Abstract:
A hinged pivoting guide for positioning a femoral tunnel in anterior cruciate ligament (ACL) reconstruction locates a drilling hole for placement that optimally penetrates a minimal depth of soft tissue (skin, muscle, etc.) yet directs drilling into a sufficiently rigid and structurally sound area of the femur. The hinged guide allows placement of an aimer point at a desired drilling exit location on the femur. The hinge is adapted to secure the aimer at a degree of rotation about an axis defined by the hinge rotation, such that the axis passes through the aimer point throughout rotation of the hinge while maintaining the aimer point in line with an insertion guide slideably movable through the aperture in the handle, the aperture defined by an insertion axis extending toward the aimer point such that the aimer point remains disposed at the intersection of the hinge axis and the insertion axis.

Description:
RELATED APPLICATIONS 
     This application is a continuation of pending application, U.S. Ser. No. 13/016,081, entitled SURGICAL AIMING DEVICE, filed Jan. 28, 2011, the entire teaching, disclosure and contents of which are incorporated herein by reference by in their entirety. 
    
    
     BACKGROUND 
     Reconstructive bone and ligament surgery often involves drilling into skeletal members to attach connective elements such as ligament and tendon grafts, as well as various artificial replacements and/or attachments for articulated joints. In particular, reconstructive surgery involving the anterior cruciate ligament (ACL) is becoming particularly significant because the effectiveness of reconstruction can have a profound effect on the subsequent athletic ability of the patient. For professional athletes, for example, an effective ACL repair can salvage an otherwise career ending injury. Similarly, an improperly treated ACL injury can be a permanent detriment even to an amateur athlete. 
     SUMMARY 
     Reconstructive surgery involving functional, structural fixation to bone members often involves drilling into a structurally sound area of the corresponding bone. In an ACL repair, antegrade drilling of the femur is becoming more common. A damaged ACL is often replaced with a graft from a patellar tendon or a semitendinosus tendon. Such a repair is facilitated by tunnels formed in the tibia and femur for use in implanting the graft in the patient&#39;s knee. Recent studies suggest more accurate placement is achievable by such antegrade femoral drilling than by conventional approaches such as drilling the femoral tunnel through the tibial tunnel. The graft may then be secured in the tunnels by fixation means, such as, for example, interference screws or sutures tied to screw posts. The femur, in particular, is often subjected to more substantial forces because it often bears the entire weight of the patient, and being the largest human bone, may be relied upon to accommodate a substantial connective force from a surgically added structure. 
     Configurations herein are based, in part, on the observation that conventional arrangements for surgical or arthroscopic drilling rely on a fixed aimer that may impede positioning of the handle and insertion guide for optimal positioning of a drill hole at an insertion point. An optimal placement defines a point of entry for a drilling hole that displaces minimal soft tissue depth while engaging a rigid structure (such as a knee bone) at a structurally sound location. Conventional approaches using such a fixed, rigid aimer hinder the ability to achieve optimal interarticular tunnel placement. 
     In ACL reconstruction involving such drilling, therefore, attachment of structural surgical tethers, such as grafts and artificial connectors, should be performed at a structurally sound location on the femur. Configurations herein disclose a drilling guide adapted for positioning a drilling tunnel in (ACL) reconstruction. Typically, a drilling guide adapted for insertion into a joint region locates a drilling exit point, while a surgeon manipulates the handle of the drilling guide to locate an entry location. Unfortunately, conventional arrangements suffer from the shortcoming that drilling guides for directing placement of the drilled hole are universal, in that a single straight design having a fixed relation of an aimer arm and a handle identify a point of drilling. Conventional approaches, therefore, do not distinguish a left from right knee, nor individual differences in the bone configuration of an individual patient, which compromises the ability to manipulate the drilling guide to pivot around the aimer arm for locating an optimal entry point for drilling. Conventional mechanisms employ a fixed aimer incapable of rotational or pivoting movement around a hinge connection to the arm denoting the drilling exit point. Such arrangements may attempt a similar range of application by employing fixed left and right guides, or a series of fixed angle guides for both right and left application, however this would result in a trial and error administration as well as requiring manufacturing of a range of multiple fixed angle guides. 
