Tissue Cavitation Device and Method

Abstract

A percutaneous surgical device and method for creating a cavity within tissue during a minimally invasive procedure. A cavitation device includes a shaft interconnected to a flexible cutting element. A flexible cutting element has a first shape suitable for minimally invasive passage into tissue. The flexible cutting element has a means to move toward a second shape suitable for forming a cavity in tissue. When used in bone, the resulting cavity is usually filled with bone cement or suitable bone replacement material that is injectable and hardens in situ. The disclosed cavitation device and methods can be used for the following applications: (1) treatment or prevention of bone fracture, (2) joint fusion, (3) implant fixation, (4) tissue harvesting (especially bone), (5) removal of diseased tissue (hard or soft tissue), and (6) general tissue removal (hard or soft tissue).

1 . A method for treating bone comprising the steps of:
 forming a passage in bone;   creating a cavity by cutting bone, wherein the cavity formed by cutting bone is generally spherical and has a larger diameter than the passage; and   expanding the volume of the cavity by expanding a device within the cavity, thereby reducing a fracture.   
     
     
         2 . The method of  claim 1  further comprising the step of filling the cavity with a material. 
     
     
         3 . The method of  claim 2 , wherein the material is selected from the group consisting of implant, in-situ curable material, and in situ hardenable material. 
     
     
         4 . The method of  claim 2 , wherein the material fills the cavity fully or partially. 
     
     
         5 . The method of  claim 1 , wherein the device is positioned proximate to cortical bone. 
     
     
         6 . The method of  claim 1 , wherein the device is a medical balloon. 
     
     
         7 . The method of  claim 1 , wherein the bone is a vertebra. 
     
     
         8 . The method of  claim 1 , wherein the step of separating creating the cavity by cutting bone uses a tissue cavitation device. 
     
     
         9 . A method of reducing a fracture comprising the steps of:
 forming a passage in bone;   providing a tissue cavitation device, wherein the tissue cavitation device comprises a deformable cutting element;   separating a portion of bone about the passage with by rotating the deformable cutting element of the tissue cavitation device to create a cavity, wherein the diameter of the cavity is larger than the diameter of the passage; and   expanding the volume of the cavity, thereby reducing the fracture.   
     
     
         10 . The method of  claim 9 , further comprising the step of filling the cavity with a material selected from the group consisting of implant material, in-situ curable material, and in situ hardenable material. 
     
     
         11 . The method of  claim 9 , wherein the step of expanding uses an expanding device that enlarges the size of the cavity. 
     
     
         12 . The method of  claim 11 , wherein the step of expanding the volume of the cavity is performed with a medical balloon. 
     
     
         13 . The method of  claim 9 , wherein the tissue cavitation device comprises a first shape for minimally invasive passage into tissue and a second shape suitable for forming the cavity. 
     
     
         14 . The method of  claim 10 , wherein the material fills the cavity fully or partially. 
     
     
         15 . The method of  claim 10 , wherein the material is selected from the group consisting of permanent, resorbable, penetrating, and combinations thereof. 
     
     
         16 . A method of reducing a fracture comprising the steps of:
 forming a passage in bone using a first device along a linear axis;   separating a portion of bone using by rotating a second device to create a cavity, wherein the cavity is substantially coincident with the linear axis and has a non-uniform diameter; and   expanding the volume of the cavity with a third device, thereby reducing the fracture.   
     
     
         17 . The method of  claim 15 , wherein the passage is selected from the group consisting of intracortical, extracortical, intrapedicular, extrapedicular, and combinations thereof. 
     
     
         18 . The method of  claim 15 , wherein the second device is a tissue cavitation device. 
     
     
         19 . The method of  claim 15 , wherein the third device is a medical balloon. 
     
     
         20 . The method of  claim 15 , further comprising the step of filling the cavity with a material, wherein the material fills the cavity fully or partially and is selected from the group consisting of permanent, resorbable, penetrating, and combinations thereof.