Shortening palm screw

1. An implant for treating a bone, comprising:

an outer sleeve extending longitudinally from a proximal end to a distal end and including a lumen extending therethrough; and

an inner element sized and shaped to be slidably received within the lumen of the outer sleeve, the inner element extending longitudinally from a proximal end received within the lumen to a distal end, the inner element housing a bone-engaging element therein, the implant is movable from an expanded configuration in which the inner element is in a distal-most position relative to the outer sleeve and the bone-engaging element extends out of the distal end of the inner element, to a shortened configuration in which the inner element slides proximally relative to the outer element and the bone-engaging element is housed within the inner element.

2. The implant of claim 1 , wherein a coupling arrangement between the inner element and the outer sleeve is configured to permit a range of shortening of the implant and to transfer a rotational force applied to the outer sleeve to the inner element.

3. The implant of claim 2 , wherein the coupling arrangement comprises a pin extending into a groove, the groove dimensioned to define the permitted range of shortening of the implant.

4. The implant of claim 3 , wherein the pin extends laterally from the outer sleeve into the groove.

5. The implant of claim 1 , wherein the proximal end of the outer sleeve includes a threading configured to engage a corresponding threading of a bone plate hole.

6. The implant of claim 1 , wherein the bone-engaging element includes a plurality of wires movable between an insertion configuration in which distal ends of the wires are housed within a lumen of the inner element and a deployed configuration in which the distal ends of the wires extend distally out of an opening at the distal end of the inner element to penetrate a portion of bone adjacent to the distal end of the inner element, the wires being biased to assume an anchoring shape when extended out of the elongated body.

7. The implant of claim 6 , wherein the plurality of wires are connected to the inner element via a connector bushing longitudinally slidable within the lumen of the inner element.

8. The implant of claim 6 , wherein, when in the anchoring shape, the wires extend distally from the inner element a first distance and then curve radially away from a longitudinal axis of the implant.

9. The implant of claim 8 , wherein, when in the anchoring shape, the wires curve through an angle of between approximately 90° and 180°.