Methods and apparatus for minimally invasive modular interbody fusion devices

Abstract

The invention is a modular interbody fusion device for fusing adjacent spinal vertebrae that is adapted to be implanted in a prepared interbody space including a first modular segment having a width including a first rail extending at least partially along one side of the width and beyond a periphery of a body portion of the first modular segment, a second modular segment having a width and slidably connected to the first rail on one side of the width and having a second rail extending at least partially along another side of the width and beyond a periphery of a body portion of the second modular segment, a third modular segment having a width and slidably connected to the second rail on one side of the width and wherein the device has an expanded position in which the second and third modular segments are extended along the first and second rails and positioned in a generally end to end configuration spaced apart by the rails prior to implantation and an implanted position in which the modular segments are positioned in a generally side by side configuration that defines a unitary body that mimics the planar shape of the vertebra such that the device contacts and supports the adjacent vertebra.

1 .- 31 . (canceled) 
     
     
         32 . A method of implanting a modular fusion device in a prepared interbody space for fusing a spinal joint, the method comprising:
 inserting a first modular segment of the modular fusion device into an intervertebral space through a hole;   inserting a second modular segment of the modular fusion device, the second modular segment sliding up a first rigid rail of the first modular segment into the intervertebral space until the second modular segment interlocks with the first modular segment;   severing a first tail stem of the first rigid rail;   inserting a third modular segment of the modular fusion device, the third modular segment sliding up a second rigid rail of the second modular segment into the intervertebral space until the second modular segment interlocks with the third modular segment;   severing a second tail stem of the second rigid rail; and   inserting the modular fusion device into the intervertebral space.   
     
     
         33 . The method of  claim 32 , further comprising:
 inserting a fourth modular segment of the modular fusion device, the fourth modular segment sliding up a third rigid rail of the third modular segment into the intervertebral space until the third modular segment interlocks with the fourth modular segment; and   severing a third tail stem of the third rigid rail.   
     
     
         34 . The method of  claim 32 , wherein the first, second, and third modular segments are adapted for a lateral surgical approach or a posterior surgical approach. 
     
     
         35 . The method of  claim 32 , wherein the first, second, and third modular segments are inserted using an insertion tool comprising a cutting mechanism, wherein the cutting mechanism is used to sever the first and second rigid tails. 
     
     
         36 . The method of  claim 32 , wherein a periphery of the modular fusion device is configured to contact a joint of the intervertebral space to be fused. 
     
     
         37 . The method of  claim 32 , wherein the first and second tail stems are between 6 cm and 20 cm in length. 
     
     
         38 . The method of  claim 32 , wherein the first and second rigid rails comprise retaining portions to prevent corresponding modular segments from sliding off 
     
     
         39 . The method of  claim 38 , wherein the retaining portions are molded into the first and second rigid rails. 
     
     
         40 . The method of  claim 32 , wherein the first modular segment is inserted using a first guide rod, and wherein the second modular segment is attached to a second guide rod to place the second modular segment in position to interlock with the first modular segment. 
     
     
         41 . The method of  claim 32 , wherein the first modular segment is inserted into the intervertebral space using an access tube at least three inches long. 
     
     
         42 . The method of  claim 32 , wherein the first, second, and third modular segments are interlocked by a barb or a stud. 
     
     
         43 . The method of  claim 32 , wherein the first, second, and third modular segments can be separated with a ratchet release tool.