Miniature Interface and Centerface are the most commonly used pins with acrylic frames. Use of these small diameter, threaded fixation pins prolongs the longevity of the pin/bone interface and reduces patient morbidity as compared to smooth pins and K-wire.  6 mm tubing is approximately the diameter of a pencil and should be reserved for the smallest of patients. The largest recommended pin for use with 6mm tubing is 1.1 mm (0.045”). Pins up to 2.0 mm (5/64”) in diameter are acceptable for use with 10 mm tubing.  

• 0.9 mm (0.035") fixation pins — used with 6 mm and 10 mm tubing
• 1.1 mm (0.045") fixation pins— use with 6 mm and 10 mm tubing
• 1.6 mm (0.062") fixation pins — used with 10 mm tubing
• 2.0 mm (5/64") fixation pins — used with10 mm tubing

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 ensures 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 appropriate drill sleeve is passed through the primary pin-gripping 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 pin-gripping 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 placing pins three and four, recheck reduction and alignment before placing additional pins. Repeat this procedure for as many additional pins as desired.