Adjustable spinal implants and related deployment instruments
The present disclosure provides adjustable spinal devices, instruments for deploying the spinal devices, methods for adjusting the height and/or lordosis angles of the spinal devices, and methods for implanting such devices. An adjustable spinal fusion device includes an upper plate having an outer surface for placement against a first vertebral body and a lower plate having an outer surface for placement against a second vertebral body. The device further includes a translation member configured to move longitudinally relative to the upper and lower plates to adjust an angle between the upper and lower plates and a locking member coupled to the translation member. The locking member is movable between an unlocked position, wherein the translation member is capable of moving in the longitudinal direction, and a locked position, wherein the translation member is inhibited from moving in the longitudinal direction.
1 . An adjustable spinal fusion device, comprising:
an upper endplate having an outer surface for placement against a first vertebral body;
a lower endplate having an outer surface for placement against a second vertebral body;
a translation member configured to move longitudinally relative to the upper and lower endplates to adjust an angle between the upper and lower endplates, wherein the translation member comprises a bore having one or more mating features for cooperating with an actuator shaft of a surgical instrument to move the translation member in the longitudinal direction; and
a locking member coupled to the translation member and configured to secure a longitudinal position of the translation member relative to the upper and lower endplates, the locking member being rotatably coupled to the translation member within the bore from an unlocked position to a locked position,
wherein, in the unlocked position, the translation member is capable of moving in the longitudinal direction, and wherein, in the locked position, the translation member is constrained from moving in the longitudinal direction.
2 . The adjustable spinal fusion device of claim 1 , wherein:
the locking member comprises one or more mating features for cooperating with the actuator shaft of the surgical instrument such that rotation of at least a portion of the surgical instrument causes rotation of the locking member within the bore; and
wherein rotation of the locking member into the unlocked position causes the mating features of the translation member to secure to mating features of the surgical instrument.
3 . The adjustable spinal fusion device of claim 2 , further comprising one or more engagement elements coupled to one of the upper and lower endplates, wherein the locking member comprises one or more locking elements that engage the engagement elements in one of the upper and lower endplates in the locked position.
4 . The adjustable spinal fusion device of claim 3 , wherein the locking elements of the locking member comprise a plurality of projections and the engagement elements of one of the upper and lower endplates comprise a plurality of teeth that engage the projections in the locked position.
5 . The adjustable spinal fusion device of claim 1 , wherein the upper and lower endplates each have proximal and distal ends, wherein the proximal ends are pivotally coupled to each other and wherein the distal ends are movable relative to each other to adjust a distance therebetween.
6 . The adjustable spinal fusion device of claim 1 , wherein the translation member comprises an angled surface extending downward from the upper endplate towards the lower endplate in a proximal direction, the device further comprising a ramp for cooperating with the angled surface of the translation member.
7 . The adjustable spinal fusion device of claim 6 , further comprising an internal support member coupled to, or integral with, the upper endplate and a hinge pivotally coupling the internal support member to the lower endplate, wherein the ramp is on the internal support member.
8 . The adjustable spinal fusion device of claim 6 , wherein proximal translation of the translation member causes the angled surface to engage the ramp and move the distal end of the upper endplate away from the distal end of the lower endplate, wherein the proximal ends of the endplates remain substantially fixed relative to each other as the distal ends are moved apart.
9 . A spinal fusion system, comprising:
an adjustable spinal fusion device comprising:
an upper endplate having an outer surface for placement against a first vertebral body;
a lower endplate having an outer surface for placement against a second vertebral body;
a translation member configured to move longitudinally relative to the upper and lower endplates to adjust an angle between the upper and lower endplates; and
a locking member coupled to the translation member and configured to secure a longitudinal position of the translation member relative to the upper and lower endplates; and
an instrument having a proximal handle, an elongate shaft and a mating feature on the elongate shaft for cooperating with the locking member, wherein the mating feature on the instrument is configured to rotate the locking member from an unlocked position to a locked position,
wherein, in the unlocked position, the translation member is capable of moving in the longitudinal direction, and wherein, in the locked position, the translation member is inhibited from moving in the longitudinal direction.
10 . The spinal fusion system of claim 9 , wherein the mating feature is a first mating feature and the instrument comprises a second mating feature, wherein the translation member comprises a bore having one or more engagement elements for cooperating with the second mating feature to secure the translation member to the instrument such that longitudinal movement of the instrument causes the translation member to move longitudinally relative to the upper and lower endplates.
11 . The spinal fusion system of claim 10 , wherein the locking member is rotatably coupled to the translation member within the bore and wherein rotation of the locking member into the unlocked position causes the engagement elements of the translation member to secure to the second mating feature of the instrument.
12 . The spinal fusion system of claim 11 , wherein:
the second mating feature comprises one or more projections extending from a distal end of the shaft of the instrument and the engagement elements of the translation member comprise one or more recesses in an interior surface of the bore; and
wherein the first mating feature comprises one or more projections extending from the distal end of the shaft of the instrument, wherein the first mating feature is located proximal to the second mating feature on the elongate shaft.
13 . The spinal fusion system of claim 9 , wherein proximal translation of the translation member causes a distal end of the upper endplate to move away from a distal end of the lower endplate and wherein proximal ends of the endplates remain substantially fixed relative to each other as the distal ends are moved apart.
14 . A surgical instrument for implanting a spinal fusion device in a patient, the instrument comprising:
an elongate shaft having a proximal handle and a distal end portion;
a first mating feature for securing the shaft of the instrument to the spinal fusion device;
a second mating feature on the distal end portion for engaging a translation member of the spinal fusion device;
a third mating feature on the distal end portion for engaging a locking member of the spinal fusion device; and
a rod extending through a lumen of the elongate shaft, wherein the second and third mating features are positioned on a distal portion of the rod, and wherein the rod is rotatable relative to the shaft to rotate the locking member of the spinal fusion device.
15 . The instrument of claim 14 , wherein the rod is configured to translate in a longitudinal direction relative to the shaft to translate the translation member of the spinal fusion device.
16 . The instrument of claim 14 , wherein the second mating feature comprises one or more projections extending from the distal portion of the rod and the third mating feature comprises one or more projections extending from the distal portion of the rod proximal to the second mating feature.
17 . The instrument of claim 16 , wherein the second mating feature is configured to secure to the translation member when the third mating feature moves the locking member into an unlocked position that allows translation of the translation member.
18 . The instrument of claim 14 , further comprising a rotatable knob on the proximal handle coupled to the rod and configured to translate the rod relative to the shaft.
19 . The instrument of claim 18 , further comprising a gauge on the proximal handle coupled to the rotatable knob and configured to indicate a lordosis angle of first and second endplates on the spinal fusion device.