Semi-constrained anchoring system
Systems, devices, and associated methods for correcting spinal column deformities that help minimize a number of attachment anchors utilized for correction, facilitate use of straight or contoured rods, and/or help promote a more natural, physiologic motion of the spinal column.
1. A rod anchor for correcting a spinal deformity comprising:
a mounting portion configured to secure the rod anchor to a first bony element and including a pedestal;
a sleeve having a revolute, convex outer surface and a sleeve passage configured to receive a rod; and
a ring-shaped receptacle portion supported by the pedestal, the ring shaped portion having a revolute concave inner surface defining a receptacle passage, the receptacle passage having a longitudinal axis passing through a center of the passage and configured to capture and substantially complementarily fit the sleeve such that the rod received within the sleeve is pivotable in pitch and yaw about a pivot point at a center of the sleeve passage while being constrained from laterally translating towards the revolute concave inner surface.
2. The rod anchor according to claim 1 , wherein the sleeve passage is configured to allow a rod received therethrough to slide longitudinally within the passage.
3. The rod anchor according to claim 1 , wherein the revolute concave inner surface is configured to allow the sleeve received therethrough to roll about the pivot point.
4. The rod anchor according to claim 1 , wherein the pedestal extends along a longitudinal axis extending in a direction parallel to the longitudinal axis of the receptacle passage and the pedestal has a center aligned with the center of the receptacle portion.
5. The rod anchor according to claim 4 , wherein the longitudinal axis of the pedestal is laterally offset from the longitudinal axis of the receptacle passage.
6. The rod anchor according to claim 1 , wherein the sleeve is allowed relative rotational and angular movement with respect to the receptacle portion while captured within the receptacle passage.
7. A rod anchor for correcting a spinal deformity comprising:
a mounting portion configured to secure the rod anchor to a first bony element and including a pedestal and a stem extending from the pedestal;
a substantially spherical sleeve having a revolute, convex outer surface defining a sleeve passage configured to receive a rod; and
a ring-shaped receptacle portion fixed relative to the mounting portion and supported by the stem, the receptacle portion having a revolute concave inner surface defining a receptacle passage, the receptacle passage having a longitudinal axis passing through a center of the receptacle passage, the receptacle passage defined by a substantially spherical mating face within the ring-shaped receptacle portion configured to allow the sleeve with the rod received therethrough to pivot in pitch and yaw about the longitudinal axis while being constrained from laterally translating relative to the longitudinal axis.
8. A rod anchor for correcting a spinal deformity comprising:
a mounting portion configured to secure the rod anchor to a first bony element and including a pedestal and a stem extending from the pedestal;
a sleeve having a revolute, convex outer surface and a sleeve passage configured to receive a rod; and
a ring-shaped receptacle portion having a revolute concave inner surface defining a receptacle passage, the receptacle passage having a longitudinal axis passing through a center of the receptacle passage, the receptacle passage configured to receive a rod therethrough such that the rod received within the sleeve is pivotable in pitch and yaw about a pivot point at a center of the sleeve passage while being constrained from laterally translating toward the revolute concave inner surface, and an outside surface from which the stem extends transverse to the longitudinal axis.
9. The rod anchor according to claim 8 , wherein the pedestal comprises a plate attached to the stem, the plate defining a first hole configured to receive a fastener to secure the plate to a first bony element.
10. The rod anchor of claim 8 , wherein the pedestal extends transverse to the stem and has a longitudinal axis extending parallel to the longitudinal axis of the receptacle passage such that the longitudinal axis of the pedestal is laterally offset from the longitudinal axis of the receptacle passage, wherein center points of the receptacle portion, stem and pedestal are aligned.