The areas of the most frequent cartilage loss in mild–moderate medial osteoarthritis (OA) were reviewed from previous studies. Implant components were designed to resurface these areas. The surface geometries of the components were based on an average femur and tibia produced from 20 magnetic resonance imaging (MRI) models of normal knees. Accuracy of fit of the components was determined on these 20 individual knees. The femoral surface was toroidal, covering a band on the distal end of the femur, angled inward anteriorly. For a five-size system, the average deviations between the implant surfaces and the intact cartilage surfaces of 20 femurs were only 0.3 mm. For the tibia, the deviations were 0.5–0.7 mm, but the errors were mainly around the tibial spine, with smaller deviations in the central bearing region. Hence, these small implant components would accurately restore the original bearing surfaces and allow for preservation of all the knee structures. Using a thin metal component for the tibia would preserve the strong cancellous bone near the surface, an advantage for fixation. In this case, the femoral component would have a plastic bearing surface, but still be less than 10 mm thickness. Such a design could have a useful place in the early treatment of medial OA of the knee.

References

References
1.
Watanabe
,
T.
,
Abbasi
,
A. Z.
,
Conditt
,
M. A.
,
Christopher
,
J.
,
Kreuzer
,
S.
,
Otto
,
J. K.
, and
Banks
,
S. A.
,
2014
, “
In Vivo Kinematics of a Robot-Assisted Uni- and Multi-Compartmental Knee Arthroplasty
,”
J. Orthop. Sci.
,
19
(
4
), pp.
552
557
.
2.
Foran
,
J. R.
,
Brown
,
N. M.
,
Della Valle
,
C. J.
,
Berger
,
R. A.
, and
Galante
,
J. O.
,
2013
, “
Long-Term Survivorship and Failure Modes of Unicompartmental Knee Arthroplasty
,”
Clin. Orthop. Relat. Res.
,
471
(
1
), pp.
102
108
.
3.
Argenson
,
J. N. A.
,
Blanc
,
G.
,
Aubaniac
,
J. M.
, and
Parratte
,
S.
,
2013
, “
Modern Unicompartmental Knee Arthroplasty With Cement: A Concise Follow-Up, as a Mean of Twenty Years, of a Previous Report
,”
J. Bone Joint Surg. Am.
,
95
(
10
), pp.
905
909
.
4.
Arno
,
S.
,
Maffei
,
D.
,
Walker
,
P. S.
,
Schwarzkopf
,
R.
,
Desai
,
P.
, and
Steiner
,
G. C.
,
2011
, “
Retrospective Analysis of Total Knee Arthroplasty Cases for Visual, Histological, and Clinical Eligibility of Unicompartmental Knee Arthroplasties
,”
J. Arthroplasty
,
26
(
8
), pp.
1396
1403
.
5.
Arno
,
S.
,
Walker
,
P. S.
,
Bell
,
C. P.
,
Krasnokutsky
,
S.
,
Samuels
,
J.
,
Abramson
,
S. B.
,
Regatte
,
R.
, and
Recht
,
M.
,
2012
, “
Relation Between Cartilage Volume and Meniscal Contact in Medial Osteoarthritic of the Knee
,”
Knee
,
19
(
6
), pp.
896
901
.
6.
Buck
,
R. J.
,
Wyman
,
B. T.
,
Le Graverand
,
H.
,
Hudelmaier
,
M.
,
Wirth
,
W.
, and
Eckstein
,
F.
,
2010
, “
Osteoarthritis May Not Be a One-Way-Road of Cartilage Loss-Comparison of Spatial Patterns of Cartilage Change Between Osteoarthritic and Healthy Knees
,”
Osteoarthritis Cartilage
,
18
(
3
), pp.
329
335
.
7.
Wirth
,
W.
,
Benichou
,
O.
,
Kwoh
,
C. K.
,
Guermazi
,
A.
,
Hunter
,
D.
,
Putz
,
R.
, and
Eckstein
,
F.
,
2010
, “
Spatial Patterns of Cartilage Loss in the Medial Femoral Condyle in Osteoarthritic Knees: Data From the Osteoarthritis Initiative
,”
Magn. Resour. Med.
,
63
(
3
), pp.
574
581
.
8.
Eckstein
,
F.
,
Wirth
,
W.
,
Hudelmaier
,
M.
,
Stein
,
V.
,
Lengfelder
,
V.
,
Cahue
,
S.
,
Marshall
,
M.
,
Prasad
,
P.
, and
Sharma
,
L.
,
2008
, “
Patterns of Femorotibial Cartilage Loss in Knees With Neutral, Varus, and Valgus Alignment
,”
Arthritis Care Res.
