Abstract:
An instrument and method for manipulating an operating member during a surgical procedure. The operating member has suture attached thereto and is supported at a distal end of the instrument. Tension is maintained on the suture material while the operating member is manipulated. For example, the operating member can be a suture anchor that is inserted through a hole formed in hard tissue and oriented to span the hole while tension is maintained on the suture material.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an instrument and method for manipulating an operating member that is attached to suture material while maintaining tension on the suture material. 
     2. Description of the Related Art 
     In many anatomical structures, soft tissue, such as tendons and ligaments, are inserted into bone tissue through small collagenous fibers. Such structures are very strong thus permitting muscles to affect force on the bone through the tendons or permitting the ligaments to stabilize the bone. Notwithstanding the strength of such structures, various injuries and degeneration often occur in which the soft tissue is torn away from the bone. Various procedures have been developed for reattaching soft tissue to bone tissue. 
     For example, it is known to utilize screws, staples, cement, or suture material to attach soft tissue to bone tissue. It is also known to insert a suture anchor into a cavity formed in bone tissue. Typically, a suture anchor has sharp burrs, threads, or the like which engage with or bite into surfaces defining the cavity in the bone tissue, and a portion to which a length of suture material is attached. The other end of the suture material is coupled to soft tissue by suturing, tying, or another procedure before or after insertion of the suture anchor into the cavity. Accordingly, soft tissue or the like can be attached to bone tissue to repair damage. However, often density of bone tissue is very low thus rendering it difficult to securely fix an anchor in a bone cavity. 
     For example, it often is desirable to reattach tendons or other soft tissue to the humerus. However, in most people over the age of 30, the cancellous bone in the humerus has absorbed to the point where the density of the bone is very low and, in some cases, only the cortical bone remains. Of course, when bone density is very low, the strength of the bone tissue is also relatively low and thus it is difficult to reliably fix an anchor to the bone tissue by embedding the anchor in a cavity formed in the bone. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to conduct a surgical procedure with an operating member that is coupled to suture material while maintaining tension on the suture material. 
     It is another object of the invention to reliably attach soft tissue to bone tissue having low density. 
     It is another object of the invention to place a suture anchor across an opening formed in a bone while maintaining tension on suture attached to the suture anchor to permit the suture anchor to be pulled against the outer surface of the bone. 
     It is another object of the invention to insert a suture anchor having suture material coupled thereto through a hole formed in bone tissue in a first longitudinal orientation and subsequently turn the suture anchor, while maintaining tension on the suture material, to a transverse orientation to thereby bridge the hole. 
     It is another object of the invention to reliably insert a suture anchor in minimally invasive and open surgical procedures. 
     To achieve these objects, the invention is an instrument for conducting a procedure with an operating member that is coupled to suture material. The instrument includes a shaft, means for manipulating the operating member, a handle and a suture tension mechanism configured to grasp a free end of the suture material and retain tension on the suture material that is attached to the operating member when the operating member is received in the guide and pushed out of the distal end of the guide by the pusher. 
     In one aspect of the invention, the operating member is a suture anchor having a longitudinal axis and the instrument includes a tubular guide having a distal end and a proximal end that is configured to receive the suture anchor and a tubular pusher extending substantially through the guide and having a proximal end and a distal end that is configured to abut the suture anchor received in the distal end of the guide. A handle mechanism is coupled to the guide and the pusher and is operative to cause relative movement between the guide and the pusher to thereby push the suture anchor out of the distal end of the guide. The suture anchor is loaded in the guide with the longitudinal axis of the suture anchor extending substantially along the length of the guide, i.e. in a “longitudinal orientation”, while inner surfaces of the guide retain the longitudinal orientation. While the suture is maintained under tension by the suture tension mechanism, the distal end of the guide can be placed adjacent or in a hole formed in bone tissue or other tissue and the handle mechanism can be operated to cause the pusher to move relative to the guide to thereby push the suture anchor out of the guide. When the suture anchor moves out of the confines of the guide and through the hole to the opposite side of the tissue, the tension on the suture material causes the suture anchor to assume a transverse orientation in which the longitudinal axis of the suture anchor is substantially transverse to the longitudinal axis of the guide. In the transverse orientation, the suture anchor bridges or spans the hole in the bone or other tissue to prevent the suture anchor from being pulled back through the hole. The suture tension mechanism can be disposed on the pusher to be movable with the pusher or otherwise configured to maintain a constant tension on the suture material regardless of the position of the pusher relative to the guide. 
