SURGICAL MEASUREMENT AND RESECTION FRAMEWORK
A frame is attachable to first and second bone portions of a patient to facilitate measurement and resection of one or more bony landmarks. The frame has two anchoring features, each of which has a semispherical surface that permits rotational adjustment of the frame against the bone portions until the frame is secured. A bridging structure couples the anchoring features together such that the anchoring features are lockably movable with respect to each other. The bridging structure may have three linear sliders that provide the relative motion. A locking mechanism exerts pressure on all three sliders to lock them in place. An external anchoring feature enables attachment of the frame to a stationary reference to stabilize the frame. The frame also has registration features that permit attachment of measurement or resection tools to the frame. The frame is particularly useful for measuring and resecting spinal facets for facet replacement.
1 . A method for measuring a bony landmark on a spine of a patient, the method comprising:
attaching a frame to a first bone portion and a second bone portion of the spine, wherein the first and second bone portions are spaced apart from each other;
registering a measurement tool with respect to the frame; and
guiding the registered measurement tool with the frame to measure at least one of a position of the bony landmark, and an orientation of the bony landmark.
2 . The method of claim 1 , wherein the frame comprises a first registration feature, wherein registering the measurement tool with respect to the frame comprises coupling the measurement tool to the first registration feature.
3 . The method of claim 2 , wherein the frame further comprises a second registration feature, wherein attaching the frame to the first and second bone portions comprises positioning the first and second registration features on opposite sides of a sagittal plane of the patient to guide instrumentation to enable performance of two distinct measurement functions substantially symmetrically across the sagittal plane.
4 . The method of claim 1 , wherein the frame comprises a first anchoring feature configured to be attached to the first bone portion and a second anchoring feature configured to be attached to the second bone portion, the frame further comprising a bridging structure comprising two arms, each of which has a first end and a second end, wherein the first ends are coupled to each other via three sliding joints, and the second ends are coupled to the first and second anchoring features, wherein attaching the frame to the first and second bone portions comprises actuating the three sliding joints to move the second end with respect to the first end along three orthogonal axes.
5 . The method of claim 1 , wherein the frame comprises an external anchoring feature, the method further comprising attaching the frame to a stationary external support to stabilize the frame via the external anchoring feature.
6 . The method of claim 1 , wherein the first and second bone portions comprise first and second pedicles of a vertebra of the spine, and each of the first and second anchoring features comprises an opening, the method further comprising:
driving first and second guide wires into the first and second pedicles; and
receiving one of the guide wires through each opening to guide positioning of the first and second anchoring features on the pedicles via the guide wires.
7 . The method of claim 1 , further comprising replacing at least a portion of a facet of a vertebra of a spine of the patient with at least one prosthesis.
8 . A method for resecting a vertebra of a spine of a patient, the method comprising:
attaching a frame to a first bone portion and a second bone portion of the spine, wherein the first and second bone portions are spaced apart from each other;
registering a resection tool with respect to the frame; and
guiding the registered resection tool with the frame to resect the vertebra.
9 . The method of claim 8 , wherein the frame comprises a first registration feature, wherein registering the resection tool with respect to the frame comprises coupling the resection tool to the first registration feature.
10 . The method of claim 9 , wherein the frame further comprises a second registration feature, wherein attaching the frame to the first and second bone portions comprises positioning the first and second registration features on opposite sides of a sagittal plane of the patient to guide instrumentation to enable performance of two distinct resection functions substantially symmetrically across the sagittal plane.
11 . The method of claim 8 , wherein the frame comprises a first anchoring feature configured to be attached to the first bone portion and a second anchoring feature configured to be attached to the second bone portion, the frame further comprising a bridging structure comprising two arms, each of which has a first end and a second end, wherein the first ends are coupled to each other via three sliding joints, and the second ends are coupled to the first and second anchoring features, wherein attaching the frame to the first and second bone portions comprises actuating the three sliding joints to move the second end with respect to the first end along three orthogonal axes.
12 . The method of claim 8 , wherein the frame comprises an external anchoring feature, the method further comprising attaching the frame to a stationary external support to stabilize the frame via the external anchoring feature.
13 . The method of claim 8 , wherein the first and second bone portions comprise first and second pedicles of a vertebra of the spine, and each of the first and second anchoring features comprises an opening, the method further comprising:
driving first and second guide wires into the first and second pedicles; and
receiving one of the guide wires through each opening to guide positioning of the first and second anchoring features on the pedicles via the guide wires.
14 . The method of claim 8 , wherein resecting the vertebra comprises removing at least a portion of a facet of the vertebra, the method further comprising replacing at least a portion of the facet with at least one prosthesis.
15 . A method for measuring a bony landmark on a spine of a patient through the use of a system comprising a frame having an external anchoring feature, and a stationary external support comprising a fixed end and a grip, the method comprising:
attaching the fixed end to a stationary structure;
positioning the frame at a desired location with respect to the spine;
attaching the grip to the external anchoring feature to restrict motion of the frame;
registering a measurement tool with respect to the frame; and
guiding the registered measurement tool with the frame to measure at least one of a position of the bony landmark, and an orientation of the bony landmark.
16 . The method of claim 15 , wherein the frame comprises a first registration feature, wherein registering the measurement tool with respect to the frame comprises coupling the measurement tool to the first registration feature.
17 . The method of claim 16 , wherein the frame further comprises a second registration feature coupled to the first registration feature and the external anchoring feature via a bridging structure, wherein positioning the frame comprises positioning the first and second registration features to enable performance of two distinct measurement functions substantially symmetrically across a sagittal plane of the patient.
18 . The method of claim 17 , wherein positioning the frame comprises positioning the first and second registration features adjacent to first and second pedicles of a vertebra of the spine.
19 . The method of claim 16 , wherein the frame further comprises a bridging structure that movably couples the first registration feature to the external anchoring feature, the method further comprising:
manipulating the bridging structure to move the first registration feature with respect to the external anchoring feature; and
locking the bridging structure to restrict further motion of the first registration feature with respect to the external anchoring feature.
20 . The method of claim 19 , wherein moving the first registration feature with respect to the external anchoring feature comprises translating the registration feature along three orthogonal axes with respect to the external anchoring feature.
21 . The method of claim 15 , wherein the external anchoring feature comprises a generally spherical surface, wherein attaching the grip to the external anchoring feature comprises gripping the generally spherical surface with the grip in any of a plurality of relative orientations between the grip and the external anchoring feature.
22 . The method of claim 21 , wherein the stationary external support further comprises at least one joint that couples the grip to the fixed end, the method further comprising:
manipulating the joint to move the grip with respect to the fixed end; and
locking the joint to restrict further motion of the grip with respect to the fixed end.
23 . The method of claim 15 , further comprising replacing at least a portion of a facet of a vertebra of a spine of the patient with at least one prosthesis.