Abstract:
A surgical device according to an exemplary aspect of the present disclosure includes, among other things, a tube and a cutting blade movable between a first position in which the cutting blade is concealed inside the tube and a second position in which the cutting blade is exposed through a sidewall of the tube.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Application No. 61/774,787, which was filed on Mar. 8, 2013. 
     
    
     BACKGROUND 
       [0002]    This disclosure relates to an orthopedic surgical device, and more particularly to an expandable reamer that can be introduced into a bone tunnel to remove areas of diseased bone. 
         [0003]    Diseased areas of bone may need removed from patients suffering from bone degeneration. For example, treatment of Avascular Necrosis (AVN) of the hip is often performed on patients that may otherwise face prosthetic joint arthroplasty, which can be a relatively invasive procedure. Core decompression procedures have been used to remove areas of diseased bone. However, efforts have continued to develop improved procedures for removing areas of diseased bone. 
       SUMMARY 
       [0004]    A surgical device according to an exemplary aspect of the present disclosure includes, among other things, a tube and a cutting blade movable between a first position in which the cutting blade is concealed inside the tube and a second position in which the cutting blade is exposed through a sidewall of the tube. 
         [0005]    In a further non-limiting embodiment of the foregoing surgical device, a shaft is surrounded by the tube. 
         [0006]    In a further non-limiting embodiment of either of the foregoing surgical devices, one of the tube and the shaft is movable relative to the other of the tube and the shaft. 
         [0007]    In a further non-limiting embodiment of any of the foregoing surgical devices, a plurality of cutting blades are moveable to a cutting position radially outward of the tube. 
         [0008]    In a further non-limiting embodiment of any of the foregoing surgical devices, the tube includes a window disposed through the sidewall and the cutting blade is incrementally advanced though the window to expose the cutting blade. 
         [0009]    In a further non-limiting embodiment of any of the foregoing surgical devices, a clutch assembly is configured to move the cutting blade between the first position and the second position. 
         [0010]    In a further non-limiting embodiment of any of the foregoing surgical devices, the clutch assembly includes a threaded hub and a clutch hub disengageable from the threaded hub. 
         [0011]    In a further non-limiting embodiment of any of the foregoing surgical devices, the tube includes a deflection pin configured to deflect the cutting blade radially outward of the tube. 
         [0012]    In a further non-limiting embodiment of any of the foregoing surgical devices, the tube is connected to a handle. 
         [0013]    In a further non-limiting embodiment of any of the foregoing surgical devices, the cutting blade includes nitinol wires having a shape memory. 
         [0014]    In a further non-limiting embodiment of any of the foregoing surgical devices, an actuator is configured to move the cutting blade between the first position and the second position. 
         [0015]    An expandable reamer according to another exemplary aspect of the present disclosure includes, among other things, a tube and at least one cutting blade configured to incrementally advance to a cutting position radially outward from the tube to create a socket in bone. 
         [0016]    In a further non-limiting embodiment of the foregoing expandable reamer, a shaft has a concentric relationship with the tube. 
         [0017]    In a further non-limiting embodiment of either of the foregoing expandable reamers, the cutting blade is hinged to the shaft. 
         [0018]    In a further non-limiting embodiment of any of the foregoing expandable reamers, the tube includes a guide pin received by a slot of the shaft to guide the tube as it moves relative to the shaft. 
         [0019]    A method for removing diseased bone, according to another exemplary aspect of the present disclosure includes, among other things, positioning a surgical device relative to diseased bone, the surgical device including at least one cutting blade that is concealed inside the surgical device during the step of positioning, and incrementally advancing the at least one cutting blade to position the at least one cutting blade into a cutting position relative to the diseased bone. 
         [0020]    In a further non-limiting embodiment of the foregoing method, the method includes the step of rotating the surgical device to remove the diseased bone. 
         [0021]    In a further non-limiting embodiment of either of the foregoing methods, the method includes reaming a tunnel into a bone that includes the diseased bone prior to the step of positioning. 
         [0022]    In a further non-limiting embodiment of any of the foregoing methods, the method includes backfilling the tunnel with a biologic after the step of incrementally advancing the at least one cutting blade. 
         [0023]    In a further non-limiting embodiment of any of the foregoing methods, the step of incrementally advancing includes axially moving a tube or shaft of the surgical device to rotationally move the at least one cutting blade to the cutting position. 
