Listract Test: A Standardized Assessment Method for Isolated Lisfranc Instability in Cadaver Models

METHODSelevator to apply stress on the joint. 12Another study found that the distracting forces applied to the joint should be in the direction of the forces that the actual ligaments bear in physiologic weightbearing condition for accurate assessment. 13n this study, we aimed to introduce a standardized and reproducible intraoperative mechanical test for Lisfranc instability, particularly in isolated Lisfranc ligament injuries.Our hypothesis is that resembling a standard distracting force applied on the Lisfranc IntroductIonInjuries to the Lisfranc joint represent 0.2% of all fractures and have an annual incidence of 1/55,000 individuals. 1,2Ligamentous type of Lisfranc injuries is difficult to detect, with 20-40% of them remaining undetected or misdiagnosed at initial presentation. 3n such cases, debilitating sequelae like midfoot instability, arch collapse, and traumatic arthritis are more likely to follow, thereby underlying the importance of timely diagnosis and treatment. 4urgical intervention is key to the preservation of the joint and to achieving anatomic reduction. 5,6A high portion of instabilities caused by joint widening is observed between the first cuneiform (C1) and second metatarsus (M2) bones (C1-M2) and between the first and second cuneiform bones (C1-C2).Various types of metal and flexible fixations are used as fixation methods for Lisfranc instabilities. 7,8Magnetic resonance imaging (MRI) and weightbearing computed tomography (WBCT) have shown high sensitivity and specificity for the detection of Lisfranc instability; radiographs, especially in weight-bearing status, are the mainstay for primary assessment.Despite various imaging methods, intraoperative examination remains the gold standard for confirmation of the diagnosis. 9,10However, the intraoperative stress examination of the Lisfranc joint by applying a distraction force is not standardized and not a reproducible method. 11Surgeons apply various amounts of force on the joint to confirm the diagnosis.This can lead to over or underdiagnosis of the instability.