Method of dynamically compressing a fracture
View Patent ↗A system, devices and methods are provided for facilitating stabilization of periarticular fractures. The system includes a compression plate and one or more of a cerclage cable for encircling the bone and securing the compression plate to the bone, a crimp lug for securing the cable in tension relative to the bone and/or a plate, and a supplemental plate coupled to the compression plate and adapted to receive bicortical or unicortical bone screws to further secure the compression plate relative to the bone. In addition, the system includes a cable tensioner for temporarily retaining the cable in tension and then applying a tension to the cable until a desired compression is effected between a plate and bone and while a cable retaining structure is secured to the cable to retain the applied tension on the cable. Also provided is a jig for use with plates for minimally invasive fracture stabilization.
1. A method of dynamically compressing a fracture of a bone, comprising: a) providing a bone plate having an elongate shaft, the shaft defining, a first screw hole having a circular opening for receiving a bone screw therein so as to longitudinally fix said plate relative to the bone, a second screw hole having an elongate opening defining a first end and second end, and a screw ramp extending in a downward slope from said first end toward said second end and extending at least one half said length of said second screw hole, said screw ramp having an upper bevel surface and a lower sidewall, a flared recess opening to said upper surface and provided above said ramp adjacent said second end of said second screw hole, and a Longitudinally flared lower recess opening to said lower surface and provided beneath said first end and flaring in a direction opposite said upper recess; b) first driving a first bone screw into the first screw hole on a first side of the fracture to longitudinally fix the bone plate relative to the bone; c) second driving a second bone screw having a shaft and a head with a lower surface into the second screw hole on a second side of the fracture, the second bone screw located at the first end of the second screw hole and driven until the lower surface of the head enters into contact with the first end of the screw hole; and d) further driving the second bone screw to cause the ramp of the bone plate to displace under the head of the second bone screw and continuing to drive the second bone screw until the second bone screw contacts the second end of the second screw hole so as to draw the bone into compression across the fracture.
2. A method according to claim 1 , wherein:
said second bone screw has a screw head radial overhang defined as the difference between a radius of said screw head and a radius of a major diameter of the screw shaft, and said further driving causes said fracture to compress by a displacement of the bone plate relative to said second bone screw that is no less than twice said radial overhang of the second bone screw.
3. A method according to claim 2 , wherein:
the displacement is four times said radial overhang.
4. The method according to claim 1 , wherein the second screw hole has a long axis obliquely oriented relative to the center line, and including
positioning the bone plate on the bone such that the bone plate extends across the fracture with the first screw hole on a first side of the fracture line and the second screw hole on a second side of the fracture line, the long axis of the second screw hole oriented relatively more perpendicular to the fracture line than the center line of the bone plate.
5. The method according to claim 1 , wherein the second screw hole has a long axis axially oriented relative to the center line.