer anchor part and the tapered outer surface of the inner anchor part retains the inner anchor part within the outer anchor part.

The present teachings further provide for a method of implanting a suture anchor into a bone hole. The method includes inserting a suture anchor into the bone hole with an inserter. The suture anchor includes an outer anchor part and an inner anchor part that are decoupled during insertion. The method further includes coupling the outer anchor part and the inner anchor part with a taper lock between a tapered outer surface of the inner anchor part and a tapered inner surface of the outer anchor part. A suture extending through a first pair of opposing apertures defined in the inner anchor part is compressed between the outer anchor part and the inner anchor part to retain the suture to the suture anchor.

The present teachings also provide a system for implanting a suture anchor in a bone hole. The insertion tool includes an elongated rod having a first coupling member proximate to a distal end thereof. An outer anchor part of the suture anchor defines a first center bore configured to receive the elongated rod. The first center bore includes a tapered proximal portion and a distal portion including a second coupling member configured to cooperate with the first coupling member of the insertion tool to couple the outer anchor part to the insertion tool. An inner anchor part of the suture anchor includes a tapered outer surface. The inner anchor part defines both a first pair of opposing apertures and a second center bore configured to receive the elongated rod to support the inner anchor part on the elongated rod at a proximal end of the outer anchor part. The insertion tool is configured to insert the inner anchor part within the outer anchor part such that the tapered outer surface of the inner anchor part contacts the tapered proximal portion of the outer anchor part to form a taper lock therebetween, and enable a suture extending through the first pair of opposing apertures to be coupled to the suture anchor by trapping the suture between the outer and inner anchor parts.

DETAILED DESCRIPTION

With initial reference toFIG. 1, a knotless suture anchor assembly according to the present teachings is generally illustrated at reference numeral10. The knotless suture anchor assembly10generally includes an insertion tool12and a suture anchor14. With additional reference toFIGS. 2-4, the suture anchor14includes an outer or first portion14A and an inner or second portion14B.

With particular reference toFIGS. 3 and 4, the outer portion14A includes a proximal end16and a distal end18, which is opposite to the proximal end16. At the distal end18is a conical or tapered tip20having a blunt end. The outer portion14A includes an outer surface22and an inner surface24. Both the outer surface22and the inner surface24extend between the proximal end16and the distal end18.

The inner surface24defines a first bore26, which is a center bore. The first bore26extends between the proximal end16and the distal end18. The inner surface24defines a first slot28A and a second opposed slot28B, which both extend from the proximal end16. The first slot28A is opposite to the second slot28B. The first and second slots28A and28B extend to retention fins30.

The retention fins30are portions of the outer portion14A that are expandable outward from the outer surface22upon implantation of the outer portion14A in bone in order to retain the outer portion14A in bone, as described in detail herein. Although four retention fins30are illustrated, with two on opposing sides of the outer portion14A and axially spaced apart, any suitable number of retention fins30can be provided. Further, any member suitable for coupling to bone can be included with the outer portion14A in order to retain the outer portion14A in bone once implanted.

With particular reference toFIG. 4, the inner surface24also includes a tapered proximal portion32of the first bore26. At the tapered proximal portion32, the inner surface24includes a tapered sidewall34. The tapered sidewall34gradually tapers inward from the proximal end16to a distal portion36of the first bore26. The distal portion36is defined by the inner surface24and extends from the proximal portion32to the distal end18of the outer portion14A. The distal portion36is generally linear and not tapered. The distal portion36is also narrower than the tapered proximal portion32. Therefore, an internal flange38is defined by the inner surface24between the tapered proximal portion32and the distal portion36.

At the distal portion36, the inner surface24includes a first locking or coupling member40. The first locking member40can be any suitable coupling member for coupling the outer portion14A to the insertion tool12. For example, the first locking member40can include threads defined in the inner surface24and a non-threaded portion.

Features of the inner portion14B of the suture anchor14will now be described. The inner portion14B generally includes a proximal end50and a distal end52, which is opposite to the proximal end50. Extending between the proximal end50and the distal end52is a tapered outer surface54and an inner surface56. The inner surface56is opposite to the tapered outer surface54. The inner surface56defines a second or center bore58. The inner surface56, and thus the second bore58as well, extends generally linearly between the proximal end50and the distal end52.

Protruding from the tapered outer surface54are a plurality of ramped retention tabs60. Although four retention tabs60are illustrated, with two on opposing sides of the tapered outer surface54and axially spaced apart, any suitable number of retention tabs60can be provided. The retention tabs60are generally rigid, and their number and location corresponds to the number and location of the retention fins30of the outer portion14A, such that upon insertion of the inner portion14B into the outer portion14A, as described in detail herein, the retention tabs60pass through the first and second slots28A and28B in order to contact the retention fins30and pivotably or hingingly force the retention fins30outward from the outer surface22to a deployed position.

The tapered outer surface54and the inner surface56of the inner portion14B define a first pair of apertures62A and62B, and a second pair of apertures64A and64B. The first pair of apertures62A and62B are aligned with one another on opposite sides of the inner portion14B. Similarly, the second pair of apertures64A and64B are aligned on opposite sides of the inner portion14B. The first pair of apertures62A/62B generally define a first suture passageway through the inner portion14B. The second pair of apertures64A/64B generally define a second suture passageway through the inner portion14B. The first and second suture passageways are spaced apart and are arranged generally parallel to one another.

