Abstract:
A cartilage trimmer according to an exemplary aspect of the present disclosure includes, inter alia, a guide pin connected to a cutter with a blade projecting from only one side of the guide pin.

Description:
BACKGROUND 
       [0001]    This disclosure relates to cartilage trimmers for use during a surgical procedure. Cartilage trimmers can be used to resect or remove damaged cartilage. In one example procedure, a cartilage trimmer can remove damaged cartilage on an articular surface, and then graft material can replace the defect. The remaining, undamaged cartilage establishes a stable border for the graft material. 
       SUMMARY 
       [0002]    This disclosure relates to a cartilage trimmer and associated methods. In an example, a disclosed cartilage trimmer can be assembled during surgery by inserting a guide pin into a joint space and connecting a cutter, which is deployed arthroscopically, to the guide pin. In another example, the cutter is selectively moveable relative to the guide pin and deployed via an opening adjacent an end of the guide pin. In an example, a disclosed cartilage trimmer can be used to resect cartilage in relatively narrow joint spaces. In an embodiment, the cartilage is articular cartilage. 
         [0003]    A cartilage trimmer according to an exemplary aspect of the present disclosure includes, inter alia, a guide pin connected to a cutter with a blade projecting from only one side of the guide pin. 
         [0004]    In a further non-limiting embodiment, an angular position of the blade is adjustable relative to the guide pin. 
         [0005]    In a further non-limiting embodiment, the angular position of the blade is adjustable relative to a normal to a longitudinal axis of the guide pin by about 20 to about 30 degrees in a distal direction and by about 20 to about 30 degrees in a proximal direction. 
         [0006]    In a further non-limiting embodiment, the guide pin includes a first connection portion adjacent a distal end thereof, the cutter includes a second connection portion, and the first and second connection portions are connectable. 
         [0007]    In a further non-limiting embodiment, the first connection portion includes an opening in a side of the guide pin, and the second connection portion is received in the opening. 
         [0008]    In a further non-limiting embodiment, the connection between the first and second connection portions is threaded. 
         [0009]    In a further non-limiting embodiment, a bushing is received in the opening, and the bushing is moveable relative to the opening to adjust an angle of the cutter relative to the guide pin. 
         [0010]    In a further non-limiting embodiment, the second connection portion includes a slot, and the first connection portion includes a retention pin selectively moveable into the slot. 
         [0011]    In a further non-limiting embodiment, the first connection portion includes threads about an exterior of the guide pin, and the second connection portion comprises a threaded bushing configured to be threadably engaged with the threads of the guide pin. 
         [0012]    In a further non-limiting embodiment, the cutter includes a socket, and the threaded bushing is received in the socket. The socket is moveable relative to the threaded bushing to adjust an angle of the cutter relative to the guide pin. 
         [0013]    A cartilage trimmer according to another exemplary aspect of the present disclosure includes, inter alia, a guide pin and a cutter. The cutter includes a blade moveable between a retracted position within the guide pin and a deployed position projecting from the guide pin. Further, the blade has a cutting surface only on a proximal edge of the blade. 
         [0014]    In a further non-limiting embodiment, the cutter further comprises a) a rod moveable within the guide pin, and b) the blade at a distal end. 
         [0015]    In a further non-limiting embodiment, the guide pin includes an internal passageway and an opening adjacent a distal end thereof. Further, the blade projects through the opening when in the deployed position. 
         [0016]    In a further non-limiting embodiment, the opening is in a side of the guide pin, and the internal passageway includes an angled wall adjacent the opening to facilitate movement of the blade between the retracted position and the deployed position. 
         [0017]    In a further non-limiting embodiment, the blade is moveable between a folded position substantially parallel to the rod and a cutting position substantially normal to the rod. The blade can also be biased to the cutting position. 
         [0018]    In a further non-limiting embodiment, the opening is at a distal end of the guide pin. 
         [0019]    A method of using a cartilage trimmer according to an exemplary aspect of the present disclosure includes connecting the cutter to a guide pin in a joint space. The cutter comprises a blade projecting from only one side of the guide pin. 
