Orthopaedic surgical instrument for extracting a femoral stem component in a hip replacement surgical procedure and method of using the same
An orthopaedic surgical instrument for extracting an implanted femoral stem component includes a clamping jaw configured to the clamp the femoral component in the instrument's extraction loop. A leaf spring applies a spring bias to the clamped femoral component. A method of using an orthopaedic surgical instrument to extract an implanted femoral component is also disclosed.
1 . An orthopaedic surgical instrument for extracting a femoral stem component during an orthopaedic hip replacement surgical procedure on a patient's femur, the orthopaedic surgical instrument comprising:
an elongated body having (i) a connector formed in a proximal end of the elongated body, the connector being configured to fit into a chuck of an automated surgical impactor, and (ii) an extraction loop formed in a distal end of the elongated body, the extraction loop has a bore that extends through the elongated body and is configured to receive a neck of the femoral stem component therein,
a locking lever having a pivot end pivotally coupled to the elongated body and an opposite latch end,
a clamping jaw slidably coupled to the elongated body, the clamping jaw being movable between (i) a clamped position in which the clamping jaw is extended toward the extraction loop, and (ii) a released position in which the clamping jaw is retracted away from the extraction loop,
a threaded drive assembly operatively coupled to the clamping jaw, the threaded drive assembly being operable to move the clamping jaw between its clamped position and its released position, and
a leaf spring having a first end pivotally coupled to the locking lever and a second end coupled to the clamping jaw,
wherein the threaded drive assembly includes a connecting link coupled to the first end of the leaf spring with a pivot pin, the connecting link being pivotally coupled to the locking lever via the pivot pin.
2 . The orthopaedic surgical instrument of claim 1 , wherein the threaded drive assembly comprises a drive screw rotatably coupled to the elongated body and a drive link slidably coupled to the elongated body, wherein:
the drive link is operatively coupled to the clamping jaw,
the drive screw has a socket defined in its proximal end and a threaded shaft extending distally away from the socket,
the drive link has a threaded bore formed therein,
the threaded shaft of the drive screw is positioned in the threaded bore of the drive link,
rotation of the drive screw in a first direction causes the drive link to be moved in the direction toward the extraction loop, and
rotation of the drive screw in a second, opposite direction causes the drive link to be moved in the direction away from the extraction loop.
3 . The orthopaedic surgical instrument of claim 1 , further comprising a pushbutton catch coupled to the elongated body, wherein the locking lever is movable between an unlocked position in which the latch end is spaced apart from the elongated body and a locked position in which the latch end is captured by the pushbutton catch.
4 . The orthopaedic surgical instrument of claim 3 , further comprising a compression spring positioned between the locking lever and the elongated body, the compression spring biases the locking lever into its unlocked position.
5 . The orthopaedic surgical instrument of claim 3 , wherein the leaf spring asserts a spring bias on the neck of the femoral stem component when the neck of the femoral stem component is positioned in the extraction loop and the locking lever is positioned in its locked position.
6 . The orthopaedic surgical instrument of claim 1 , wherein the clamping jaw asserts a clamping force on the neck of the femoral stem component when the neck of the femoral stem component is positioned in the extraction loop and the clamping jaw is positioned in its clamped position.
7 . The orthopaedic surgical instrument of claim 1 , wherein the second end of the leaf spring is pivotally coupled to the clamping jaw.
8 . The orthopaedic surgical instrument of claim 1 , further comprising a knuckle link pivotally coupled to the elongated body, wherein:
the second end of the leaf spring is pivotally coupled to a first end of the knuckle link, and
a second end of the knuckle link is coupled to the clamping jaw.
9 . The orthopaedic surgical instrument of claim 1 , wherein the locking lever has a slot formed therein, and wherein the pivot pin is located in the slot to translate within the slot in the direction toward, and the direction away from, the extraction loop.
10 . The orthopaedic surgical instrument of claim 1 , wherein the locking lever has a connection point located between the pivot end and the latch end thereof, and the first end of the leaf spring and the connecting link are coupled to the locking lever at the connection point.
11 . An orthopaedic surgical instrument for extracting a femoral stem component during an orthopaedic hip replacement surgical procedure on a patient's femur, the orthopaedic surgical instrument comprising:
an elongated body having (i) a connector formed in a proximal end of the elongated body, the connector being configured to fit into the chuck of an automated surgical impactor, and (ii) an extraction loop formed in a distal end of the elongated body, the extraction loop has a bore that extends through the elongated body and is configured to receive a neck of the femoral stem component therein,
a locking lever having a pivot end pivotally coupled to the elongated body and an opposite latch end,
a drive link slidably coupled to the elongated body, the drive link being movable within the elongated body in a direction toward, and a direction away from, the extraction loop,
a connecting link having a first end pivotally coupled to the locking lever and a second end pivotally coupled to the drive link,
a clamping jaw slidably coupled to the elongated body, the clamping jaw being movable between (i) a clamped position in which the clamping jaw is extended toward the extraction loop, and (ii) a released position in which the clamping jaw is retracted away from the extraction loop, and
a leaf spring having a first end pivotally coupled to the locking lever and a second end coupled to the clamping jaw,
wherein (i) movement of the drive link in the direction toward the extraction loop causes the clamping jaw to be positioned in its clamped position, and (ii) movement of the drive link in the direction away from the extraction loop causes the clamping jaw to be positioned in its released position.
12 . The orthopaedic surgical instrument of claim 11 , further comprising a drive screw rotatably coupled to the elongated body, wherein:
the drive screw has a socket defined in its proximal end and a threaded shaft extending distally away from the socket,
the drive link has a threaded bore formed therein,
the threaded shaft of the drive screw is positioned in the threaded bore of the drive link,
rotation of the drive screw in a first direction causes the drive link to be moved in the direction toward the extraction loop, and
rotation of the drive screw in a second, opposite direction causes the drive link to be moved in the direction away from the extraction loop.
13 . The orthopaedic surgical instrument of claim 11 , wherein:
the locking lever has a slot formed therein, and
the first end of the leaf spring and the first end of the connecting link are coupled to one another by a pivot pin that translates within the slot of the locking lever.
14 . The orthopaedic surgical instrument of claim 11 , further comprising a pushbutton catch coupled to the elongated body, wherein the locking lever is movable between an unlocked position in which the latch end is spaced apart from the elongated body and a locked position in which the latch end is captured by the pushbutton catch.
15 . The orthopaedic surgical instrument of claim 14 , further comprising a compression spring positioned between the locking lever and the elongated body, the compression spring biases the locking lever into its unlocked position.
16 . The orthopaedic surgical instrument of claim 14 , wherein the leaf spring asserts a spring bias on the neck of the femoral stem component when the neck of the femoral stem component is positioned in the extraction loop and the locking lever is positioned in its locked position.
17 . The orthopaedic surgical instrument of claim 11 , wherein the clamping jaw asserts a clamping force on the neck of the femoral stem component when the neck of the femoral stem component is positioned in the extraction loop and the clamping jaw is positioned in its clamped position.
18 . The orthopaedic surgical instrument of claim 11 , wherein the second end of the leaf spring is pivotally coupled to the clamping jaw.
19 . The orthopaedic surgical instrument of claim 11 , further comprising a knuckle link pivotally coupled to the elongated body, wherein:
the second end of the leaf spring is pivotally coupled to a first end of the knuckle link, and
a second end of the knuckle link is coupled to the clamping jaw.