Each of the apertures62A,62B,64A, and64B include a first portion66and a second portion68to provide each of the apertures generally with a “tear drop” shape. The first and second portions66and68are connected to one another. The first portion66is larger than the second portion68. More specifically, the second portion68is more narrow than the first portion66. The second portion68is generally sized such that when a suture is moved from the first portion66to the second portion68, the suture will be pinched in the second portion68thereby restricting movement of the suture through the second portion68.

The suture anchor14can be made of any suitable biocompatible material, such as a suitable metallic or polymer. Exemplary polymers include polyether ether ketone (PEEK) and polyether ketone (PEK).

With reference toFIG. 3, prior to implantation of the suture anchor14, one or more suitable sutures, such as suture160, can be threaded through the first pair of apertures62A/62B and the second pair of apertures64A/64B. More specifically, the suture160can be threaded through the suture passageway defined by the apertures62A and62B such that it extends through each of the apertures62A and62B using a suitable insertion device, such as a Nitinol threader. Similarly, the suture160can be threaded through the suture passageway defined by the apertures64A and64B.

The suture160is threaded through the first portion66of each of the apertures62A,62B,64A, and64B. The first portion66has a diameter larger than that of the suture160, and thus the suture160is free to be maneuvered through the apertures62A,62B,64A, and64B in order to adjust the suture160and tension the tissue162. The suture160can be threaded through the apertures62A,62B,64A, and64B either before or after the inner portion14B is mounted to the insertion tool12. Before or after threading the suture160through the apertures62A,62B,64A, and64B, the suture160can be connected to any suitable tissue or bone to be anchored, such as the tissue162.

With reference toFIGS. 1-3, features of the insertion tool12will now be described. The insertion tool12generally includes a body102with a handle104and a lever106. Extending from the body102is an elongated shaft108. Within the elongated shaft108is an inner rod110(FIGS. 3 and 5). The inner rod110is movable within the elongated shaft108upon actuation of the lever106. Actuation of the lever106draws the inner rod110proximally toward the body102.

The inner rod110extends beyond a distal end112of the elongated shaft108. The inner rod110includes a distal end116with a pointed tip118. Proximate to the distal end116, the inner rod110includes a second locking member120. The second locking member120can include any suitable feature for coupling with the first locking member40of the outer portion14A, such as threads. The elongated shaft108defines an annular flange114proximate to, but spaced apart from, the distal end112. Both the elongated shaft108and the inner rod110are generally rigid.

The suture anchor is coupled to the insertion tool12such that the proximal end50of the inner portion14B abuts, or is proximate to, the distal end112of the elongated shaft108. The inner rod110of the insertion tool12extends through the second bore58of the inner portion14B and into the first bore26of the outer portion14A. The distal end116and the pointed tip118of the inner rod110protrude from the second bore58at the distal end18of the outer portion14A. The second locking member120of the inner rod110couples with the first locking member40to retain the outer portion14A on the inner rod110. The second locking member120can threadably engage the first locking member40when the first and second locking members40and120include threads. The inner portion14B is thus retained between the outer portion14A and the elongated shaft108. The inner rod110has a diameter164such that a suture160can extend around the inner rod110through the first pair of apertures62A/62B and the second pair of apertures64A/64B.

With additional reference toFIGS. 5 and 6, a method of implanting the suture anchor14using the insertion tool12will now be described. With the suture anchor14mounted to the insertion tool12and the suture160threaded through the first pair of apertures62A/62B and the second pair of apertures64A/64B, the suture anchor14is inserted into bone hole150. The bone hole150can be predrilled or the suture anchor14can be impacted into the bone152in order to form the bone hole150due in part to the presence of the pointed tip118of the inner rod110.

The insertion tool12is pushed into the bone hole150until the annular flange114abuts an outer surface of the cortical bone layer154, which results in the suture anchor14being positioned such that both the outer portion14A and the inner portion14B are arranged beyond cortical bone layer154and within cancellous bone layer156. After the suture160and the tissue162are positioned and tensioned, the inner portion14B and the outer portion14A are brought together such that the inner portion14B is distally inserted into the tapered proximal portion32of the first bore26of the outer portion14A.

The inner portion14B can be inserted into the tapered proximal portion32in any suitable manner. For example, the outer portion14A and the inner portion14B will be drawn together upon simultaneously actuating the lever106and pushing the elongated shaft108into the bone hole150, or by pulling the elongated shaft108proximally, keeping annular flange114in contact with cortical bone layer154. The inner portion14B will be retained within the tapered proximal portion32by way of a Morse taper lock between the inner surface24of the outer portion14A and the outer surface54of the inner portion14B.

As the inner portion14B enters the tapered proximal portion32, the retention tabs60will force the retention fins30into the cancellous bone156surrounding the bone hole150to retain the suture anchor14within the cancellous bone156. The suture160will be compressed between the inner surface24of the outer portion14A and the outer surface54of the inner portion14B in order to couple the suture160to the suture anchor14. As the inner portion14B enters the tapered proximal portion32, the suture160will move from the first portion66of the apertures62A,62B,64A, and64B and into the second portion68. Because the second portion68has a smaller diameter than the first portion66, and a smaller diameter than the suture160, the suture160will be compressed and tensioned within the second portion68between opposed walls thereof to further couple the suture160to the suture anchor14. As the lever106is pressed further, the inner rod110will decouple from engagement with the first locking member40. For example, the threads of the second locking member120will strip or pull away from cooperation with the threads of the first locking member40.