Transversely displacing structures in the body

A device for creating a cavity during spinal surgery, the device comprising:

• an inner body with a first end and a second end;
• an outer sleeve coaxial with the inner body, the outer sleeve movable relative to the inner body between a retracted position and an extended position;
• a trigger mechanism connected to the outer sleeve and configured to apply an axial force to the outer sleeve;
• a first strip of resilient material having a first end and a second end, the first end of the first strip of resilient material fixed in position relative to the outer sleeve;
• and
• a second strip of resilient material having a first end and a second end, the first end of the second strip of resilient material fixed in position relative to the outer sleeve;
• wherein the second ends of the first strip of resilient material and the second strip of resilient material are releasably engaged with the inner body when the outer sleeve is in its extended position and disengaged from the inner body when the outer sleeve is in its retracted position.