1
|
Wang X, Liu H, Dong Z, Chen X, Xu C, Ji G, Kang H, Wang F. Contact area and pressure changes of patellofemoral joint during stair ascent and stair descent. BMC Musculoskelet Disord 2023; 24:767. [PMID: 37770867 PMCID: PMC10537124 DOI: 10.1186/s12891-023-06882-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 09/13/2023] [Indexed: 09/30/2023] Open
Abstract
PURPOSE To investigate the differences of patellofemoral joint pressure and contact area between the process of stair ascent and stair descent. METHODS The finite element models of 9 volunteers without disorders of knee (9 males) to estimate patellar cartilage pressure during the stair ascent and the stair descent. Simulations took into account cartilage morphology from magnetic resonance imaging, joint posture from weight-bearing magnetic resonance imaging, and ligament model. The three-dimension models of the patella, femur and tibia were developed with the medical image processing software, Mimics 11.1. The ligament was established by truss element of the non-linear FE solver. The equivalent gravity direction (-z direction) load was applied to the whole end of femur (femoral head) according to the body weight of the volunteers, and the force of patella was observed. A paired-samples t-test or Wilcoxon rank sum test to make comparisons between stair ascent and stair descent. Statistical analyses were performed using SPSS 22.0 using a P value of 0.05 to indicate significance. RESULTS During the stair descent (knee flexion at 30°), the contact pressure of the patella was 2.59 ± 0.06Mpa. The contact pressure of femoral trochlea cartilage was 2.57 ± 0.06Mpa. During the stair ascent (knee flexion at 60°), the contact pressure with patellar cartilage was 2.82 ± 0.08Mpa. The contact pressure of the femoral trochlea cartilage was 3.03 ± 0.11Mpa. The contact area between patellar cartilage and femoral trochlea cartilage was 249.27 ± 1.35mm2 during the stair descent, which was less than 434.32 ± 1.70mm2 during the stair ascent. The area of high pressure was located in the lateral area of patella during stair descent and the area of high pressure was scattered during stair ascent. CONCLUSION There are small change in the cartilage contact pressure between stair ascent and stair descent, indicating that the joint adjusts the contact pressure by increasing the contact area.
Collapse
Affiliation(s)
- Xiaomeng Wang
- Foot and Ankle Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Huixin Liu
- Ultrasound medicine department, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Zhenyue Dong
- Department of Joint Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Xiaobo Chen
- Department of Joint Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Chenyue Xu
- Department of Joint Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Gang Ji
- Department of Joint Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Huijun Kang
- Department of Joint Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Fei Wang
- Department of Joint Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China.
| |
Collapse
|
2
|
Hull ML, Howell SM. Differences in Trochlear Morphology from Native Using a Femoral Component Interfaced with an Anatomical Patellar Prosthesis in Kinematic Alignment and Mechanical Alignment. J Knee Surg 2022; 35:625-633. [PMID: 32927493 DOI: 10.1055/s-0040-1716413] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Patellofemoral complications following total knee arthroplasty can be traced in part to alignment of the femoral component. Kinematic alignment (KA) and mechanical alignment (MA) use the same femoral component but align the component differently. Our objective was to determine differences in trochlear morphology from native for a femoral component interfaced with an anatomical patellar prosthesis in KA and MA. Ten three-dimensional femur-cartilage models were created by combining computed tomography and laser scans of native human cadaveric femurs free of skeletal abnormalities. The femoral component was positioned using KA and MA. Measurements of the prosthetic and native trochlea were made along the arc length of the native trochlear groove and differences from native were computed for the medial-lateral and radial locations of the groove and sulcus angle. Mean medial-lateral locations of the prosthetic groove were within 1.5 and 3.5 mm of native for KA and MA, respectively. Mean radial locations of the prosthetic groove were as large as 5 mm less than native for KA and differences were greater for MA. Sulcus angles of the prosthetic trochlea were 10 degrees steeper proximally, and 10 degrees flatter distally than native for both KA and MA. Largest differences from native occurred for radial locations and sulcus angles for both KA and MA. The consistency of these results with those of other fundamentally different designs which use a modified dome (i.e., sombrero hat) patellar prosthesis highlights the need to reassess the design of the prosthetic trochlea on the part of multiple manufacturers worldwide.
Collapse
Affiliation(s)
- Maury L Hull
- Department of Biomedical Engineering, University of California Davis, Davis, California.,Department of Mechanical Engineering, University of California Davis, Davis, California.,Department of Orthopaedic Surgery, University of California Davis, Davis, California
| | - Stephen M Howell
- Department of Biomedical Engineering, University of California Davis, Davis, California
| |
Collapse
|
3
|
Seyedpour SM, Nafisi S, Nabati M, Pierce DM, Reichenbach JR, Ricken T. Magnetic Resonance Imaging-based biomechanical simulation of cartilage: A systematic review. J Mech Behav Biomed Mater 2021; 126:104963. [PMID: 34894500 DOI: 10.1016/j.jmbbm.2021.104963] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/30/2021] [Accepted: 11/06/2021] [Indexed: 11/19/2022]
Abstract
MRI-based mathematical and computational modeling studies can contribute to a better understanding of the mechanisms governing cartilage's mechanical performance and cartilage disease. In addition, distinct modeling of cartilage is needed to optimize artificial cartilage production. These studies have opened up the prospect of further deepening our understanding of cartilage function. Furthermore, these studies reveal the initiation of an engineering-level approach to how cartilage disease affects material properties and cartilage function. Aimed at researchers in the field of MRI-based cartilage simulation, research articles pertinent to MRI-based cartilage modeling were identified, reviewed, and summarized systematically. Various MRI applications for cartilage modeling are highlighted, and the limitations of different constitutive models used are addressed. In addition, the clinical application of simulations and studied diseases are discussed. The paper's quality, based on the developed questionnaire, was assessed, and out of 79 reviewed papers, 34 papers were determined as high-quality. Due to the lack of the best constitutive models for various clinical conditions, researchers may consider the effect of constitutive material models on the cartilage disease simulation. In the future, research groups may incorporate various aspects of machine learning into constitutive models and MRI data extraction to further refine the study methodology. Moreover, researchers should strive for further reproducibility and rigorous model validation and verification, such as gait analysis.