     Another aspect of the invention is a method for manipulating an operating member during a surgical procedure while maintaining tension on suture material attached to the operating member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The invention will be described through a preferred embodiment illustrated in the drawing in which: 
     FIG. 1 is a side view of an instrument according to the invention; 
     FIG. 2 is a side view of the instrument of FIG. 1 in partial section taken along line  2 — 2  of FIG. 3; 
     FIG. 3 is an exploded perspective view of the instrument of FIG. 1; 
     FIG. 4A is an end view of an anchor for use with the instrument; 
     FIG. 4B is a side view of an anchor for use with the instrument; 
     FIG. 4C is a top view of an anchor for use with the instrument; 
     FIG. 5 is a side view of a threading tool for use with the instrument of FIG. 1; 
     FIG. 6 is a side view of the instrument of FIG. 1 with the tool of FIG. 5 inserted therethrough; 
     FIG. 7 is a side view of the instrument of FIG. 1 with suture material passed therethrough; 
     FIG. 8 is a side view, in partial section, of the instrument of FIG. 1 with the pusher extended for loading a suture; 
     FIG. 9 is a side view of the instrument of FIG. 1 as an anchor is being drawn into the guide; 
     FIG. 10 is a sectional view of the distal end of the instrument in the position of FIG. 9; 
     FIG. 11 is a side view of the instrument of FIG. 1 with a distal end placed adjacent a hole formed through bone tissue; 
     FIG. 12 is a sectional view of the distal end of the instrument in the position of FIG. 11; 
     FIG. 13 is a side view of the instrument of FIG. 1 after an anchor has been inserted through a hole in bone tissue; 
     FIG. 14 is a sectional view of the distal end of the instrument in the position of FIG. 13; 
     FIG. 15 is a side view of the instrument of FIG. 1 being withdrawn after inserting an anchor; and 
     FIG. 16 is a sectional view of the distal end of the instrument in the position of FIG.  16 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As illustrated in FIGS. 1-3, instrument  20  includes a shaft constituted of tubular guide  30  and tubular pusher or manipulating member  40 , handle mechanism  50 , and suture tension mechanism  60 . Guide  30  and pusher  40  are in the form of elongated cylinders in the preferred embodiment. However, guide  30  and pusher  40  can be of any cross-sectional shape as long as pusher  40  can be inserted in guide  30  and a channel can be defined through or along instrument  20  for receiving suture material in the manner described below. 
     Guide  30  has distal end  32  that is configured to be loaded with an operating member and placed adjacent or into a hole formed through tissue in the manner described below. Guide  30  also has proximal end  34  that is coupled to fixed handle  52  of handle mechanism  50 . Pusher  40  is slidingly disposed inside guide  30 , has distal end  42  that extends substantially to distal end  32  of guide  30  (depending on the relative position of pusher  40  with respect to guide  30 ), and proximal end  44  that extends through fixed handle  52  beyond proximal end  34  of guide  30  (see FIG.  2 ). Distal end  42  and distal end  32  constitute means for manipulating the suture anchor in the preferred embodiment. 
     Flange  56  having tab  59  extending therefrom is fixed on pusher  40  near proximal end  44 . Pivotal handle  54  is pivotally mounted on fixed handle  52  and has notch  55  formed in a top portion thereof for receiving tab  59  as best illustrated in FIG.  2 . When a lower portion of pivotal handle  54  is pressed towards fixed handle  52 , the upper portion of pivotal handle  54  having notch  55  moves distally to cause pusher  40  to move distally with respect to guide  30 , as illustrated in FIG. 8 for example. Fixed handle  52  and pivotal handle  54  are shaped to facilitate being grasped by one hand of the surgeon. Therefore, the surgeon need only tighten his grip to press a lower portion of pivotal handle  54  towards fixed handle  52 . Coil spring  58  is disposed between an upper portion of fixed handle  52  and flange  56  to bias pusher  40  distally with respect to guide  30  and to thereby bias pivotal handle  54  away from fixed handle  52 . 
