Abstract:
A modular bone resection guide system includes a positioning base configured to be attached to a bone, a modular resection block configured to be removably attached to various locations of the positioning base and a cutting tool configured to be supported and guided by the modular resection block while cutting the bone.

Description:
CROSS REFERENCE TO RELATED CO-PENDING APPLICATIONS 
     This application claims the benefit of U.S. provisional application Ser. No. 61/563,075 filed on Nov. 23, 2011 and entitled SYSTEM AND METHOD FOR A MODULAR RESECTION GUIDE which is commonly assigned and the contents of which are expressly incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a system and a method for a modular resection guide, and in particular, to an osteotomy resection guide that includes a positioning base and a modular resection block. 
     BACKGROUND OF THE INVENTION 
     In several bone pathologies, bone resection is applied. Typically, bone resections are made using saws or milling devices. Accuracy in the bone resection operation is critical for reducing neighboring tissue damage and excessive bleeding and for limiting the amount of the resected bone. Accuracy in the bone cutting operation is also required in the preparation of a bone contour for receiving prosthesis. In order to perform accurate cuts with these cutting instruments, surgeons utilize cutting guide blocks. These cutting guide blocks include guiding surfaces or slots and the cutting instruments are aligned with the cutting surfaces or slide within a slot in order to perform an accurately positioned bone incision. The fabrication of cutting surfaces and slots in the cutting guide blocks requires high precision manufacturing, and therefore is time consuming and expensive. Furthermore, the locations of these slots and surfaces are fixed and their dimensions, shapes and position cannot be changed or rearranged in order to accommodate patients with different anatomies and in order to perform resections in different anatomic locations or resections that prepare the bone contour for receiving different type of prostheses. 
     Accordingly, there is a need for a low cost cutting guide block and in particular for a cutting guide block that provides flexibility and modularity in the bone cutting process. 
     SUMMARY OF THE INVENTION 
     The present invention provides a modular resection guide that includes a positioning base, a modular resection block and a saw blade. 
     In general, in one aspect, the invention features a modular bone resection guide system including a positioning base configured to be attached to a bone, a modular resection block configured to be removably attached to various locations of the positioning base and a cutting tool configured to be supported and guided by the modular resection block while cutting the bone. 
     Implementations of this aspect of the invention may include one or more of the following features. The positioning base includes a parallelepiped body having a central through-opening and a plurality of peripheral openings surrounding the central through opening. The modular resection block includes a parallelepiped body having a first slot extending from a front surface to a back surface of the parallelepiped body and the first slot is shaped and dimensioned to slidably support and guide the cutting tool. The modular resection block further includes first and second pins and the modular resection block is removably attached to the positioning base by inserting the first and second pins into first and second peripheral openings of the positioning base, respectively. The system further includes a fastening screw configured to secure the position of the cutting tool relative to the modular resection block. The cutting tool comprises a saw blade and the saw blade includes an elongated body extending along a first direction and having a rounded proximal end and a straight distal end. The distal end has saw teeth. The elongated body of the saw blade further has an elongated slot extending along the first direction and the modular resection block further includes an elongated second slot being perpendicular to the first slot and extending along a second direction. The second direction intersects the first direction at a first location and the fastening screw is inserted into the first location and secures the position of the saw blade relative to the modular resection block. The rounded proximal end includes a through opening shaped and dimensioned to support a power tool. The positioning base includes an outer surface contoured to fit the bone&#39;s surface anatomy. The cutting tool may be one of knifes, scissors, milling devices, drills, or blades. 
     In general, in another aspect, the invention features a method for a modular bone resection including the following: First providing a positioning base and attaching the positioning base to a bone, Next, providing a modular resection block and removably attaching the modular resection block to various locations of the positioning base. Next, providing a cutting tool and supporting and guiding the cutting tool by the modular resection block while cutting the bone. 
     Among the advantages of this invention may be one or more of the following. The modular design of the present invention reduces the overall cost of the traditional cutting block by removing the necessity for multiple slots. The cutting block slots are costly due to tight positional and feature tolerances. Additionally, the overall weight of the system is reduced, which makes it easier for the surgeon to handle the device during surgery. Overall, the duration of the surgery may be reduced. The cutting accuracy of the bone is improved and potential complications due to excessive bleeding because of inaccurate cuttings are avoided. The modularity of the position base design and the cutting block design allows a quick and easy development of a custom resection system for each patient, for each anatomic location and for each type of prostheses. 