Collapse
Affiliation(s)
- S M Seyedpour
- Institute of Mechanics, Structural Analysis and Dynamics, Faculty of Aerospace Engineering and Geodesy, University of Stuttgart, Pfaffenwaldring 27, 70569 Stuttgart, Germany; Biomechanics Lab, Institute of Mechanics, Structural Analysis and Dynamics, Faculty of Aerospace Engineering and Geodesy, University of Stuttgart, Pfaffenwaldring 27, 70569 Stuttgart, Germany
| | - S Nafisi
- Faculty of Pharmacy, Istinye University, Maltepe, Cirpici Yolu B Ck. No. 9, 34010 Zeytinburnu, Istanbul, Turkey
| | - M Nabati
- Department of Mechanical Engineering, Faculty of Engineering, Boğaziçi University, 34342 Bebek, Istanbul, Turkey
| | - D M Pierce
- Department of Mechanical Engineering, University of Connecticut, 191 Auditorium Road, Unit 3139, Storrs, CT, 06269, USA; Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Unit 3247, Storrs, CT, 06269, USA
| | - J R Reichenbach
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital-Friedrich Schiller University Jena, Jena, Germany; Center of Medical Optics and Photonics, Friedrich Schiller University Jena, Germany; Michael Stifel Center for Data-driven and Simulation Science Jena, Friedrich Schiller University Jena, Germany
| | - T Ricken
- Institute of Mechanics, Structural Analysis and Dynamics, Faculty of Aerospace Engineering and Geodesy, University of Stuttgart, Pfaffenwaldring 27, 70569 Stuttgart, Germany; Biomechanics Lab, Institute of Mechanics, Structural Analysis and Dynamics, Faculty of Aerospace Engineering and Geodesy, University of Stuttgart, Pfaffenwaldring 27, 70569 Stuttgart, Germany.
| |
Collapse
|
4
|
Load Distribution at the Patellofemoral Joint During Walking. Ann Biomed Eng 2020; 48:2821-2835. [DOI: 10.1007/s10439-020-02672-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 10/21/2020] [Indexed: 12/24/2022]
|
5
|
Thompson RL, Gardner JK, Zhang S, Reinbolt JA. Lower-limb joint reaction forces and moments during modified cycling in healthy controls and individuals with knee osteoarthritis. Clin Biomech (Bristol, Avon) 2020; 71:167-175. [PMID: 31765912 DOI: 10.1016/j.clinbiomech.2019.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 09/14/2019] [Accepted: 11/08/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Osteoarthritis (OA) is a clinical problem affecting an estimated 27 million adults in the United States, with the only clear treatment options being pain management. Cycling is an integral component of exercise for individuals with knee osteoarthritis, while the joint reaction forces during cycling remain unknown. METHODS Thirteen subjects with medial compartment knee osteoarthritis and eleven healthy subjects performed a cycling protocol with a neutral pedal and four pedal modifications. Six hundred muscle-actuated inverse-dynamic simulations (24 subjects, 5 trials in each of 5 conditions) were performed to estimate joint reaction force differences between conditions. FINDINGS Subjects with knee osteoarthritis had many significant changes among them was a reduction in knee adduction-abduction moment by 45% (5° lateral wedge), 77% (10° lateral wedge), 54% (5° toe-in) and 58% (10° toe-in). Conversely the healthy subjects had no significant changes in the knee adduction-abduction moment for the lateral wedge conditions and the 5° toe-in but did decrease by 18% for the 10° toe-in condition. When comparing the cohorts across the different pedal conditions, the data showed many significant differences among the groups. INTERPRETATION This study showed that while cycling in different pedal modifications, the knee osteoarthritis subjects had more beneficial changes in their knee adduction-abduction moment compared to the healthy subjects with the lateral-wedge modification resulting in the greatest impact on the subjects with knee osteoarthritis. Both groups had greater contact forces at the hip and ankle across pedal modifications compared to neutral. For the knee, subjects with osteoarthritis mostly decreased their knee contact forces but the healthy subjects mostly increased these forces with all pedal modifications.
