Locking system for femoral neck fracture fixation
A fixation device for providing rotation stability to a femoral neck fracture. The device includes a bone plate having at least one opening, a compression screw housing extendable through the opening of the bone plate, a compression screw being at least partially disposed within the bore of the housing and selectively moveable through the bore, and a collapsible and expandable anchoring member coupled to the compression screw. The anchoring member is configured to transition between a collapsed condition and an expanded condition upon advancement of the anchoring member from the compression screw housing to rotationally stabilize the compression screw within a femur.
1 . A fixation device for stabilizing fractured bone portions comprising:
a housing having a proximal end, a distal end opposite the proximal end and a bore extending between the proximal and distal ends, the housing defining a longitudinal axis and a length from the proximal end to the distal end;
an actuator being at least partially disposed within the bore of the housing and selectively moveable through the bore, the actuator having expanding legs; and
a first anchoring member coupled to the actuator and configured to transition between a first condition in which a portion of the first anchoring member has a first distance from the longitudinal axis and a second condition in which the portion of the first anchoring member has a second distance from the longitudinal axis, the second distance being greater than the first distance,
wherein the housing maintains the length and is shaped to prevent the actuator from backing out of the housing upon expansion of the expanding legs.
2 . The fixation device of claim 1 , wherein the portion of the first anchoring member transitions from the first condition to the second condition to allow the portion of the first anchoring member to engage bone and assist in axially and rotationally securing the fractured bone portions.
3 . The fixation device of claim 1 , wherein the housing includes a protrusion which is configured to prevent the actuator from backing out of the housing.
4 . The fixation device of claim 3 , wherein the protrusion is a stopper extending radially inward from an inner surface of the housing.
5 . The fixation device of claim 1 , wherein the actuator is a compression screw.
6 . The fixation device of claim 1 , further comprising a wedge adapted to transition the first anchoring member from the first condition to the second condition.
7 . The fixation device of claim 6 , further comprising a second anchoring member coupled to the actuator and configured to transition between a first condition in which a portion of the second anchoring member has a first distance from the longitudinal axis and a second condition in which the portion of the second anchoring member has a second distance from the longitudinal axis, the second distance being greater than the first distance, wherein the wedge is adapted to transition the second anchoring member from the first condition to the second condition.
8 . The fixation device of claim 7 , wherein the wedge is conical and the first and second anchoring members are pivotal arms, and wherein the wedge is configured to engage the pivotal arms to force the pivotal arms to radially expand into surrounding bone.
9 . A fixation device for stabilizing fractured bone portions comprising:
a housing having a proximal end, a distal end opposite the proximal end and a bore extending between the proximal and distal ends, the housing defining a longitudinal axis;
an actuator being at least partially disposed within the bore of the housing and moveable distally through the bore, the actuator having an expandable portion;
a first anchoring member coupled to the actuator and configured to transition between a first condition in which a portion of the first anchoring member has a first distance from the longitudinal axis and a second condition in which the portion of the first anchoring member has a second distance from the longitudinal axis, the second distance being greater than the first distance; and
a wedge configured to be inserted axially into the housing to expand the expandable portion,
wherein the expandable portion is configured to prevent the actuator from backing out of the housing upon expansion and the housing includes a ledge extending radially inward from an inner surface of the housing configured to engage the expandable portion to prevent proximal movement of the actuator, the ledge defining a gap therebetween spanning a first distance, wherein an outer diameter of the expandable portion in an expanded condition defines a second distance greater than the first distance.
10 . The fixation device of claim 9 , further comprising a wedge configured to actuate the expandable portion.
11 . The fixation device of claim 10 , wherein the wedge is conical in shape having a diameter which tapers in the axial direction.
12 . The fixation device of claim 9 , further comprising a second anchoring member coupled to the actuator and configured to transition between a first condition in which a portion of the second anchoring member has a first distance from the longitudinal axis and a second condition in which the portion of the second anchoring member has a second distance from the longitudinal axis, the second distance being greater than the first distance, the fixation device further comprising a wedge adapted to transition the first anchoring member from the first condition to the second condition and the second anchoring member from the first condition to the second condition.
13 . The fixation device of claim 12 , wherein the wedge is conical and the first and second anchoring members are pivotal arms, and wherein the wedge is configured to engage the pivotal arms to force the pivotal arms to radially expand into surrounding bone.
14 . A fixation device for stabilizing fractured bone portions comprising:
a housing having a proximal end, a distal end opposite the proximal end and a bore extending between the proximal and distal ends, the housing defining a longitudinal axis;
an actuator being at least partially disposed within the bore of the housing and moveable distally through the bore, the actuator having an expandable portion;
a first anchoring member coupled to the actuator and configured to transition between a first condition in which a portion of the first anchoring member has a first distance from the longitudinal axis and a second condition in which the portion of the first anchoring member has a second distance from the longitudinal axis, the second distance being greater than the first distance; and
a second anchoring member coupled to the actuator and configured to transition between a first condition in which a portion of the second anchoring member has a first distance from the longitudinal axis and a second condition in which the portion of the second anchoring member has a second distance from the longitudinal axis, the second distance being greater than the first distance, the fixation device further comprising a wedge adapted to transition the first anchoring member from the first condition to the second condition and the second anchoring member from the first condition to the second condition,
wherein the expandable portion is configured to prevent the actuator from backing out of the housing upon expansion.
15 . The fixation device of claim 14 , wherein the wedge is conical and the first and second anchoring members are pivotal arms, and wherein the wedge is configured to engage the pivotal arms to force the pivotal arms to radially expand into surrounding bone.