         [0020]    In a further non-limiting embodiment, a method includes resecting cartilage with the blade. 
         [0021]    In a further non-limiting embodiment, the cartilage is articular cartilage. 
         [0022]    In a further non-limiting embodiment, the method includes adjusting an angle of the blade relative to the guide pin while resecting cartilage. 
         [0023]    The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The drawings can be briefly described as follows: 
           [0025]      FIG. 1  illustrates a first example cartilage trimmer relative to a knee joint. In  FIG. 1 , the cartilage trimmer is unassembled. 
           [0026]      FIG. 2  illustrates the first example cartilage trimmer relative to the knee joint. In  FIG. 2 , the cartilage trimmer is assembled. 
           [0027]      FIG. 3  is a cross-sectional view of the first example cartilage trimmer. 
           [0028]      FIG. 4  is a close-up view of the encircled area in  FIG. 3 . 
           [0029]      FIG. 5  is a cross-sectional view of a second example cartilage trimmer. 
           [0030]      FIG. 6  is an exploded view of a third example cartilage trimmer. 
           [0031]      FIG. 7  is an exploded view of a bushing, socket, and plate associated with the third example cartilage trimmer. 
           [0032]      FIG. 8  is a cross-sectional view of the bushing, socket, and plate associated with the third example cartilage trimmer. 
           [0033]      FIG. 9  is a cross-sectional view of a fourth example cartilage trimmer. 
           [0034]      FIG. 10  is a cross-sectional view of a fifth example cartilage trimmer. 
       
    
    
     DETAILED DESCRIPTION 
       [0035]    This disclosure relates to a cartilage trimmer and associated methods. In an example, a disclosed cartilage trimmer can be assembled during surgery by inserting a guide pin into a joint space and connecting a cutter, which is deployed arthroscopically, to the guide pin. In another example, the cutter is selectively moveable relative to the guide pin and deployed via an opening adjacent an end of the guide pin. In an example, a disclosed cartilage trimmer can be used to resect cartilage in relatively narrow joint spaces. In an embodiment, the cartilage is articular cartilage. 
         [0036]      FIGS. 1-2  illustrate an example cartilage trimmer  20 , which includes a guide pin  22  and a cutter  24 , relative to a joint space  26 . In this example, the joint space  26  is a joint cavity in a knee, and is specifically a cavity between a femur  28  and a tibia  30 . While a knee joint is illustrated, this disclosure extends to cartilage trimmers for other joints. 
         [0037]    The cartilage trimmer  20  is configured to resect torn or damaged cartilage in the joint space  26 . In this example, the cartilage trimmer  20  is used to resect a tear  32  in a meniscus  34 . The cartilage trimmer  20  can be used to resect other cartilage structures, including articular cartilage. 
         [0038]    As generally mentioned above, the cartilage trimmer  20  is configured to be assembled during surgery. In the example of  FIGS. 1-2 , the cartilage trimmer  20  is assembled by first inserting the guide pin  22  into the joint space  26 . In this example, the guide pin  22  is inserted into the joint space  26  by way of a tunnel  36  formed in the tibia  30 . Once the guide pin  22  is positioned in the joint space  26 , the cutter  24  is deployed arthroscopically, as generally shown in  FIG. 1 , and connected to the guide pin  22  by a tool  38  such as a grasper, as generally shown in  FIG. 2 . The assembled cartilage trimmer  20  is then used to resect the tear  32 . Because cartilage is relatively soft, a surgeon typically maneuvers the guide pin  22  by hand. However, in some examples, the guide pin  22  can be rotated using an automated tool, such as a drill. 
         [0039]    Once the tear  32  is resected, the cutter  24  can then be removed from the guide pin  22  (for example, using the tool  38 ). The guide pin  22  and the cutter  24  are then separately removed from the joint space  26 . By assembling and disassembling the cartilage trimmer  20  during surgery, the cartilage trimmer  20  is able to reach relatively narrow joint spaces. A “narrow” joint space is a joint space, or a portion of a joint space, that is relatively small and perhaps difficult to visualize or access during surgery. Example narrow joint spaces include the lateral and medial compartments of a knee joint. 