     Configurations herein substantially overcome the above described shortcomings by employing a hinged pivoting guide for positioning a femoral or tibial tunnel, for example, in anterior cruciate ligament (ACL) reconstruction. Locating the drilling hole for placement of the tunnel optimally penetrates a minimal depth of soft tissue (skin, muscle, etc.) yet directs drilling into a sufficiently rigid and structurally sound area of the femur. The hinged guide allows placement of an aimer point at a desired drilling exit location on the femur. The handle includes an aperture indicative of the drilling location, and a surgeon may manipulate the handle by pivoting around the hinge to dispose the aperture at an optimal location while maintaining the same exit location defined by the aimer point. In this manner, an optimal drilling location is selectable by positioning the handle to an area of minimal soft tissue depth and in line with a structurally sound path through the femur. 
     In further detail, the surgical aiming device as disclosed herein includes a handle coupled to a proximate end of an elongated arm, in which the elongated arm further has a distal end, and a hinge securing an aimer to the distal end for rotational communication around a hinge axis. The aimer has an elongated aimer tip and an aimer point, such that the aimer point is at a distal end of the aimer tip from the hinge, and the aimer tip couples to the arm via the hinge at a proximate end. The hinge is adapted to secure the aimer at a degree of rotation about an axis defined by the hinge rotation, such that the axis passes through the aimer point throughout rotation of the hinge while maintaining the aimer point in line with an insertion guide slideably movable through the aperture in the handle, in which the aperture defines an insertion axis extending toward the aimer point such that the aimer point remains disposed at the intersection of the hinge axis and the insertion axis. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other objects, features and advantages of the invention will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. 
         FIG. 1  shows a side view of the surgical aiming device as disclosed herein; 
         FIG. 2  shows a perspective view of the surgical aiming device of  FIG. 1 ; 
         FIG. 3  shows a side view of the surgical aiming device as in  FIG. 1  with a partially extended arced section; 
         FIG. 4  shows an opposed side view of the surgical aiming device of  FIG. 1 ; 
         FIG. 5  shows an alternate view of the surgical aiming device of  FIG. 4  having a partially extended arced section and disengaged arm; 
         FIG. 6  shows a perspective view of the aimer arm disposed at a surgical site; 
         FIG. 7  shows an exploded view of the arm of  FIG. 1 ; and 
         FIGS. 8-9  show a procedural sequence employing the surgical aiming device of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Disclosed below is an example configuration and deployment of the surgical aimer arm. In an example arrangement, an ACL repair employing the surgical aiming device for femoral drilling is shown. Alternate configurations may employ placement on other skeletal structures, or on softer tissue surfaces, and may or may not employ a drilling approach for excavating the insertion tunnel for a guidewire. 
       FIG. 1  shows a side view of the surgical aiming device  100  including a handle  102  having a slot  104  defining an arc  106 . The handle  102  is shaped for a secure grasp by a surgeon or other operator. An arm  110  has an arced section  112  and a straight section  114 . The arced section  112  is shaped to slideably engage with the slot  104  in the handle  102  for movement according to arrow  116 . The straight section  114  has a hinge  120  for securing an aimer  130  to the straight section  114  at the opposed end distal from the arced section  112 . The hinge  120  adapts the aimer  130  for rotational communication with the straight section  114  around a hinge axis  122 , as shown by arrow  124 . The hinge  120  secures the aimer  130  via a screw  126  or other suitable pivotal coupling around the hinge axis  122 . 
     The aimer  130  includes an elongated aimer tip  132  extending from the hinge and an aimer point  134  at a distal end of the aimer tip  132  from the hinge  120 . The aimer tip  132  couples to the straight section  114  via the hinge  120  at a proximate end. The handle  102  further includes an insertion guide  140  adapted for slideable movement within an aperture  144  in the handle  102  along an insertion axis  142 . The insertion guide  140  has slanting teeth  146  for selective ratcheting engagement with a pawl  148  when the insertion guide  140  is rotated via an insertion knob  149  such that the teeth  146  engage the pawl  148 . The insertion axis  142  passes through the aimer point  134  at an intersection  150  of the hinge axis  122 , thus the aimer tip  132  extends such that the aimer point  134  is disposed on the insertion axis  142  throughout the range of rotation  124  of the aimer  130 . 
