Abstract:
A method and system is provided for of attaching a rotator cuff tendon to its associated humeral head. The method includes the steps of passing a positional guide through the tendon toward the humeral head at a target site and positioning a suture anchor between the humeral head and the tendon at the target site by passing the suture anchor under the tendon. The suture anchor is driven into the humeral head and suture is passed from the suture anchor and through the tendon to attach the tendon to the humeral head at the target site.

Description:
BACKGROUND 
       [0001]    The present application relates to systems and methods for performing a repair of a partial thickness rotator cuff tear. 
         [0002]    A PASTA (partial articular surface tendon avulsion) lesion in a rotator cuff of a shoulder can be particularly difficult to repair. The rotator cuff comprises a group of muscles which surround the shoulder and tendons which attach those muscles to the humeral head. The tendons have a footprint where they attach to the humeral head and in a PASTA lesion a portion of the tendon&#39;s footprint becomes detached from the humeral head. Such lesions are most commonly found on the supraspinatus tendon. 
         [0003]    One option for treatment is completion of the tear and repair using standard techniques for a full thickness tear. Preservation of the existing attachment is thus lost and the entire tendon must be reattached. Another option comprises passing a suture anchor through the tendon and into the humeral head, passing suture through the tendon and tying down the tendon to effect reattachment. This causes further trauma to the tendon. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention provides systems and methods for repairing a PASTA lesion which provides advantages over current treatment options. 
         [0005]    A method, according to the present invention, provides for attaching a partially torn rotator cuff tendon to its associated humeral head. The method comprises the steps of: passing a positional guide through the tendon toward the humeral head at a target site; positioning a suture anchor between the humeral head and the tendon at the target site by passing the suture anchor laterally under the tendon; driving the suture anchor into the humeral head; and passing suture from the suture anchor and through the tendon to attach the tendon to the humeral head at the target site. 
         [0006]    Preferably, the positional guide is a needle. 
         [0007]    In one aspect of the invention, the step of driving the suture anchor into the humeral head comprises rotating the suture anchor via a tool inserted laterally between the tendon and the humeral head. The tool could employ a ratchet drive. 
         [0008]    In another aspect of the invention, the step of driving the suture anchor comprises passing a driver over the positional guide and through the tendon to engage the suture anchor. The suture anchor can be threaded such that the driver rotates the suture anchor into the humeral head, or the driver can merely push or mallet the suture anchor into the humeral head. 
         [0009]    In one aspect of the invention, the suture anchor comprises a first portion and a second portion which can assemble with each other and wherein the step of positioning the suture anchor at the target site comprises the steps of passing the first portion and the second portion in a disassembled state laterally under the tendon and then assembling the first portion to the second portion around the positional guide. Preferably, the positional guide is engaged with the humeral head during the step of assembling the first portion to the second portion. 
         [0010]    Preferably, the step of passing an awl head laterally under the tendon to the target site and engaging the awl head against the humeral head via the positional guide. The awl head can then be driven into the humeral head to create a bone hole. Preferably, the positional guide comprises a threaded distal tip and the step of driving the awl head into the humeral head comprises engaging the awl head with the threaded distal tip of the positional guide, impacting the awl head via the positional guide to create the bone hole and then disengaging the awl head from the positional guide by unthreading the positional guide therefrom. Then the suture anchor can be driven into the humeral head comprises inserting the suture anchor into the bone hole. 
         [0011]    One aspect of the invention involves inserting an inner portion into the suture anchor, the inner portion passing through the tendon and into a recess in the suture anchor and engaging it therein. Preferably, the inner portion has at least one suture attached thereto. 
         [0012]    A suture anchor kit according to the present invention comprises a suture anchor having at least one suture limb extending therefrom, a distal end for entering bone, an opposite proximal end and a side between the distal end and proximal end. A suture anchor passing tool is adapted to grasp the suture anchor side. 
         [0013]    Preferably the passing tool has a height adjacent the suture anchor and over a length thereof sufficient to pass the suture anchor under a tendon in a rotator cuff and wherein the height is less than a length of the suture anchor between its distal end and proximal end. 
         [0014]    In one aspect of the invention the suture anchor has an aperture in its side and the tool has a distal tip sized to fit within the aperture whereby to grasp the anchor. 
         [0015]    Preferably the suture anchor kit according further comprises instructions for use which include an instruction to pass the suture anchor under a tendon in a rotator cuff 
         [0016]    A suture anchor kit according to the present invention comprises a positional guide adapted to pass through a rotator cuff tendon, a suture anchor, a driver adapted to drive the suture anchor into the humeral head; and instructions for positioning the suture anchor a target site by passing the suture anchor laterally underneath a rotator cuff tendon to intercept the positional guide which is passed through the rotator cuff tendon. 
