Basic Application Steps for Linear SK™ ESF System
Do the basic application steps of the SK™ ESF device differ from the KE device?
No, the basic application steps are the same; however, using SK™ components makes frame construction much easier due to the ability to add or subtract clamps at any time and place multiple pin sizes directly through the pin-gripping bolt. In addition, the secondary bolt is designed to hold the clamp in place during pre-drilling and pin placement thus assuring that pins are accurately placed through the pre-drilled hole.
What is the first step in application of the ESF frame?
After approximate reduction of the fracture, a single pin is placed in the major proximal fragment and a single pin is placed into the major distal fragment. All fixator pins are placed through liberal release incisions. A connecting rod is secured to these first two pins using SK™ single clamps. One can pre-place empty clamps onto the rod (faster) or place them one at a time later (less crowded.) Accuracy of reduction is rechecked and adjusted if necessary. Some difficulty in maintaining reduction may occur until additional pins are added to stabilize the environment.
Is there a sequence and technique for placement of subsequent pins?
Typically, the third and fourth pins placed into an ESF frame are the two pins on each side and closest to the fracture. This is not mandatory; however, it is easier to verify accuracy of reduction and insures good pin placement. These pins are placed via liberal release incisions and through pre-drilled holes. Placing the SK™ clamp over the area of soft tissue release, and using the secondary bolt to secure it in perfect alignment for the desired drill hole and pin position, ensures correct targeting and pin placement. Next, the appropriately sized drill sleeve is passed through the primary clamp bolt to protect the soft tissue as the bone is pre-drilled. One must be careful not to crush the thin walled drill sleeve by tightening the primary clamp bolt more than just enough to hold the sleeve in position. Pre-drilling is performed through the drill sleeve while exercising care not to exert undue pressure on the drill bit. Excess pressure results in drill bit flexing and a sudden “push through” of the drill bit into the opposite soft tissues as it breaks through the bone. The drill sleeve is then removed and low speed insertion of the fixator pin is performed. After placement of pins three and four, it is recommended to recheck reduction and alignment before placing additional pins. Repeat this procedure for as many additional pins as desired.
What is the proper way to tighten fixator nuts and bolts?
Tightening torque has the potential to cause loss of fracture reduction or alignment – especially early in frame construction when pin numbers are minimal. Applying minimal torque to the pin bolts early in frame design followed by increases as subsequent pins are placed can minimize this potentially disruptive force. Tightening torque can be neutralized during clamp tightening with use of the “two-wrench technique.” An open-end wrench placed on the flat surfaces of the head of the primary bolt, or on the flats of the clamp body, is used to neutralize torque force while a second wrench is used to tighten the clamp. After complete frame construction and verification of reduction accuracy, apply final torque to all bolts in an alternating fashion.