The success of total knee arthroplasty depends, in part, on the ability of the surgeon to properly manage the soft tissues surrounding the joint, but an objective definition as to what constitutes acceptable postoperative joint stability does not exist. Such a definition may not exist due to lack of suitable instrumentation, as joint stability is currently assessed by visual inspection while the surgeon manipulates the joint. Having the ability to accurately and precisely measure knee stability at the time of surgery represents a key requirement in the process of objectively defining acceptable joint stability. Therefore, we created a novel sterilizable device to allow surgeons to measure varus-valgus, internal-external, or anterior-posterior stability of the knee during a total knee arthroplasty. The device can be quickly adjusted between 0 deg and 90 deg of knee flexion. The device interfaces with a custom surgical navigation system, which records the resultant rotations or translations of the knee while the surgeon applies known loads to a patient’s limb with a handle instrumented with a load cell. We validated the performance of the device by having volunteers use it to apply loads to a mechanical linkage that simulated a knee joint; we then compared the joint moments calculated by our stability device against those recorded by a load cell in the simulated knee joint. Validation of the device showed low mean errors (less than 0.21 ± 1.38 Nm and 0.98 ± 3.93 N) and low RMS errors (less than 1.5 Nm and 5 N). Preliminary studies from total knee arthroplasties performed on ten cadaveric specimens also demonstrate the utility of our new device. Eventually, the use of this device may help determine how intra-operative knee stability relates to postoperative function and could lead to an objective definition of knee stability and more efficacious surgical techniques.

References

References
1.
Siston
,
R. A.
,
Goodman
,
S. B.
,
Delp
,
S. L.
, and
Giori
,
N. J.
, 2007, “
Coronal Plane Stability Before and After Total Knee Arthroplasty
,”
Clin. Orthop. Relat. Res.
,
463
, pp.
43
49
.
2.
Yercan
,
H. S.
,
Ait Si Selmi
,
T.
,
Sugun
,
T. S.
, and
Neyret
,
P.
, 2005, “
Tibiofemoral Instability in Primary Total Knee Replacement: A Review, Part 1: Basic Principles and Classification
,”
The Knee
,
12
(
4
), pp.
257
266
.
3.
Fehring
,
T. K.
, and
Valadie
,
A. L.
, 1994, “
Knee Instability after Total Knee Arthroplasty
,”
Clin. Orthop. Relat. Res.
,
299
, pp.
157
162
.
4.
Keeney
,
J. A.
,
Clohisy
,
J. C.
,
Curry
,
M.
, and
Maloney
,
W. J.
, 2005, “
Revision Total Knee Arthroplasty for Restricted Motion
,”
Clin. Orthop. Relat. Res.
,
440
, pp.
135
140
.
5.
Insall
,
J. N.
,
Binazzi
,
R.
,
Soudry
,
M.
, and
Mestriner
,
L. A.
, 1985, “
Total Knee Arthroplasty
,”
Clin. Orthop. Relat. Res.
,
192
, pp.
13
22
.
6.
Wasielewski
,
R. C.
,
Galante
,
J. O.
,
Leighty
,
R. M.
,
Natarajan
,
R. N.
, and
Rosenberg
,
A. G.
, 1994, “
Wear Patterns on Retrieved Polyethylene Tibial Inserts and Their Relationship to Technical Considerations During Total Knee Arthroplasty
,”
Clin. Orthop. Relat. Res.
,
299
, pp.
31
43
.
7.
Mulhall
,
K. J.
,
Ghomrawi
,
H. M.
,
Scully
,
S.
,
Callaghan
,
J. J.
, and
Saleh
,
K. J.
, 2006, “
Current Etiologies and Modes of Failure in Total Knee Arthroplasty Revision
,”
Clin. Orthop. Relat. Res.
,
446
, pp.
45
50
.
8.
Bellemans
,
J.
,
D’hooghe
,
P.
,
Vandenneucker
,
H.
,
Van Damme
,
G.
, and
Victor
,
J.
, 2006, “
Soft Tissue Balance in Total Knee Arthroplasty: Does Stress Relaxation Occur Perioperatively?
,”
Clin. Orthop. Relat. Res.
,
452
, pp.
49
52
.
9.
Griffin
,
F. M.
,
Insall
,
J. N.
, and
Scuderi
,
G. R.
, 2000, “
Accuracy of Soft Tissue Balancing in Total Knee Arthroplasty
,”
J. Arthroplasty
,
15
(
8
), pp.
970
973
.
10.
Markolf
,
K. L.
,
Mensch
,
J. S.
, and
Amstutz
,
H. C.
, 1976, “
Stiffness and Laxity of the Knee–the Contributions of the Supporting Structures. A Quantitative in vitro Study
,”
J. Bone Jt. Surg. Am.
,
58
(
5
), pp.
583
594
.
11.
Van Damme
,
G.
,
Defoort
,
K.
,
Ducoulombier
,
Y.
,
Van Glabbeek
,
F.
,
Bellemans
,
J.
, and
Victor
,
J.
, 2005, “
What Should the Surgeon Aim for When Performing Computer-Assisted Total Knee Arthroplasty?
,”
J. Bone Jt. Surg. Am.
,
87
(
Suppl 2
), pp.
52
58
.
12.
Fukubayashi
,
T.
,
Torzilli
,
P. A.
,
Sherman
,
M. F.
, and
Warren
,
R. F.
, 1982, “
An In Vitro Biomechanical Evaluation of Anterior-Posterior Motion of the Knee. Tibial Displacement, Rotation, and Torque
,”
J. Bone Jt. Surg. Am.
,
64
(
2
), pp.
