摘要:
A bone anchor locking device for receiving a bone anchor having a shank and an enlarged head, the device has a bone anchor, a dome and a conical split washer. The receiving portion has a base extending radially outward and inwardly to a wall. The dome has a center aperture sized to pass a bone anchor. The split washer has an inner conical surface sloped to slide and expand against at least a portion of the base on insertion of a bone anchor to allow a maximum diameter of a head of a bone anchor to pass and thereafter the split washer retracts overlying the maximum diameter of the head to prevent a bone anchor from backing out.
摘要:
An orthopedic fastener (10) has a head (50) and a shank (20). The shank (20) extends from the head (50) to a distal tip (11). The shank (20) has a leading end (1) adjacent the distal tip (11) and a trailing end (3) adjacent the head (50). An intermediate transition (2) is positioned between the leading (1) and trailing ends (3). The leading end (1) has first threads (40) with one or more self-tapping cutting grooves (41) extending adjacent the distal tip (11) and through a plurality of the first threads (40). The trailing end (3) has a second thread (60) extending toward the head (50) from the intermediate transition (2). The intermediate transition (2) has one or more second cutting grooves (61) extending from at least a first thread (40) in the intermediate transition (2) through at least one of said second threads (60) to initiate tapping of the second threads (60) into cortical bone. The first and second cutting grooves (41, 61) in combination with the threads (40, 60) form threads in the bone to hold the fastener (10).
摘要:
An orthopedic fastener has a head and a shank. The shank has a leading end portion adjacent a distal tip and a trailing end portion adjacent a head. An intermediate transition is positioned between the leading and trailing end portions. At the intermediate transition, the shank increases in diameter. The leading end portion has a first thread which optionally may include one or more self-tapping cutting grooves extending adjacent the distal tip and through a plurality of the first threads. The trailing end portion has second threads extending toward the head from the intermediate transition. The second threads of the trailing end portion are larger in outer diameter than the first threads in the leading end portion. The intermediate transition has one or more cutting grooves traversing the increasing diameter.
摘要:
Bone anchor assemblies having a large diameter for fixing a spinal connection element to bone and methods of assembly are described. The assembly includes a receiver member for receiving the spinal connection element, a bone-engaging shank for engaging bone and a sleeve member for retaining the head of the shank within the receiver member.
摘要:
A stabilizer for a bone anchor includes a tubular body having an outer wall and an inner wall and a plurality of projections spaced about and extending from the outer wall of the tubular body. The inner wall defines a lumen sized and shaped to receive a portion of the bone anchor and the projections are configured to engage bone to inhibit rotation of the stabilizer and distribute forces on the bone anchor to the bone.
摘要:
An instrument for inserting, adjusting and engaging an implant, such as a polyaxial screw of a spinal fixation system, includes at least one retratractable tab for engaging a corresponding recess on the implant and a shaft that moves relative to the retractable tab. The movable shaft selectively moves the tab between an expanded position for engaging the recess and a retracted position out of engagement with the recess. The shaft selectively engages a portion of the implant to rigidify the implant after the retractable tab engages the recess. The axially extending shaft may be disposed within an axially extending passageway of a body assembly. A rotatable collar surrounding the body assembly is coupled to the shaft for moving the shaft relative to the retractable tab.