Measuring relative positions and orientations of the tibia with respect to the femur using one-channel 3D-tracked A-mode ultrasound tracking system: A cadaveric study. (July 2018)

• Record Type: Journal Article
• Authors: Niu, Kenan; Homminga, Jasper; Sluiter, Victor; Sprengers, André; Verdonschot, Nico
• Is Part Of: Medical engineering & physics. Volume 57(2018)
• Page Start: 61
• Page End: 68
• Publication Date: 2018-07
• Subjects: A-mode ultrasound -- Motion tracking -- Tibiofemoral kinematics -- Non-invasive -- Cadaver experiment -- Position and orientation; Biomedical engineering -- Periodicals; Biomedical Engineering -- Periodicals; Physics -- Periodicals; Génie biomédical -- Périodiques; Biomedical engineering; Electronic journals; Periodicals; 610.28
• DOI: 10.1016/j.medengphy.2018.04.015
• Languages: English
• ISSNs: 1350-4533

Abstract

Highlights: The feasibility of measuring relative positions and orientations of tibia with respect to the femur has been proved. 3D-tracked A-mode US system has potential to mitigate soft tissue artifacts. The accuracy of registration determines the accuracy of angular and translation measurements. Multi-channel 3D-tracked A-mode US system has potential for dynamic measurements. Abstract: The purpose of this study is to investigate the technical feasibility of measuring relative positions and orientations of the tibia with respect to the femur in an in-vitro experiment by using a 3D-tracked A-mode ultrasound system and to determine its accuracy of angular and translational measurements. As A-mode ultrasound is capable of detecting bone surface through soft tissue in a non-invasive manner, the combination of a single A-mode ultrasound transducer with an optical motion tracking system provides the possibility for digitizing the 3D locations of bony points at different anatomical regions on the thigh and the shank. After measuring bony points over a large area of both the femur and tibia, the bone models of the femur and tibia that were segmented from CT or MRI images were registered to the corresponding bony points. Then the relative position of the tibia with respect to the femur could be obtained and the angular and translational components could also be measured. A cadaveric experiment was conducted to assess its accuracy compared to the reference measurement obtained by optical markers fixed to intra-cortical bone pins placed in the femur and tibia. The results showed that the ultrasound system could achieve 0.49 ± 0.83°, 0.85 ± 1.86° and 1.85 ± 2.78° (mean ± standard deviation) errors for Flexion–Extension, Adduction–Abduction and External–Internal rotations, respectively, and −2.22 ± 3.62 mm, −2.80 ± 2.35 mm and −1.44 ± 2.90 mm errors for Anterior–Posterior, Proximal–Distal and Lateral–Medial translations, respectively. It was concluded that this technique is feasible and facilitates the integration of arrays of A-mode ultrasound transducers with an optical motion tracking system for non-invasive dynamic tibiofemoral kinematics measurement. Graphical abstract: Image, graphical abstract