         [0024]    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. 
         [0025]    The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIGS. 1A and 1B  illustrate an exemplary expandable reamer. 
           [0027]      FIG. 2  illustrates an exploded view of the expandable reamer of  FIGS. 1A and 1B . 
           [0028]      FIGS. 3A and 3B  illustrate additional features of an expandable reamer. 
           [0029]      FIGS. 4 ,  5 ,  6 ,  7 ,  8  and  9  schematically illustrate an exemplary method of removing areas of diseased bone. 
           [0030]      FIGS. 10A and 10B  illustrate another exemplary expandable reamer. 
           [0031]      FIGS. 11A and 11B  illustrate yet another exemplary expandable reamer. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    Among other features, this disclosure relates to a surgical device, such as an expandable reamer, that can be introduced through a bone tunnel to remove areas of diseased bone. In one non-limiting embodiment, the expandable reamers described by this disclosure can be used to treat Avascular Necrosis (AVN) of the hip. However, this disclosure is not limited to the treatment of AVN and could extend to other treatments, such as Osteochondritis Dissecans (OCD) of the knee or any other treatment requiring the removal of diseased bone in either human or animal patients. 
         [0033]      FIGS. 1A ,  1 B and  2  illustrate an exemplary expandable reamer  10 . The expandable reamer  10  is an orthopedic surgical device that may be part of a surgical instrumentation set for removing diseased bone from a patient. In one embodiment, the expandable reamer  10  includes a clutch assembly  12 , an inner shaft  14  (best illustrated in  FIG. 2 ), and an outer tube  16  that generally surrounds the inner shaft  14 . For example, the inner shaft  14  and the outer tube  16  may include a concentric relationship relative to one another. 
         [0034]    In one non-limiting embodiment, the inner shaft  14  is affixed to the clutch assembly  12  and the outer tube  16  is movable along a longitudinal axis A (see  FIG. 1B ) of the expandable reamer  10 . An opposite configuration is also contemplated in which the outer tube  16  is affixed and the inner shaft  14  is moveable along the longitudinal axis A. Movement of either the inner shaft  14  or the outer tube  16  relative to the other of the inner shaft  14  and the outer tube  16  positions a cutting blade  18  for reaming diseased tissue, as discussed in greater detail below. 
         [0035]    The expandable reamer may include one or more cutting blades  18 . In this embodiment, a single cutting blade  18  is shown. However, multiple cutting blades could also be provided (see, e.g., the embodiment of  FIGS. 10A ,  10 B,  11 A and  11 B). 
         [0036]    The cutting blade  18  may be attached to a distal end portion  21  of the inner shaft  14 , such as with a pin  22  (i.e., the cutting blade  18  is hinged to the inner shaft  14 , see  FIGS. 2 ,  3 A and  3 B). In one embodiment, the cutting blade  18  may be incrementally advanced through a window  20  (best illustrated in  FIGS. 3A and 3B ) disposed at a distal end portion  24  of the outer tube  16  to create a retrograded socket in bone that can be filled with biologics. In one embodiment, the window  20  extends through a sidewall  69  of the outer tube  16  such that the cutting blade  18  is exposed outside of the outer tube  16  through the sidewall  69 . 
         [0037]    A cap  26  (see  FIG. 2 ) may be welded or otherwise affixed to a distal-most portion  28  of the outer tube  16  such that the outer tube  16  includes at least one closed end. In this way, in a closed position P1 of the cutting blade  18  (see  FIG. 1A ), the expandable reamer  10  provides an atraumatic device that substantially reduces risk of inadvertent damage to surrounding tissue during positioning of the expandable reamer  10 . The cutting blade  18  of the expandable reamer  10  may be advanced radially outward from the outer tube  16  to a cutting position P2 (see  FIG. 1B ) that is configured to prepare a socket in bone. In the cutting position P2, the cutting blade  18  is non-parallel to the longitudinal axis A and is exposed outside of the outer tube  16 . 
