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THE RELATIONSHIP BETWEEN GAIT & TIBIOFEMORAL BONE STRUCTURE IN KNEE OSTEOARTHRITIS: A PILOT STUDY
S372
Presentation 1157 − Topic 29. Knee biomechanics
THE RELATIONSHIP BETWEEN GAIT & TIBIOFEMORAL BONE STRUCTURE IN KNEE OSTEOARTHRITIS: A PILOT STUDY Stevan Jordan (1), Lynsey Duffell (1), Justin Cobb (1), Alison McGregor (1)
1. MSK Lab, Imperial College London, UK
Introduction Despite knee osteoarthritis (OA) being the most common joint disorder in the UK, the pathogenesis of the disease is not fully understood. Mechanical loading is thought to be a key factor in OA development [Andriacchi, 2009]. Specifically, the knee adduction moment (KAM) has been related to disease progression in medial knee OA [Miyazaki, 2002]. Alterations in subchondral bone have also been proposed as having a role in the pathogenesis of knee OA [Wang, 2005]. A recent review concluded that subchondral bone expansion may be the primary event in knee OA and represent an important target for prevention of cartilage loss and joint replacement [Ding, 2007]. Whilst changes to the tibiofemoral bone size and mechanical loading have been implicated in knee OA, the relationship between the two is unclear. This pilot study aimed to explore the relationship between gait and the tibiofemoral bone size in patients with knee OA.
Methods Patients with established medial knee OA, who were scheduled for knee replacement surgery (n=4) were recruited for the study. 35 markers were placed on the patients using a pre-existing marker setup [Van Sint, 2005]. Marker data was captured using a 10-camera Vicon optical motion tracking system. A static trial was captured first followed by 5 walking trials along a 6m walkway at the subject’s natural self-selected walking speed. Data analysis was carried out on the affected leg for three gait cycles. Model outputs were calculated using a modified version of Vicon’s Plug-in Gait. Tibia and femur subchondral bone measurements were made from computed tomography (CT) scans using Robin’s 3D software. Markers were used to accurately measure both tibial and femoral structures using 3D reconstructions of the knee joint (Fig.1). Measurements were carried out using previously validated methods [Martelli, 2002] and standardised using the medial flexion facet, a structure relatively well preserved in OA [Malek 2009].
Results A positive correlation was observed between the first peak KAM and the size of the medial extension facet (MEF) and medial tibial plateau Journal of Biomechanics 45(S1)
(MTP, r2 0.55, 0.93). A similar correlation was seen between the KAM impulse and the size of the MEF and MTP (r2 0.58, 0.88). No correlation was observed in lateral structures (LFF, LTP; Table 1).
Figure 1: Measurement of the medial tibial plateau radius using Robins 3D.
MEF LFF MTP LTP
First Peak KAM 0.55 0.02 0.93 0.00
KAM Impulse 0.58 0.00 0.88 0.01
Table 1: Correlations between tibiofemoral measurements and first peak KAM /KAM impulse.
Discussion This novel pilot study indicates a relationship between both mechanical load and bone shape in patients with medial knee OA. Despite low subject numbers, this correlation indicates a relationship between morphology, gait patterns and the development of knee OA.
Acknowledgements The authors acknowledge support from the Medical Engineering Solutions in Osteoarthritis Centre of Excellence, funded by the Wellcome Trust and the EPSRC.
References Andriacchi et al, J Bone Joint Surg Am, 91:95-101, 2009. Ding et al, Osteoarthritis Cartilage, 15(5):479-486, 2007. Malek et al, Clin Anat, 22(4):517-522, 2009. Martelli et al, J Bone Joint Surg Br, 84(4):607-613, 2002. Miyazaki et al, Ann Rheum Dis, 61(7):617-622, 2002. Van-Sint et al, Clin Biomech, 20(6):659-660, 2005. Wang et al, Arthritis Res Ther, 7(3):687-693, 2005.
