Posterior stabilized (PS) total knees are regarded as one classification, although there are considerable differences in condylar and cam-post geometries which may affect their kinematic outputs. Evaluation methods for kinematics have included Oxford type machines [1], robots [2], knee simulators [3,4], computer models [5], and loading rigs specifically designed to measure laxity in line with the ASTM standard on constraint [6].

We developed a desktop machine for kinematic evaluation of total knee models under a full range of loading conditions and flexion angles, and proposed that the data from the anatomic knee be used as the benchmark [7].

Our hypotheses were that current PS designs will show a large variation in kinematic output, that these would differ from anatomic characteristics, and that an asymmetric guided motion design could potentially restore anatomic...

References

References
1.
Varadarajan
,
K. M.
,
Harry
,
R. E.
,
Johnson
,
T.
, and
Li
,
G.
,
2010
, “
Can In Vitro Systems Capture the Characteristic Differences Between the Flexion-Extension Kinematics of the Healthy and TKA Knee?
,”
Med Eng Phys.
,
31
(
8
), pp.
899
906
.10.1016/j.medengphy.2009.06.005
2.
Li
,
G.
,
Most
,
E
.,
Sultan
,
P. G.
,
Schule
,
S.
,
Zayontz
,
S
.,
Park
,
S. E.
, and
Rubash
,
H. E.
, 2004, “
Knee Kinematics With a High-Flexion Posterior Stabilized Total Knee Prosthesis: An In Vitro Robotic Experimental Investigation,” JBJS Am.
,
86-A
(
8
), pp.
1721
1729
.
3.
DesJardins
,
J. D.
,
Banks
,
S. A.
,
Benson
,
L. C.
,
Pace
,
T.
, and
LaBerge
,
M. A.
,
2007
, “
Direct Comparison of Patient and Force-Controlled Simulator Total Knee Replacement Kinematics,” J. Biomech.
,
40
(
15
), pp.
3458
3466
.
4.
Haider
,
H.
,
Walker
,
P. S.
,
Desjardins
,
J.
, and
Blunn
,
G.
, 2006, “
Effects of Patient and Surgical Alignment Variables on Kinematics in TKR Simulation Under Force-Control,” JAI.
,
3
(
10
).
5.
Mihalko
,
W. M.
,
Conner
,
D. J.
,
Benner
,
R.
, and
Williams
,
J. L.
, 2012, “
How does TKA Kinematics Vary With Transverse Plane Alignment Changes in a Contemporary Implant?,” Clin. Orthop. Relat. Res.
,
470
(
1
), pp.
186
192
.
6.
ASTM Standard
F1223-08,
2008
, “
Determination of Total Knee Replacement Constraint
,”
ASTM International, West Conshohocken
, PA, 2008, DOI: 10.1520/F1223-08, www.astm.org
7.
Walker
,
P. S.
,
Heller
,
Y.
,
Yildirim
,
I.
, and
Immerman
,
I.
, 2011, “
Reference Axes for Comparing the Motion of Knee Replacements With the Anatomic Knee,” Knee
,
18
(
5
), pp.
312
316
.
8.
Haider
,
H.
,
Walker
,
P. S.
,
Desjardins
,
J.
, and
Blunn
,
G.
, “
Effects of Patient and Surgical Alignment Variables on Kinematics in TKR Simulation Under Force-Control
,” JAI,
3
(
10
).
You do not currently have access to this content.