Diagnosing anterior cruciate ligament injuries using a knee arthrometer: Design, fabrication, and clinical evaluation

摘要

Every year many people suffer from knee injuries. Previous studies on patients with knee injuries have shown that about 40% of knee injuries are Ligament injuries, and about 50% of the ligament injuries are the Anterior Cruciate Ligament (ACL) injuries. Along with other methods, knee arthrometers are widely used to diagnose ACL injuries. In the current research, a knee arthrometer was designed and developed to provide a reliable and repeatable measurement of knee laxity under anteriorposterior applied loads. Testretest configurations to examine repeatability of the device resulted in less than 1.5-mm difference for more than 97% of tests under applied loads of up to 90 N. These tests included 166 tests on the left knees and 147 tests on the right knees of 37 healthy subjects. Also, this device was tested on 27 confirmed ACL ruptured patients, and the results were analyzed to find a better criterion than standard criteria to diagnose ACL rupture using knee arthrometers by finding specificity and sensitivity of the device using those criteria. Among the 20 criteria evaluated, a combination of side-to-side difference under 150 N of applied load, and CI@90-60 (compliance index calculated between 90 N, and 60 N) resulted in the best sensitivity (96.4%) and specificity (100%).