A knee simulating machine for performance evaluation of total knee replacements

Walker, Peter S.; Blunn, Gordon; Broome, D R; Perry, Jacquelin; Watkins, Alan; Sathasivam, Shivani; Dewar, M. E.; Paul, J. P.

doi:10.1016/s0021-9290(96)00118-2

Cited by 144 publications

(86 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The AP and IE kinematic results for the semiconstrained design compared well with experimental data for the implant 23 obtained from force controlled gait simulation in the knee simulator 9,12 (Fig. 2).…”

Section: Resultssupporting

confidence: 63%

“…Springs representing soft tissue constraint on the knee simulator were also included in the model. 12,23 Mesh convergence was verified previously. 23 For computational efficiency, the components were represented as rigid bodies with a previously verified pressure-overclosure relationship that was optimized for each implant geometry and mesh.…”

Section: Finite Element Modelmentioning

confidence: 87%

“…9,12 The semi-constrained geometry had a single sagittal radius, while the unconstrained implant was flat centrally with a posterior lip. The meshes and boundary conditions of the FE model (Fig.…”

Section: Finite Element Modelmentioning

confidence: 99%

“…12,25 A femoral flexion angle and compressive load were applied to the femoral component, while an AP force and IE torque were applied to the tibial component. The tibial component was constrained in the inferior-superior (IS), flexion-extension (FE), and VV degrees of freedom and was free in the medial-lateral (ML) degree of freedom.…”

Section: Finite Element Modelmentioning

confidence: 99%

“…Force controlled wear simulators 9,12 aim to reproduce knee joint loading to evaluate kinematics and wear of implant designs. Component wear is related to interface contact pressures and relative motions, [13][14][15] and changes in kinematics have been directly related to wear rate in in vitro studies.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Effects of knee simulator loading and alignment variability on predicted implant mechanics: A probabilistic study

et al. 2006

View full text Add to dashboard Cite

Inherent variability in total knee arthroplasty loading and alignment, present in vivo and in simulator testing, may ultimately influence polyethylene tibial insert wear and long-term performance. The effect of this variability was quantified on implant kinematics and contact mechanics during simulated gait loading conditions using semi-constrained and unconstrained fixed bearing, cruciate retaining implants. A probabilistic finite element model of the Stanmore knee wear simulator was utilized to estimate the envelope of anterior-posterior (AP) and internal-external (IE) position and contact pressure and to evaluate the variability in corresponding ranges of motion (ROM). Variability levels were represented by standard deviations of up to 10% of the maximum value for load inputs and 0.25 mm and 0.58 for component alignment inputs. Model predictions compared well with experimental simulator results for the semi-constrained implant, with predicted positional envelopes of up to 1.8 mm (AP) an 3.48 (IE) for the semi-constrained and upto 2.6 mm (AP) and 3.78 (IE) for the unconstrained implant at the variability levels evaluated. ROM varied by up to 22%, while peak contact pressure variations averaged less than 2 MPa for both designs. For each implant, loading variability was more influential during the swing phase of gait, while alignment variability affected kinematics more during stance. The relative rank of sensitivities showed differences between the two designs, providing insight into critical parameters affecting kinematics and contact characteristics. ß

show abstract

Section: Resultssupporting

confidence: 63%

Section: Finite Element Modelmentioning

confidence: 87%

Section: Finite Element Modelmentioning

confidence: 99%

Section: Finite Element Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effects of knee simulator loading and alignment variability on predicted implant mechanics: A probabilistic study

et al. 2006

View full text Add to dashboard Cite

show abstract

Effects of A-P translation and rotation on the wear of UHMWPE in a total knee joint simulator

Kawanabe

Clarke

Tamura

et al. 2000

J. Biomed. Mater. Res.

View full text Add to dashboard Cite

We developed a three-channel total knee joint simulator and studied the effect of tibial anterior-posterior translation and internal/external rotation on the wear of polyethylene tibial inserts in total knee replacements (Anatomic Graduated Component knees). The wear rate was the lowest in experiment (Exp.) 1, without translation and rotation [1.74 mg/million (mg/Mc) cycles]. In Exp. 2, with +/-5 degrees tibial rotation added, the wear rate increased to 10.6 mg/Mc. In Exp. 3, with rotation and -12 mm tibial translation added, the wear rate was 15.1 mg/Mc, whereas in Exp. 4, with rotation and +12 mm tibial translation, the wear rate was 18.7 mg/Mc. Internal/external rotation and anterior-posterior translation added a 6- to 11-fold increase in the wear rates of tibial knee inserts. The shapes of the tibial wear tracks were rectangular and the area of the track increased when rotation and translation were added.

show abstract

References

2011

Mathematical and Computational Methods in Biomechanics of Human Skeletal Systems

View full text Add to dashboard Cite

A knee simulating machine for performance evaluation of total knee replacements

Cited by 144 publications

References 12 publications

Effects of knee simulator loading and alignment variability on predicted implant mechanics: A probabilistic study

Effects of knee simulator loading and alignment variability on predicted implant mechanics: A probabilistic study

Effects of A-P translation and rotation on the wear of UHMWPE in a total knee joint simulator

References

Contact Info

Product

Resources

About