Collapse
Affiliation(s)
- Rachel L Thompson
- Department of Mechanical, Aerospace, and Biomedical Engineering, The University of Tennessee, Knoxville, TN, USA.
| | - Jacob K Gardner
- Department of Kinesiology and Health Science, Biola University, La Mirada, CA, USA
| | - Songning Zhang
- Department of Kinesiology, Recreation, and Sport Studies, The University of Tennessee, Knoxville, TN, USA
| | - Jeffrey A Reinbolt
- Department of Mechanical, Aerospace, and Biomedical Engineering, The University of Tennessee, Knoxville, TN, USA
| |
Collapse
|
6
|
Akbar M, Farahmand F, Arjmand N. Mechanical characterization of the ligaments in subject-specific models of the patellofemoral joint using in vivo laxity tests. Knee 2019; 26:1220-1233. [PMID: 30948304 DOI: 10.1016/j.knee.2018.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 06/22/2018] [Accepted: 10/02/2018] [Indexed: 02/02/2023]
Abstract
BACKGROUND The purpose of this study was to propose a methodology for mechanical characterization of the ligaments in subject-specific models of the patellofemoral joint (PFJ) of living individuals. METHOD PFJ laxity tests were performed on a healthy volunteer using a specially designed loading apparatus under biplane fluoroscopy. A three-dimensional (3D) parametric model of the PFJ was developed in the framework of the rigid body spring model using the geometrical data acquired from the subject's computed tomography and magnetic resonance images. The stiffness and pre-strains of the medial and lateral PFJ ligaments were characterized using a two-step optimization procedure which minimized the deviation between the model predictions and the calibration test results. Sensitivity analyses were performed to investigate the effect of mechanical properties of the non-characterized model components on the characterization procedure and its results. RESULTS The overall findings indicate that the proposed methodology is applicable and can improve the model predictions effectively. For the subject under study, ligament characterization reduced the root mean square of the deviations between the patellar shift and tilt predicted by the model and obtained experimentally for the validation laxity test (from 6.2 mm to 0.5 mm, and from 8.4° to 1.5°, respectively) and passive knee flexion test (from 1.4 mm to 0.3 mm, and from 2.3° to 1.3°, respectively). The non-characterized mechanical properties were found to have a minimal effect on the characterization procedure and its results. CONCLUSION The proposed methodology can help in developing truly patient-specific models of the PFJ, to be used for personalized preplanning of the clinical interventions.
Collapse
Affiliation(s)
- Mohammad Akbar
- Mechanical Engineering Department, Sharif University of Technology, Tehran, Iran
| | - Farzam Farahmand
- Mechanical Engineering Department, Sharif University of Technology, Tehran, Iran; RCBTR, Tehran University of Medical Sciences, Tehran, Iran.
| | - Navid Arjmand
- Mechanical Engineering Department, Sharif University of Technology, Tehran, Iran
| |
Collapse
|
7
|
High Tibial Osteotomy: Review of Techniques and Biomechanics. JOURNAL OF HEALTHCARE ENGINEERING 2019; 2019:8363128. [PMID: 31191853 PMCID: PMC6525872 DOI: 10.1155/2019/8363128] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 04/15/2019] [Indexed: 12/15/2022]
Abstract
High tibial osteotomy becomes increasingly important in the treatment of cartilage damage or osteoarthritis of the medial compartment with concurrent varus deformity. HTO produces a postoperative valgus limb alignment with shifting the load-bearing axis of the lower limb laterally. However, maximizing procedural success and postoperative knee function still possess many difficulties. The key to improve the postoperative satisfaction and long-term survival is the understanding of the vital biomechanics of HTO in essence. This review article discussed the alignment principles, surgical technique, and fixation plate of HTO as well as the postoperative gait, musculoskeletal dynamics, and contact mechanics of the knee joint. We aimed to highlight the recent findings and progresses on the biomechanics of HTO. The biomechanical studies on HTO are still insufficient in the areas of gait analysis, joint kinematics, and joint contact mechanics. Combining musculoskeletal dynamics modelling and finite element analysis will help comprehensively understand in vivo patient-specific biomechanics after HTO.
Collapse
|
8
|
Osborne JD, Luczak SB, Acker WB, Bicos J. Patellofemoral Joint Contact Pressures: Current Concepts and Use in Patellar Instability Studies. Orthopedics 2019; 42:e172-e179. [PMID: 30668882 DOI: 10.3928/01477447-20190118-05] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 06/21/2018] [Indexed: 02/03/2023]
Abstract
The patellofemoral joint is thought to be a common source for knee pain. Improper alignment and function of the patellofemoral joint can lead to abnormal contact pressures, which may explain patients' symptoms. In this review, the authors examine techniques for measuring patellofemoral joint contact pressures and summarize the relevant patellofemoral joint anatomy and contact pressures in normal knee kinematics. Finally, they discuss the results of studies investigating contact pressure changes in cases of patellar instability. This includes both reconstruction of the medial patellofemoral ligament and tibial tubercle osteotomy. [Orthopedics. 2019; 42(2):e172-e179.].
Collapse
|
9
|
Edama M, Okuyama R, Goto S, Sasaki M. Influence of loading rate and limb position on patellar tendon mechanical properties in vivo. Clin Biomech (Bristol, Avon) 2019; 61:52-57. [PMID: 30471637 DOI: 10.1016/j.clinbiomech.2018.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 11/04/2018] [Accepted: 11/09/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND The aims of this study were to clarify the changes of patellar tendon length during isometric knee joint extension and the double leg squat position using ultrasonography. METHODS The left legs of 17 healthy adults were investigated. Isometric knee extension motion was performed at three positions of knee flexion 30° (knee 30°), knee flexion 60° (knee 60°), knee flexion 90° (knee 90°), and at each limb position, 0% (0% peak torque (PT)), 40% (40% PT), 50% (50% PT), and 60% (60% PT) of the maximum knee joint extension torque were executed at random. Both double leg squat motions were randomly performed in three positions: hip flexion 30°, knee flexion 30°, ankle dorsiflexion 10° (squat 30°); hip joint flexion 60°, knee joint flexion 60°, ankle dorsiflexion 20° (squat 60°); and hip joint flexion 90°, knee joint flexion 90°, ankle dorsiflexion 30° (squat 90°). Ultrasonography was used to measure patellar tendon length. FINDINGS There were no significant changes in patellar tendon length and strain between knee flexion angles of 30°, 60°, and 90° in isometric knee joint extension and the double leg squat limb position. INTERPRETATION The loading rate and limb position do not appear to affect the length and strain of the patellar tendon.
