Devices and Injectable or Implantable Compositions for Intervertebral Fusion

Abstract

A device for injecting materials for intervertebral fusions, kits containing the device, injectable and implantable modified poly(methyl methacrylate) (mPMMA) materials, and methods of use thereof, particularly in interverterbral fusions or intravertebral structural fortification, are described herein. The device contains an outer canula ( 20 ), an inner canula ( 30 ) that is in telescoping relation with respect to the outer canula ( 20 ) and removable therefrom, and one or more barrier forming materials, preferably two balloons. When the mPMMA material is cured, it produces a cement with a sufficient porosity to allow for bone growth through the cement to connect one vertebral endplate to the adjacent endplate. The mPMMA cement has sufficient compressive strength to withstand physiologic loads of the body during weight bearing activity and exhibits a Young's modulus of elasticity which is slightly less than cortical bone. Additionally, the mPMMA is able to bind to calcium phosphate and/or BMP.

1 . A device for injecting a curable material in an intervertebral fusion, comprising an outer canula, an inner canula, wherein the inner canula comprises a first delivery portion and a second delivery portion, wherein each delivery portion has a proximal end and a distal end, and one or more barrier forming materials, wherein the one or more barrier forming materials are attached to the proximal end of the first delivery portion, and wherein the one or more barrier forming materials form a barrier upon inflation. 
     
     
         2 . The device of  claim 1 , wherein the one or more barrier forming materials are balloons. 
     
     
         3 . The device of  claim 2 , comprising two balloons. 
     
     
         4 . The device of  claim 3 , wherein the balloons form an asymmetric, discontinuous ring upon inflation, wherein the proximal ends of the balloons are sufficiently close following inflation to prevent release of an injectable modified poly(methyl methacrylate) material from the center of the ring. 
     
     
         5 . The device of  claim 4 , wherein one portion of the ring is higher than the portion on the opposite side of the ring. 
     
     
         6 . The device of  claim 1 , further comprising a first syringe and a catheter, wherein the first syringe is attached to the distal end of the catheter, and the proximal end of the catheter is attached to the distal end of the first delivery portion. 
     
     
         7 . The device of  claim 1 , further comprising a second syringe, wherein the second syringe is in fluid communication with the distal end of the second delivery portion, and wherein the second syringe comprises a injectable, curable modified poly(methyl methacrylate). 
     
     
         8 . A method for injecting a curable material into an intervertebral space in need of treatment, comprising
 (i) inserting into the intervertebral space a device, comprising an outer canula, an inner canula, wherein the inner canula comprises a first delivery portion and a second delivery portion, wherein each delivery portion has a proximal end and a distal end, and one or more barrier forming materials,   wherein the one or more bather forming materials are attached to the proximal end of the first delivery portion, and   wherein the one or more barrier forming materials form a barrier upon inflation,   (ii) inflating the one or more barrier forming materials to form a barrier surrounding a hollow portion,   (iii) injecting the curable material into the hollow portion, and   (iv) curing the material to form a porous cement via an isothermic reaction.   
     
     
         9 . The method of  claim 8 , wherein the material is a modified poly(methyl methacrylate). 
     
     
         10 . The method of  claim 8 , further comprising deflating the one or more barrier forming materials after step (iv). 
     
     
         11 . The method of  claim 8 , wherein step (iv) comprises exposing the material to a UV light source to initiate the curing step. 
     
     
         12 . The method of  claim 8 , wherein the resulting porous cement has a sufficient porosity to allow blood to pass through from one endplate to the adjacent vertebral endplate and to allow for sufficient bone growth through the cement to create an endplate-to-endplate fusion. 
     
     
         13 . A method of forming an intervertebral fusion in a patient in need of treatment comprising implanting into the intervertebral space in need of treatment a modified poly(methyl methacrylate) implant, wherein the implant is a porous cement with a sufficient porosity to allow blood to pass through from one endplate to the adjacent vertebral endplate and to allow for sufficient bone growth through the cement to create an endplate-to-endplate fusion. 
     
     
         14 . The method of  claim 13 , wherein the implant has a shape selected from the group consisting of rectangular implant with a tapered or lordotic cross section; crescent shape with a tapered or lordotic cross section; oblong, rectangular implant with a tapered or lordotic cross section; and circular. 
     
     
         15 . A kit comprising (i) a powdered precursor for a modified poly(methyl methacrylate) (mPMMA) or an injectable mPMMA, (ii) a trocar, (iii) an outer canula, (iv) an inner canula, wherein the inner canula comprises a first delivery portion and a second delivery portion, wherein each delivery portion has a proximal end and a distal end, and (v) one or more barrier forming materials,
 wherein the one or more barrier forming materials are attached to the proximal end of the first delivery portion, and   wherein the one or more barrier forming materials form a barrier upon inflation.   
     
     
         16 . The kit of  claim 15  further comprising a first syringe for inflating the one or more barrier forming materials. 
     
     
         17 . The kit of  claim 16  further comprising a plunger and a second syringe for administration of the mPMMA.