,
59
(
11
), pp.
1563
1570
.
9.
Halder
,
A.
,
Kutzner
,
I.
,
Graichen
,
F.
,
Heinlein
,
B.
,
Beier
,
S.
, and
Bergmann
,
G.
,
2012
, “
Influence of Limb Alignment on Mediolateral Loading in Total Knee Replacement
,”
J. Bone Joint Surg. Am.
,
94
(
11
), pp.
1023
1029
.
10.
Minns
,
R. J.
, and
Hardinge
,
K.
,
1983
, “
Failure of One Design of Surface Replacement Knee Arthroplasty Due to Loosening, Deformation and Wear of the Plastic Femoral Component
,”
Biomaterials
,
4
(
3
), pp.
147
152
.
11.
Purbach
,
B.
,
Wroblewski
,
B. M.
,
Siney
,
P. D.
, and
Fleming
,
P. A.
,
2004
, “
The Charnley Load Angle Inlay Knee Replacement. Long-Term Results 20–28 Years
,”
Bioengineering Conference
, Leeds, UK.
12.
Miniaci
,
A.
,
2014
, “
UniCAP as an Alternative for Unicompartmental Arthritis
,”
Clin. Sports Med.
,
33
(
1
), pp.
57
65
.
13.
Hancock
,
C. W.
,
Winston
,
M. J.
,
Bach
,
J. M.
,
Davidson
,
B. S.
, and
Eckhoff
,
D. G.
,
2013
, “
Cylindrical Axis, Not Epicondyles, Approximates Perpendicular to Knee Axes
,”
Clin. Orthop. Res.
,
471
(
7
), pp.
2278
2283
.
14.
Mahfouz
,
M.
,
Fatah
,
E. E. H. A.
,
Fatah
,
A.
,
Bowers
,
L. S.
, and
Scuderi
,
G.
,
2012
, “
Three-Dimensional Morphology of the Knee Reveals Ethnic Differences
,”
Clin. Orthop. Relat. Res.
,
470
(
1
), pp.
172
185
.
15.
Khamaisy
,
S.
,
Nam
,
D.
,
Thein
,
R.
,
Rivkin
,
G.
,
Liebergall
,
M.
, and
Pearle
,
A.
,
2015
, “
Limb Alignment, Subluxation, and Bone Density Relationship in the Osteoarthritic Varus Knee
,”
J. Knee Surg.
,
28
(
3
), pp.
207
212
.
16.
Goldstein
,
S.
,
Wilson
,
D.
,
Sonstegard
,
D.
, and
Matthews
,
L.
,
1983
, “
The Mechanical Properties of Human Tibial Trabecular Bone as a Function of Metaphyseal Location
,”
J. Biomech.
,
16
(
12
), pp.
965
969
.
17.
Hvid
,
I.
,
1988
, “
Trabecular Bone Strength at the Knee
,”
Clin. Orthop. Relat. Res.
,
227
, pp.
210
221
.http://journals.lww.com/corr/Abstract/1988/02000/Trabecular_Bone_Strength_at_the_Knee_.25.aspx
18.
Chaudhary
,
M. E.
, and
Walker
,
P. S.
,
2014
, “
Analysis of an Early Intervention Tibial Component for Medial Osteoarthritis
,”
ASME J. Biomech. Eng.
,
136
(
6
), p.
061008
.
19.
Scott
,
R. D.
,
Joyce
,
M. J.
,
Ewald
,
F. C.
, and
Thomas
,
W. H.
,
1985
, “
McKeever Metallic Hemiarthroplasty of the Knee in Unicompartmental Degenerative Arthritis. Long-Term Clinical Follow-Up and Current Indications
,”
J. Bone Joint Surg. Am.
,
67
(
2
), pp.
203
207
.http://jbjs.org/content/67/2/203.long
20.
Gladnick
,
B. P.
,
Nam
,
D.
,
Khamaisy
,
S.
,
Paul
,
S.
, and
Pearle
,
A. D.
,
2015
, “
Onlay Tibial Implants Appear to Provide Superior Clinical Results in Robotic Unicompartmental Knee Arthroplasty
,”
HSSJ
,
11
(
1
), pp.
43
49
.
21.
Saenz
,
C. L.
,
McGrath
,
M. S.
,
Marker
,
D. R.
,
Seyler
,
T. M.
,
Mont
,
M. A.
, and
Bonutti
,
P. M.
,
2010
, “
Early Failure of a Unicompartmental Knee Arthroplasty Design With an All-Polyethylene Tibial Component
,”
Knee
,
17
(
1
), pp.
53
56
.
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