Collapse
Affiliation(s)
- M Edama
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Shimami-cho 1398, Kita-ku, Niigata City 950-3198, Japan.
| | - R Okuyama
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Shimami-cho 1398, Kita-ku, Niigata City 950-3198, Japan
| | - S Goto
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Shimami-cho 1398, Kita-ku, Niigata City 950-3198, Japan
| | - M Sasaki
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Shimami-cho 1398, Kita-ku, Niigata City 950-3198, Japan
| |
Collapse
|
10
|
Utilizing Atlas-Based Modeling to Predict Knee Joint Cartilage Degeneration: Data from the Osteoarthritis Initiative. Ann Biomed Eng 2018; 47:813-825. [DOI: 10.1007/s10439-018-02184-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 12/05/2018] [Indexed: 02/07/2023]
|
11
|
The influences of walking, running and stair activity on knee articular cartilage: Quantitative MRI using T1 rho and T2 mapping. PLoS One 2017; 12:e0187008. [PMID: 29136015 PMCID: PMC5685565 DOI: 10.1371/journal.pone.0187008] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 10/11/2017] [Indexed: 01/16/2023] Open
Abstract
OBJECTIVE To explore the different influences of walking, running and stair activity on knee articular cartilage with T1 rho and T2 mapping sequences. MATERIALS AND METHODS MRI (3.0-T) scans of the right knee were performed in twenty-three young healthy adults immediately after 30 minutes of rest, walking, running and stair activity respectively. Articular cartilage was quantitatively assessed based on T1 rho and T2 relaxation times. Analysis of variance for random block design data, bonferroni test and paired samples t tests were performed to estimate the different influences of physiological activities on articular cartilage. RESULTS T1 rho and T2 values had reductions after physiological activities in all regions of articular cartilage. T1 rho and T2 values were decreased more after running than walking. T1 rho and T2 values were decreased more after stair activity than running, except for femoral cartilage. The superficial layer of patella cartilage had higher reduction rates than the deep layer. The T1 rho and T2 values of articular cartilage were reduced in the following order: patellofemoral cartilage> medial tibiofemoral cartilage> lateral tibiofemoral cartilage. Patellofemoral cartilage experienced reductions in the following order: lateral part> middle part> medial part. Tibiofemoral cartilage had reductions in the following order: posterior part> middle part> anterior part. CONCLUSIONS T1 rho and T2 mapping sequences can quantitatively reflect the different influences of physiological activities on knee articular cartilage. Fluid shifts, collagen fiber deformation, spatial heterogeneity, inherent differences in material properties and tissue stiffness have close relationship with cartilage loading characteristics.
Collapse
|
12
|
Mazzoli V, Schoormans J, Froeling M, Sprengers AM, Coolen BF, Verdonschot N, Strijkers GJ, Nederveen AJ. Accelerated 4D self-gated MRI of tibiofemoral kinematics. NMR IN BIOMEDICINE 2017; 30:e3791. [PMID: 28873255 DOI: 10.1002/nbm.3791] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 07/17/2017] [Accepted: 07/19/2017] [Indexed: 06/07/2023]
Abstract
Anatomical (static) magnetic resonance imaging (MRI) is the most useful imaging technique for the evaluation and assessment of internal derangement of the knee, but does not provide dynamic information and does not allow the study of the interaction of the different tissues during motion. As knee pain is often only experienced during dynamic tasks, the ability to obtain four-dimensional (4D) images of the knee during motion could improve the diagnosis and provide a deeper understanding of the knee joint. In this work, we present a novel approach for dynamic, high-resolution, 4D imaging of the freely moving knee without the need for external triggering. The dominant knee of five healthy volunteers was scanned during a flexion/extension task. To evaluate the effects of non-uniform motion and poor coordination skills on the quality of the reconstructed images, we performed a comparison between fully free movement and movement instructed by a visual cue. The trigger signal for self-gating was extracted using principal component analysis (PCA), and the images were reconstructed using a parallel imaging and compressed sensing reconstruction pipeline. The reconstructed 4D movies were scored for image quality and used to derive bone kinematics through image registration. Using our method, we were able to obtain 4D high-resolution movies of the knee without the need for external triggering hardware. The movies obtained with and without instruction did not differ significantly in terms of image scoring and quantitative values for tibiofemoral kinematics. Our method showed to be robust for the extraction of the self-gating signal even for uninstructed motion. This can make the technique suitable for patients who, as a result of pain, may find it difficult to comply exactly with instructions. Furthermore, bone kinematics can be derived from accelerated MRI without the need for additional hardware for triggering.
