Abstract:
An orthopedic distraction sock for circumscribing at least a portion of an appendage, the distraction sock comprising a hollow braided sleeve having opposing open ends and including a non-braided tether mounted to the sleeve so that tension on the tether constricts the sleeve. The instant invention also includes a method of securing the relative position of an ankle during an arthroscopic procedure, the method comprising: (a) retarding movement of an upper leg; (b) sliding a constrictable sleeve axially over at least a majority of a foot, the sleeve including a distal open end and a proximal open end nearer an ankle than the distal open end; (c) mounting the sleeve to a support structure; and (d) tensioning the sleeve by increasing a distance between the support structure and the foot to constrict the sleeve circumferentially around the foot to securely mount the sleeve to the foot, where tensioning of the sleeve, after retarding movement of the femur, is operative to maintain the relative orientation between the foot and a lower leg.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/854,854, filed Oct. 27, 2006, and entitled “SCOPE SOCK,” the disclosure of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]    The present invention is directed to orthopedic equipment and techniques for using such equipment and, more specifically, to orthopedic equipment for distraction of an appendage and techniques for distracting appendages using the orthopedic equipment of the present invention. 
       INTRODUCTION TO THE INVENTION 
       [0003]    The instant invention includes an orthopedic distraction sock for circumscribing at least a portion of an appendage, the distraction sock comprising a hollow braided sleeve having opposing open ends and including a non-braided tether mounted to the sleeve so that tension on the tether constricts the sleeve. In a more detailed embodiment, the sleeve includes a plurality of attachment loops distributed generally in parallel with a longitudinal axis of the sleeve for secondarily mounting the sleeve to a support structure. In a further detailed embodiment, the sleeve includes a plurality of attachment loops distributed along a length of the sleeve generally perpendicular to a longitudinal axis of the sleeve for secondarily mounting the sleeve to a support structure. In a still further exemplary detailed embodiment, the sleeve is a bias weaved and a major portion of the sleeve is substantially cylindrical. The exemplary embodiment may also include a repositionable loop mounted to the sleeve, wherein the tether is mounted to a distal open end of the sleeve and the repositionable loop is mounted to a proximal open end of the sleeve. In yet another embodiment, the tether comprises a plurality of lines circumferentially mounted to the sleeve approximate a distal open end of the sleeve and bound to have a substantially common point of origin. In an even further embodiment, the sleeve comprises a plurality of braided layers. 
         [0004]    A second exemplary embodiment includes an orthopedic distraction sock for circumscribing at least a portion of an appendage, the distraction sock comprising: (a) a constrictable sleeve having opposing first and second open ends; (b) a tether mounted to the sleeve; and (c) a constrictor entwined with the sleeve approximate the first open end. 
         [0005]    A third exemplary embodiment includes a method of securing the relative position of an ankle during an arthroscopic procedure, the method comprising: (a) retarding movement of an upper leg; (b) sliding a constrictable sleeve axially over at least a majority of a foot, the sleeve including a distal open end and a proximal open end nearer an ankle than the distal open end; (c) mounting the sleeve to a support structure; and (d) tensioning the sleeve by increasing a distance between the support structure and the foot to constrict the sleeve circumferentially around the foot to securely mount the sleeve to the foot, where tensioning of the sleeve, after retarding movement of the femur, is operative to maintain the relative orientation between the foot and a lower leg. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a profile view of an operating table and a distraction assembly of the present invention; 
           [0007]      FIG. 2  is a profile view of the operating table and distraction assembly of  FIG. 1  in another position; 
           [0008]      FIG. 3  is a profile view of the operating table and distraction assembly of  FIG. 1  in a further position; 
           [0009]      FIG. 4  is a profile view of the operating table and distraction assembly of  FIG. 1  in still a further position; and 
           [0010]      FIG. 5  is an elevated perspective view of alternate exemplary embodiment in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    The exemplary embodiments of the present invention are described and illustrated below to encompass orthopedic distraction equipment and methods for using the same. Of course, it will be apparent to those of ordinary skill in the art that the embodiments discussed below are exemplary in nature and may be reconfigured without departing from the scope and spirit of the present invention. However, for clarity and precision, the exemplary embodiments as discussed below may include optional steps, methods, and features that one of ordinary skill should recognize as not being a requisite to fall within the scope of the present invention. 
