Functional knee assessment with advanced imaging

Abstract

The purpose of anterior cruciate ligament (ACL) reconstruction is to restore the native stability of the knee joint and to prevent further injury to meniscus and cartilage, yet studies have suggested that joint laxity remains prevalent in varying degrees after ACL reconstruction. Imaging can provide measurements of translational and rotational motions of the tibiofemoral joint that may be too small to detect in routine physical examinations. Various imaging modalities, including fluoroscopy, computed tomography (CT), and magnetic resonance imaging (MRI), have emerged as powerful methods in measuring the minute details involved in joint biomechanics. While each technique has its own strengths and limitations, they have all enhanced our understanding of the knee joint under various stresses and movements. Acquiring the knowledge of the complex and dynamic motions of the knee after surgery would help lead to improved surgical techniques and better patient outcomes.

Keywords: ACL; Advanced imaging; Anterior cruciate ligament; Knee assessment; Knee joint; Reconstruction.

Fig. 1

3D cloud points are generated from semi-automatic segmentations on T2 FSE images to generate a 3D representation of the tibia. Image courtesy of Musculoskeletal Quantitative Imaging Research, University of California, San Francisco

Fig. 2

Color map of T_1ρ relaxation times which correlate with proteoglycan content within the articular cartilage. Image courtesy of Musculoskeletal Quantitative Imaging Research, University of California, San Francisco

Fig. 3

Left image shows high-resolution 3D FSE showing meniscus tear in the posterior horn of the lateral meniscus. Right image shows T_1ρ-weighted image shows a color map overlay of T_1ρ relaxation times corresponding to the tear. Image courtesy of Musculoskeletal Quantitative Imaging Research, University of California, San Francisco