Abstract:
A bone cutting guide may include a support that contains a shaft movable relative to the support. The shaft may carry a guide member having one or more cut guides through which a clinician inserts a cutting member to cut bone positioned under the guide cut guides. In operation, a clinician may fixate the support of the bone cutting guide to a bone and translate the guide member until the one or more cut guides are positioned at a desired cut location. The clinician may then perform a cut through the cut guide.

Description:
RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 62/192,290, filed Jul. 14, 2015, the entire contents of which are hereby incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This disclosure relates generally to devices and methods for cutting bones. 
       BACKGROUND 
       [0003]    Bones, such as the bones of a foot, may be anatomically misaligned. In certain circumstances, surgical intervention is required to correctly align the bones to reduce patient discomfort and improve patient quality of life. 
       SUMMARY 
       [0004]    In general, this disclosure is directed to bone cutting guide systems and techniques for cutting bones. In some examples, a bone cutting guide includes a support that houses a shaft that can translate relative to the support. The shaft may carry a main guide member that defines one or more cutting guide surfaces. For example, the main guide member may define opposed guide surfaces configured to receive a cutting member. In use, the cutting member may be inserted between the opposed guide surfaces and bounded within a range of movement by the guide surfaces, causing the cutting member to be directed at a cutting location under the guide surfaces. Additionally or alternatively, the main guide member may define a single cutting surface/plane. The cutting surface/plane may be a surface against which a clinician can position a cutting member and then guide the cutting member along the cutting surface/plane to perform a cutting operation. 
         [0005]    In some configurations, the bone cutting guide includes fixation members, such as fixation pins or apertures, that allow the main body to be fixated on or adjacent a bone to be cut. For example, in use, a clinician may fixate the main body to a bone (e.g., a first metatarsal). Thereafter, the clinician may translate the main guide member having at least one cutting guide surface (e.g., opposed cutting guide surfaces) relative to the fixed main body. The clinician can translate the main guide member by sliding or rotating the shaft housed within the main body, e.g., causing the distal end of the shaft and main guide member carried thereon away from or towards the main body. Once suitably positioned, the clinician may or may not lock the location of the shaft and perform one or more cuts through the guide surfaces of the main guide member. 
         [0006]    To perform a surgical procedure, a clinician may attach the support of the bone cutting guide to a bone. For example, the clinician may insert fixation members, such as fixation pins or screws, through apertures in the support to fixate the support to the bone (e.g., first metatarsal). Thereafter, the clinician may translate the main guide member having at least one cutting guide surface (e.g., opposed cutting guide surfaces) relative to the support. The clinician can translate the main guide member by moving a shaft housed within the inner cavity of the support, e.g., causing the distal end of the shaft and main guide member carried thereon to move away from or towards the support. Once suitably positioned, the clinician may or may not lock the location of the shaft and perform one or more cuts through the guide surfaces of the main guide member. 
         [0007]    The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view of a bone cutting guide in accordance with an embodiment of the invention. 
           [0009]      FIG. 2  is a perspective view of the bone cutting guide of  FIG. 1 , with a spacer detached. 
           [0010]      FIG. 3  is a top view of the bone cutting guide of  FIG. 1 . 
           [0011]      FIG. 4  is a top view of the bone cutting guide of  FIG. 1 , with the spacer removed. 
           [0012]      FIG. 5  is a side perspective view of a bone cutting guide on a foot in accordance with a medical procedure of an exemplary embodiment of the invention. 
           [0013]      FIG. 6  is a side perspective view of a bone cutting guide on a foot held by fixation pins and positioned for a first bone cut in accordance with an embodiment of the invention. 
           [0014]      FIG. 7  is a perspective view of a bone cutting guide and a bone positioning guide on a foot in accordance with an embodiment of the invention. 
           [0015]      FIG. 8  is a perspective view of a bone cutting guide and a bone positioning guide on a foot depicting a bone adjustment in accordance with an embodiment of the invention. 
           [0016]      FIG. 9  is a perspective view of a bone cutting guide and a bone positioning guide on a foot depicting a bone adjustment in accordance with an embodiment of the invention. 