         [0012]    Referring initially to  FIG. 1 , a conventional operating table  10  includes a standard Clark rail  12  attached to a distal end of the table in a well known manner. The patient is positioned supine on the operating table  10  with the leg  14  of the patient supported at the back of the knee vertically above the table, generally with some flexion of the knee. Leg support is provided by a conventional gynecological or urological leg holder  16  attached in a known manner to the Clark rail  12 . The leg holder  16  includes a support shaft  18  adjustably attached to the Clark rail  12  by a clamp  20  that allows the holder to be slid along the rail in a horizontal direction, pivoted in a vertical plane, and moved vertically up or down. The upper end of the support shaft  18  is connected to the leg holder  16  with a pivot joint  22  that allows the holder to be adjustably pivoted in either a horizontal or a vertical plane. The leg holder  16  can easily be adjusted in three planes of rotation and its height readily varied. The leg holder  16  includes padding  24  to provide cushioning to the leg  14 , thereby reducing the pressure on the posterior thigh and leg, primarily in the popliteal area. 
         [0013]    The distraction apparatus  26  of the present invention includes an axially adjustable braided sock  28  attached proximally to a proximal end  30  of the patient&#39;s foot  32  and distally to the operating table  10 , via an arm  34 , which is adjustably attached to the Clark rail  12 . A second arm  36 , also attached to the Clark rail  12 , is attached to the underside of the sock  28 . 
         [0014]    Referring to  FIGS. 1 and 2 , attachment of the sock  28  to the foot  32  of the patient is provided by a braided tubular sleeve  38  having a generally diametrical loop  40  at one axial end, which is placed around and behind the ankle above the heel and instep, and a webbed tether  44  at an opposite axial end to be mounted to the arm  34  by a swivel  46 . The sleeve  38  also includes a plurality of rings  48  attached to a circumferential side of the sleeve, such as by interweaving, that are linearly spaced apart and adapted to be oriented parallel to the longitudinal axis of the foot  32  and/or perpendicular to the longitudinal axis of the foot  32  when the sleeve is slid over the foot  32 . Attachment of the sleeve  38  to the second arm  36  is facilitated by a tether  50  having a caribiner  52  at one end to engage at least one of the rings  48 . The opposite end of the tether  50  is mounted to the second arm  36  by a swivel  54 . 
         [0015]    Referencing  FIG. 2 , the tubular sleeve  38  of the sock  28  is braided, such as by using a bias weaving process. This process produces two sets of continuous yarns, one clockwise and the other counterclockwise, where each fiber from one set is interwoven with every fiber from the other set in a continuous spiral pattern. This braided fiber architecture resembles a hybrid of filament winding and weaving. Like filament winding, tubular braid features seamless fiber continuity that is mechanically interlocked with one another. These interlocking connections allow the sleeve to exhibit highly efficient distributions of loads. In terms of compression fitting the sleeve  38  to the contours of the foot  32 , the interlocking of the fibers constricts to map the contours and evenly distribute compressive forces about the foot. In particular, braiding of the sleeve  38  offers natural conformability. This quality makes braid ideal for performance as a scope sock sleeve since it takes on the exact shape of the body part that it is mounted to. Therefore, extensive constraints on the sleeve itself are not necessary to mount the sleeve to the body part. 
         [0016]    Repeated use of the sock  28  is brought about, in part, by the construction of the sleeve  38 , which has excellent resistance to fatigue. Like a filament wound structure, braided fibers are coiled into a helix just like wire in a spring. The difference, however, is the mechanical interlocking. As a structure is exposed to high fatigue cycles, cracks will propagate through the matrix of filament. However, a braided structure arrests the propagation of cracks by intersection of the fibers. 
         [0017]    Referring also to  FIGS. 3 and 4 , the arms  34 ,  36  of the distraction apparatus  26  each include a threaded bolt to which the swivel  46  is attached. A length adjustment mechanism is attached to the second end of the threaded bolt. The adjustment mechanism includes a manually operable, threaded adjustment nut and an attached mount for an attachment strap. The mount is connected to the adjustment nut with a swivel connection so that the adjustment nut can be rotated on the threaded bolt to change the position of the adjustment mechanism therealong without rotating the sock  28 . 