     The arm  110  is adapted for arcuate movement relative to the handle  102  as defined by the arc  106 , shown by arrows  116 . The aimer point  134  is the center of a circle defining the arc  106  in the handle  102  through which the arced section  112  slideably engages, thus the aimer point  134  retains its position at the intersection  150  during the arcuate movement  116 . Further, as the hinge  120  is adapted to secure the aimer  130  at a degree of rotation about an axis  122  defined by the hinge  120  and passing through the aimer point  134 , the aimer point remains at the intersection  150  throughout movement of the arm  130  and arced section  112 . 
     The insertion guide  140  has a hollow core ( 176 ,  FIG. 6  below) for subsequent guidewire access, discussed further below. A taper, serration, or other suitable engaging edge on the tip  141  of the insertion guide facilitates identification of an incision point, and subsequently for engaging a bone or other hard surface for fixing the insertion guide for the guidewire. Typically a soft tissue incision is made where the tip  141  contacts soft tissue, the insertion guide  140  inserted until hard material (i.e. bone) is encountered, and the tip engages the bone facilitated by the ratcheting action to avoid slippage during guidewire insertion. 
       FIG. 2  shows a perspective view of the surgical aiming device of  FIG. 1 . Referring to  FIGS. 1 and 2 , the handle  102  includes apertures  103  for weight reduction. The insertion guide  140  is extendable to the aimer point  134  to define a drilling and/or insertion hole for a guide wire along the insertion axis  142  through a range from the aperture  144  in the handle to the aimer point  134 . A pivot knob  127  rotates the hinge screw  126  (arrow  125 ) for securing and releasing the hinge  120  at various degrees of rotation (pivot) through a range, shown at a pivot angle  124 . The arced section  112  is fixable by fixation knob  113 . 
       FIG. 3  shows a side view of the surgical aiming device as in claim  1  with a partially extended arced section  112 . Referring to  FIGS. 1 and 3 , the arced section  112  is partially extended exposing the apertures  103  in the handle  102 . The insertion axis  142  and hinge axis  122  still intersect  150  at the aimer point  134 , since the arm  110  travels along an arc  116  on the circle  152  with the aimer point  134  at the center. 
       FIG. 4  shows an opposed side view of the surgical aiming device of  FIG. 1 . Referring to  FIGS. 1 and 4 , the aperture  144  in the handle is visible showing the slanting teeth  146  providing ratcheting movement to the insertion guide  140 . The hollow core  176  of the insertion guide  140  allows passing of a guidewire  154  ( FIG. 6 , below) through an insertion tunnel  174  formed from rotation of the insertion guide  140  or from a separate drilling device. 
       FIG. 5  shows an alternate view of the surgical aiming device of  FIG. 4  having a partially extended arced section  112  and disengaged arm  130 . The partial extension of the arced portion  112  of the arm  110  is shown by the apertures  103  only partially obscured by the arced portion  112 . The hinge  120  employs the securing screw  126  for securing the arm  130 , shown detached with a threaded portion of the securing screw  126  visible. 
       FIG. 6  shows a perspective view of the surgical device  100  disposed at a surgical site. As indicated above, ACL repairs often involve surgical drilling through the femur  160  and tibia  162  for passing a guidewire  154  through the insertion guide  140 . Referring to  FIGS. 1 and 6 , an example of using the surgical aiming device  100  for such an application is shown. The surgeon disposes the aimer point  134  at a target location  170  within the surgical site, such as an anatomically sound location on the femur  160 . Typically this would be the same location as the prior attachment of the ligament being repaired, but other suitable locations may be marked/aimed. The surgeon frees the securing mechanism of the hinge  120  such as by loosening the hinge knob  127 , and disposes the arm  110  and handle  102  to a suitable location for drilling as defined by an incision point and corresponding drilling site  172  (note that the incision point often defines a soft tissue location along the insertion axis for insertion of the insertion guide towards the drilling site  172 ). A serrated or tapered edge at the tip  141  of the insertion guide  140  passes soft tissue, and contacts the drilling site  172  at the bone, cartilage, or other hard surface. The tip  141  is formed so as to engage the bone surface after penetrating the soft tissue through the insertion, and may be a pyramidal, serration, or tapered edge, for example. A drill may subsequently be employed to further excavate an insertion tunnel  174 , formed from the guide wire  154  passing through the hollow core  176  of the insertion guide  140 . 