         [0017]    A suture anchor kit according to the present invention comprises a positional guide adapted to pass through a rotator cuff tendon, a suture anchor, a driver adapted to drive the suture anchor into the humeral head, and wherein the driver engages laterally with the suture anchor whereby to allow the suture anchor and the driver to be placed at a target site under a rotator cuff tendon by passing them laterally underneath the rotator cuff tendon. The driver can comprise a ratchet mechanism. The driver can also comprise a powered rotational drive head adapted to rotate the suture anchor about a central axis thereof. 
         [0018]    A suture anchor kit according to the present invention comprises a positional guide adapted to pass through a rotator cuff tendon, a suture anchor having a central bore through a central axis thereof, the bore being open laterally whereby to be engageable laterally with the positional guide at a target site beneath the rotator cuff tendon; and a driver adapted to drive the suture anchor into the humeral head. 
         [0019]    The suture anchor can comprises a first lateral portion and a second lateral portion, the first lateral portion and second lateral portion engageable with each other laterally at a target site beneath a rotator cuff tendon with the positional guide within the central bore. 
         [0020]    A suture anchor kit according to the present invention comprises a longitudinally extended positional guide having a sharp distal tip adapted to pass through a rotator cuff tendon, an awl head threadably engageable with the distal tip of the positional guide and adapted to form a bone hole in a humeral head, a suture anchor, and a driver adapted to insert the suture anchor into the bone hole. 
         [0021]    Preferably a manipulator is provided which is engagable laterally with at least one of the suture anchor and awl, whereby to allow insertion thereof underneath the rotator cuff tendon. Preferably, a suture extends from the anchor and a suture engaging notch is provided in one of the driver or the positional guide whereby to allow capture of the suture in the suture engaging notch and passage of the suture through the rotator cuff tendon. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is a side elevation view of a humerus and a tendon of the rotator cuff showing a PASTA lesion; 
           [0023]      FIG. 2  is a side elevation view of an instrument set according to the present invention; 
           [0024]      FIG. 3  is a side elevation view of the humerus of  FIG. 1  and showing a step in a procedure according to the present invention in which an awl of  FIG. 2  is positioned underneath the tendon and a first driver of  FIG. 2  is passed through the tendon to engage the awl; 
           [0025]      FIG. 4  is a side elevation view of the procedure of  FIG. 3  showing the awl creating a bone hole in the humerus beneath the tendon; 
           [0026]      FIG. 5  is a side elevation view of the procedure of  FIG. 3  showing the bone hole and showing awl and first driver being removed from the site; 
           [0027]      FIG. 6  is a side elevation view of the procedure of  FIG. 3  showing a suture anchor of  FIG. 2  being positioned beneath the tendon at the bone hole and a second driver of  FIG. 2  being passed through the tendon to engage the suture anchor; 
           [0028]      FIG. 7  is a side elevation view of the procedure of  FIG. 3  showing the anchor being driven into the bone hole; 
           [0029]      FIG. 8  is a side elevation view of a humerus and a second embodiment of an instrument set and procedure according to the present invention, wherein an awl is passed through the tendon; 
           [0030]      FIG. 9  is a side elevation view of the procedure of  FIG. 8  showing the awl tapping a bone hole in the humerus beneath the tendon; 
           [0031]      FIG. 10  is a side elevation view of the procedure of  FIG. 8  showing an outer body of a suture anchor being passed beneath the tendon to the bone hole; 
           [0032]      FIG. 11  is a side elevation view of the procedure of  FIG. 8  showing the outer body being driven into the bone hole; 
           [0033]      FIG. 12  is a side elevation view of the procedure of  FIG. 8  showing the outer body positioned in the bone hole with a guide wire passing out through the tendon; 
           [0034]      FIG. 13  is a side elevation view of the procedure of  FIG. 8  showing an inner body of the suture anchor having a pair of suture limbs extending therefrom and a cannulated driver therefor being passed down the guide wire to engage the inner body; 
           [0035]      FIG. 14  is a perspective view of a humerus and a third embodiment of an instrument set and procedure according to the present invention , wherein a spinal needle has been passed through the tendon to a desired location of placing a suture anchor; 
           [0036]      FIG. 15  is a perspective view of a suture anchor having a side slot for the procedure of  FIG. 14  and a holding tool for the suture anchor; 
           [0037]      FIG. 16  is a perspective view of the procedure of  FIG. 14  showing the suture anchor being passed beneath the tendon; 
           [0038]      FIG. 17  is a perspective view of a humerus and a fourth embodiment of an instrument set and procedure according to the present invention showing a suture anchor which has been passed under the tendon being driven into the humerus via a driver passed through the tendon; and 
           [0039]      FIG. 18  is a side elevation view of a fifth embodiment of an instrument set according to the present invention in which a driver provides torque to a suture anchor laterally rather than axially. 
