Seamless augmented reality integration in arthroscopy: a pipeline for articular reconstruction and guidance

Arthroscopy is a minimally invasive surgical procedure used to diagnose and treat joint problems. The clinical workflow of arthroscopy typically involves inserting an arthroscope into the joint through a small incision, during which surgeons navigate and operate largely by relying on their visual assessment through the arthroscope. However, the arthroscope's restricted field of view and lack of depth perception pose challenges in navigating complex articular structures and achieving surgical precision during procedures. Aiming at enhancing intraoperative awareness, a robust pipeline that incorporates simultaneous localization and mapping, depth estimation, and 3D Gaussian splatting (3D GS) is presented to realistically reconstruct intra-articular structures solely based on monocular arthroscope video. Extending 3D reconstruction to augmented reality (AR) applications, the solution offers AR assistance for articular notch measurement and annotation anchoring in a human-in-the-loop manner. Compared to traditional structure-from-motion and neural radiance field-based methods, the pipeline achieves dense 3D reconstruction and competitive rendering fidelity with explicit 3D representation in 7 min on average. When evaluated on four phantom datasets, our method achieves root-mean-square-error <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mtext>(RMSE)</mml:mtext> <mml:mo>=</mml:mo> <mml:mn>2.21</mml:mn> <mml:mspace></mml:mspace> <mml:mtext>mm</mml:mtext></mml:mrow> </mml:mrow> </mml:math> reconstruction error, peak signal-to-noise ratio <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mtext>(PSNR)</mml:mtext> <mml:mo>=</mml:mo> <mml:mn>32.86</mml:mn></mml:mrow> </mml:mrow> </mml:math> and structure similarity index measure <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mtext>(SSIM)</mml:mtext> <mml:mo>=</mml:mo> <mml:mn>0.89</mml:mn></mml:mrow> </mml:mrow> </mml:math> on average. Because the pipeline enables AR reconstruction and guidance directly from monocular arthroscopy without any additional data and/or hardware, the solution may hold the potential for enhancing intraoperative awareness and facilitating surgical precision in arthroscopy. The AR measurement tool achieves accuracy within <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mrow><mml:mn>1.59</mml:mn> <mml:mo>±</mml:mo> <mml:mn>1.81</mml:mn> <mml:mspace></mml:mspace> <mml:mtext>mm</mml:mtext></mml:mrow> </mml:mrow> </mml:math> and the AR annotation tool achieves a mIoU of 0.721.