         [0040]      FIG. 3  is a cross-sectional view of the cartilage trimmer  20 . In this example, the guide pin  22  includes an opening  40  on one side  42 . The opening  40  is provided adjacent, yet spaced-apart from, a distal end  44  (the “distal” and “proximal” directions are labeled in the Figures) of the guide pin  22 . The opening  40  includes a first connection portion  46  configured to mate with a second connection portion  48  of the cutter  24 . In this example, the first and second connection portions  46 ,  48  are threaded and thus provide a threaded connection. Other types of connections are also within the scope of this disclosure. 
         [0041]    The cutter  24  includes a blade  50  extending from the second connection portion  48 . The blade  50  includes a blunt distal edge  52  and a cutting surface  54  providing a sharp surface at a proximal edge  56 . The cutting surface  54  is configured to resect cartilage. The cutting surface  54  can optionally include a tooth  58  at a free end  59  of the blade  50  opposite the second connection portion  48 . 
         [0042]    Providing the blade  50  with a blunt distal edge  52  and a cutting surface  54  only at the proximal edge  56  decreases the risk of damage to healthy cartilage and increases the precision to resect damaged cartilage. Providing the blade  50  on only one side of the guide pin  22  also increases precision, and further allows the cartilage trimmer  20  access to relatively narrow joint spaces. 
         [0043]    The blade  50  is configured to connect to the guide pin  22  and project along a blade axis  60 , which is substantially normal to a longitudinal axis  62  of the guide pin  22 . In the example of  FIG. 3 , an angular position of the blade  50  relative to the guide pin  22  is adjustable. In particular, the blade  50  can be inclined away from a normal to the longitudinal axis  62  in both a direction D 1 , which is generally in the distal direction, and in a direction D 2 , which is generally in the proximal direction. In one example, the blade  50  is adjustable away from the normal by about 20 to about 30 degrees in either of the directions D 1  or D 2 . In a further example, the blade  50  is adjustable away from the normal by about 25 degrees in either of the directions D 1  or D 2 . In a further example, the blade  50  is adjustable away from the normal by about 24 degrees in either of the directions D 1  or D 2 . In a further example, the blade  50  is adjustable away from the normal by about 23 degrees in either of the directions D 1  or D 2 . In a further example, the blade  50  is adjustable away from the normal by about 26 degrees in either of the directions D 1  or D 2 . In a further example, the blade  50  is adjustable away from the normal by about 27 degrees in either of the directions D 1  or D 2 . In order to facilitate the angular adjustment of the blade  50 , the first connection portion  46  is provided by a bushing  64  received in the opening  40 . Details of the bushing  64  are illustrated in  FIG. 4 . In this example, the bushing  64  includes at least one tab  66  projecting into a corresponding channel  68  in the opening  40 . In the illustrated embodiment, two tabs  66  are provided on opposed sides of the bushing  64 , and the opening  40  includes two channels  68  corresponding to the tabs  66 . 
         [0044]    The bushing  64  is moveable relative to the opening  40 , and the movement of the bushing  64  is restricted by the arrangement of the tab  66  and the channel  68 . Specifically, the bushing  64  is moveable in the directions D 1  and D 2 , until the tab  66  contacts either end  70  of the channel  68 . The ends  70  of the channel could be provided with resilient members, for example, configured to bias the blade  50  to a position where the blade axis  60  is normal to the longitudinal axis  62 . 
         [0045]    In an example, the angular position of the blade  50  is passively adjustable. As the cutter  24  resects cartilage, the angular position of the blade  50  is influenced by the position of the guide pin  22  relative to the adjacent cartilage. Alternatively, the guide pin  22  could incorporate a rod connected to the bushing  64  to allow for active adjustment. By allowing an angular adjustment of the blade  50 , the blade  50  can be positioned at an optimal angle for resecting cartilage. The blade  50  can further be maneuvered into relatively narrow joint spaces that are not otherwise easily accessed. 
