Cement delivering device and method

Abstract

A delivery system includes a reservoir for storing pressurized fluid and a piston rod passing through the reservoir and having an end portion with a dimension larger than the piston rod. A sleeve is configured to engage the end portion of the piston rod such that when the piston rod is advanced, the end portion seals an opening in the sleeve. The sleeve and the end portion function as a piston for extracting fluid from a delivery chamber. When the piston rod is retracted, the sleeve engages a portion of the end portion to permit the reservoir to communicate with the delivery chamber through the opening. Methods of use are disclosed.

1 - 20 . (canceled) 
     
     
         21 . A delivery system, comprising:
 a housing comprising a proximal end defining a reservoir for storing fluid and a distal end comprising a nozzle defining a chamber;   a sleeve movably positioned within the nozzle and comprising an opening; and   a piston rod having an end portion positioned within the sleeve such that the end portion seals the opening off from the chamber,   wherein the system is movable between a first mode in which the piston rod is moved proximally relative to the housing to space the end portion apart from the opening such that the fluid moves from the reservoir and into the chamber through the opening and a second mode in which the piston rod is moved distally relative to the housing such that the sleeve moves relative to the housing to eject the fluid from the chamber.   
     
     
         22 . The delivery system recited in  claim 21 , wherein a proximal portion of the piston rod extends through the fluid when the fluid is stored in the reservoir. 
     
     
         23 . The delivery system recited in  claim 21 , wherein the opening has a circular cross sectional configuration and the end portion has a spherical shape that forms an interference fit with the opening to seal the opening off from the chamber. 
     
     
         24 . The delivery system recited in  claim 21 , wherein the end portion includes a ball shape configured to engage the opening in the sleeve to form a valve, the valve being opened when the system is in the first mode, and the valve being closed when the system is in the second mode. 
     
     
         25 . The delivery system recited in  claim 21 , further comprising a biased reservoir piston configured to pressurize the fluid stored within the reservoir. 
     
     
         26 . The delivery system recited in  claim 25 , wherein the biased reservoir piston is biased by a spring disposed within the housing, the spring being fixed to a proximal end of the housing. 
     
     
         27 . The delivery system recited in  claim 21 , wherein the sleeve comprises a second opening positioned proximal to the opening, the opening and the second opening each having a maximum width that is less than that of the end portion such that the end portion is positioned between the opening and the second opening when the system is in the first mode and when the system is in the second mode and the end portion is retained within the sleeve. 
     
     
         28 . The delivery system recited in  claim 21 , wherein the sleeve includes at least two opposing supports that are configured to maintain the end portion within the sleeve when the system is in the first mode. 
     
     
         29 . The delivery system recited in  claim 21 , further comprising the fluid, wherein the fluid comprises poly(methyl methacrylate). 
     
     
         30 . The delivery system recited in  claim 21 , wherein a dispensing pressure for the fluid is achieved only in the chamber. 
     
     
         31 . The delivery system recited in  claim 21 , wherein pressure within the chamber is greater than pressure within the reservoir when the system is in the second mode. 
     
     
         32 . The delivery system recited in  claim 21 , wherein the piston rod is reciprocated to move the system between the first mode and the second mode to alternately fill and dispense the fluid from the chamber. 
     
     
         33 . A method for delivering bone cement comprising:
 providing the delivery system recited in  claim 21 ;   moving the system to the first mode to fill the chamber with the fluid; and   moving the system from the first mode to the second mode to eject the fluid from the chamber.   
     
     
         34 . A method for delivering bone cement as recited in  claim 33 , wherein the system is moved between the first mode and the second mode by reciprocating the piston rod. 
     
     
         35 . A delivery system, comprising:
 bone cement;   a housing comprising a proximal end defining a reservoir for storing the bone cement and a distal end comprising a nozzle defining a chamber;   a sleeve movably positioned within the nozzle and comprising an opening; and   a piston rod having a proximal portion that extends through the bone cement and an end portion positioned within the sleeve such that the end portion seals the opening off from the chamber,   wherein the system is movable between a first mode in which the piston rod is moved proximally relative to the housing to space the end portion apart from the opening such that the bone cement moves from the reservoir and into the chamber through the opening and a second mode in which the piston rod is moved distally relative to the housing such that the sleeve moves relative to the housing to eject the bone cement from the chamber.   
     
     
         36 . The delivery system recited in  claim 35 , wherein the sleeve comprises a second opening positioned proximal to the opening, the opening and the second opening each having a maximum width that is less than that of the end portion such that the end portion is positioned between the opening and the second opening when the system is in the first mode and when the system is in the second mode and the end portion is retained within the sleeve. 
     
     
         37 . The delivery system recited in  claim 35 , wherein the sleeve includes at least two opposing supports that are configured to maintain the end portion within the sleeve when the system is in the first mode. 
     
     
         38 . The delivery system recited in  claim 35 , wherein the opening has a circular cross sectional configuration and the end portion has a spherical shape that forms an interference fit with the opening to seal the opening off from the chamber. 
     
     
         39 . The delivery system recited in  claim 35 , wherein the end portion includes a ball shape configured to engage the opening in the sleeve to form a valve, the valve being opened when the system is in the first mode, and the valve being closed when the system is in the second mode. 
     
     
         40 . A delivery system, comprising:
 bone cement;   a housing comprising a proximal end defining a reservoir for storing the bone cement and a distal end comprising a nozzle defining a chamber;   a biased reservoir piston configured to pressurize the bone cement, the biased reservoir piston being biased by a spring disposed within the housing, the spring being fixed to a proximal end of the housing;   a sleeve movably positioned within the nozzle and comprising an opening; and   a piston rod having a proximal portion that extends through the bone cement and an end portion positioned within the sleeve such that the end portion seals the opening off from the chamber,   wherein the system is movable between a first mode in which the piston rod is moved proximally relative to the housing to space the end portion apart from the opening such that the bone cement moves from the reservoir and into the chamber through the opening and a second mode in which the piston rod is moved distally relative to the housing such that the sleeve moves relative to the housing to eject the bone cement from the chamber.