Quantitative evaluation of knee laxity after partial anterior cruciate ligament injury with a novel digital arthrometer

Zhu Zheyue; Zhang Chen; Ge Ying; Xue Han; Li Ruochen; Wu Guangwei; Ma Rui

doi:10.12307/2025.184

Abstract：BACKGROUND:Quantitative measurement of knee laxity after partial anterior cruciate ligament injury is crucial for timely diagnosis,post-treatment,and rehabilitation.There is a lack of research on the use of articular ligament digital arthrometer in the diagnosis of partial anterior cruciate ligament injury. OBJECTIVE:To investigate the diagnostic value of a new articular ligament digital arthrometer in partial anterior cruciate ligament injury. METHODS:Totally 30 patients with partial anterior cruciate ligament injury and 20 healthy volunteers were included.The anterior tibial translation values under 80,120,and 150 N loads were measured by a homebred digital arthrometer.The anterior tibial translation and side-to-side difference were compared between the partial anterior cruciate ligament group and control group.The receiver operating characteristic curve was analyzed and area under curve was calculated,and the diagnostic sensitivity and specificity of the digital arthrometer were determined. RESULTS AND CONCLUSION:(1)There was no significant difference in age,sex,body mass index,and course of disease between the partial anterior cruciate ligament injury group and control group(P＞0.05).(2)The side-to-side difference values of the partial anterior cruciate ligament injury group were significantly higher than those of the control group(P＜0.05),and the anterior tibial translation values of the injured side were significantly higher than those of the healthy side in the partial anterior cruciate ligament injury group(P＜0.05).(3)When the load was applied at 80 N,the diagnostic accuracy was highest(cutoff value=10.45 mm);the area under curve was 0.813(95％CI:0.708-0.919),and the sensitivity and specificity were 76.7％and 70.0％,respectively.(4)It is indicated that the digital arthrometer can objectively and quantitatively evaluate knee laxity after partial anterior cruciate ligament injury,and provide objective diagnostic basis for patients with partial anterior cruciate ligament iniurv.