PRESSON PEDICLE SCREW VARIATIONS
Variations on improved pedicle screw coupling assemblies, along with methods for use of such assemblies provide improved functional characteristics over existing devices. A coupling assembly is capable of providing rigid fixed attachment between a pedicle screw fully seated to underlying bone and a member extending between adjacent pedicle screws. The coupling assembly includes a pedicle screw having a threaded shaft and a head portion. The head portion includes a driving feature and a proximally oriented bore having a bore diameter. In one version, the coupling assembly includes a member adapted to extend between adjacent pedicle screws. The member includes a protrusion adapted for insertion into the bore of the pedicle screw, the protrusion having a protrusion diameter that is larger than the bore of the pedicle screw head portion. In another version, the coupling assembly includes a spherical bore in the screw head. Additional implementations are described.
1 . A coupling assembly comprising:
a first pedicle screw comprising:
a threaded shaft; and
a head portion comprising:
a driving feature; and
a proximally oriented bore; and
a member adapted to extend between the first pedicle screw and a second pedicle screw, the member comprising:
a first protrusion adapted for insertion into the bore of the first pedicle screw, the protrusion having a protrusion diameter that is larger than a portion of the proximally oriented bore.
2 . The coupling assembly of claim 1 , wherein a distal end portion of the first protrusion that is configured to be received within a distal end portion of the proximally oriented bore comprises a contiguous surface.
3 . The coupling assembly of claim 1 , wherein the first protrusion is integrally coupled to a first end portion of the member.
4 . The coupling assembly of claim 3 , wherein the member further comprises a second protrusion that is integrally coupled to a send end portion of the member.
5 . A coupling assembly comprising:
a pedicle screw comprising:
a threaded shaft; and
a head portion comprising:
a driving feature;
an external bore-engaging surface defining an external diameter of the head portion; and
a proximally oriented screw bore having a proximal portion defining an opening having a continuous perimeter with a first, narrower internal width and a medial portion with a second, broader internal width; and
a member adapted to extend between adjacent pedicle screws, the member comprising:
a female member comprising a receiving bore adapted to receive the head portion of the pedicle screw, the receiving bore having an inner diameter that is smaller than the external diameter of the head portion.
6 . The coupling assembly of claim 5 , wherein the continuous perimeter of the opening is generally circular.