Compression hip screw
First Claim
1. A compression hip screw for fixation of a femoral head in a femur, the compression hip screw comprising a plate adapted for attachment to the femur, the plate including a barrel extending into an opening, the opening being formed in the femur and the femoral head, the barrel defining a bore extending therethrough, a first member coupled to the femoral head and extending into the barrel bore, a second member cooperating with the first member to oppose withdrawal of the barrel from the opening, and locking means cooperating with the first member and the barrel to limit rotation between the barrel and the first member, characterized in that the barrel defines an inferior side adjacent the portion of the plate attached to the femur and a superior side remote from the plate portion, the locking means comprising a groove defined in the barrel on the inferior side and a pin disposed in the groove, the pin extending into the barrel bore, and the first member defining a recess for receiving the pin whereby the pin forms an interference fit with the first member and the barrel whereby rotation is limited therebetween.
3 Assignments
0 Petitions
Accused Products
Abstract
A compression hip screw comprises a plate with a barrel, a lag screw adapted for fixation to a femoral head, a compression screw engageable with the lag screw to retain the plate and barrel attached with the femur and a locking pin to oppose rotation between the barrel and the lag screw. The locking pin is disposed on one side of the barrel to provide a robust structure for the lag screw and enable the barrel to transmit loads developed during the walking mode for the hip.
201 Citations
12 Claims
- 1. A compression hip screw for fixation of a femoral head in a femur, the compression hip screw comprising a plate adapted for attachment to the femur, the plate including a barrel extending into an opening, the opening being formed in the femur and the femoral head, the barrel defining a bore extending therethrough, a first member coupled to the femoral head and extending into the barrel bore, a second member cooperating with the first member to oppose withdrawal of the barrel from the opening, and locking means cooperating with the first member and the barrel to limit rotation between the barrel and the first member, characterized in that the barrel defines an inferior side adjacent the portion of the plate attached to the femur and a superior side remote from the plate portion, the locking means comprising a groove defined in the barrel on the inferior side and a pin disposed in the groove, the pin extending into the barrel bore, and the first member defining a recess for receiving the pin whereby the pin forms an interference fit with the first member and the barrel whereby rotation is limited therebetween.
- 7. A compression hip screw for fixation of a femoral head in a femur bone, the compression hip screw comprising a plate adapted for attachment to the femur, the plate leading superiorly to a barrel extending into an opening, the opening being provided on the femur and the femoral head, a pair of members cooperating with the femoral head and the barrel to retain the femoral head connected to the femur and oppose withdrawal of the barrel from the opening, the barrel superior side being loaded in tension during a normal walking mode for the hip, the barrel inferior side being loaded in compression during a normal walking mode for the hip, and locking means cooperating with one of the pair of members and the barrel to oppose rotation between the one member and the barrel, the locking means cooperating with the barrel solely on the inferior side and substantially along a length of the barrel in order to provide a uniform cylindrical profile of constant radial thickness for the superior side of the barrel in the absence of holes through the radial thickness, whereby the tension imparted of the superior side of the barrel is spread evenly over the uniform cylindrical profile of constant radial thickness.
- 11. In a compression hip crew for fixation of a femoral head in a femur, a plate adapted for attachment to the femur and including a barrel disposed within an opening formed in the femur, the barrel defining a bore therethrough for receiving a lag screw which threadably couples with the femoral head, a compression screw engageable with the lag screw and abutting the plate to oppose separation of the plate from the lag screw, and locking means cooperating with the lag screw and the barrel to prevent rotation therebetween, characterized in that the lag screw is slotted at a distal end with a pair of recesses extending substantially along the length of the lag screw, the barrel includes a single groove extending longitudinally on an inferior side, and the locking means comprises a pin separate from the barrel and disposed within one of the pair of recesses and within the single groove, the pin extending substantially over the length of the barrel to provide a robust interference between the lag screw and the barrel to prevent rotation and the pin being confined to the one recess and single groove for a compact arrangement between the lag screw and the barrel.
Specification