         [0018]    The other leg of the lever arm has its free end attached to the Clark rail  12  for adjustable rotational positioning about its free end and axially along the leg. Attachment of the leg to the Clark rail  12  is provided by an adjustable clamp. The clamp includes a clamp body mounted for slidable movement along the Clark rail and a clamp head rotatably attached to the clamp body and movable into clamping engagement therewith by rotation of an operating arm. The clamp body includes a set screw for fixing the position of the clamp along the Clark rail. The clamp head includes a diametral through bore for receiving the leg of the lever arm, and the clamp head is configured internally to simultaneously clamp the leg in the bore and the clamp head to the clamp body by rotation of the operating arm. Similarly, rotation of the operating arm in the opposite direction simultaneously unclamps the clamp head from the body so the head and lever arm may be rotated with respect thereto and the leg can be positioned axially in the through bore. 
         [0019]    Arthroscopic procedures utilizing non-invasive distraction techniques are preferably commenced utilizing the distraction position shown in  FIG. 1 . The support arm for the leg holder is positioned in a mid-height position and fixed with the clamp. With the patient in a supine position, the leg is placed in the leg holder with the knee slightly flexed to about 20 degrees. This initial position of near extension reduces the pressure on the posterior thigh and leg, primarily the popliteal area. The proximal end of the sleeve  38  is placed around the foot and is secured/anchored to the back of the foot by the connecting strap  40 . One arm  36  of the distraction apparatus  26  is attached to the underside of the sleeve  38  via one or more of the rings  48 , while the distal end of the sleeve  38  is mounted to the arm  34  operative to pull the foot along its longitudinal axis. The clamp bodies are positioned in an appropriate position on the Clark rail and clamped thereto with the set screw. Each arm  34 ,  36  may then be manually rotated (e.g. by the surgeon&#39;s assistant) around the end held in the clamp in a counterclockwise direction as viewed in  FIG. 1 . The position of clamps on the Clark rail  12  or the position along the leg of the lever arms may be adjusted as necessary. Continued rotation of the lever arm  36  in the clockwise direction will impose a tensile load on the ankle joint and provide an initial level of joint distraction. The initial level of distraction need only be very slight and just enough to hold the patient&#39;s leg and the apparatus firmly in position. The operating arm of each clamp is then turned to clamp the lever arms  34 ,  36  to establish its angular position with respect to the operating table and its axial position along the length of the leg. 
         [0020]    With the leg and distractor held firmly in its initial position, the final desired level of joint distraction may be reached by turning the adjustment nut on the adjustment mechanism to change its position along the threaded bolt, to increase or decrease the tensile force applied to the foot strap and thus the level of distraction force. The level of distraction is generally judged by the surgeon based on his preliminary examination of the patient and considering such factors as the nature of the pathology, the age of the patient, the relative degree of ligament laxity, and other indications. After the arthroscope has been inserted into the joint, the need for increased (or even decreased) distraction may be indicated. Any desired adjustment can be easily made by turning the adjustment nut. 
         [0021]    If additional distraction is needed beyond a level which can be adequately supported by the patient&#39;s knee only slightly flexed (FIG. I), it may be necessary to more acutely flex the knee to a position shown, for example, in  FIGS. 2 and 4 . The  FIG. 2  angle of the lower leg may also position the posterior of the ankle joint in a more desirable position for the surgeon requiring entry through the posterior portals. The adjustment from the  FIG. 1  to the  FIG. 2  position is easily effected by raising the leg holder to a slightly higher position and sliding each clamp along the Clark rail toward the leg holder. These adjustments may be made simply and with little loss of time and without affecting the sterile draping. 
         [0022]    In either of the positions shown in  FIG. 1  or  FIG. 2 , it will be appreciated that the vertical position of the ankle above the operating table can be varied considerably and as desired by varying the position of the leg with respect to the Clark rail. Furthermore, if necessary, the leg could be flexed even more acutely than shown in the  FIG. 2  position with similar adjustments to the leg holder and distractor as previously described. However, in the more acutely flexed positions, the pressure which can be applied to the popliteal area is potentially greater and circulation must be monitored. 
