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 tissue cavitation device, comprising:
 a shaft having a diameter associated with a longitudinal axis, an elongated element associated with the shaft, the elongated element adapted to assume an elastically deformed first shape colinear with the longitudinal axis of the shaft and a second shape extending away from the shaft.   
     
     
         2 . The device of  claim 1 , wherein the elongated element changes from the elastically deformed first shape to the second shape as a result of spring bias. 
     
     
         3 . The device of  claim 1 , wherein the second shape is an arcuate shape extending away from shaft. 
     
     
         4 . The device of  claim 3 , wherein the elongated element has a first end associated with the shaft and a second end that is a free end. 
     
     
         5 . The device of  claim 1 , wherein the shaft has an internal passage. 
     
     
         6 . The device of  claim 1 , wherein the elongated element has a tip portion extending in a radial direction from the elongated element. 
     
     
         7 . A method comprising the steps of:
 a. providing a tool for forming a pilot hole in tissue; and   b. providing a tissue cavitation device for insertion in the pilot hole, wherein the tissue cavitation device comprises a shaft having a diameter and a longitudinal axis, and an elongated element associated with the shaft; wherein the elongated element is adapted to assume a first shape colinear with the longitudinal axis of the shaft and a second shape non-colinear with the axis of the shaft;   c. wherein, when the elongated element assumes the second shape, movement of the elongated element in the pilot hole with respect to the longitudinal axis forms a tissue cavity extending radially from the pilot hole.   
     
     
         8 . The method of  claim 7 , wherein the tissue cavity is enlarged by rotating the tissue cavitation device about the longitudinal axis of the shaft. 
     
     
         9 . The method of  claim 7 , wherein the tissue cavity is enlarged by axially translating the tissue cavitation device with respect to the longitudinal axis of the shaft. 
     
     
         10 . The method of  claim 7 , wherein the tissue cavitation device includes a tension element to apply compression-bending forces to the elongated element. 
     
     
         11 . The method of  claim 7 , comprising the step of providing a second tissue cavitation device, wherein the tissue cavity is enlarged by the second tissue cavitation device. 
     
     
         12 . The method of  claim 11 , wherein the tissue cavity is enlarged by axially translating or rotating the second tissue cavitation device with respect to the longitudinal axis of the shaft. 
     
     
         13 . The method of  claim 11 , wherein the second tissue cavitation device enlarges the tissue cavity by forcefully pressing radially against the tissue. 
     
     
         14 . The method of  claim 7 , wherein the tissue cavity is adapted for placement of an implant. 
     
     
         15 . The method of  claim 7 , comprising the step of providing an injectable and hardenable biomaterial, wherein the implant is supported in the tissue cavity by the injectable and hardenable biomaterial. 
     
     
         16 . A tissue cavitation device, comprising:
 a shaft having a diameter associated with a longitudinal axis and an elongated element associated with the shaft, wherein the elongated element has a first end associated with the shaft and a second end associated with a cutting tip, wherein the cutting tip has a first position with respect to the longitudinal axis for passage into tissue and the cutting tip has a second position with respect to the longitudinal axis.   
     
     
         17 . The device of  claim 16 , wherein the cutting tip extends radially from the elongated element. 
     
     
         18 . The device of  claim 16 , wherein the second position of the cutting tip is established by centrifugal force when the tissue cavitation device is rotated about the longitudinal axis. 
     
     
         19 . The device of  claim 16 , wherein the cutting tip has a beveled edge. 
     
     
         20 . The device of  claim 16 , wherein the elongated element has a first end associated with the shaft and a second end that is a free end in association with the cutting tip.