       FIG. 7  shows an exploded view of the arm  110  of  FIG. 1 , showing tick markings  113  metering arcuate extension of the arced portion  112 , and the separation of the hinge  120  rotationally securing the straight portion  114  of the arm  110  to the aimer  130 . 
       FIGS. 8-9  show a procedural sequence employing the surgical aiming device of  FIG. 1 . Referring to FIGS.  1  and  8 - 9 , locating an optimal insertion point allows locating the aimer point  134  at a target location, and manipulating the handle  102  via pivoting of the hinge  120  and sliding the arced section  110  to dispose the insertion guide  140  accordingly, as follows. 
     A method for surgical drilling using the surgical aiming device disclosed herein includes, at step  200  engaging a handle  102  having a slot  104  defining an arc  106  in a surgical field for defining a drilling hole  174  by disposing an arm  110  having an arced section  112  and a straight section  114 , such that the arced section  112  slideably engages with the slot  104  in the handle  110  for arcuate movement therein, as depicted at step  201 . 
     The arm  110  hingedly attaches to the aimer  110  having an elongated aimer tip  132  and an aimer point  134 , such that the aimer point  134  is at a distal end of the aimer tip  132  from the hinge  120 , and the aimer tip  132  couples to the straight section  114  via the hinge  120  at a proximate end, as disclosed at step  202 . 
     An operator pivots the hinge  120  securing the aimer  130  to the straight section  114  distal from the arced section  112  for rotational communication with the straight section  114  around a hinge axis  122 , as shown at step  203 . The hinge axis  122  passes through the aimer point  134  throughout a range of motion  116  of the arced section  112  through the slot  104 , as depicted at step  204 . The aimer point  134  remains defined by the center of a circle  152  defining the arc  106  in the handle through which the arced section  112  slideably engages, as disclosed at step  205 . The surgeon or operator disposes, via the pivoting, the aimer tip  134  at a placement point  170  along the axis  142  defining an insertion path, as shown at step  206 . The hinge  120  is adapted to secure the aimer  130  at a degree of rotation  124 , such that the degree of rotation  124  is about an axis  122  defined by the hinge  120  and passing through the aimer point  134 , as depicted at step  207 . The hinge axis  122  is defined by a securing mechanism, such that the rotational communication  124  is about the axis  122  defined by the securing mechanism, and the degree of rotation  124  is fixable by the securing mechanism, as shown at step  208 . In the example arrangement, the securing mechanism is provided by the securing screw  126  and knob  127 , however alternate securement arrangements may be employed. 
     The operator or surgeon disposes the insertion guide  140 , such that the insertion guide  140  is slideably movable through an aperture  144  in the handle  110 . The aperture  144  defines an insertion axis  142  extending toward the center of a circle  152  defined by the arc  106 , as disclosed at step  209 . This includes, at step  210 , wherein the aperture  144  axis passes through the aimer point  134 , as the insertion guide  140  is disposed toward the aimer point  134 . This allows marking and fixing, via the edge at the tip  141  of the insertion guide  140 , an optimal insertion point  172 . The optimal insertion point  172  lies on the insertion axis where the insertion guide  140  meets bone, and the edge of the tip  141  allows fixing the insertion guide  140  against the bone for guidewire  154  insertion. The hinge axis  122  and the insertion axis  142  therefore define a placement point  170  representative of an optimal insertion point on the insertion axis  142  for surgical entry, in which the aimer point  134  of the arm disposed at the placement point  172  (target location), as depicted at step  211 . 
     While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present application as defined by the appended claims. Such variations are intended to be covered by the scope of this present application. As such, the foregoing description of embodiments of the present application is not intended to be limiting, the full scope rather being conveyed by the appended claims.