     The details of one or more embodiments of the invention are set forth in the accompanying drawings and description below. Other features, objects and advantages of the invention will be apparent from the following description of the preferred embodiments, the drawings and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring to the figures, wherein like numerals represent like parts throughout the several views: 
         FIG. 1  is a schematic diagram of a modular resection guide system of this invention; 
         FIG. 2  is side view of the modular resection guide system of  FIG. 1 ; 
         FIG. 3  is a front perspective view of a saw blade inserted and secured in the modular resection block of  FIG. 1 ; 
         FIG. 4  is a side view of a positioning base that conforms to the patient&#39;s bone anatomy. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention provides a modular resection guide that includes a positioning base, a modular resection block and a saw blade. 
     Referring to  FIG. 1 , a modular resection guide system  100  includes a positioning base  110 , and a modular resection block  120 . Positioning base  110  is attached to a bone  102  and the modular resection block  120  is configured to be attached to various locations of the positioning base  110 . Positioning base  110  includes a rectangular parallelepiped body  111  that has a central through opening  116  and apertures  112   a ,  113   a ,  114   a ,  115   a  arranged on the right front side  111   a  and apertures  112   b ,  113   b ,  114   b ,  115   b  arranged on the left front side  111   b . Opening  116  extends from the front side to the backside of the body  111 . Apertures  112   a ,  113   a ,  114   a ,  115   a  are arranged linearly from the top to the bottom of body  111 . Similarly apertures  112   b ,  113   b ,  114   b ,  115   b  are arranged linearly from the top to the bottom of body  111 . The number and geometric arrangement of apertures  112   a ,  113   a ,  114   a ,  115   a  and  112   b ,  113   b ,  114   b ,  115   b  varies in order to accommodate modular resection blocks  120  with different geometries and in order to position the modular resection block  120  in different locations of the positioning base  110 . Modular resection block  120  includes a rectangular parallelepiped body  121  that has a slot  124  extending from its front surface  121   a  to the back surface  121   b , as shown in  FIG. 2 . Modular resection block  120  also includes pins  122   a ,  122   b  extending from its back surface  121   b , as shown in  FIG. 1  and  FIG. 2 . Pins  122   a ,  122   b  are aligned with apertures  112   a  and  112   b  and are inserted into apertures  112   a  and  112   b , respectively. This alignment and insertion of the pins  122   a ,  122   b  into apertures  112   a ,  112   b  results in positioning the modular resection block  120  at a first location of the positioning base  110  near the top, as shown in  FIG. 2 . A saw blade  130  is inserted into the slot  124  from the front side  121   a  of the resection block  120  and is used to cut a first opening  141  into a first location of the bone  102 . Once the cut is completed in this first location, the resection block  120  is removed and then placed in a second location of the positioning base  110 . In one example, the resection block pins  122   a ,  112   b  are aligned with the apertures  115   a ,  115   b  of the positioning based  110 , respectively, in order to position the resection block  120  in a second location of the position base  110  near the bottom. Saw blade  130  is then inserted into the slot  124  from the front side  121   a  of the resection block  120  and is used to cut a second opening  142  into a second location of the bone  102 . 
     In another embodiment, saw blade  130  and modular resection block  120  are attached to each other and form a single unit. Referring to  FIG. 3 , saw blade  130  is slidably attached to modular resection block  120 . Saw blade  130  includes an elongated body  131  extending along elongated axis  137  and having a rounded conical back end  131   b  and a straight front-end  131   a . Front-end  131  a includes saw teeth or serrations  132  used to cutting out openings in the bone. Body  131  also includes an elongated opening  136  extending also along axis  137  and a round opening  135  near the back end  135 . Round opening  135  is used for connecting to a power tool. In this embodiment, modular resection block  120  includes an elongated opening  126  extending along axis  127 , which is arranged perpendicular to axis  137 . Saw blade  130  is inserted into slot  124  from the front side  121   a  of the resection block  120  and is configured to slide within slot  124  along axis  137 . The two elongated slots  136  and  126  are arranged perpendicular to each other and a fastening screw  134  is used to secure their relative position. 
     In some embodiments, positioning base  110  is designed to fit the contour of the specific surface anatomy of the bone to which it is attached. Referring to  FIG. 4 , the surface anatomy of bone  102  is determined via an X-ray computed tomography (CT) scan of the patient&#39;s bone and then the back surface  118  of position block  110  is cutout or molded to complement the bone surface  102   a . This design of the positioning base  110  provides a more secure attachment and alignment of the positioning base  110  to the bone  102  and results in better accuracy of the bone cutting. 
     Other embodiments include the following, among others. Knifes, scissors, milling devices, drills and blades with different designs may be used instead of a saw blade. 
     The system of this invention may be used in total knee replacement (TKR) surgery, for resection of the femoral neck during hip arthroplasty, for resection of the distal tibia during ankle arthroplasty, for resection of the distal radius during wrist arthroplasty, for resection of the proximal humerus during shoulder arthroplasty and for various corrective osteotomies. 
     Several embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.