Collapse
Affiliation(s)
- Valentina Mazzoli
- Department of Radiology, Academic Medical Center, Amsterdam, the Netherlands
- Orthopedic Research Laboratory, Radboud University Medical Center, Nijmegen, the Netherlands
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Jasper Schoormans
- Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, the Netherlands
| | - Martijn Froeling
- Department of Radiology, University Medical Center, Utrecht, the Netherlands
| | - Andre M Sprengers
- Orthopedic Research Laboratory, Radboud University Medical Center, Nijmegen, the Netherlands
- Laboratory for Biomechanical Engineering, University of Twente, Enschede, the Netherlands
| | - Bram F Coolen
- Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, the Netherlands
| | - Nico Verdonschot
- Orthopedic Research Laboratory, Radboud University Medical Center, Nijmegen, the Netherlands
- Laboratory for Biomechanical Engineering, University of Twente, Enschede, the Netherlands
| | - Gustav J Strijkers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
- Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, the Netherlands
| | - Aart J Nederveen
- Department of Radiology, Academic Medical Center, Amsterdam, the Netherlands
| |
Collapse
|
13
|
Kang KT, Koh YG, Son J, Kim SJ, Choi S, Jung M, Kim SH. Finite Element Analysis of the Biomechanical Effects of 3 Posterolateral Corner Reconstruction Techniques for the Knee Joint. Arthroscopy 2017; 33:1537-1550. [PMID: 28454998 DOI: 10.1016/j.arthro.2017.02.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 02/10/2017] [Accepted: 02/10/2017] [Indexed: 02/02/2023]
Abstract
PURPOSE To compare the forces exerted on the cruciate ligaments and the contact stresses on the tibiofemoral (TF) and patellofemoral (PF) joints with respect to 3 different tibial- and fibular-based posterolateral corner (PLC) reconstructions under dynamic loading conditions. METHODS A subject-specific finite element knee model was developed by using 3-dimensional anatomic data from motion captures in gait and squat activities, including in vivo knee joint kinematics and muscle forces for the single subject. Cruciate ligament forces and contact stresses on the TF and PF joints under 3 PLC reconstruction techniques (tibial-based, TBR; modified fibular-based, mFBR; conventional fibular-based, cFBR) and PLC-deficient models were compared with those of the intact model in gait and squat loading conditions. RESULTS The cruciate ligament forces in the 3 surgical models differed from those in the intact model. The greatest differences in ligament forces from the intact model were found in the cFBR model, whereas there were no remarkable differences between the TBR and mFBR models in both gait and squat loading conditions. Contact stresses on the lateral TF and PF joints of the 3 surgical models were greater than those of the intact model under the squat loading condition. CONCLUSIONS The biomechanical effects achieved using the anatomic reconstruction technique were found to be improved compared with those using nonanatomic reconstruction techniques. However, the ligament forces and contact stresses under normal conditions could not be restored through any of the 3 techniques. CLINICAL RELEVANCE Anatomic TBR and FBR for grade III PLC injuries could restore better biomechanics in the knee joint compared with nonanatomic reconstruction. However, discrepancy with the normal condition requires further modification of surgical techniques.
Collapse
Affiliation(s)
- Kyoung-Tak Kang
- Department of Mechanical Engineering, Yonsei University, Seoul, Republic of Korea
| | - Yong-Gon Koh
- Joint Reconstruction Center, Department of Orthopaedic Surgery, Yonsei Sarang Hospital, Seoul, Republic of Korea
| | - Juhyun Son
- Department of Mechanical Engineering, Yonsei University, Seoul, Republic of Korea
| | - Sung-Jae Kim
- Joint Reconstruction Center, Department of Orthopaedic Surgery, Yonsei Sarang Hospital, Seoul, Republic of Korea
| | - Sungryul Choi
- Department of Orthopedic Surgery, Arthroscopy and Joint Research Institute, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Republic of Korea
| | | | - Sung-Hwan Kim
- Department of Orthopedic Surgery, Arthroscopy and Joint Research Institute, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Republic of Korea.
| |
Collapse
|
14
|
Ukachukwu V, Duncan R, Belcher J, Marshall M, Stefanik J, Crossley K, Thomas MJ, Peat G. Clinical Significance of Medial Versus Lateral Compartment Patellofemoral Osteoarthritis: Cross-Sectional Analyses in an Adult Population With Knee Pain. Arthritis Care Res (Hoboken) 2017; 69:943-951. [PMID: 27696767 PMCID: PMC5519922 DOI: 10.1002/acr.23110] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 09/15/2016] [Accepted: 09/27/2016] [Indexed: 01/17/2023]
Abstract
OBJECTIVE To determine the comparative prevalence, associations with selected patient characteristics, and clinical outcomes of medial and lateral compartment patellofemoral (PF) joint osteoarthritis (OA). METHODS Information was collected by questionnaires, clinical assessment, and radiographs from 745 eligible community-dwelling symptomatic adults age ≥50 years. PF joint space narrowing (JSN) and osteophytes were scored from skyline radiographs using the Osteoarthritis Research Society International atlas. Multilevel models were used to assess associations of compartmental PF joint OA with age, sex, body mass index (BMI) and varus-valgus malalignment, while median regression was used to examine associations with clinical outcomes (current pain intensity on a numeric rating scale [0-10] and the function subscale of the Western Ontario and McMaster Universities Osteoarthritis Index [0-68]). RESULTS Isolated lateral PF joint OA was more common than isolated medial PF joint OA, particularly at higher severity thresholds. Irrespective of severity threshold, age (≥2 odds ratio [OR] 1.19 [95% confidence interval (95% CI) 1.12, 1.26]), BMI (≥2 OR 1.15 [95% CI 1.07, 1.24]), and valgus malalignment (≥2 OR 2.58 [95% CI 1.09, 6.07]) were associated with increased odds of isolated lateral JSN, but isolated medial JSN was only associated with age (≥2 OR 1.20 [95% CI 1.14, 1.27]). The pattern of association was less clear for PF joint osteophytes. Isolated lateral PF joint OA, defined by JSN or osteophytes, was associated with higher pain scores than isolated medial PF joint OA, but these differences were modest and were not significant. A similar pattern of association was seen for functional limitation but only when PF joint OA was defined by JSN. CONCLUSION Isolated lateral PF joint OA is more common than isolated medial PF joint OA, and it is more consistently associated with established OA risk factors. It is also associated with higher, but clinically nonsignificant, pain and function scores than isolated medial PF joint OA, particularly when PF joint OA is defined using JSN.
