Presentation on theme: "Load the Crimp into the jaws of the Crimper/Tensioner instrument."— Presentation transcript:
Load the Crimp into the jaws of the Crimper/Tensioner instrument.
Align the tensioning spools Rotate the hex by hand until the black line on the spool is in line with the handle of the instrument, as shown below.
Rotate outer collars to line up the holes in the spools. Each collar must be rotated individually so that the hole in the collar corresponds with the black line.
Install all 4 cables Cables should be placed in a figure of eight. The first two cables will bear the majority of the pressure, and should be placed close together. The remaining two may be spaced evenly on the remaining sternum. (The figure below shows the end result) When threading the figure eight, the point where the cables cross may be configured to be on top of (as shown), or beneath the sternum with equal success. Depending on surgeon preference, cables may be threaded around the sternum, through the intercostal spaces (peri-sternal), or directly through the bone (trans-sternal).
TIP! When cutting the needle off the end of the cable, it is important that the cut is made on the wire leader and not the cable itself. If the cable is cut, the end will fray, making it difficult to thread the end through the crimp or the tensioning spools.
Approximate the sternum and tension cables 1.Start with cable #1 at the manubrium. Approximate the sternum and apply tension. Do not crimp yet. 2.Using the second tensioner/crimper instrument, tighten cable #3, near the middle of the sternum. When satisfied with the tension of the #3 cable, go back to the #1 cable and apply final desired tension. Double check to ensure that number 3 is still satisfactorily tight and then crimp both. 3.It is important to strive for the same tension on each cable! Do not crimp until satisfied that each cable is tightened to the same degree. 4.Repeat this process with cables 2 and 4. 1. 2. 3. 4.
TIP! While tensioning each individual cable, it is important to also periodically pull up firmly while grasping the handle of the entire instrument. This ensures that no slack is occurring beneath the sternum, and also provides a visual guideline of the tension applied. When the cable is tight enough, the crimp will only lift slightly off the sternum when lifting the instrument.
TIP! Avoid Crossing the cables – This can happen occasionally where the end of the cable exits the crimp. If the cables cross, they can jam at the edge of the crimp, not allowing the cable to slide and tighten. Because of this, the tension scale will show that the cable is tight, when in fact it may not be. If further tensioning attempts are made at this point, the cable may break. If a cable ever breaks during tensioning, the cables almost surely were crossed.
Tension Scale There is no “recommended” tension for the cable. The tensioning housing contains a spring which allows for some “give” while tightening the cable. Always be aware of the possibility of “bottoming out” the scale. Once the spring runs out of travel, the potential of pulling the cable through the bone increases. Although the scale is helpful in determining relative tension between constructs, the ultimate tension is usually achieved through tactile assessment.