Funee app processes videos of laxity tests and calculates the anterior-posterior (AP) translation of the tibia with respect to the knee in five steps. 1) The surgeon only needs to place three green adhesive markers at three knee landmarks: Gerdy’s tubercle, the center of the fibula head, and the lateral epicondyle. 2) Then, the surgeon performs the laxity test as usual while another person is recording the movement, for instance using a mobile phone. 3) The user introduces the distance between the Gerdy’s tubercle and the fibula head. 4) The app calculates the AP translation by processing the video recorded, according to Serrancolí et al. Applied Sciences 2020, 10(17), 5896. 5) The user can identify the AP range of motion in the screen, as well as can compare this range of AP translation with the other leg.

Note: Videos transferred via Whatsapp (or other applications) might not work since the quality is usually reduced or compressed. Videos recorded with the same mobile phone or transferred via email should work fine.