Adjustable implant and insertion tool

Abstract

An adjustable spinal implant includes a lower body, an upper body, a locking pawl, and a locking key. The upper body and the lower body are pivotable relative to one another between a collapsed position and an expanded position. The upper body includes a locking flange that extends towards the lower body. The locking pawl is coupled to the lower body and is moveable between a locked position such that the upper and lower bodies are fixed relative to the one another and an unlocked position such that the upper and lower bodies are moveable relative to one another. The locking key is moveable between a locked state such that the locking pawl is fixed in the locked position and an unlocked state wherein the locking pawl is moveable between the locked position and the unlocked position.

What is claimed: 
     
       1. A method of expanding an adjustable implant, the method comprising:
 positioning the adjustable implant in an intervertebral space, the adjustable implant including:
 a lower body; 
 an upper body including a locking flange extending towards the lower body; 
 a locking pawl secured to the lower body, the locking pawl preventing the upper body and the lower body from pivoting towards one another; and 
 a locking key; 
 
 pivoting at least one of a distal end of the upper body and a distal end of the lower body away from the distal end of the other one of the upper and lower bodies, the locking pawl ratcheting between a locked position and an unlocked position as one of the upper body and the lower body pivots away from the other one of the upper and lower bodies; and 
 transitioning the locking key to a locked state to fix the locking pawl in the locked position such that the upper body is fixed relative to the lower body. 
 
     
     
       2. The method according to  claim 1 , wherein pivoting the at least one of a distal end of the upper body and a distal end of the lower body away from the distal end of the other one of the upper and lower bodies includes inserting an insertion tool in a passage defined by the upper and lower bodies. 
     
     
       3. The method according to  claim 2 , further comprising capturing a portion of the lower body within a cutout defined in a distal portion of the insertion tool to longitudinally fix the implant relative to the insertion tool. 
     
     
       4. The method according to  claim 2 , further comprising translating a spreading rod of the insertion tool into the passage to pivot the distal end of the upper body and the distal end of the lower body away from one another. 
     
     
       5. The method according to  claim 4 , wherein translating the spreading rod of the insertion tool includes engaging the upper body with a rod guide to pivot the distal end of the upper body and the distal end of the lower body away from one another. 
     
     
       6. The method according to  claim 5 , wherein translating the spreading rod includes rotating a thumb wheel threadably coupled to a proximal end of the spreading rod. 
     
     
       7. The method according to  claim 1 , wherein transitioning the locking key to the locked state includes rotating the locking key. 
     
     
       8. The method according to  claim 7 , wherein rotating the locking key includes engaging a stop pin coupled to the locking pawl with a keyed ring of the locking key to limit rotation of the locking key. 
     
     
       9. The method according to  claim 1 , further comprising engaging the locking key with a locking rod of an insertion tool and wherein transitioning the locking key to the locked state includes rotating the locking rod to rotate the locking key. 
     
     
       10. The method according to  claim 9 , wherein engaging the locking key includes receiving a proximal end of the locking key in a recess defined in a distal end of the locking rod. 
     
     
       11. The method according to  claim 9 , wherein engaging the locking key includes rotating a proximal engagement end of the locking rod disposed within a transport portion of a locking recess defined in an upper section of the insertion tool in a first radial direction and sliding the proximal engagement end of the locking rod within an engagement portion of the locking recess until the locking rod is engaged with the locking key, the engagement portion positioned distal to the transport portion. 
     
     
       12. The method according to  claim 11 , wherein transitioning the locking key to the locked state includes rotating the locking rod within a locking portion of the locking recess in the first radial direction, the locking portion positioned distal of the engagement portion. 
     
     
       13. The method according to  claim 12 , further comprising disengaging the locking rod from the proximal end of the locking key by translating the proximal engagement portion proximally within the locking portion of the locking recess. 
     
     
       14. A method of pivoting at least one of an upper body and a lower body of an adjustable implant relative to one another, the method comprising:
 pivoting a distal end of at least one of the upper and lower bodies away from one the distal end of the other one of the upper and lower bodies such that a locking pawl, which is in an unlocked state and pivotally secured to the lower body, ratchets against a locking flange of the upper body, the locking flange extending towards the lower body; and 
 transitioning a locking key having a distal end that extends through the locking pawl and received in the locking flange to a locked position to fix the locking pawl in a locked state such that the upper and lower bodies are fixed relative to one another. 
 
