A technique is presented for computer-assisted planning of fastener placement in vertebrae that are to be stabilized by a pre-formed spinal rod, wherein two or more fasteners are to couple the rod to the vertebrae. At least one of a target shape of the spine and a shape of the pre-formed rod is defined in patient-specific shape data, a bone density of at least one of the vertebrae is defined in patient-specific bone density data, and patient-specific anatomical data are provided. A force distribution along a length of the rod may be calculated based on the shape data and the anatomical data. A planning result for fastener placement may be generated based on the bone density data of a given vertebra and the calculated force distribution.

A polyaxial rod connector comprising a body having an external surface. The connector body is intersected by an imaginary first reference plane and an imaginary second reference plane perpendicular to the first plane. The first body portion is on one side of the first plane and defines a first spinal rod passage defining a first passage axis and a first set screw opening defining a first axis perpendicular to the first passage axis. A second body portion is adjoined to the first body portion, defining a second spinal rod passage defining a plurality of passage axes, and a second set screw opening defining a second axis perpendicular to the plurality of second passage axes. The first passage axis is non-parallel with one of second passage axes in the second plane. Either the first or second spinal rod passage have an hourglass shaped cross-section parallel to the second plane.

This application describes surgical instruments and implants for building a posterior fixation construct across one or more segments of the spinal column. More specifically, the application describes instruments and methods for building a posterior fixation construct across one or more segments of the spinal column in a minimally invasive fashion.

A length adjustable modular screw includes a neck assembly and a shank. The neck assembly has proximal and distal ends and includes an expander component and a collet component that are slidably engagable by insertion of the expander component in a through channel of the collet component along a common axis. The length adjustable modular screw also includes a shank suitable for insertion and retention within a bone, the shank including a threaded portion between proximal and distal ends and a socket adapted to coaxially receive at least a portion of the distal end of the neck assembly. The length adjustable modular screw has a length that is selected by splaying at least a portion of the distal end of the engaged expander and collet components of the neck assembly within the socket of the shank.

A pivotal bone anchor system includes a plurality of bone anchors having rounded capture portions with circumferentially extending capture recesses. The system also includes multi-planar receiver sub-assemblies, each comprising a multi-planar receiver defining a cavity with a multi-planar seating surface, and a multi-planar pivoting retainer configured for multi-planar motion upon engagement with the multi-planar seating surface and to snap into a capture recess to capture a bone anchor within the multi-planar receiver. The system further includes uni-planar receiver sub-assemblies, each comprising a uni-planar receiver defining a cavity with a uni-planar seating surface, and a uni-planar pivoting retainer configured for uni-planar motion upon engagement with the uni-planar seating surface and to snap into a capture recess to capture a bone anchor within the uni-planar receiver. The capture portions of the bone anchors are configured for capture by either a multi-planar or uni-planar receiver sub-assembly without further modification or adjustment.

Embodiments are directed to spinal treatments and, more particularly, to a fenestrated pedicle nail, wherein the pedicle nail performs as an anchored system for pedicle instrument constructs that prevents fracturing from over-compressing of bone of poor quality. Embodiments include a pedicle nail comprising a shank and a nail head. The shank may comprise a proximal end and a distal bone engagement end. The nail head may be disposable on the proximal end of the shank, wherein the nail head may threadably engage the proximal end thereof. The nail head may have external bone threads.

The present invention is an implant for bone. The current implant is particularly useful in spinal surgical procedures.

A pivotal bone anchor assembly includes a shank with a head, an anchor portion, and a neck extending between the head and the anchor portion, and a receiver with upright arms defining a channel for receiving a rod and a central bore extending downward to a lower portion of the receiver. The assembly also includes a retaining structure rotatably coupled with the receiver with an internal seating structure pivotally supporting the head while providing for independent rotation of the shank prior to locking the assembly with the rod and a closure. The retaining structure includes an external surface and a slot extending between the seating structure and the external surface with a concave cut-out configured to closely receive the neck so as to provide for increased articulation between the shank and the receiver along the slot, and with the shank and the retaining structure being rotatable together around a centerline axis to align the increased articulation in any radial direction around the circumference of the receiver.

A pedicle fixation system (10) may include a first fastener (12) and a second fastener (14). The first fastener (12) may include a first shank (40) extending along a first fastener axis (41) and a channel (52) extending along a skew axis (51). The skew axis (51) may be transverse to the first fastener axis (41) and the channel (52) may have a channel diameter perpendicular to the skew axis (51). The second fastener (14) may extend through the channel (52) and include a second shank (60) extending along a second fastener axis (63). At least a distal part of the second shank (60) may have a second fastener diameter perpendicular to the second fastener axis (63). The second fastener diameter may be smaller than the channel diameter.

A polyaxial bone screw assembly includes a receiver, a shank, an articulation structure for retaining the shank in the receiver and a compression insert for engagement with a longitudinal connecting member such as a rod. The articulation structure includes substantially spherical convex and concave surfaces that slidably engage both shank and receiver surfaces to provide compound articulation between the receiver and the shank. The receiver includes inwardly directed spring tabs engaging the insert and prohibiting rotation of the insert within the receiver.