       
    
    
     DETAILED DESCRIPTION 
       [0040]      FIG. 1  depicts a humerus  10  having a humeral head  12  and a tendon  14  attached to the humeral head  12 . The tendon  14  has a footprint  16  where it attaches to the humeral head  12  and it can be seen that a portion  18  of the footprint  16  has come detached. The space between the tendon  14  and the humeral head  12  is exaggerated for clarity. 
         [0041]      FIG. 2  depicts and a suture anchor  20  and instruments  22  for placement of the suture anchor  20  into the humeral head  12  beneath the detached portion  18  of the tendon footprint  16 . The instruments  22  include a first driver  24 , an awl head  26  and a second driver  28 . The first driver  24  has an elongated shaft  30  and terminates at its distal end  32  with threads  34  and a sharp point  36 . The awl head  26  has a threaded opening  38  at its proximal end  40  and a conical section  42  at its distal end  44 . The threads  34  of the first driver  24  mate with the threaded opening  38  of the awl head  26 . The second driver  28  comprises an elongated shaft  46  and near its distal end  48  has a hexagonal cross section  50  and terminates in a sharp point  52 . The suture anchor  20  has a distal end  54 , proximal end  56 , a threaded outer surface  58  and a hexagonal opening  60  at its proximal end  56  which mates with the hexagonal portion  50  of the second driver  28 . A pair of sutures  62  extend from the suture anchor  20 . 
         [0042]    Turning also now to  FIGS. 3 to 7 , to effect a repair a surgeon inserts the point  36  of the first driver  24  through the tendon  14  and locates the point  36  at a location on the humeral head  12  at which the surgeon desires to implant the suture anchor  20 . The point  36  is malleted slightly into the humeral head  12  to make a defect. A small amount of biocompatible dye can be carried by the point  36  which is then transferred to the bone during malleting to ease later finding the defect visually. Then as depicted in  FIG. 3  specifically a grasper  64  having the awl head  26  attached thereto is inserted under the tendon  14  and the awl head distal end  44  is placed into the defect made by the first driver  24 . The first driver  24  is threaded into the awl head  26  and the grasper  64  is removed. The awl head  26  is then malleted into the humeral head  12  via the first driver  24  (see specifically  FIG. 4 ) to create a hole  66  for receipt of the suture anchor  20 . The awl head  26  is then held by the grasper  64 , detached from the first driver  24  and removed (see specifically  FIG. 5 ). 
         [0043]    Now that the hole  66  has been prepared the suture anchor  20  is passed under the tendon  14  and position at the hole  66  via the grasper  64 . The second driver  28  is passed through the tendon  14 , preferably through the same location as which the first driver was passed, and engages the suture anchor  20  (see specifically  FIG. 6 ). The anchor  20  is then driven into the hole  66  via the second driver  28 . Completion of the repair can then be affected now that an anchor  20  is successfully located beneath the tendon  14 . For instance, the sutures  62  can be passed through the tendon  14  in different locations via a suture grasper (not shown) and then tensioned and knotted above the tendon  14  to hold the tendon  14  against the humeral head  12 . 
         [0044]    Preferably each of the drivers  24  and  28  are of the minimum diameter necessary for strength such that minimal damage is caused to the tendon  14  as they are passed therethrough. Preferably they have diameters, at least of the portion passing through the tendon  14 , of less than 4 mm and more preferably less than 3 mm. In an alternate embodiment not shown, the features (namely the threads  34  and hexagonal cross section  50 ) of the first and second drivers  24  and  28  are combined into a single driver so only one pass need be made through the tendon  14 . The suture anchor  20  can be formed of any biocompatible material such as stainless steel or a bioabsorbable polymer. The HEALIX BR dual threaded suture anchor in BIOCRYL RAPIDE available from DePuy Mitek, Inc. of Raynham, Mass. BIOCRYL RAPIDE is a bioabsorbable polymer formed of homogenous blend of TriCalcium Phosphate (TCP) and Polylactic/polyglycolic Acid (PLGA). Although, a threaded anchor  20  is disclosed the invention is not so limited and other anchor types, such as a push-in anchor, could also be employed. 
