Distal bone anchors for bone fixation with secondary compression

摘要

There is disclosed a bone fixation device (512), comprising:
an elongate body (28 having a proximal end (30) and a distal end (32), the elongate body (28) comprising a first portion (536) and a second portion (538);
a cancellous bone anchor (34) on the distal end (32);
a proximal anchor (36) axially movably carried on the body (28);
an anti-rotational structure on the first portion (536) of the body (28), the anti-rotational structure preventing rotational movement of the first portion (536) of the body (28) with respect to the proximal anchor (36); and
complimentary surface structures (554, 558) in between the body (28) and the proximal anchor (36) that permit advancing the proximal anchor (36) in the distal direction to tighten the fixation device (512) but that resist axial proximal movement of the proximal anchor (36).