TY - JOUR
T1 - A novel non-invasive method for measuring knee joint laxity in four dof
T2 - In vitro proof-of-concept and validation
AU - Pedersen, Dennis
AU - Vanheule, Valentine
AU - Wirix-Speetjens, Roel
AU - Taylan , Orçun
AU - Delport, Hendrik Pieter
AU - Scheys, Lennart
AU - Andersen, Michael Skipper
PY - 2019/1/3
Y1 - 2019/1/3
N2 - Knee joint laxity or instability is a common problem that may have detrimental consequences for patients. Unfortunately, assessment of knee joint laxity is limited by current methodologies resulting in suboptimal diagnostics and treatment. This paper presents a novel method for accurately measuring non-invasive knee joint laxity in four degrees-of-freedom (DOF). An arthrometer, combining a parallel manipulator and a six-axis force/moment sensor, was developed to be used in combination with a low-dose biplanar x-ray system and 3D image data to reconstruct tibiofemoral position and orientation of laxity measurements. As proof-of-concept, four cadaveric knees were tested in the device. Each cadaveric knee was mounted in the device at approximately 30° of flexion and twelve monoplanar anteroposterior, mediolateral and internal/external load cases were applied. Additionally, four biplanar load cases were applied, consisting of different combinations of anteroposterior and internal/external loads. The arthrometer was limited to four DOF to address the specific measurements. For validation purposes, the pose reconstructions of tibia and femur were compared with pose reconstructions of bone pin marker frames mounted on each bone. The measurements from the arthrometer in terms of translation and rotations displayed comparable values to what have previously been presented in the literature. Furthermore, the measurements revealed coupled motions in multiple planes, demonstrating the importance of multi DOF laxity measurements. The validation displayed an average mean difference for translations of 0.08 mm and an average limit of agreement between −1.64 mm and 1.80 mm. The average mean difference for rotations was 0.10° and the limit of agreement was between −0.85° and 1.05°. The presented method eliminates several limitations present in current methods and may prove a valuable tool for assessing knee joint laxity.
AB - Knee joint laxity or instability is a common problem that may have detrimental consequences for patients. Unfortunately, assessment of knee joint laxity is limited by current methodologies resulting in suboptimal diagnostics and treatment. This paper presents a novel method for accurately measuring non-invasive knee joint laxity in four degrees-of-freedom (DOF). An arthrometer, combining a parallel manipulator and a six-axis force/moment sensor, was developed to be used in combination with a low-dose biplanar x-ray system and 3D image data to reconstruct tibiofemoral position and orientation of laxity measurements. As proof-of-concept, four cadaveric knees were tested in the device. Each cadaveric knee was mounted in the device at approximately 30° of flexion and twelve monoplanar anteroposterior, mediolateral and internal/external load cases were applied. Additionally, four biplanar load cases were applied, consisting of different combinations of anteroposterior and internal/external loads. The arthrometer was limited to four DOF to address the specific measurements. For validation purposes, the pose reconstructions of tibia and femur were compared with pose reconstructions of bone pin marker frames mounted on each bone. The measurements from the arthrometer in terms of translation and rotations displayed comparable values to what have previously been presented in the literature. Furthermore, the measurements revealed coupled motions in multiple planes, demonstrating the importance of multi DOF laxity measurements. The validation displayed an average mean difference for translations of 0.08 mm and an average limit of agreement between −1.64 mm and 1.80 mm. The average mean difference for rotations was 0.10° and the limit of agreement was between −0.85° and 1.05°. The presented method eliminates several limitations present in current methods and may prove a valuable tool for assessing knee joint laxity.
KW - Arthrometry
KW - EOS Imaging
KW - Laxity
KW - Tibiofemoral joint
UR - http://www.scopus.com/inward/record.url?scp=85055623229&partnerID=8YFLogxK
U2 - 10.1016/j.jbiomech.2018.10.016
DO - 10.1016/j.jbiomech.2018.10.016
M3 - Journal article
VL - 82
SP - 62
EP - 69
JO - Journal of Biomechanics
JF - Journal of Biomechanics
SN - 0021-9290
ER -