         [0046]    While the first and second connection portions  46 ,  48  of  FIGS. 3-4  provide a threaded connection, other types of connections are also within the scope of this disclosure. For example,  FIG. 5  illustrates a cartilage trimmer  20  having a slot-and-pin connection. In this example, the first connection portion  46  includes a retention pin  74  selectively moveable into the opening  40 . A surgeon, for example, can selectively move the retention pin  74  relative to the remainder of the guide pin  22 . 
         [0047]    The second connection portion  48  of the cutter  24  includes a slot  75 . The retention pin  74  is selectively moveable into the slot  75  to retain the cutter  24  relative to the guide pin  22 . The slot-and-pin connection could allow for the angular adjustment of the blade as generally discussed above. In that case, the second connection portion  48  could include a bushing. 
         [0048]      FIG. 6  is an exploded view of another embodiment of the disclosed cartilage trimmer  20 . In this example, the first connection portion  46  includes threads  76  provided about an exterior of the guide pin  22 . The second connection portion  48  is provided by a bushing  78  having internal threads  80  and configured to be threadably engaged with the threads  76  of the first connection portion  46 . The threads  76 ,  80  may be handed such that they do not become unwound during normal use of the cartilage trimmer  20 . 
         [0049]    In one example, the cartilage trimmer  20  can be rotated primarily in a clockwise direction from the perspective of the surgeon (i.e., when viewed from a location proximal to the cartilage trimmer  20 ). Such rotation may cause the threads  80  to rotate relative to the threads  76  in a counter-clockwise direction. To prevent unintended unwinding, the threads  76 ,  80  are handed such that the bushing  78  continues to tighten to the guide pin  22  as the surgeon rotates the cartilage trimmer  20  clockwise. In this example, the threads  76 ,  80  are right-handed threads. This disclosure is not limited to right-handed threads. For example, the threads  76 ,  78  could be left-handed threads for counter-clockwise rotation of the cartilage trimmer  20 . 
         [0050]    In the embodiment of  FIGS. 6-7 , the second connection portion  48  includes a socket  82  receiving the bushing  78 . The blade  50  is rigidly connected to the socket  82  and is provided on one side of the guide pin  22 . The inner surface of the socket  82  has a contour corresponding to an outer contour of the bushing  78 . Thus, the socket  82  and blade  50  are moveable relative to the bushing  78  to adjust a cutting angle of the blade  50  relative to the guide pin  22 . 
         [0051]    With reference to  FIG. 7 , movement of the socket  82  relative to the bushing  78  is regulated in part by a plate  84  provided over the socket  82 . Movement is further limited by a plurality of channels  86  formed in the socket  82 . The channels  86  receive tabs  88  projecting from the bushing  78 . The tabs  88  are sized to allow movement of the socket in the directions D 1  and D 2 . In this example, angular adjustments of the socket  82  are passive. As the guide pin  22  moves proximally during resection, the socket  82  and the blade  50  tilt in the direction D 1 . 
         [0052]      FIG. 8  shows the assembled cutter  24  in cross-section. Further, in  FIG. 8 , the blade  50  has been adjusted such that the blade axis  60  is transverse of a normal axis  89  and is inclined in the direction D 1  relative to the normal axis  89 . In this example, the right-hand tab  88  is in contact with an end  90  of the channel  86 . Thus, the blade  50  has moved off the normal to a limit. In this example, a resilient member  92  is provided at the end  90  of the channel to bias the blade  50  toward the normal  89 . The resilient member  92  is not required in all examples. Alternatively or additionally, resilient members could be provided on the plate  84 . 
         [0053]      FIGS. 1-8  illustrate cartilage trimmers that are configured to be assembled during surgery. This disclosure also extends to cartilage trimmers with cutters that are selectively moveable relative to the guide pin and deployed via an opening adjacent an end of the guide pin.  FIGS. 9 and 10  illustrate two such examples. 
