Apparatus and method for connecting surgical rods
View Patent ↗An exemplary apparatus for connecting surgical rods according the principles of the present disclosure includes an elongate first arm, an elongate second arm, and a clamping assembly. The elongate first arm includes a first end that couples with a first rod and a second end with a first engagement portion. The elongate second arm includes a first end that couples with a second rod and a second end terminating in a second engagement portion. The clamping assembly includes a passageway that slidably receives the first engagement portion and that retains the second engagement portion and an adjustment member offset from the passageway that adjusts a clamping force to restrict positioning of the second engagement portion relative to the first engagement portion.
1. An apparatus for connecting surgical rods, comprising:
a first arm having a first length extending along a first longitudinal axis that terminates in a first free end configured to couple with a first rod and a second end with a first engagement portion having a curved channel disposed in an upper surface of the first engagement portion and a lower surface opposite the upper surface, the curved channel extending along the first longitudinal axis a predetermined length, the lower surface being generally planar;
a second arm having a second length extending along a second longitudinal axis that terminates in a second free end configured to couple with a second rod and a second end with a second engagement portion comprising a first hemispherical portion with a first radius and a second hemispherical portion with a second radius, the second radius being greater than the first radius, configured to slidably move along the curved channel and rotatable about the curved channel; and
a collar with a passageway having a lower portion, the lower portion having a generally planar surface so as to be slidably engaged with the lower surface of the first engagement portion and allow translation of the first arm relative to the collar along the first longitudinal axis and that engages the first hemispherical portion to allow rotation of the second arm relative to the collar in at least two planes and to prevent translation of the second arm relative to the collar along the second longitudinal axis; and
an adjustment member within an aperture of the collar that adjusts a clamping force on the first engagement portion and the second engagement portion to increase an amount of friction between at least one of the first engagement portion and the passageway, the first hemispherical portion and the passageway so as to fix the first hemispherical portion to a desired position along the predetermined length of the curved channel, and wherein the adjustment member includes a concave inner surface having a radius similar to the first radius of the first hemispherical portion.
2. The apparatus of claim 1 , wherein the first engagement portion terminates in a lip on the lower surface.
3. The apparatus of claim 2 , wherein the lip of the first arm engages the lower portion of the collar to retain the first arm within the passageway.
4. The apparatus of claim 1 , wherein the second arm further comprises a pair of flat surfaces adjacent to the first hemispherical portion and that engages the passageway to restrict rotation about the second longitudinal axis of the second arm.
5. The apparatus of claim 1 , wherein the second hemispherical portion translates within the curved channel to adjust an overall length of the apparatus.
6. The apparatus of claim 1 , wherein the second arm rotates about the second longitudinal axis.
7. The apparatus of claim 1 , wherein the second arm pivots about a common axis extending through the first hemispherical portion and the second hemispherical portion.
8. The apparatus of claim 1 , further comprising chamfered edges around the aperture in an upper surface of the collar and a threaded section in the aperture of a lower portion to receive threads of the adjustment member.
9. The apparatus of claim 1 , further comprising a first rod aperture in the first free end configured to receive a first rod setscrew to couple a first hook formed in the first free end with the first rod.
10. The apparatus of claim 1 , further comprising a second rod aperture in the second free end configured to receive a second rod setscrew to couple a second hook formed in the second free end with the second rod.
11. An apparatus for connecting surgical rods, comprising:
a first arm having a first length extending along a first longitudinal axis that terminates in a first free end configured to couple with a first rod and a second end with a first engagement portion having a curved channel disposed in an upper surface of the first engagement portion and a lower surface opposite the upper surface, the curved channel extending along the first longitudinal axis a predetermined length, the lower surface being generally planar;
a second arm having a second length extending along a second longitudinal axis that terminates in a second free end configured to couple with a second rod and a second end with a second engagement portion comprising a first hemispherical portion with a first radius and a second hemispherical portion with a second radius, the second radius being greater than the first radius, configured to slidably move along the first longitudinal axis of the curved channel and rotatable about the curved channel; and
a collar with a passageway having a lower portion, the lower portion having a generally planar surface so as to be slidably engaged with the lower surface of the first engagement portion and allow translation of the first arm relative to the collar along the first longitudinal axis and that engages the first hemispherical portion to allow rotation of the second arm relative to the collar in at least two planes and to prevent translation of the second arm relative to the collar along the second longitudinal axis; and wherein the collar includes a concave inner surface having a radius similar to the fist radius of the first hemispherical portion and
an adjustment member within an aperture of the collar that adjusts a clamping force on the first engagement portion and the second engagement portion to increase an amount of friction between at least one of the first engagement portion and the passageway, the first hemispherical portion and the passageway so as to fix the first hemispherical portion to a desired position along the predetermined length of the curved channel.
12. The apparatus of claim 11 , wherein the passageway includes the concave inner surface configured to retain the first hemispherical portion.
13. The apparatus of claim 11 , wherein the aperture in the collar extends through an upper portion and a lower portion of the collar that are offset from the passageway and the first and second longitudinal axes of the first and second arms respectively.
14. The apparatus of claim 11 , wherein the adjustment member extends through the aperture without contacting the first arm and the second arm.
15. The apparatus of claim 11 , wherein the aperture does not intersect the passageway.
16. The apparatus of claim 11 , wherein the adjustment member does not engage the first arm and the second arm.