title: Constrained Statistical Modelling of Knee Flexion From Multi-Pose Magnetic Resonance Imaging.
abstract: Reconstruction of the anterior cruciate ligament (ACL) through arthroscopy is one of the most common procedures in orthopaedics. It requires accurate alignment and drilling of the tibial and femoral tunnels through which the ligament graft is attached. Although commercial computer-assisted navigation systems exist to guide the placement of these tunnels, most of them are limited to a fixed pose without due consideration of dynamic factors involved in different knee flexion angles. This paper presents a new model for intraoperative guidance of arthroscopic ACL reconstruction with reduced error particularly in the ligament attachment area. The method uses 3D preoperative data at different flexion angles to build a subject-specific statistical model of knee pose. To circumvent the problem of limited training samples and ensure physically meaningful pose instantiation, homogeneous transformations between different poses and local-deformation finite element modelling are used to enlarge the training set. Subsequently, an anatomical geodesic flexion analysis is performed to extract the subject-specific flexion characteristics. The advantages of the method were also tested by detailed comparison to standard Principal Component Analysis (PCA), nonlinear PCA without training set enlargement, and other state-of-the-art articulated joint modelling methods. The method yielded sub-millimetre accuracy, demonstrating its potential clinical value.
authors: Mihaela A M
authors: MA
authors: Constantinescu
authors: Su-Lin
authors: SL
authors: Lee
authors: Nikhil V
authors: NV
authors: Navkar
authors: Weimin
authors: W
authors: Yu
authors: Saifedeen
authors: S
authors: Al-Rawas
authors: Julien
authors: J
authors: Abinahed
authors: Guoyan
authors: G
authors: Zheng
authors: Jennifer
authors: J
authors: Keegan
authors: Abdulla
authors: A
authors: Al-Ansari
authors: Nabil
authors: N
authors: Jomaah
authors: Philippe
authors: P
authors: Landreau
authors: Guang-Zhong
authors: GZ
authors: Yang
mesh_terms: D016118:Anterior Cruciate Ligament; D059549:Anterior Cruciate Ligament Reconstruction; D006801:Humans; D007719:Knee Joint; D008279:Magnetic Resonance Imaging; D013977:Tibia