Summary

Compared with traditional hip arthroscopy, arthroscopic surgery assisted with MR technology can reduce the number of intraoperative fluoroscopies, shorten the operation time, and make it easy to operate. The surgeon can observe the lesion area more clearly and get an accurate range of resection.

Abstract

Hip arthroscopy is more difficult than other arthroscopies because of the anatomical features of hip such as deep joint position, narrow joint space, and tensional joint capsule. X-ray fluoroscopy is needed to determine the surgical approach and range of resection. The mixed reality (MR) technology can generate virtual objects that do not exist in the real environment through computer graphics technology and visualization technology, superimpose the virtual objects into the real environment through sensing technology, and display them in the same picture or space synchronously to assist the surgical navigation. Purpose: To apply the MR technology to the navigation of hip arthroscopy, and to explore the feasibility and effectiveness of the technique in assisting intraoperative positioning comparing with traditional hip arthroscopy. Methods: 10 patients underwent hip arthroscopy in our hospital were included and randomly divided into 2 groups. Experimental group (n=5): The positioning markers were fixed at anterior superior iliac spine and greater trochanter of the femur before surgery, perform three-dimensional CT scan of the hip joint and reconstruct the three-dimensional(3D) model of the bone. To scan the markers on patient through the Hololens MR wearing device during surgery, match the the human tissue with the 3D model, thereby assisting in establishing a surgical approach and achieving precise navigation of surgical area. Control group (n=5): Only conventional C-arm X-ray machine was used for navigation during surgery. Compare the number of times and time required for establishing the surgical approach, the total operation time between the two groups, and the ease of operation and accuracy of the two navigation methods. Result: In the experimental group, the human tissue was successfully matched with the 3D model, and the subsequent operation can be performed under the guidance of the virtual model. The number of fluoroscopies required to establish the surgical approach was (1.5 ± 0.5) times, the required time was (4.3 ± 1.7) minutes, and the total operation time was (50 ± 17) minutes. In the control group, the number of fluoroscopies required to establish the surgical approach was (3.5 ± 1.5) times, the required time was (8.5 ± 3.5) minutes, and the total operation time was (62 ± 12) minutes. Conclusion: Compared with traditional hip arthroscopy, arthroscopic surgery assisted with MR technology can reduce the number of intraoperative fluoroscopies, shorten the operation time, and make it easy to operate. The surgeon can observe the lesion area more clearly and get an accurate range of resection. However, there has slight difference in synchronous position change between the positioning markers and the bone, and the accuracy of the navigation technology needs to be improved.