Abstract: A fastener with improved threading for resisting multi-axial forces and off-axis loading scenarios is provided. The fastener may include a shaft and a plurality of helical threads disposed about the shaft. The plurality of helical threads may include a first helical thread and a second helical thread adjacent the first helical thread. The first helical thread may include a first concave undercut surface and a first convex undercut surface. The second helical thread may include a second concave undercut surface and a second convex undercut surface. When the fastener is viewed in section along a plane intersecting a longitudinal axis of the shaft, the first concave undercut surface and the second convex undercut surface may be oriented toward the proximal end of the shaft, and the first convex undercut surface and the second concave undercut surface may be oriented toward the distal end of the shaft.

Abstract: A joint replacement implant may include a shaft having a proximal end, a distal end, and a threaded shaft portion, a helical thread disposed about the shaft defining a length of the threaded shaft portion and including a concave undercut surface angled towards one of the proximal end and the distal end of the shaft, and an attachment feature at the proximal end of the joint replacement implant. The attachment feature may be configured to couple an articular member to the joint replacement implant. The articular member may include at least one artificial articular surface that may be shaped to replace at least a portion of a natural articular surface of a joint of a patient.

Abstract: A pedicle bone fastener may include a shaft, a helical thread, and an integrated attachment feature. The shaft may include a proximal end, a distal end, and a longitudinal axis. The helical thread may be disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft. The helical thread may include a first undercut surface and a second undercut surface. The first undercut surface may be angled toward one of the proximal end and the distal end of the shaft and the second undercut surface may be angled toward the other one of the proximal end and the distal end of the shaft. The integrated attachment feature may be disposed at the proximal end of the shaft and configured to be adjustably secured to a spinal stabilization implement.

Abstract: A bone disunion instrument system may include a first bone pin, a second bone pin, and a guide block. The guide block may include first and second bone pin holes to receive the first and second bone pins, and a window intermediate the first and second bone pin holes. The first bone pin may be anchored in a first bone portion and inserted through the first bone pin hole, and the second bone pin may be anchored in a second bone portion and inserted through the second bone pin hole to impart a compression or distraction force on a bone disunion between the first and second bone portions. The window formed through the guide block may provide access for an implant placed through the window to stabilize the bone disunion while the bone disunion is placed under a compression or distraction force.

Abstract: 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.

Abstract: 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.

Abstract: A bone implant may include a shaft having a proximal end, a distal end, a longitudinal axis, a proximal shaft portion, and a distal shaft portion. The proximal shaft portion may include a first minor diameter, and a first helical thread disposed about the proximal shaft portion defining a first major diameter. The first helical thread may include a first concave undercut surface. The distal shaft portion may include a second minor diameter, and a second helical thread disposed about the distal shaft portion defining a second major diameter. The second helical thread may include a second concave undercut surface. The first and second concave undercut surfaces may be angled towards the distal end of the shaft. The second minor diameter may be smaller than the first minor diameter and the second major diameter may be smaller than the first major diameter.

Abstract: A pedicle bone fastener may include a shaft, a helical thread, and an integrated attachment feature. The shaft may include a proximal end, a distal end, and a longitudinal axis. The helical thread may be disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft. The helical thread may include a first undercut surface and a second undercut surface. The first undercut surface may be angled toward one of the proximal end and the distal end of the shaft and the second undercut surface may be angled toward the other one of the proximal end and the distal end of the shaft. The integrated attachment feature may be disposed at the proximal end of the shaft and configured to be adjustably secured to a spinal stabilization implement.

Abstract: A method of preventing bone blowout may include forming a hole in a bone, the hole having a bone hole diameter, and inserting a bone fastener into the hole. The bone fastener may include a shaft having a minor diameter and a helical thread. The helical thread may be disposed about the shaft and may include a first undercut surface and a second undercut surface. The first undercut surface may be angled toward one of the proximal end and the distal end of the shaft, and the second undercut surface may be angled toward the other one of the proximal end and the distal end of the shaft. The minor diameter of the shaft may not be greater than 5% larger the bone hole diameter.

Abstract: A process of forming a fastener with improved threading to resist multi-axial forces and off-axis loading scenarios is provided. The process may include placing first and second mill tools adjacent a shaft of the fastener having a proximal end and a distal end, rotating the shaft and the first and second mill tools, and translating the first and second mill tools along at least part of a length of the shaft to form: a first concave undercut surface oriented toward the proximal end, a first convex undercut surface oriented toward the distal end, a second concave undercut surface oriented toward the distal end, and a second convex undercut surface oriented toward the proximal end.

Abstract: A fastener with improved threading for resisting multi-axial forces and off-axis loading scenarios is provided. The fastener may include a shaft and a plurality of helical threads disposed about the shaft. The plurality of helical threads may include a first helical thread and a second helical thread adjacent the first helical thread. The first helical thread may include a first concave undercut surface and a first convex undercut surface. The second helical thread may include a second concave undercut surface and a second convex undercut surface. When the fastener is viewed in section along a plane intersecting a longitudinal axis of the shaft, the first concave undercut surface and the second convex undercut surface may be oriented toward the proximal end of the shaft, and the first convex undercut surface and the second concave undercut surface may be oriented toward the distal end of the shaft.

Abstract: A shoulder implant system includes a humeral stem implant, a humeral neck implant component, a humeral head implant component, and a glenoid implant. The humeral stem implant has a fin coupled to an exterior surface thereof that is inwardly tapered at an angle relative to vertical. At least a portion of the fin forms a wedge that directly engages and compacts cancellous bone during installation of the humeral stem implant. The humeral neck implant component is configured to be coupled with the humeral stem implant. The humeral head implant component is configured to be coupled to the humeral stem implant via the humeral neck implant component. The glenoid implant has a plurality of peripheral pegs. Each of the peripheral pegs has a plurality of sets of resilient lobes.

Abstract: A shoulder implant system includes a humeral stem implant, a humeral neck implant component, a humeral head implant component, and a glenoid implant. The humeral stem implant has a fin coupled to an exterior surface thereof that is inwardly tapered at an angle relative to vertical. At least a portion of the fin forms a wedge that directly engages and compacts cancellous bone during installation of the humeral stem implant. The humeral neck implant component is configured to be coupled with the humeral stem implant. The humeral head implant component is configured to be coupled to the humeral stem implant via the humeral neck implant component. The glenoid implant has a plurality of peripheral pegs. Each of the peripheral pegs has a plurality of sets of resilient lobes.

Abstract: A shoulder implant system includes a humeral stem implant, a humeral neck implant component, a humeral head implant component, and a glenoid implant. The humeral stem implant has a fin coupled to an exterior surface thereof that is inwardly tapered at an angle relative to vertical. At least a portion of the fin forms a wedge that directly engages and compacts cancellous bone during installation of the humeral stem implant. The humeral neck implant component is configured to be coupled with the humeral stem implant. The humeral head implant component is configured to be coupled to the humeral stem implant via the humeral neck implant component. The glenoid implant has a plurality of peripheral pegs. Each of the peripheral pegs has a plurality of sets of resilient lobes.