           [0017]      FIG. 10  is a perspective view of a bone cutting guide and a bone positioning guide on a foot positioned for a second bone cut in accordance with an embodiment of the invention. 
           [0018]      FIG. 11  is a perspective view of a bone positioning guide on a foot in accordance with an embodiment of the invention. 
           [0019]      FIG. 12  is a side perspective view of a bone positioning guide on a foot depicting an olive pin providing compression between first and second bones in accordance with an embodiment of the invention. 
           [0020]      FIG. 13  is a side perspective view of a foot depicting bone plates across a joint between first and second bones in accordance with an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the following description provides some practical illustrations for implementing exemplary embodiments of the present invention. Examples of constructions, materials, and dimensions are provided for selected elements, and all other elements employ that which is known to those of ordinary skill in the field of the invention. Those skilled in the art will recognize that many of the noted examples have a variety of suitable alternatives. 
         [0022]    Embodiments of the present invention include a bone cutting guide. In an exemplary application, embodiments of the bone cutting guide can be useful during a surgical procedure, such as a bone alignment, osteotomy, fusion procedure, and/or other procedures where one or more bones are to be cut. Such a procedure can be performed, for example, on bones (e.g., adjacent bones separated by a joint or different portions of a single bone) in the foot or hand, where bones are relatively smaller compared to bones in other parts of the human anatomy. In one example, a procedure utilizing the bone cutting guide can be performed to correct an alignment between a metatarsal (e.g. a first metatarsal) and a cuneiform (e.g., a first cuneiform), such as a bunion correction. An example of such a procedure is a Lapidus procedure. In another example, the procedure can be performed by modifying an alignment of a metatarsal (e.g. a first metatarsal). An example of such a procedure is a basilar metatarsal osteotomy procedure. 
         [0023]      FIGS. 1-4  show an embodiment of a bone cutting guide  250 . The bone cutting guide  250  includes a support  300  that defines an inner cavity. In one embodiment, the support  300  includes at least one fixation aperture  310  to receive at least one fixation pin. As shown, fixation apertures  310  can extend through the support  300  at a vertical angle (e.g., parallel to the longitudinal axis of the support) or a skewed angle relative to the longitudinal axis of the support (e.g., an angle ranging from 10 degrees to 55 degrees relative to the longitudinal axis of the support, such as an angle of approximately 20 degrees). In some configurations, the bone cutting guide  250  also includes an adjustable stabilization screw  320  engaged with the support  300  that can be used to stabilize the support with respect to a bone. 
         [0024]    In the configuration of  FIGS. 1-4 , the bone cutting guide  250  includes a slot  330  and a securing component  340 . The slot  330  is formed on and/or through at least a portion of a surface of the support  300 . The securing component  340  is positioned at least partially within the slot  330  and configured to translate along the slot relative to the support  300 . For example, the securing component  340  can have a first end with a diameter greater than a diameter of a second opposite end, such that the first end of the securing component  340  is supported by the slot  330  (e.g., the first end has a diameter greater than a width of the slot) while the second end of the securing component  340  is positioned within the slot (e.g., the second end has a diameter less than a width of the slot). 
         [0025]    As shown best in  FIG. 2 , a shaft  350  can be positioned at least partially within the inner cavity of the support  300 . The shaft  350  can be configured to translate within the inner cavity relative to the support  300 , such that the shaft can project out from the inner cavity and retract into the inner cavity (compare shaft position in  FIG. 1  to  FIG. 2 ). In one embodiment, the securing component  340  can be threadingly engaged with the support  300  to bear against the shaft  350  to prevent the shaft  350  from traveling with the cavity when desired. 
         [0026]    The bone cutting guide  250  in the illustrate example includes a main guide member  280  disposed on the shaft  350 . In some embodiments, the main guide member  280  can be integral with the shaft, while in other embodiments the main guide member and the shaft can be separate components coupled together. The main guide member  280  can have a first guide surface  130 A and, optionally, a second guide surface  130 B. The first and second guide surfaces  130 A and  130 B can be adjacent surfaces facing one another with a space defined between the first and second guide surfaces  130 A and  130 B. In use, a clinician can position a cutting member (e.g., a saw) against first guide surface  130 A (e.g., between first and second guide surfaces  130 A and  130 B) and translate the cutting member along or through the guide surface(s). In this way, the guide surface(s) can align the cutting member with the surface of a bone to be cut. 