         [0038]    In one embodiment, the clutch assembly  12  of the expandable reamer  10  includes a threaded hub  30 , a clutch hub  32  and a connector  34 , such as a Hudson connector for connecting to powered equipment. The threaded hub  30  and the clutch hub  32  may be disengaged from one another to advance or retract the cutting blade  18 . For example, the clutch hub  32  may be moved in a Y direction (e.g., away from the threaded hub  30 ) to overcome a biasing force of a spring  36  located within the clutch hub  32  to disengage the clutch hub  32  from the threaded hub  30 . When disengaged, teeth  38  of the clutch hub  32  are removed from recesses  40  of the threaded hub  30  (or vice versa) such that the threaded hub  30  may be turned in the Z direction to either advance or retract the cutting blade  18  between the positions P1 and P2. It should be understood that the cutting blade  18  could be incrementally advanced to any position between positions P1 and P2. 
         [0039]    A distance D between each tooth/recess  38 ,  40  of the threaded hub  30  and/or the clutch hub  32  may correspond to a specific radially outward advancement of the cutting blade  18 . In other words, the cutting blade  18  may be incrementally advanced or retracted. In one non-limiting embodiment, the cutting blade  18  is incrementally advanceable by a distance of between 7 and 10 millimeters (0.276 to 0.394 inches). However, other advancement and retraction distances are also contemplated as within the scope of this disclosure. 
         [0040]    In one embodiment, best illustrated in  FIG. 2 , the outer tube  16  includes a threaded proximal end portion  42  that is received by a corresponding threaded portion (not shown) of the threaded hub  30 . The inner shaft  14  may include a connector  44  for attaching the inner shaft  14  to the threaded hub  30 . In one embodiment, the threaded hub  30  is pinned to the connector  44 . Turning the threaded hub  30  in the Z direction moves the threaded hub  30  relative to the threaded proximal end portion  42  in order to axially advance or retract the outer tube  16  relative to the threaded hub  30 . 
         [0041]    Referring to  FIGS. 3A and 3B , axial (i.e., linear) movement of the outer tube  16  (which is caused by rotational movement of the threaded hub  30 ) can be converted to rotational movement of the cutting blade  18  to position the cutting blade  18  in the cutting position P2. The outer tube  16  may include a deflection pin  46  that deflects a tip  51  of the cutting blade  18  radially outwardly from the window  20 . For example, a tapered edge  48  of the cutting blade  18  may contact the deflection pin  46  during linear movement of the outer tube  16  to expose the cutting blade  18 . In other words, the deflection pin  46  acts as a ramp to cause the cutting blade  18  to rotate about an axis that extends through the pin  22 , thereby incrementally advancing the cutting blade  18  radially outwardly from the window  20  to the cutting position P2 (see  FIGS. 1B and 3B ). The outer tube  16  of the expandable reamer  10  may additionally include a guide pin  45  that is received within a slot  47  of the inner shaft  14  to guide the outer tube  16  as it moves relative to the inner shaft  14 . 
         [0042]      FIGS. 4 through 9  schematically illustrate an example method for removing diseased bone using the expandable reamer  10  described above and illustrated by  FIGS. 1A ,  1 B,  2 ,  3 A and  3 B. The exemplary expandable reamer  10  provides a cutting blade  18  that can be incrementally controlled, thus controlling the size of a socket that is formed in bone. It should be understood that the method described herein and shown in  FIGS. 4 ,  5 ,  6 ,  7 ,  8  and  9  may include a greater or fewer number of steps and that the steps could be performed in a different order within the scope of this disclosure. 
         [0043]    In one non-limiting embodiment, as illustrated by  FIG. 4 , the method begins by inserting a guide pin  50  into a bone  52 . In this embodiment, the bone  52  is a femur that includes a femoral head  54 , although the method may be beneficially used elsewhere in a patient. A surgeon or other person of ordinary skill in the art would be able to select an appropriate positioning and/or placement of the guide pin  50  and could use fluoroscopic guidance and/or a targeting guide to achieve proper placement within the bone  52 . 
         [0044]    The guide pin  50  is inserted into diseased bone  56  (i.e., a lesion). In one embodiment, the guide pin  50  is positioned such that it does not pierce the endosteal surface of the femoral head  54 . In other words, the method may be performed subchondrally. 
         [0045]    Once the guide pin  50  has been positioned, a cannulated drill bit  58  is placed over the guide pin  50  to ream a tunnel  60  into the bone  52 , as shown in  FIG. 5 . The size of the guide pin  50  and the cannulated drill bit  58  may vary depending upon the size of the patient, among other criteria. Once the bone  52  has been reamed, the cannulated drill bit  58  and guide pin  50  may be removed. 