     Suture tensioning mechanism  60  is disposed on pusher  40  near proximal end  44  and includes projection  46  in the form of an annular flange extending from pusher  40 , barrel  62 , having end faces  64  and  66  and respective openings formed in the end faces through which pusher  40  extends, slidingly disposed on guide  40  near proximal end  44 , tube  67  extending from end face  66 , flange  68  fixedly disposed on an end of tube  67 , and flange  69  slidingly disposed on tube  67 . Additionally, suture tensioning device  60  includes coil spring  63 , serving as a biasing member, disposed between projection  46  and an inner surface of end face  66 , and coil spring  65 , also serving as a biasing member, disposed between an outer surface of end face  66  and flange  69 . It can be seen that coil spring  63  biases barrel  62 , flange  68 , and flange  69  proximally with respect to pusher  40 . Also, it can be seen that coil spring  65  biases flange  69  toward flange  68 . The elements described above will be understood more clearly after the description of operation of instrument  20  set forth below. 
     Prior to an attachment procedure, suture anchor  100 , as an operating member, is loaded into instrument  20 . As illustrated in FIGS. 4A-4C, suture anchor  100  has arcuate body  102  having convex side  104  and concave side  106  (see FIG.  4 B). Eyelet  108  is defined on a central portion of convex side  104  by a ring-like projection  109  or the like to permit attachment of suture material to suture anchor  100  as described below. Width w of ring-like projection  109  preferably is about half of width W of arcuate body  102 , as illustrated in FIG.  4 C. Also, length l of ring-like projection  109  preferably is about {fraction (1/3+L )} of length L of arcuate body  102 , also as illustrated in FIG.  4 C. 
     FIG. 5 illustrates threading tool  130  for threading suture attached to anchor  100  through instrument  20  for loading suture anchor  100 . Threading tool  130  includes elongated stem  134  having handle  132  at one end and loop  136  at another end. As illustrated in FIG. 6, stem  134  is inserted through pusher  40  and guide  30  from proximal end  44  until loop  136  extends from distal end  32 . It is apparent that stem  134  should be long enough to extend through the entirety of instrument  20 . With loop  136  extending out of distal end  32 , end portions of suture material S are passed through loop  136 , as illustrated in FIG.  6 . Note that suture material S previously has been passed through eyelet  108  of suture anchor  100  with a central portion of suture material S being received in eyelet  108 . With suture material S passed through loop  136 , handle  132  is pulled in a proximal direction to withdraw stem  134  and loop  136  from instrument  20  to thereby pull the end portions of suture material S through pusher  40  and out of proximal end  44  as illustrated in FIG.  7 . 
     In the state illustrated in FIG. 7, a double length of suture material S extends through instrument  20 , free ends of suture material S extend out of proximal end  44 , and suture anchor  100  is coupled to a portion of suture material S that extends out of distal end  32 . From the position illustrated in FIG. 7, pivotal handle  54  is compressed towards fixed handle  52  to cause distal end  42  of pusher  40  to extend beyond distal end  32  of guide  30  and the free ends of suture material S can be wrapped manually around tube  67  to thereby be gripped between flanges  68  and  69  as illustrated in FIG.  8 . As suture material S is wrapped around tube  67 , with tension in suture material S, suture material S is drawn between flanges  68  and  69  due to the tapered shape of the opposing faces of flanges  68  and  69 . Spring  65  presses flange  69  towards flange  68  to secure suture material S. Also, slit  70  is provided in flange  68  to facilitate entry of suture material S between flanges  68  and  69  (see FIGS.  2  and  8 ). Ordinarily, two or three wraps of suture material S around tube  67  will be sufficient to secure the free ends of suture material S between flanges  68  and  69 . It can be seen that tension can be applied to suture material S during the wrapping procedure to compress spring  63 . Barrel  62  can be pushed distally while suture material S is wrapped around tube  67  to assist in placing suture material S under tension. Therefore, spring  63  will tend to push flanges  68  and  69  proximally while suture anchor  100  abuts distal end  42  and thus a constant tension will be maintained on suture material S. 