     
     
       15. The method according to  claim 14 , wherein pivoting a distal end of at least one of the upper and lower bodies away from one the distal end of the other one of the upper and lower bodies includes inserting an inserter through a passage defined between proximal ends of the upper and lower bodies which are pivotally coupled to one another. 
     
     
       16. The method according to  claim 15 , further comprising capturing a portion of the lower body within a cutout defined in a distal portion of the insertion tool to longitudinally fix the implant relative to the insertion tool. 
     
     
       17. The method according to  claim 14 , wherein transitioning the locking key includes rotating the locking key such that the distal end of the locking key prevents the locking pawl from pivoting away from locking flange. 
     
     
       18. The method according to  claim 14 , further comprising engaging the locking key with a locking rod of an insertion tool, and wherein transitioning the locking key includes rotating the locking rod to affect rotation of the locking key. 
     
     
       19. The method according to  claim 14 , wherein ratcheting the locking pawl against the locking flange includes positioning a biasing member between the lower body and a biasing finger of the locking pawl to urge the locking pawl towards the locking flange. 
     
     
       20. A method of expanding an adjustable implant, the method comprising:
 positioning an adjustable implant in an intervertebral space between an upper vertebral body and a lower vertebral body spaced apart from one another in a height dimension;   advancing a spreader having an engagement surface along an axis within a passage between an upper body and a lower body of the adjustable implant such that the advancement of the spreader along the axis causes the engagement surface of the spreader to engage and slide along a portion of the inner surface of the adjustable implant along the passage while pushing the portion of the inner surface laterally away from the axis, to thereby spread the upper and lower bodies of the adjustable implant away from one another in the height dimension to an expanded configuration; and   removing the spreader from between the upper and lower bodies of the adjustable implant while maintaining the expanded configuration.   
     
     
       21. The method according to claim 20, wherein advancing the spreader along the axis comprises advancing the spreader from a proximal end of the adjustable implant towards a distal end of the adjustable implant. 
     
     
       22. The method according to claim 20, wherein spreading the upper and lower bodies away from one another comprises pivoting the upper and lower bodies away from one another. 
     
     
       23. The method according to claim 22, wherein advancing the spreader comprises advancing the spreader in a distal direction along the axis, and wherein pivoting the upper and lower bodies away from one another comprises pivoting the upper and lower bodies about a pivot axis at a proximal end of the adjustable implant. 
     
     
       24. The method according to claim 20, wherein the engagement surface of the spreader is obliquely oriented with respect to the axis. 
     
     
       25. The method according to claim 20, wherein the portion of the inner surface of the adjustable implant is obliquely oriented with respect to the axis. 
     
     
       26. The method according to claim 25, wherein the obliquely oriented portion of the inner surface is disposed in a proximal region of the adjustable implant. 
     
     
       27. The method according to claim 20, wherein maintaining the expanded configuration can be achieved at each of a plurality of different amounts of expansion, such that the spreader is removable from between the upper and lower bodies at any selected one of the amounts of expansion. 
     
     
       28. The method according to claim 27, wherein maintaining the expanded configuration includes utilizing a ratchet that permits the upper and lower bodies to move in one direction but prevents the upper and lower bodies from moving in another direction. 
     
     
       29. The method according to claim 28, further comprising locking the ratchet such that, at the selected amount of expansion, the upper and lower bodies are prevented from moving further away from one another and are also prevented from moving towards one another. 
     
     
       30. The method according to claim 20, wherein removing the spreader from between the upper and lower bodies comprises removing an implant insertion tool connected to a proximal end of the adjustable implant, the spreader being a component of the implant insertion tool. 
     
     
       31. The method according to claim 30, wherein advancing the spreader along the axis comprises advancing at least a distal end of the spreader into an opening at the proximal end of the adjustable implant. 
     
     
       32. The method according to claim 31, wherein advancing the spreader along the axis comprises advancing at least the distal end of the spreader into an open interior region of the adjustable implant. 
     
     
       33. The method according to claim 32, further comprising filling the open interior region of the adjustable implant with a bone growth facilitator material.