         [0045]    Turning now to  FIGS. 8 to 13  which illustrate an alternative embodiment of the invention, an awl  68  having a sharp distal tip  70  and a hexagonal cross section  72  proximal thereof penetrates the tendon  14  and is malleted into the humeral head  12  to form a pilot hole  74  . An anchor outer body  76  has external threads  78 , a lateral aperture  80  and an axial opening  82  at a proximal end  84  of the anchor outer body  76 . The axial opening has a distal hexagonal section  86  which mates with the hexagonal cross section  72  of the awl  68  and also has a proximal threaded portion  88 . The anchor out body  76  is passed under the tendon  14  via a passing stick  90  inserted through the lateral aperture  80  and the awl  68  is then engaged to the anchor outer body  76  via the hexagonal section  86 . With the passing stick  90  removed, the awl is used to drive the anchor outer body  76  into the humeral head  12  at the pilot hole  74 . A guide wire  92  is left extending out of the anchor body and is withdrawn through the tendon  14  as the awl  68  is removed. It is preferably held in the anchor body by friction to allow easy removal later during the procedure. A cannulated inner anchor  94  can then be passed down over the guidewire  92  to engage the threaded portion  88  of the anchor outer body  76 . The inner anchor  94  comprises a threaded outer surface  96 , a hexagonal proximal opening  98 , an axial cannulation  100  for receiving the guide wire  92 , a suture attachment  102  and a pair of suture ends  104  extending therefrom. The inner anchor  94  is loaded onto a driver  106  having a distal hexagonal portion  108  and a cannulation  110  for receiving the guide wire  92 . The guide wire  92  is threaded into the cannulations  100  and  110  and the inner anchor  94  is passed down the guide wire  92  to mate with the threaded section  88  of the anchor outer body  76 . Although the connection between the inner anchor  94  and outer body  76  is shown as threaded, other connection types are possible as for instance a snap-fit with radially extending barbs on the inner anchor  94  engaging a lip on the outer body  76  to prevent proximal withdrawal of the inner anchor  94 . The driver  106  and guide wire  92  are then removed leaving the inner anchor  94  affixed to the humeral head  12  beneath the tendon  14  with the pair of suture ends  104  passing through the tendon  14 . 
         [0046]      FIGS. 14 to 16  illustrate a further embodiment of the invention in which a push-in anchor  112  comprises a sharp distal tip  114 , barbed exterior ridges  116  for enhanced fixation in bone, and an axial cannulation  118  which has a full length side opening  120 . A grasper  122  has a semi-circular cut-out  124  at its distal end  126  adapted to snap fit with the anchor  112 . To effect a repair of a PASTA lesion a surgeon places a needle  128 , such as a spinal needle, through the tendon  14  and engages the humeral head  12  at a desired location for placement of the anchor  112 . The anchor  112 , via the grasper  122 , is slid under the tendon  14  and adjusted to engage the needle  128  in the cannulation  118  through its side opening  120 . The opening  120  can be sized to effect a snap-fit of the anchor  112  to the needle  128 . A cannulated driver  130  is then passed down over the needle  128  to engage the anchor  112  at its proximal end  132  so that the anchor  112  can be malleted into the humeral head  12 . 
         [0047]      FIG. 17  illustrates a similar embodiment in which a push-in anchor  132 , having a sharp distal tip  134 , barbed ridges  136  and a proximal tool receiving opening  138  is manipulated with a grasper  140  similar to the grasper  122 . Here, a driver  142  has a sharp distal tip  144  which is first used to punch a small pilot hole into the humeral head  12  at the desired location for placing the anchor  132 . Then the anchor  132  is slid under the tendon  14  and positioned with its tip  134  in the hole. The driver tip  144  engages the opening  138  in the anchor  132  and the anchor  132  is then malleted into the humeral head  12 . 
         [0048]      FIG. 18  illustrates another alternative for engaging a threaded anchor  146  and a driver  148  having an anchor engagement  150 , such as a hex head, which engages the anchor  146  from the side rather than axially. For an open procedure the driver could have a simple ratchet mechanism  152  to allow it to apply torque to the anchor  146  through the engagement  150  and cause it to spiral into bone beneath a tendon. The driver  142  could then be used for downward force and would not have to supply rotational force. For arthroscopic procedures it would be preferred to have an electric drive in which a rotating shaft engages a worm gear or similar gear connected to the engagement  150  to translate the rotation into the proper axis for rotating the anchor  146 . Other drive mechanisms could include a chain and sprocket or belt drive. 
         [0049]    Various modifications and alterations of this invention will be apparent to those skilled in the art without departing from the scope and spirit of this invention. It should be understood that the invention is not limited to the embodiments disclosed herein, and that the claims should be interpreted as broadly as the prior art allows. For instance, alternative grasper designs may be employed such as where a distal tip thereof fits into a hole in the anchor and is held by friction, snap-fit, temporary adhesive, threading, frangible connection, magnetism or the like. Such enhancements can be employed with other graspers. Further, the anchor can have indentations or flats on its outer surface to more easily allow grasping by a jaw-type grasper or snap-fit external grasper such as in  FIG. 15B  etc.