         [0046]    Next, as illustrated by  FIG. 6 , the expandable reamer  10  may be passed into the tunnel  60  and positioned within the bone  52  such that it extends into the diseased bone  56 . During this step of positioning, the cutting blade  18  of the expandable reamer  10  is concealed inside of the outer tube  16  (see position P1 of  FIGS. 1A and 3A ). The tunnel  60  could alternatively be formed without using the guide pin  50 . 
         [0047]    Referring now to  FIG. 7 , the cutting blade  18  of the expandable reamer  10  may next be incrementally to a cutting position. For example, the cutting blade  18  can be advanced by disengaging the clutch hub  32  from the threaded hub  30  and subsequently turning the threaded hub in the Z direction to effectuate axial movement of the outer tube  16 , which is converted to rotational movement of the cutting blade  18  by the deflection pin  46  (see  FIGS. 3A and 3B ) to position the cutting blade  18  in the desired cutting position. The desired cutting position may vary depending on the amount of diseased bone  56 . 
         [0048]    The entire expandable reamer  10  may then be rotated, such as with power equipment (not shown), to create a retrograded socket  62  in the bone  52  with the cutting blade  18 , thereby removing the diseased bone  56 . The cutting blade  18  may then be retracted (by turning the threaded hub  30  in an opposite direction) and the expandable reamer  10  removed from the bone  52  after the socket  62  has been adequately formed as shown in  FIG. 8 . The tunnel  60  and the socket  62  may be aspirated, such as with a combination of suction and irrigation, to remove any debrided tissue that may exist after reaming. 
         [0049]    Finally, as shown in  FIG. 9 , the tunnel  60  and the socket  62  may be backfilled with a biologic  64 . The biologic  64  could include a graft, a bone graft, calcium phosphate bone cement, or any other known biologic material. In one embodiment, the biologic  64  is injected with a needle  66  working from the socket  62  toward the tunnel  60 . In another embodiment, the tunnel  60  and the socket  62  are completely filled with the biologic  64 . 
         [0050]      FIGS. 10A and 10B  illustrate another exemplary expandable reamer  110 . The expandable reamer  110  could be used in place of the expandable reamer  10  when performing the method shown in  FIGS. 4 through 9 , or some other similar method, for removing diseased bone. The expandable reamer  110  includes a handle  70  and a tube  72  that extends from the handle  70 . In one embodiment, the handle  70  and the tube  72  are cannulated along their entire lengths. The tube  72  includes a plurality of windows  76 . A plurality of cutting blades  78  are positioned inside of the tube  72  and may be incrementally advanced to protrude from the windows  76  in order to ream a socket in bone. 
         [0051]    In one embodiment, the cutting blades  78  are expandable nitinol wires that have a shape memory. The handle  70  includes an actuator  80  that can be moved into the handle  70  (or vice versa) to position the cutting blades  78  radially outwardly from the windows  76  (i.e., a cutting position in which the cutting blades  78  are transverse to the tube  72 ). Movement of the actuator  80  in an opposite direction returns the cutting blades  78  to a straight position inside of the tube  72  (i.e., a closed position in which the cutting blades  78  are generally parallel to the tube  72 ). The actuator  80  can also be turned to adjust the shape of the cutting blades  78 . 
         [0052]      FIGS. 11A and 11B  illustrate yet another exemplary expandable reamer  210  that can be used to remove diseased bone. In this embodiment, the expandable reamer  210  includes a handle  270 , and an outer tube  272  and an inner shaft  273  that extend from the handle  270 . The outer tube  272  generally surrounds the inner shaft  273 . The handle  270  and the outer tube  272  may be cannulated along their entire lengths. 
         [0053]    The inner shaft  273  can include a plurality of cutting blades  278  that may be incrementally advanced to protrude radially outward from the outer tube  272  in order to ream a socket in bone. In one embodiment, the cutting blades  278  are expandable nitinol wires that have a shape memory. The handle  270  includes an actuator  280  that can be moved away from the handle  270  (or vice versa) to move the outer tube  272 , thereby positioning the cutting blades  278  radially outwardly to a cutting position. In one embodiment, movement of the outer tube  272  causes the cutting blades  278  to spring outwardly. Movement of the actuator  280  in an opposite direction returns the cutting blades  278  to a straight position inside of the outer tube  272  (i.e., a closed position). 
         [0054]    Although the different non-limiting embodiments are illustrated as having specific components, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
         [0055]    It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure. 
         [0056]    The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.