| 摘要 |
A fixation system for use with a fixation member having a top surface, a bottom surface and a bore defined therethrough. The fixation system comprises a fastener having an elongated shaft, a headed portion engagable with the bore at the top surface of the fixation member when the shaft extends therethrough, a first diameter non-threaded portion adjacent said headed portion, and a second larger diameter threaded portion remote from said headed portion. The fixation system also comprises an apparatus for preventing the fastener from backing out of said bore when said shaft extends therethrough including an annular collar having an initial inner diameter deformably sizable to slidingly receive the elongated shaft threrethrough and an outer diameter sized to engage said bottom surface of said fixation member. The collar is formed of a material such that said inner diameter shrinks to a final diameter less than the second diameter threaded portion of the fastener in response to a change in temperature thereof to thereby trap said fixation member between said collar and the headed portion of the fastener. |