ESB2012: 18th Congress of the European Society of Biomechanics
Presentation 1157 − Topic 29. Knee biomechanics
THE RELATIONSHIP BETWEEN GAIT & TIBIOFEMORAL BONE STRUCTURE IN KNEE OSTEOARTHRITIS: A PILOT STUDY Stevan Jordan (1), Lynsey Duffell (1), Justin Cobb (1), Alison McGregor (1)
1. MSK Lab, Imperial College London, UK
Introduction Despite knee osteoarthritis (OA) being the most common joint disorder in the UK, the pathogenesis of the disease is not fully understood. Mechanical loading is thought to be a key factor in OA development [Andriacchi, 2009]. Specifically, the knee adduction moment (KAM) has been related to disease progression in medial knee OA [Miyazaki, 2002]. Alterations in subchondral bone have also been proposed as having a role in the pathogenesis of knee OA [Wang, 2005]. A recent review concluded that subchondral bone expansion may be the primary event in knee OA and represent an important target for prevention of cartilage loss and joint replacement [Ding, 2007]. Whilst changes to the tibiofemoral bone size and mechanical loading have been implicated in knee OA, the relationship between the two is unclear. This pilot study aimed to explore the relationship between gait and the tibiofemoral bone size in patients with knee OA.
Methods Patients with established medial knee OA, who were scheduled for knee replacement surgery (n=4) were recruited for the study. 35 markers were placed on the patients using a pre-existing marker setup [Van Sint, 2005]. Marker data was captured using a 10-camera Vicon optical motion tracking system. A static trial was captured first followed by 5 walking trials along a 6m walkway at the subject’s natural self-selected walking speed. Data analysis was carried out on the affected leg for three gait cycles. Model outputs were calculated using a modified version of Vicon’s Plug-in Gait. Tibia and femur subchondral bone measurements were made from computed tomography (CT) scans using Robin’s 3D software. Markers were used to accurately measure both tibial and femoral structures using 3D reconstructions of the knee joint (Fig.1). Measurements were carried out using previously validated methods [Martelli, 2002] and standardised using the medial flexion facet, a structure relatively well preserved in OA [Malek 2009].
Results A positive correlation was observed between the first peak KAM and the size of the medial extension facet (MEF) and medial tibial plateau Journal of Biomechanics 45(S1)
(MTP, r2 0.55, 0.93). A similar correlation was seen between the KAM impulse and the size of the MEF and MTP (r2 0.58, 0.88). No correlation was observed in lateral structures (LFF, LTP; Table 1).
Figure 1: Measurement of the medial tibial plateau radius using Robins 3D.
MEF LFF MTP LTP
First Peak KAM 0.55 0.02 0.93 0.00
KAM Impulse 0.58 0.00 0.88 0.01
Table 1: Correlations between tibiofemoral measurements and first peak KAM /KAM impulse.
Discussion This novel pilot study indicates a relationship between both mechanical load and bone shape in patients with medial knee OA. Despite low subject numbers, this correlation indicates a relationship between morphology, gait patterns and the development of knee OA.
Acknowledgements The authors acknowledge support from the Medical Engineering Solutions in Osteoarthritis Centre of Excellence, funded by the Wellcome Trust and the EPSRC.
References Andriacchi et al, J Bone Joint Surg Am, 91:95-101, 2009. Ding et al, Osteoarthritis Cartilage, 15(5):479-486, 2007. Malek et al, Clin Anat, 22(4):517-522, 2009. Martelli et al, J Bone Joint Surg Br, 84(4):607-613, 2002. Miyazaki et al, Ann Rheum Dis, 61(7):617-622, 2002. Van-Sint et al, Clin Biomech, 20(6):659-660, 2005. Wang et al, Arthritis Res Ther, 7(3):687-693, 2005.
ESB2012: 18th Congress of the European Society of Biomechanics