         [0027]    In the illustrated embodiment, the second guide surface  130 B contains a gap bisecting the planar face of the second guide surface, such that the second guide surface  130 B is not a single, continuous surface. This gap can be used by the clinician to visualize the cutting member when positioned between the first and second guide surfaces  130 A and  130 B. In other embodiments, the second guide surface  130 B can be a single, continuous surface lacking any such gap. 
         [0028]    As shown in  FIGS. 1 and 2 , the first guide surface  130 A may define a first plane while the second guide surface  130 B may define a second plane. The first guide surface  130 A and the second guide surface  130 B can be arranged such that the first plane is parallel to the second plane, with the space therebetween, as shown in  FIGS. 1 and 2 . Alternatively, the guide surfaces can be arranged such that the first and/or second planes are skewed (e.g., non-parallel relative to each other). Additionally, in some embodiments, the main guide member  280  includes a viewing window  290  to provide a visual path to bones during cuts. 
         [0029]    In the embodiment shown in  FIGS. 1 and 2 , the cutting guide  250  includes a removable spacer  260  engageable with the main guide member  280 . The spacer  260  can have a first portion  360  configured to extend into a joint space (e.g., in a joint space between a first metatarsal and medial cuneiform) and a second portion  370  engageable with the main guide member  280 . Such a spacer can be useful for positioning the main cut guide at a desired position with respect to a joint. Further, the first and second surfaces of the main cut guide and/or the surfaces of the spacer can be used to establish a pre-determined cut thickness. 
         [0030]    Some embodiments of the cutting guide  250  include an anchor  400  to connect to a bone portion that is spaced from a bone portion to which the support  300  is connected. For example, cutting guide  250  may bridge a joint, fracture, or cut with the adjustable stabilization screw  320  positioned on one bone portion (e.g., a metatarsal or cuneiform) and the anchor positioned on the opposite side (e.g., the other of the metatarsal or cuneiform). In some embodiments, the anchor  400  is translatable with the shaft  350  and located along the shaft  350  on a side of the main guide member  280  opposite the support  300 . 
         [0031]    In one embodiment, the anchor  400  includes at least one fixation aperture  410  to receive at least one fixation pin. Such aperture(s) may extend through the anchor at a parallel (e.g., vertical) or skewed angle relative to the longitudinal axis of the anchor. Further, as shown, a second adjustable stabilization screw  420  can be provided to stabilize the anchor with respect to a bone. In some embodiments, after making an angular correction to a bone, the anchor  400  can be used to hold the angular orientation of the bone so that a second cut can be made parallel to the first cut. 
         [0032]    In practice, the bone cutting guide  250  can be used to guide one or more cutting operations performed on a bone or bones. For example, the bone cutting guide  250  can be used to cut the end faces of adjacent bones to prepare the end faces (e.g., leading edges) of the bones. Such adjacent end faces can end faces of two different bones separated by a joint, or can be different portions of a single bone, separated by a fracture. In some embodiments, a clinician may attach the bone cutting guide  250  to the bone or bones to be cut then advance a cutting member along one or more guide surfaces of the bone cutting guide to cut the end faces of the one or more bones. The clinician may realign the bones relative to each other before or after the bones are cut and may also perform additional surgical steps, such as bone plating, after the cuts have been made. 
