Augmented Reality-based Surgical Guidance for Anterior and Posterior Cruciate Ligament Reconstruction

Abstract

Anterior and posterior cruciate ligament (ACL and PCL) reconstructions are common knee arthroscopic surgeries. ACL and PCL reconstruction have small incision sites, thus enabling fast recovery of the patient. However, an arthroscope provides a limited view due to the small size of the camera lens, and a small incision restricts the motion of surgical instruments. As a result, finding the exact bone drilling position that was preoperatively determined to connect a new ligament between the femur and tibia is challenging during surgery. A previous study verified that the complication ratio of ACL and PCL reconstruction is 9.0 % and 20.1 %, respectively, which are particularly high compared to other knee arthroscopic surgeries [1]. Augmented reality (AR)-based surgical guidance can assist in difficult ACL and PCL reconstruction. Hu et al. [2] proposed AR-based non-invasive drilling guidance for the femur in open knee surgery. To implement the non-invasive system, they performed the registration between the depth data of the femur obtained from RGBD sensors and the pre-scanned femur model. However, this method is suitable for open knee surgery and is not for arthroscopic surgeries such as ACL and PCL reconstruction. Recently, Chen et al. [3] introduced non-invasive AR for knee arthroscopy. However, to reflect knee movements occurring during surgery in AR, it is necessary to manually select four anatomical landmarks in the arthroscopic view. Manual selection is inconvenient and may be inconsistent, interfering with surgical procedures. In this study, we propose a non-invasive AR-based surgical guidance for ACL and PCL reconstruction with compensation of the intraoperative knee movement. Unlike preoperative CT and MR, which are taken under the extension state, the knee is under the flexion state during surgery, which requires compensation for the knee movement. The proposed method estimates knee movement without direct bone exposure or manual intervention by exploring the correlation between the knee surface and the internal bones (femur and tibia) based on a finite element method. The proposed method can enhance the AR for knee arthroscopic procedures, leading to more accurate bone drilling for ACL or PCL reconstruction.