Expandable interbody spacer

Abstract

An expandable intervertebral spacer includes a body, a proximal end, and a distal end. The body includes quadrants that form a substantially cylindrical shape in a first configuration and a substantially cuboidal shape in a second configuration. Each quadrant includes a ramp portion with a ramp and a landing and a sliding portion with a sliding side and a foot. The ramp portion of a first quadrant engages the sliding portion of a second quadrant. The proximal end and the distal end couple with the plurality of quadrants and transfer an actuating force to expand the body from the first configuration to the second configuration.

1 . An expandable intervertebral spacer, comprising:
 a body having quadrants that form a substantially cylindrical shape in a first configuration and a substantially cuboidal shape in a second configuration, wherein each quadrant includes
 a ramp portion with a ramp and a landing; and 
 a sliding portion with a sliding side and a foot; 
 wherein the ramp portion of a first quadrant engages the sliding portion of a second quadrant, and 
   a proximal end and a distal end coupled with the quadrants and configured to transfer an actuating force to expand the body from the first configuration to the second configuration.   
     
     
         2 . The spacer of  claim 1 , wherein the quadrants are integrally formed within the body. 
     
     
         3 . The spacer of  claim 1 , wherein the ramp of the first quadrant engages a sliding side of the second quadrant in the first configuration. 
     
     
         4 . The spacer of  claim 1 , wherein the landing of the first quadrant engages a foot of the second quadrant in the second configuration. 
     
     
         5 . The spacer of  claim 1 , further comprising a plurality of integral linking members coupling the proximal and distal ends with the body. 
     
     
         6 . The spacer of  claim 1 , further comprising a plurality of integral linking members that conform to the cylindrical shape in the first configuration and plastically deform when the body transforms to the second configuration. 
     
     
         7 . The spacer of  claim 1 , further comprising a tension member coupling the first quadrant and the second quadrant. 
     
     
         8 . The spacer of  claim 1 , further comprising a tension member within the body having a first length in the first configuration and a second length greater than the first length in the second configuration. 
     
     
         9 . The spacer of  claim 1 , further comprising an integral tension member within the body that provides tension between the first quadrant with the second quadrant as the body expands from the first configuration to the second configuration. 
     
     
         10 . The spacer of  claim 1 , further comprising a threaded aperture within at least one of the proximal end and the distal end. 
     
     
         11 . An apparatus for expanding an intervertebral space, comprising:
 a plurality of interlocking sections integrally formed in a body and configurable between a first geometry and a second geometry; and   a proximal end and a distal end integrally formed in the body and configured to transfer an applied force to configure the body between the first geometry and the second geometry.   
     
     
         12 . The apparatus of  claim 11 , wherein a first of the interlocking sections slidably engages a second of the interlocking sections as the body transforms from the first geometry to the second geometry. 
     
     
         13 . The apparatus of  claim 11 , wherein the plurality of interlocking sections includes four quadrants that form a cylindrical arrangement in the first geometry and a cuboidal arrangement in the second geometry. 
     
     
         14 . The apparatus of  claim 11 , wherein at least one of the interlocking sections includes a sliding quadrant and at least one of the interlocking sections includes a ramp quadrant. 
     
     
         15 . The apparatus of  claim 11 , wherein a sliding side of a first interlocking section slides along a ramp of an adjacent second interlocking section as the applied force compresses the proximal and distal ends. 
     
     
         16 . The apparatus of  claim 11 , wherein a first of the interlocking sections includes a first sliding quadrant linked to a first ramp quadrant by a first bridge. 
     
     
         17 . The apparatus of  claim 11 , further comprising a tension member integrally formed in the body links two of the interlocking sections. 
     
     
         18 . The apparatus of  claim 11 , wherein the first geometry fills a first volume and the second geometry fills a second volume greater than the first volume. 
     
     
         19 . The apparatus of  claim 11 , wherein one of the proximal and distal ends includes an attachment feature and the other of the proximal and distal ends includes an anti-rotation feature. 
     
     
         20 . The apparatus of  claim 11 , further comprising a tension member linking two of the interlocking sections that plastically deforms when the interlocking sections transform from the first configuration to the second configuration.