         [0023]    To facilitate certain procedures or to accommodate the personal preference of the surgeon, the apparatus and method of the present invention allows further significant adjustments in the height and relative position of the ankle joint in a manner utilizing simple adjustment of the type previously described, with little loss of time, and without affecting the sterile draping. By additionally utilizing a table end which can be pivoted or tilted downwardly about a laterally disposed hinge and locked in a tilted position, the lower leg may be positioned nearly vertical or even below the level of the operating table, if desired. The hinge is positioned between the adjustable clamp for the lever arm and the clamp for the leg holder support arm. The leg holder clamp may be adjusted to position the leg holder close to the hinge to accommodate the downwardly depending positions of the leg as shown in  FIGS. 3 and 4 . The  FIG. 3  position may be suitable for most diagnostic work and some surgery. In this position, the ankle may be placed closer vertically to the horizontal top of the operating table, but because of the downwardly dependent table end, the table does not provide as significant an obstruction to surgical procedures and access to the entire ankle joint is relatively uninhibited. 
         [0024]    If posterior lateral entry is required or if a lower position of the ankle is more convenient to the surgeon, the table end may be tilted downwardly to an even greater acute angle with respect to the horizontal table top and locked in the  FIG. 4  position. This position may require the leg holder to be positioned closer to the hinge by repositioning the leg holder clamp. This, in turn, may also necessitate repositioning the adjustable clamps on the table end to move it closer to the distal end thereof. 
         [0025]    Should invasive distraction techniques, such as those described in prior U.S. Pat. No. 5,063,918, become necessary during procedures performed in any of the positions of  FIGS. 1-4 , conversion to such invasive techniques can be made quickly and without reprepping or redraping as indicated in that patent. 
         [0026]    It is also within the scope of the present invention to utilize multiple braided sleeves that circumscribe one another or that are interwoven with one another to provide selective tensioning of the sock along the longitudinal axis of the sock  28 . Those skilled in the art, in light of this disclosure, will be familiar with the points along a sock that could be advantageously constricted to attach the sock to the body part in question. Thus, by tensioning the sock longitudinally, the circumferential forces along the longitudinal axis may be adjusted, particularly where the circumference of the sock is constant, but the constricting forces are not. Moreover, interposing multiple ply sleeves may be utilized to generate a constant circumferential force along the longitudinal axis of the sock when an outer ply circumference is not constant along the longitudinal axis of the sock. 
         [0027]    Referring to  FIG. 5 , it is also within the scope of the invention to incorporate a constrictor  60  at one open end of the tubular sleeve  38 ′ of the sock  28 ′, generally opposite a distal portion of the foot. In such an alternate exemplary embodiment, the constrictor  60  may comprise a string, chord, or other device used to constrict an open end of the sleeve  38 ′. In exemplary form, the constrictor  60  comprises a pliable chord entwined with sleeve in a circumscribing manner. Opposing ends of the constrictor  60  may be free, or one end of the constrictor fixed to the sleeve  38 ′, so that tension on the constrictor  60  reduces the cross-section of the sleeve  38 ′. Likewise, constrictors  60  may be distributed along the length of the sleeve and, in a further alternate exemplary embodiment, a constrictor  60  may be used in lieu of one or more rings  48 . In this manner, tensioning forces applied to the constrictor are operative to decrease or maintain the cross-section of the sleeve. 
         [0028]    Following from the above description and invention summaries, it should be apparent to those of ordinary skill in the art that, while the methods and apparatuses herein described constitute exemplary embodiments of the present invention, the invention contained herein is not limited to this precise embodiment and that changes may be made to such embodiments without departing from the scope of the invention as defined by the claims. Additionally, it is to be understood that the invention is defined by the claims and it is not intended that any limitations or elements describing the exemplary embodiments set forth herein are to be incorporated into the interpretation of, any claim element unless such limitation or element is explicitly stated. Likewise, it is to be understood that it is not necessary to meet any or all of the identified advantages or objects of the invention disclosed herein in order to fall within the scope of any claims, since the invention is defined by the claims and since inherent and/or unforeseen advantages of the present invention may exist even though they may not have been explicitly discussed herein.