         [0054]    Referring to  FIG. 9 , the cartilage trimmer  20  includes a guide pin  22  having an internal passageway  94  extending from a proximal end to an opening  96  adjacent a distal end  44 . In this example, the opening  96  is provided in a side  42  of the guide pin  22  and is spaced proximally from the distal end  44 . The internal passageway  94  includes an angled wall  98  adjacent the opening  96  to facilitate movement of the blade  50  between the internal passageway  94  and the opening  96 . The angled wall  98  is inclined at an acute angle  100  relative to the longitudinal axis  62  of the guide pin  22 . While the angled wall  98  has a constant angle in this example, the angled wall  98  could be curved in other embodiments. Further, the angled wall  98  could include more than one wall segment. 
         [0055]    The cutter  24  in this example includes a blade  50  connected to a distal end of a rod  102 . The blade includes a blunt distal edge  52  and a cutting surface  54  at a proximal edge  56  only. The rod  102  is made of a semi-rigid material and is selectively moveable within the internal passageway  94  by a surgeon. Movement of the rod  102  translates to movement of the blade  50  between a retracted position within the internal passageway  94  and a deployed, or cutting, position projecting from the guide pin  22  via the opening  96 . 
         [0056]    The rod  102  is formed such that the blade axis  60  is biased substantially normal to the longitudinal axis  62  when the blade  50  projects through the opening  96 . The material of the rod  102  allows movement of the blade  50  off of the normal in the directions D 1  and D 2 . Further, the material of the rod  102  allows the blade  50  to project in a direction parallel to the internal passageway  94  when passing within the internal passageway. Example materials for the rod  102  include, but are not limited to, nitinol, PEEK, or a combination of PEEK and metal (e.g., a PEEK rod with a metal blade). 
         [0057]      FIG. 10  shows an example cartilage trimmer  20  with a fully cannulated guide pin  22 . In particular, the internal passageway  94  extends in a direction substantially parallel to the longitudinal axis  62  from a proximal end of the guide pin  22  to the distal end  44 . The internal passageway  94  in this example terminates at an opening  104  at the distal end  44 . 
         [0058]    The cutter  24  in this example includes a blade  50  connected to a rod  102  by way of a hinge  106 . In this example, the hinge  106  is provided by a bend in the rod  102 . The hinge  106  is configured to bias the blade  50  such that the blade axis  60  is substantially normal to the longitudinal axis  62  when the blade  50  is deployed through the opening  104 . The blade  50  in this example is moveable between a folded position (shown near the bottom of  FIG. 10 ), in which the blade axis  60  is substantially parallel to the rod  102  and a cutting surface  54  is positioned adjacent the rod  102 , and a cutting position (shown near the top of  FIG. 10 ) substantially normal to the rod  102 . 
         [0059]    As with previously discussed embodiments, the distal edge  52  of the blade  50  can be blunt, which prevents damage to adjacent soft tissue as the blade  50  moves from the folded position to the cutting position. When the blade  50  is retracted back into the guide pin  22 , the blade  50  would not be folded. Instead, the blade  50  would be distal of the hinge  106 . 
         [0060]    It should be understood that terms such as “proximal,” “distal,” “medial,” and “lateral” are used consistent with their art-accepted meanings, and are used for purposes of explanation only. Terms such as “longitudinal,” “axial,” and “radial,” are used above with reference to the respective axis and are also used only for purposes of explanation, and should not be considered otherwise limiting. Terms such as “generally,” “substantially,” and “about” are not intended to be boundaryless terms, and should be interpreted consistent with the way one skilled in the art would interpret those terms. 
         [0061]    Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples. 
         [0062]    One of ordinary skill in this art would understand that the above-described embodiments are exemplary and non-limiting. That is, modifications of this disclosure would come within the scope of the claims. Accordingly, the following claims should be studied to determine their true scope and content.