Collapse
Affiliation(s)
- Vincent Ukachukwu
- Arthritis Research UK Primary Care Centre, Research Institute for Primary Care & Health Sciences, Keele University, Keele, Staffordshire, UK, and Moss Lane Surgery, Moss LaneMadeleyCreweUK
| | - Rachel Duncan
- Institute of Health & Society, Newcastle UniversityNewcastle upon TyneUK
| | - John Belcher
- Arthritis Research UK Primary Care Centre, Research Institute for Primary Care & Health Sciences, Keele UniversityKeeleStaffordshireUK
| | - Michelle Marshall
- Arthritis Research UK Primary Care Centre, Research Institute for Primary Care & Health Sciences, Keele UniversityKeeleStaffordshireUK
| | | | | | - Martin J. Thomas
- Arthritis Research UK Primary Care Centre, Research Institute for Primary Care & Health Sciences, Keele UniversityKeeleStaffordshireUK
| | - George Peat
- Arthritis Research UK Primary Care Centre, Research Institute for Primary Care & Health Sciences, Keele UniversityKeeleStaffordshireUK
| |
Collapse
|
15
|
Louis MJ, Malayalamurthi R. Stress response of patellofemoral joint subjected to femoral retroversion with various patellar kinematics and flexions – An FEA study. Biocybern Biomed Eng 2017. [DOI: 10.1016/j.bbe.2016.12.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
16
|
Prophylactic knee bracing alters lower-limb muscle forces during a double-leg drop landing. J Biomech 2016; 49:3347-3354. [PMID: 27592299 DOI: 10.1016/j.jbiomech.2016.08.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 07/04/2016] [Accepted: 08/20/2016] [Indexed: 11/24/2022]
Abstract
Anterior cruciate ligament (ACL) injury can be a painful, debilitating and costly consequence of participating in sporting activities. Prophylactic knee bracing aims to reduce the number and severity of ACL injury, which commonly occurs during landing maneuvers and is more prevalent in female athletes, but a consensus on the effectiveness of prophylactic knee braces has not been established. The lower-limb muscles are believed to play an important role in stabilizing the knee joint. The purpose of this study was to investigate the changes in lower-limb muscle function with prophylactic knee bracing in male and female athletes during landing. Fifteen recreational athletes performed double-leg drop landing tasks from 0.30m and 0.60m with and without a prophylactic knee brace. Motion analysis data were used to create subject-specific musculoskeletal models in OpenSim. Static optimization was performed to calculate the lower-limb muscle forces. A linear mixed model determined that the hamstrings and vasti muscles produced significantly greater flexion and extension torques, respectively, and greater peak muscle forces with bracing. No differences in the timings of peak muscle forces were observed. These findings suggest that prophylactic knee bracing may help to provide stability to the knee joint by increasing the active stiffness of the hamstrings and vasti muscles later in the landing phase rather than by altering the timing of muscle forces. Further studies are necessary to quantify whether prophylactic knee bracing can reduce the load placed on the ACL during intense dynamic movements.
Collapse
|
17
|
Halonen KS, Mononen ME, Jurvelin JS, Töyräs J, Kłodowski A, Kulmala JP, Korhonen RK. Importance of Patella, Quadriceps Forces, and Depthwise Cartilage Structure on Knee Joint Motion and Cartilage Response During Gait. J Biomech Eng 2016; 138:2520868. [DOI: 10.1115/1.4033516] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Indexed: 11/08/2022]
Abstract
In finite-element (FE) models of the knee joint, patella is often omitted. We investigated the importance of patella and quadriceps forces on the knee joint motion by creating an FE model of the subject's knee. In addition, depthwise strains and stresses in patellar cartilage with different tissue properties were determined. An FE model was created from subject's magnetic resonance images. Knee rotations, moments, and translational forces during gait were recorded in a motion laboratory and used as an input for the model. Three material models were implemented into the patellar cartilage: (1) homogeneous model, (2) inhomogeneous (arcadelike fibrils), and (3) random fibrils at the superficial zone, mimicking early stages of osteoarthritis (OA). Implementation of patella and quadriceps forces into the model substantially reduced the internal–external femoral rotations (versus without patella). The simulated rotations in the model with the patella matched the measured rotations at its best. In the inhomogeneous model, maximum principal stresses increased substantially in the middle zone of the cartilage. The early OA model showed increased compressive strains in the superficial and middle zones of the cartilage and decreased stresses and fibril strains especially in the middle zone. The results suggest that patella and quadriceps forces should be included in moment- and force-driven FE knee joint models. The results indicate that the middle zone has a major role in resisting shear forces in the patellar cartilage. Also, early degenerative changes in the collagen network substantially affect the cartilage depthwise response in the patella during walking.
