An intervertebral implant may include a shaft having a proximal end, a distal end, a longitudinal axis, a minor diameter, and a helical thread disposed about the shaft along the longitudinal axis between the proximal end and the distal end of the shaft. The helical thread may include a major diameter and a concave undercut surface angled towards one of the proximal end and the distal end of the shaft. The intervertebral implant may be implanted within an intervertebral space between a superior vertebral body and an inferior vertebral body. A ratio of the major diameter to the minor diameter may be less than 1.50. The concave undercut surface may engage the superior vertebral body and the inferior vertebral body and may be shaped to resist at least one force transmitted between the superior vertebral body and the inferior vertebral body to stabilize the intervertebral space.

A bone disunion fastener may include a fastener shaft, a helical thread, and a bone staple. The helical thread may include a concave undercut surface oriented towards one end of the fastener shaft. The bone staple may include a first bone-engaging feature, a second bone-engaging feature, and a middle portion with an opening. The bone disunion fastener may be implanted along a disunion between a first bone portion and a second bone portion. The concave undercut surface may be shaped to resist at least one force transmitted between the first bone portion and the second bone portion to stabilize the disunion. The first bone-engaging feature may engage the first bone portion and the second bone-engaging feature may engage the second bone portion to couple the bone staple to the bone portions and resist at least one force transmitted between the bone portions to stabilize the disunion.

Disclosed are bone screw drill targeting guides and methods for using such targeting guides that are useful in surgical procedures for correcting hallux valgus deformity.

A stemless humeral head replacement system including a base plate and a humeral head implant. The base plate includes a bone facing side, an implant side opposite the bone facing side, a curvate perimeter, at least one fin protruding from the bone facing side a first distance and extending linearly a length along the bone facing side, and an implant engagement structure on the implant side. The humeral head implant includes a curvate implant surface and a base plate engagement structure opposite the curvate implant surface, the base plate engagement structure configured to couple to the implant engagement structure of the base plate.

A bone fixation system comprises a first fastener configured to anchor into a first vertebrae, a second fastener configured to anchor into a second vertebrae, and a set screw to retain the second fastener to the first fastener. The first fastener includes a shaft extending along a longitudinal axis and a head. The shaft includes a first cylindrical body. The head of the first fastener includes a second cylindrical body defining a passageway having an interior surface. The passageway defines a longitudinal axis that is different than the longitudinal axis of the shaft. The first cylindrical body of the shaft and the second cylindrical body of the head are angled relative to each other. A head of the second fastener is configured to engage the interior surface of the passageway of the head of the first fastener. The set screw retains the head of the second fastener in the passageway.

One aspect of the disclosure relates to a surgical instruments and surgical instrument guides, and associated methods. The surgical instrument may include: an elongated body having a distal end; a housing disposed at least partially within the elongated body and pivotably coupled to the elongated body; and an actuator engaged with a proximal end of the elongated body and operably associated with the housing such that the housing pivots about a pivot point upon actuation of the actuator. In another embodiment, the surgical instrument may include: an elongated body having a segmented distal tip; a guide barrel extending longitudinally within the elongated body, the guide barrel being substantially aligned with a bore within the segmented distal tip, wherein the segmented distal tip is configured to transition between an unexpanded configuration and an expanded configuration.

Systems and methods include solutions for fixation at the rib head for fractures and osteotomies adjacent to the rib head and transverse process. The disclosed rib plates, anchor systems, other implants, and instrumentation may also be applied to mid-rib fractures. The systems and methods may be used in the treatment of rib deformities, including the correction of rib hump deformity via thoracoplasty, as well as general corrections of chest and rib deformities. Systems and methods herein may be used in chest wall reconstructions due to trauma, cancer, or deformity.

Implant positioning devices for use with and assisting in positioning orthopaedic fixation devices (such as bone plates, etc.). An implant positioning device may include a body that has a fastener guide with slits in a first end of the fastener guide that form a retaining arm proximal to the first end of the fastener guide. The implant positioning device may also be coupled to a bone plate by a retaining beam positioned within the implant positioning device to facilitate ease of alignment and insertion of the fastener into a fastener apertures of the bone plate.

An implant for insertion into a disc space between vertebrae, wherein the implant includes a spacer portion, a plate portion coupled to the spacer portion, two bone fixation elements for engaging the vertebrae and a retention mechanism for preventing the bone fixation elements from postoperatively backing-out of the plate portion. The retention mechanism may be in the form of a spring biased snapper element that is biased into communication with the bone fixation elements so that once the bone fixation element advances past the snapper element, the snapper element is biased back to its initial position in which the snapper element interfaces with the bone fixation elements. Alternatively, the retention mechanism may be in the form of a propeller rotatable between a first position in which the bone fixation elements are insertable to a second position where the bone fixation elements are prevented from backing-out.

A surgical system for operating on a bone of a patient is described. The surgical system includes a reference device including one or more radiopaque markers, a first sensor configured to generate a first signal pertaining to orientation data of the reference device relative to a first coordinate system, a surgical instrument for coupling to an end effector, a second sensor configured to generate a second signal pertaining to orientation data of at least one of the end effector and the surgical instrument relative to a second coordinate system, and a navigation system. The navigation system is configured to determine an orientation of at least one of the end effector and the surgical instrument and superimpose a virtual representation of at least one of the end effector and the surgical instrument over the image based on the determined orientation and user input.