258
264
.
13.
Mills
,
O. S.
, and
Hull
,
M. L.
, 1991, “
Rotational Flexibility of the Human Knee Due to Varus/Valgus and Axial Moments In Vivo
,”
J. Biomech.
,
24
(
8
), pp.
673
690
.
14.
Markolf
,
K. L.
,
Graff-Radford
,
A.
, and
Amstutz
,
H. C.
, 1978, “
In Vivo Knee Stability. A Quantitative Assessment Using an Instrumented Clinical Testing Apparatus
,”
J Bone Jt. Surg Am.
,
60
(
5
), pp.
664
674
.
15.
Fleming
,
B. C.
,
Brattbakk
,
B.
,
Peura
,
G. D.
,
Badger
,
G. J.
, and
Beynnon
,
B. D.
, 2002, “
Measurement of Anterior-Posterior Knee Laxity: A Comparison of Three Techniques
,”
J. Orthop. Res.
,
20
(
3
), pp.
421
426
.
16.
Van Der Esch
,
M.
,
Steultjens
,
M.
,
Ostelo
,
R. W.
,
Harlaar
,
J.
, and
Dekker
,
J.
, 2006, “
Reproducibility of Instrumented Knee Joint Laxity Measurement in Healthy Subjects
,”
Rheumatology
,
45
(
5
), pp.
595
599
.
17.
Shultz
,
S. J.
, and
Nguyen
,
A. D.
, 2007, “
Bilateral Asymmetries in Clinical Measures of Lower-Extremity Anatomic Characteristics
,”
Clin. J. Sport Med.
,
17
(
5
), pp.
357
361
.
18.
Cromie
,
M. J.
,
Siston
,
R. A.
,
Giori
,
N. J.
, and
Delp
,
S. L.
, 2008, “
Posterior Cruciate Ligament Removal Contributes to Abnormal Knee Motion During Posterior Stabilized Total Knee Arthroplasty
,”
J. Orthop. Res.
,
26
(
11
), pp.
1494
1499
.
19.
Siston
,
R. A.
,
Giori
,
N. J.
,
Goodman
,
S. B.
, and
Delp
,
S. L.
, 2006, “
Intraoperative Passive Kinematics of Osteoarthritic Knees before and After Total Knee Arthroplasty
,”
J. Orthop. Res.
,
24
(
8
), pp.
1607
1614
.
20.
Shultz
,
S. J.
,
Shimokochi
,
Y.
,
Nguyen
,
A. D.
,
Schmitz
,
R. J.
,
Beynnon
,
B. D.
, and
Perrin
,
D. H.
, 2007, “
Measurement of Varus-Valgus and Internal-External Rotational Knee Laxities In Vivo–Part I: Assessment of Measurement Reliability and Bilateral Asymmetry
,”
J. Orthop. Res.
,
25
(
8
), pp.
981
988
.
21.
Yoshioka
,
Y.
,
Siu
,
D. W.
,
Scudamore
,
R. A.
, and
Cooke
,
T. D.
, 1989, “
Tibial Anatomy and Functional Axes
,”
J. Orthop. Res.
,
7
(
1
), pp.
132
137
.
22.
Mills
,
O. S.
, and
Hull
,
M. L.
, 1991, “
Apparatus to Obtain Rotational Flexibility of the Human Knee Under Moment Loads In Vivo
,”
J. Biomech.
,
24
(
6
), pp.
351
369
.
23.
Siston
,
R. A.
,
Giori
,
N. J.
,
Goodman
,
S. B.
, and
Delp
,
S. L.
, 2007, “
Surgical Navigation for Total Knee Arthroplasty: A Perspective
,”
J. Biomech.
,
40
(
4
), pp.
728
735
.
24.
Sharma
,
L.
,
Lou
,
C.
,
Felson
,
D. T.
,
Dunlop
,
D. D.
,
Kirwan-Mellis
,
G.
,
Hayes
,
K. W.
,
Weinrach
,
D.
, and
Buchanan
,
T. S.
, 1999, “
Laxity in Healthy and Osteoarthritic Knees
,”
Arthritis Rheum.
,
42
(
5
), pp.
861
870
.
25.
Siston
,
R. A.
,
Patel
,
J. J.
,
Goodman
,
S. B.
,
Delp
,
S. L.
, and
Giori
,
N. J.
, 2005, “
The Variability of Femoral Rotational Alignment in Total Knee Arthroplasty
,”
J. Bone Jt. Surg. Am.
,
87
(
10
), pp.
2276
2280
.
26.
Insall
,
J. N.
,
Dorr
,
L. D.
,
Scott
,
R. D.
, and
Scott
,
W. N.
, 1989, “
Rationale of the Knee Society Clinical Rating System
,”
Clin. Orthop. Relat. Res.
,
248
, pp.
13
14
.
27.
Wasielewski
,
R. C.
,
Galat
,
D. D.
, and
Komistek
,
R. D.
, 2005, “
Correlation of Compartment Pressure Data From an Intraoperative Sensing Device With Postoperative Fluoroscopic Kinematic Results in TKA Patients
,”
J. Biomech.
,
38
(
2
), pp.
333
339
.
28.
Schmitt
,
L. C.
, and
Rudolph
,
K. S.
, 2008, “
Muscle Stabilization Strategies in People With Medial Knee Osteoarthritis: The Effect of Instability
,”
J. Orthop. Res.
,
26
(
9
), pp.
1180
1185
.
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