Collapse
Affiliation(s)
- K. S. Halonen
- Department of Applied Physics, University of Eastern Finland, POB 1627, Kuopio FI-70211, Finland e-mail:
| | - M. E. Mononen
- Department of Applied Physics, University of Eastern Finland, POB 1627, Kuopio FI-70211, Finland
| | - J. S. Jurvelin
- Department of Applied Physics, University of Eastern Finland, POB 1627, Kuopio FI-70211, Finland
- Diagnostic Imaging Centre, Kuopio University Hospital, POB 100, Kuopio FI-70029, Finland
| | - J. Töyräs
- Department of Applied Physics, University of Eastern Finland, POB 1627, Kuopio FI-70211, Finland
- Diagnostic Imaging Centre, Kuopio University Hospital, POB 100, Kuopio FI-70029, Finland
| | - A. Kłodowski
- Laboratory of Machine Design, Lappeenranta University of Technology, Lappeenranta 53850, Finland
| | - J.-P. Kulmala
- Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä 40014, Finland
| | - R. K. Korhonen
- Department of Applied Physics, University of Eastern Finland, POB 1627, Kuopio FI-70211, Finland
- Diagnostic Imaging Centre, Kuopio University Hospital, POB 100, Kuopio FI-70029, Finland
| |
Collapse
|
18
|
Calliess T, Ettinger M, Schado S, Becher C, Hurschler C, Ostermeier S. Patella tracking and patella contact pressure in modular patellofemoral arthroplasty: a biomechanical in vitro analysis. Arch Orthop Trauma Surg 2016; 136:849-55. [PMID: 27052369 DOI: 10.1007/s00402-016-2451-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Indexed: 01/10/2023]
Abstract
INTRODUCTION In the recent years modular partial knee prosthesis with the opportunity to combine unicompartmental tibiofemoral (UKA) and patellofemoral prosthesis (PFJ) were introduced to the clinics. To date, little is known about the biomechanics of these bi-cruciate retaining prosthetic designs. Aim of this study was to evaluate the influence of a PFJ in bicompartmental arthroplasty (UKA + PFJ) on patella tracking and retropatella pressure distribution. METHODS A dynamic in vitro knee kinemator simulating an isokinetic extension cycle of the knee was used on eight knee specimen. Patella tracking and patellofemoral contact pressure were evaluated using pressure sensitive films after implantation of a medial UNI and after subsequent implantation of a PFJ. RESULTS Whereas the area contact pressure remained the same after PFJ implantation, the contact area was reduced significantly and significantly elevated peak pressures were determined in deep flexion and close to extension. The patella tracking was not significantly altered, however, effects of edge loading could be shown. CONCLUSION When using PFJ prosthesis, one must be aware of altered pressure introduction on the retropatella surface compared to the physiological situation. The elevated peak pressures and reduced contact area may be an argument for patella resurfacing and the problems of edge loading indicate that care must be taken on the correct implantation of the device with no implant overhang.
Collapse
Affiliation(s)
- Tilman Calliess
- Department of Orthopaedic Surgery, Hannover Medical School, Anna-von-Borries-Str. 3, 30625, Hannover, Germany.
| | - Max Ettinger
- Department of Orthopaedic Surgery, Hannover Medical School, Anna-von-Borries-Str. 3, 30625, Hannover, Germany
| | - Ssuheib Schado
- Department of Orthopaedic Surgery, Hannover Medical School, Anna-von-Borries-Str. 3, 30625, Hannover, Germany
| | - Christoph Becher
- Department of Orthopaedic Surgery, Hannover Medical School, Anna-von-Borries-Str. 3, 30625, Hannover, Germany
| | - Christof Hurschler
- Department of Orthopaedic Surgery, Hannover Medical School, Anna-von-Borries-Str. 3, 30625, Hannover, Germany
| | - Sven Ostermeier
- Department of Orthopaedic Surgery, Hannover Medical School, Anna-von-Borries-Str. 3, 30625, Hannover, Germany.,Orthopädische Praxis und Gelenk-Klinik, Alte Bundesstrasse 58, 79194, Gundelfingen, Germany
| |
Collapse
|
19
|
Venäläinen M, Mononen M, Väänänen S, Jurvelin J, Töyräs J, Virén T, Korhonen R. Effect of bone inhomogeneity on tibiofemoral contact mechanics during physiological loading. J Biomech 2016; 49:1111-1120. [DOI: 10.1016/j.jbiomech.2016.02.033] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 12/16/2015] [Accepted: 02/16/2016] [Indexed: 11/30/2022]
|
20
|
Chen TL, An WW, Chan ZYS, Au IPH, Zhang ZH, Cheung RTH. Immediate effects of modified landing pattern on a probabilistic tibial stress fracture model in runners. Clin Biomech (Bristol, Avon) 2016; 33:49-54. [PMID: 26945721 DOI: 10.1016/j.clinbiomech.2016.02.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 02/12/2016] [Accepted: 02/17/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Tibial stress fracture is a common injury in runners. This condition has been associated with increased impact loading. Since vertical loading rates are related to the landing pattern, many heelstrike runners attempt to modify their footfalls for a lower risk of tibial stress fracture. Such effect of modified landing pattern remains unknown. This study examined the immediate effects of landing pattern modification on the probability of tibial stress fracture. METHODS Fourteen experienced heelstrike runners ran on an instrumented treadmill and they were given augmented feedback for landing pattern switch. We measured their running kinematics and kinetics during different landing patterns. Ankle joint contact force and peak tibial strains were estimated using computational models. We used an established mathematical model to determine the effect of landing pattern on stress fracture probability. FINDINGS Heelstrike runners experienced greater impact loading immediately after landing pattern switch (P<0.004). There was an increase in the longitudinal ankle joint contact force when they landed with forefoot (P=0.003). However, there was no significant difference in both peak tibial strains and the risk of tibial stress fracture in runners with different landing patterns (P>0.986). INTERPRETATION Immediate transitioning of the landing pattern in heelstrike runners may not offer timely protection against tibial stress fracture, despite a reduction of impact loading. Long-term effects of landing pattern switch remains unknown.
