Anterior cruciate ligament reconstruction examination device

Abstract

The article of this design is a device for measuring ligament tension used in reconstruction surgery for anterior cruciate ligament (ACL) rupture. This device is composed of a double tension gauge and a goniometer. The reconstruction surgery involves first drilling two through holes in the femur and tibia, then crossing two natural ligaments extended with an artificial ligament and passing them through the holes in the femur and tibia. The femur side is fastened with an end button, and then the tibia side is pulled with an appropriate tension (about 30N), and while maintaining this tension, the knee is bent from 0 to 120 degrees and then returned to 0 degrees. The angle is measured while the goniometer is placed on the knee. Next, the double tension gauge is tilted to align the ligament with the tibia, and the tension is adjusted again before staples are inserted to complete the surgery. The double tension gauge is firmly fixed in place by driving two 3mm stainless steel wires into the tibia to prevent it from shaking. By pulling the rotation lock knob, the double tension gauge rotates at the rotation center at the bottom of the fixed part, changing the inclination angle. The tension is displayed in large, conspicuous letters for easy confirmation during surgery. The double tension meter has two hooks in the center, to which two artificial ligaments are attached. The hooks are tensioned by turning the tension knob via a load cell, which increases the tension. Next is the goniometer, which bends and straightens the knee while placing a rod on the leg, and outputs an angle signal from the goniometer's potentiometer. The signals from the load cell and potentiometer are converted by a controller and the values ​​and graphs are displayed on a computer screen, which can be saved and used as a reference for follow-up visits. In this surgery, it is necessary to fix the ligament to the bone with the appropriate tension. Currently, tension is measured with a spring scale or determined by feel. It is expected that the use of this device will reduce surgery time and improve accuracy, even for non-experienced doctors.

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