Expanding vertebral body implant

Abstract

An expandable medical implant for supporting bone structures is disclosed. The implant may include an outer member and an inner member receivable in the outer member. One of the outer and inner members includes a tapered surface and the other of the outer and inner members includes a scalloped surface. The implant may also include a locking element disposed between the tapered surface and the scalloped surface. The tapered surface may be movable relative to the locking element to transversely shift the locking element into engagement with the scalloped surface to inhibit a decrease in the overall implant height.

1 - 35 . (canceled) 
     
     
         36 . A method of supporting bone structures with an expandable medical implant, the implant having an overall implant height adjustable along a longitudinal axis, the method comprising:
 placing the implant between bone structures to be supported;   displacing an inner member having a scalloped surface relative to an outer member having a tapered inner surface in order to increase the overall implant height, the outer member being configured to cooperatively engage a first bone structure and the inner member being configured to cooperatively engage a second bone structure, wherein displacing the inner member allows a locking element to disengage the scalloped surface; and   supporting a compressive load from the bone structures on the inner and outer members, wherein the compressive load causes the tapered surface to shift the locking element into engagement with the scalloped surface and to inhibit a decrease in the overall implant height.   
     
     
         37 . The method of  claim 36 , wherein the implant includes two locking elements disposed at opposite sides of the inner member, and wherein displacing the inner member allows the two locking elements to disengage the scalloped surface, and wherein supporting the compressive load shifts the two locking elements into engagement with scalloped surfaces. 
     
     
         38 . The method of  claim 36 , including at least two locking elements disposed between the inner and outer members at opposing sides of the inner member, wherein the locking elements are cylindrical rollers. 
     
     
         39 . The method of  claim 36 , further including decreasing the overall height of the implant by displacing a locker member containing the locking element so that the locking element is allowed to move along the tapered surface of the outer member and is allowed to move away from the scalloped surface of the inner member. 
     
     
         40 . The method of  claim 36 , wherein the locking element is a cylinder, and the shifting the locking element into engagement with the scalloped surface includes contacting the scalloped surface along at least a line of contact transverse to the longitudinal axis of the implant. 
     
     
         41 . The method of  claim 36 , wherein at least one of the inner and outer members includes vascularization openings formed on opposing sides of the implant, and wherein the vascularization openings on one opposing side are larger than the vascularization openings on the other opposing side, the method including the step of placing a bone growth material through the larger vascularization openings. 
     
     
         42 - 45 . (canceled) 
     
     
         46 . A method of supporting bone structures with an expandable medical implant,
 placing the implant between bone structures to be supported, the implant comprising:
 an overall implant height adjustable along a longitudinal axis; 
 an outer member being configured to cooperatively engage a first bone structure; 
 an inner member receivable in the outer member and movable relative to the outer member to increase and decrease the overall implant height, the inner member being configured to cooperatively engage a second bone structure, 
 wherein one of the outer and inner members includes a tapered surface and the other of the outer and inner members includes a roughened locking surface; and 
 a locking element disposed between the tapered surface and the roughened locking surface, the tapered surface being longitudinally movable relative to the locking element to shift the locking element in a direction transverse to the longitudinal axis into engagement with the roughened locking surface to inhibit a decrease in the overall implant height. 
   displacing an inner member having a scalloped surface relative to an outer member having a tapered inner surface in order to increase the overall implant height, the outer member being configured to cooperatively engage a first bone structure and the inner member being configured to cooperatively engage a second bone structure, wherein displacing the inner member allows a locking element to disengage the scalloped surface; and   supporting a compressive load from the bone structures on the inner and outer members, wherein the compressive load causes the tapered surface to shift the locking element into engagement with the scalloped surface and to inhibit a decrease in the overall implant height.   
     
     
         47 . The method of  claim 46 , further including decreasing the overall height of the implant by displacing a locker member containing the locking element so that the locking element is allowed to move along the tapered surface of the outer member and is allowed to move away from the scalloped surface of the inner member. 
     
     
         48 . The method of  claim 46  wherein the expandable implant further includes a locker member disposed between the inner and outer member, the locker member including a receiving aperture containing the locking element. 
     
     
         49 . The method of  claim 48  wherein the locker member is configured to act on the locking element to affect the position of the locking element relative to the tapered surface, and wherein the tapered surface is configured to affect the position of the locking element relative to the roughened locking surface. 
     
     
         50 . The method of  claim 48  wherein the locker member and the locking element are movable relative to the tapered surface between a locked condition and a free condition. 
     
     
         51 . The method of  claim 46 , wherein the locking element is a cylinder, and the shifting the locking element into engagement with the scalloped surface includes contacting the scalloped surface along at least a line of contact transverse to the longitudinal axis of the implant. 
     
     
         52 . The method of  claim 46 , wherein at least one of the inner and outer members includes vascularization openings formed on opposing sides of the implant, and wherein the vascularization openings on one opposing side are larger than the vascularization openings on the other opposing side, the method including the step of placing a bone growth material through the larger vascularization openings. 
     
     
         53 . A method of supporting bone structures with an expandable medical implant,
 placing the implant between bone structures to be supported, the implant comprising:
 an overall implant height adjustable along a longitudinal axis; 
 an outer member having an inner surface and being configured to cooperatively engage a first bone structure; 
 an inner member receivable in the outer member and movable relative to the outer member to increase and decrease the overall implant height; the inner member having a roughened locking surface and being configured to cooperatively engage a second bone structure; and 
 a locking element disposed between the inner surface of the outer member and the roughened locking surface of the inner member, the locking element being movable by axial translation between a locked condition and an unlocked condition, and 
 a biasing member operable to bias the locking element in a longitudinal direction toward the locked condition, the locking element being disposed to selectively engage the roughened locking surface to inhibit a decrease in the overall implant height, 
   displacing an inner member having a scalloped surface relative to an outer member having a tapered inner surface in order to increase the overall implant height, the outer member being configured to cooperatively engage a first bone structure and the inner member being configured to cooperatively engage a second bone structure, wherein displacing the inner member allows a locking element to disengage the scalloped surface; and   supporting a compressive load from the bone structures on the inner and outer members, wherein the compressive load causes the tapered surface to shift the locking element into engagement with the scalloped surface and to inhibit a decrease in the overall implant height.   
     
     
         54 . The method of  claim 53 , further including decreasing the overall height of the implant by displacing a locker member containing the locking element so that the locking element is allowed to move along the tapered surface of the outer member and is allowed to move away from the scalloped surface of the inner member. 
     
     
         55 . The method of  claim 53 , wherein the locking element is a cylinder, and the shifting the locking element into engagement with the scalloped surface includes contacting the scalloped surface along at least a line of contact transverse to the longitudinal axis of the implant. 
     
     
         56 . The method of  claim 53 , wherein at least one of the inner and outer members includes vascularization openings formed on opposing sides of the implant, and wherein the vascularization openings on one opposing side are larger than the vascularization openings on the other opposing side, the method including the step of placing a bone growth material through the larger vascularization openings. 
     
     
         57 . The method of  claim 53 , wherein the expandable implant further includes a locker member disposed between the inner and outer member, the locker member including a receiving aperture containing the locking element. 
     
     
         58 . The method of  claim 57 , wherein the locker member is configured to act on the locking element to affect the position of the locking element relative to the outer member, and wherein the tapered surface of the outer member is configured to affect the position of the locking element relative to the roughened locking surface of the inner member. 
     
     
         59 . The method of  claim 57 , wherein the expandable implant further includes a leaf spring biasing member configured to bias the locker member toward the locked condition.