SYSTEMS AND METHODS FOR MANIPULATING BONE

摘要

Systems and methods are disclosed in which a distraction sleeve can be attached to a bone anchor assembly to lock or limit the polyaxial degree of freedom of the bone anchor assembly and facilitate true parallel distraction. In some embodiments, the distraction sleeve can lock polyaxial movement of the bone anchor assembly without directly engaging the shank of the bone anchor assembly, without directly engaging the exterior of the receiver member of the bone anchor assembly, and/or without requiring that a rod or closure mechanism be installed in the bone anchor assembly. The distraction sleeve can be preloaded onto the bone anchor assembly prior to inserting the bone anchor assembly using a selectively detachable driver, thereby providing simplified, streamlined insertion and facilitating use with protection and/or retraction sheaths. Countertorque tubes, torque wrenches, and other related instrumentation are also disclosed herein.

主权项

1. A bone manipulation system, comprising:
a bone anchor assembly that includes a bone anchor implantable in bone, a receiver member that is movable relative to the bone anchor, and a compression cap that, when advanced distally within the receiver member, engages the bone anchor to limit or prevent movement between the bone anchor and the receiver member, the compression cap having first and second arms that define a recess therebetween for receiving a spinal fixation element; and a distraction sleeve having an elongate tubular body with a distal end that engages the first and second arms of the compression cap as the sleeve is advanced into the receiver member to urge the compression cap distally, wherein the distal end of the distraction sleeve rotates relative to the receiver member as the sleeve is advanced into the receiver member and wherein a proximal end of the distraction sleeve protrudes from the receiver member and defines an inner lumen for receiving an instrument.