Adjustable length strut apparatus for orthopaedic applications

Abstract

An adjustable-length orthopaedic strut apparatus having minimal x-ray absorption, the capability to produce small length adjustments with minimal axial backlash, and a body devoid of exposed threads, the apparatus having an outer telescoping strut element, an inner telescoping strut element, a threaded drive element rotationally mounted inside the outer telescoping strut element and engaging threads inside the inner telescoping strut element, and an input gear-train arranged to produce fine adjustment of the strut length by generating rotation of the threaded drive element that can be smaller than the input gear rotation. A preferred embodiment also includes compliant preload structures for reducing axial backlash between all moving elements, and one or more locking pins which can be selectively disengaged to adjust the compressive stiffness of the adjustable length strut.

Dependencies are inferred from the claim text.