Collapse
Affiliation(s)
- T L Chen
- Gait & Motion Analysis Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong
| | - W W An
- Gait & Motion Analysis Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong
| | - Z Y S Chan
- Gait & Motion Analysis Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong
| | - I P H Au
- Gait & Motion Analysis Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong
| | - Z H Zhang
- Gait & Motion Analysis Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong
| | - R T H Cheung
- Gait & Motion Analysis Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong.
| |
Collapse
|
21
|
Latypova A, Arami A, Becce F, Jolles-Haeberli B, Aminian K, Pioletti DP, Terrier A. A patient-specific model of total knee arthroplasty to estimate patellar strain: A case study. Clin Biomech (Bristol, Avon) 2016; 32:212-9. [PMID: 26651475 DOI: 10.1016/j.clinbiomech.2015.11.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 11/19/2015] [Accepted: 11/19/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND Inappropriate patellar cut during total knee arthroplasty can lead to patellar complications due to increased bone strain. In this study, we evaluated patellar bone strain of a patient who had a deeper patellar cut than the recommended. METHODS A patient-specific model based on patient preoperative data was created. The model was decoupled into two levels: knee and patella. The knee model predicted kinematics and forces on the patella during squat movement. The patella model used these values to predict bone strain after total knee arthroplasty. Mechanical properties of the patellar bone were identified with micro-finite element modeling testing of cadaveric samples. The model was validated with a robotic knee simulator and postoperative X-rays. For this patient, we compared the deeper patellar cut depth to the recommended one, and evaluated patellar bone volume with octahedral shear strain above 1%. FINDINGS Model predictions were consistent with experimental measurements of the robotic knee simulator and postoperative X-rays. Compared to the recommended cut, the deeper cut increased the critical strain bone volume, but by less than 3% of total patellar volume. INTERPRETATION We thus conclude that the predicted increase in patellar strain should be within an acceptable range, since this patient had no complaints 8 months after surgery. This validated patient-specific model will later be used to address other questions on groups of patients, to eventually improve surgical planning and outcome of total knee arthroplasty.
Collapse
Affiliation(s)
- Adeliya Latypova
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Biomechanical Orthopedics, Lausanne, Switzerland
| | - Arash Arami
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Movement Analysis and Measurement, Lausanne, Switzerland
| | - Fabio Becce
- Lausanne University Hospital (CHUV), Department of Diagnostic and Interventional Radiology, Lausanne, Switzerland
| | | | - Kamiar Aminian
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Movement Analysis and Measurement, Lausanne, Switzerland
| | - Dominique P Pioletti
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Biomechanical Orthopedics, Lausanne, Switzerland
| | - Alexandre Terrier
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Biomechanical Orthopedics, Lausanne, Switzerland.
| |
Collapse
|
22
|
Guan S, Gray HA, Keynejad F, Pandy MG. Mobile Biplane X-Ray Imaging System for Measuring 3D Dynamic Joint Motion During Overground Gait. IEEE TRANSACTIONS ON MEDICAL IMAGING 2016; 35:326-336. [PMID: 26316030 DOI: 10.1109/tmi.2015.2473168] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Most X-ray fluoroscopy systems are stationary and impose restrictions on the measurement of dynamic joint motion; for example, knee-joint kinematics during gait is usually measured with the subject ambulating on a treadmill. We developed a computer-controlled, mobile, biplane, X-ray fluoroscopy system to track human body movement for high-speed imaging of 3D joint motion during overground gait. A robotic gantry mechanism translates the two X-ray units alongside the subject, tracking and imaging the joint of interest as the subject moves. The main aim of the present study was to determine the accuracy with which the mobile imaging system measures 3D knee-joint kinematics during walking. In vitro experiments were performed to measure the relative positions of the tibia and femur in an intact human cadaver knee and of the tibial and femoral components of a total knee arthroplasty (TKA) implant during simulated overground gait. Accuracy was determined by calculating mean, standard deviation and root-mean-squared errors from differences between kinematic measurements obtained using volumetric models of the bones and TKA components and reference measurements obtained from metal beads embedded in the bones. Measurement accuracy was enhanced by the ability to track and image the joint concurrently. Maximum root-mean-squared errors were 0.33 mm and 0.65° for translations and rotations of the TKA knee and 0.78 mm and 0.77° for translations and rotations of the intact knee, which are comparable to results reported for treadmill walking using stationary biplane systems. System capability for in vivo joint motion measurement was also demonstrated for overground gait.
Collapse
|