     From the position illustrated in FIG. 8, suture anchor  100  can be pivoted manually to a longitudinal orientation in which the longitudinal axis of suture anchor  100  corresponds substantially with the longitudinal axis of guide  30  and pusher  40 , and pivotal handle  54  can be released partially, as illustrated in FIGS. 9 and 10. Note that width W of arcuate body  102  is large enough to prevent suture anchor  100  from entering distal end  42  of pusher  40  to thereby maintain the tension on suture material S regardless of the orientation of suture anchor  100 . Also, when suture anchor  100  is moved to the longitudinal orientation, eyelet  108  is moved distally to place additional tension on suture material S and further compress coil spring  63 . With suture anchor  100  in the longitudinal orientation, pivotal handle  54  is released completely and thus moves away from fixed handle  52  due to the force of spring  58 , and therefore, distal end  42  of pusher  40  and suture anchor  100  are drawn into distal end  32  of guide  30 , as illustrated in FIGS. 11 and 12. Note that the relative dimensions of suture anchor  100  and the inner diameter of guide  30  are adjusted to maintain the substantially longitudinal orientation of suture anchor  100  when suture anchor  100  is disposed inside guide  30 . 
     The position illustrated in FIGS. 11 and 12 is referred to herein as the “loaded” position or state, i.e. suture anchor  100  is loaded in instrument  20 . FIG. 11 illustrates the instrument in a loaded state with distal end  32  of guide  30  pressed against tissue T around a hole formed in tissue T, such as bone tissue. Note that distal end  32  can be introduced to the area proximate the bone through a portal sleeve disposed in a puncture created by an obturator, such as a trocar, or through other minimally invasive procedures. Also, distal end  32  can be introduced through an incision in open surgery. 
     From the position illustrated in FIG. 11, pivotal handle  54  is pressed toward fixed handle  52  to cause pusher  40  to move distally. Since suture tensioning mechanism  60  is coupled to pusher  40 , the tension on suture material S remains constant during movement of pusher  40 . When pusher  40  advances far enough to move suture anchor  100  out of guide  30  and through the hole formed in tissue T, suture anchor  100  will no longer be constrained in the longitudinal orientation. Accordingly, as illustrated in FIGS. 13 and 14, suture anchor  100  will rotate to a position in which the longitudinal axis of suture anchor  100  is transverse to the longitudinal axis of guide  40 , i.e the “transverse orientation”. 
     Note that the diameter of the hole formed in tissue T is set to substantially correspond to the inner diameter of guide  30  thus permitting distal end  32  of guide  30  to abut tissue T and permitting distal end  42  of pusher  40  to pass through the bore, as best illustrated in FIG.  14 . With suture anchor  100  in the transverse orientation, suture anchor  100  bridges the hole formed in tissue T, abuts an outer or inside surface of tissue T, and cannot pass back through the hole formed in tissue T. In this manner suture material S is fixed to tissue T and soft tissue or the like can be attached to the suture material in a known manner. To remove instrument  20  suture material S is unwrapped from around tube  67  and instrument  20  is withdrawn, as illustrated in FIGS. 15 and 16, while free ends of suture material S are manually grasped. 
     Various elements, such as soft tissue, can be attached to suture material S in a known manner. The hole is formed in tissue T through known minimally invasive or open procedures. The relative dimensions of the pusher, guide, suture anchor, and hole are predetermined to facilitate insertion of the suture anchor in the longitudinal orientation and subsequent movement to the transverse orientation. The convex surface of the suture anchor facilitates seating of the suture anchor in the hole. However, the suture anchor may have any shape that permits insertion through the hole and subsequent bridging of the hole. For example, the suture anchor can be rectangular, cylindrical, or triangular. Also, the suture anchor can be flexible or made of one or more pivoting parts to expand after being inserted through the hole to prevent the suture anchor from passing back through the hole. 
     The preferred embodiment is used with a suture anchor for attaching suture to tissue. However, the instrument can be used with any type of operating member having suture material attached thereto and the instrument can be used in various procedures. For example, the invention can be applied to a ligating procedure or any procedure in which it is desirable to maintain tension on suture while manipulating an operating member coupled to the suture. The means for manipulating the operating member can be of any form to manipulate the operating member in any desired manner. 
     The cross sectional shape of the guide and pusher can be varied. For example, the cross-sectional shape of either or both of the guide and pusher can be square, rectangular, triangular or any appropriate shape. The operating member can be retained in position by the general shape of the guide or by inserts placed inside the distal end of the guide. The suture can be fixedly or releasably attached to the operating member. 
     The disclosed mechanisms for causing relative movement between the guide and the pusher, for retaining the free ends of the suture material, and for placing tension on the suture material are only exemplary and any structure can be used to accomplish these functions. 
     Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that all subject matter discussed above or shown in the accompanying drawings be interpreted as illustrative only and not be taken in a limiting sense.