         [0033]      FIGS. 5-13  illustrate steps of an exemplary method for cutting a bone using a bone cutting guide, such as bone cutting guide  250  described with respect to  FIGS. 1-4 , during a medical procedure.  FIGS. 5-13  depict a foot  200  having a first metatarsal  210  and a first cuneiform  220  (medial cuneiform). In  FIG. 5 , the bone cutting guide  250  is positioned in longitudinal alignment with the long axis of the first metatarsal  210  and the first cuneiform  220 , generally on the dorsal or dorsal-medial surface. As shown, the spacer  260  can be positioned within the joint between the first metatarsal and the first cuneiform. As shown in  FIG. 6 , fixation pins  270  can be inserted into the support  300  of the bone cutting guide  250  through angled apertures to fix the position of the cutting guide  250  to the first metatarsal  210  and the spacer can be removed. The end of the first metatarsal  210  facing the first cuneiform  220  can be cut with a cutting member (e.g., saw) inserted through the main guide member  280  having parallel first and second surfaces. The main guide member can also include a viewing window  290  adjacent the first and second surfaces to facilitate visualization of the cutting procedure by the clinician. The cutting guide  250  can be removed vertically from the fixation pins  270  and the bone slice removed. As shown in  FIG. 7 , the cutting guide  250  can be inserted back on the foot  200 , such as by inserting the fixation pins  270  through vertical apertures in support  300 . 
         [0034]    Also shown in  FIG. 7 , a bone positioning guide  10  can be attached to the first metatarsal  210  and adjacent second metatarsal  292  (e.g., by installing the bone positioning guide over the top of the cutting guide  250 ). In some examples, a concave surface of a bone engagement member  40  can be placed in apposition to a medial surface of the first metatarsal  210  and a tip  50  can be placed in apposition to a lateral side of a different metatarsal, such as a second metatarsal  292 .  FIG. 8  shows repositioning of the first metatarsal  210  with respect to the second metatarsal  292  by moving the bone engagement member  40  with respect to the tip  50  to correct a transverse plane deformity.  FIG. 9  shows rotation of the first metatarsal  210  with respect to the bone engagement member  40  to correct a frontal plane deformity. In some embodiments, the fixation pins  270  can be used to impart rotational force to the first metatarsal  210 , e.g., by the clinician grasping one or more of the pins and using the pins to physically manipulate the position of the first metatarsal  210 . The bone positioning guide  10  can hold the desired position of the first metatarsal. 
         [0035]    As shown in  FIG. 10 , the main guide member  280  can be extended from the support  300  to make a parallel cut in the first cuneiform  220 . Additional fixation pins  270  can be inserted through apertures in the anchor  400  to fix the cutting guide  250  to the first cuneiform  220 . A section of the cuneiform can be cut with a cutting member inserted through the main guide member  280  and removed. In some embodiments the cuneiform cut and the metatarsal cut are parallel, conforming cuts. As shown in  FIG. 11 , the cutting guide  250  can then be removed with the bone positioning guide  10  in place.  FIG. 12  depicts a threaded olive pin  450  inserted through the first metatarsal  210  and into the first cuneiform  220  to provide compression between the first metatarsal and the first cuneiform. The bone positioning guide may then be removed. The position of the bones can then be fixed with a bone screw and/or one or more bone plates of any shape.  FIG. 13  shows a first bone plate  460  (e.g., a straight or curved bone plate positioned on a dorsal-medial side) and a second bone plate  470  (e.g., a helical bone plate positioned from a medial side of the cuneiform to a plantar side of the metatarsal (other embodiments, not shown, may include a second straight or curved bone plate)) across the joint space. After the screws are inserted and/or the plates are applied with the insertion of bone screws, the fixation and olive pins may be removed. 
         [0036]    Additional details on example surgical technical techniques that can be performed using a bone cutting guide in accordance with the disclosure, as well as details on example features that can be used in conjunction with such bone cutting guide, are described in U.S. patent application Ser. No. 14/981,335, entitled “BONE POSITIONING AND PREPARING GUIDE SYSTEMS AND METHODS” and filed on Dec. 28, 2015, and U.S. patent application Ser. No. 14/990,368, entitled “BONE PLATING SYSTEM AND METHOD” and filed on Jan. 7, 2016, the entire contents of both of which are incorporated herein by reference. 
         [0037]    Thus, embodiments of the invention are disclosed. Although the present invention has been described with reference to certain disclosed embodiments, the disclosed embodiments are presented for purposes of illustration, and not limitation, and other embodiments of the invention are possible. One skilled in the art will appreciate that various changes, adaptations, and modifications may be made without departing from the spirit of the invention.