For systematic laboratory studies of bone fractures in general and intra-articular fractures in particular, it is often necessary to control for injury severity. Quantitatively, a parameter of primary interest in that regard is the energy absorbed during the injury event. For this purpose, a novel technique has been developed to measure energy absorption in experimental impaction. The specific application is for fracture insult to porcine hock (tibiotalar) joints in vivo, for which illustrative intra-operative data are reported. The instrumentation allowed for the measurement of the delivered kinetic energy and of the energy passed through the specimen during impaction. The energy absorbed by the specimen was calculated as the difference between those two values. A foam specimen validation study was first performed to compare the energy absorption measurements from the pendulum instrumentation versus the work of indentation performed by an MTS machine. Following validation, the pendulum apparatus was used to measure the energy absorbed during intra-articular fractures created in 14 minipig hock joints in vivo. The foam validation study showed close correspondence between the pendulum-measured energy absorption and MTS-performed work of indentation. In the survival animal series, the energy delivered ranged from 31.5 to 48.3 Js (41.3 ± 4.0, mean ± s.d.) and the proportion of energy absorbed to energy delivered ranged from 44.2% to 64.7% (53.6% ±4.5%). The foam validation results support the reliability of the energy absorption measure provided by the instrumented pendulum system. Given that a very substantial proportion of delivered energy passed—unabsorbed—through the specimens, the energy absorption measure provided by this novel technique arguably provides better characterization of injury severity than is provided simply by energy delivery.

References

References
1.
Backus
,
J. D.
,
Furman
,
B. D.
,
Swimmer
,
T.
,
Kent
,
C. L.
,
McNulty
,
A. L.
,
Defrate
,
L. E.
,
Guilak
,
F.
, and
Olson
,
S. A.
,
2011
, “
Cartilage Viability and Catabolism in the Intact Porcine Knee Following Transarticular Impact Loading With and Without Articular Fracture
,”
Orthop Res.
29
(
4
), pp.
501
510
.10.1002/jor.21270
2.
Tochigi
,
Y.
,
Buckwalter
,
J. A.
,
Martin
,
J. A.
,
Hillis
,
S. L.
,
Zhang
,
P.
,
Vaseenon
,
T.
,
Lehman
,
A. D.
, and
Brown
,
T. D.
,
2011
, “
Distribution and Progression of Chondrocyte Damage in a Whole-Organ Model of Human Ankle Intra-articular Fracture
,”
J. Bone Joint Surg. Am.
,
93
(
6
), pp.
533
539
.10.2106/JBJS.I.01777
3.
Borrelli
,
J.
Jr.
,
Burns
,
M. E.
,
Ricci
,
W. M.
, and
Silva
,
M. J.
,
2002
, “
A Method for Delivering Variable Impact Stresses to the Articular Cartilage of Rabbit Knees
,”
J. Orthop. Trauma
,
16
(
3
), pp.
182
188
.10.1097/00005131-200203000-00008
4.
Isaac
,
D. I.
,
Meyer
,
E. G.
, and
Haut
,
R. C.
,
2008
, “
Chondrocyte Damage and Contact Pressures Following Impact on the Rabbit Tibiofemoral Joint
,”
ASME J. Biomech. Eng.
,
130
(
4
), p.
041018
.10.1115/1.2948403
5.
Rundell
,
S. A.
,
Baars
,
D. C.
,
Phillips
,
D. M.
, and
Haut
,
R. C.
,
2005
, “
The Limitation of Acute Necrosis in Retro-Patellar Cartilage After a Severe Blunt Impact to the in Vivo Rabbit Patello-Femoral Joint
,”
J. Orthop. Res.
,
23
(
6
), pp.
1363
1369
.
6.
Marsh
,
J. L.
,
Slongo
,
T. F.
,
Agel
,
J.
,
Broderick
,
J. S.
,
Creevey
,
W.
,
DeCoster
,
T. A.
,
Prokuski
,
L.
,
Sirkin
,
M. S.
,
Ziran
,
B.
,
Henley
,
B.
, and
Audigé
,
L.
,
2007
, “
Fracture and Dislocation Classification Compendium—2007: Orthopaedic Trauma Association Classification, Database and Outcomes Committee
,”
J. Orthop. Trauma
,
21
(
suppl
), pp.
S1
S133
.10.1097/00005131-200711101-00001
7.
McKinley
,
T. O.
,
Borrelli
,
J.
Jr.
,
D'Lima
,
D. D.
,
Furman
,
B. D.
, and
Giannoudis
,
P. V.
,
2010
, “
Basic Science of Intra-Articular Fractures and Posttraumatic Osteoarthritis
,”
J. Orthop. Trauma
,
24
(
9
), pp.
567
570
.10.1097/BOT.0b013e3181ed298d
8.
Saterbak
,
A. M.
,
Marsh
,
J. L.
,
Nepola
,
J. V.
,
Brandser
,
E. A.
, and
Turbett
,
T.
,
2000
, “
Clinical Failure After Posterior Wall Acetabular Fractures: The Influence of Initial Fracture Patterns
,”
J. Orthop. Trauma
,
14
(
4
), pp.
230
237
.10.1097/00005131-200005000-00002
9.
Lansinger
,
O.
,
Bergman
,
B.
,
Körner
,
L.
, and
Andersson
,
G. B.
,
1986
, “
Tibial Condylar Fractures. A Twenty-Year Follow-Up
,”
J. Bone Joint Surg. Am.
,
68
(
1
), pp.
13
19
.
10.
Stevens
,
D. G.
,
Beharry
,
R.
,
McKee
,
M. D.
,
Waddell
,
J. P.
, and
Schemitsch
,
E. H.
,
2001
, “
The Long-Term Functional Outcome of Operatively Treated Tibial Plateau Fractures
,”
J. Orthop. Trauma
,
15
(
5
), pp.
312
320
.10.1097/00005131-200106000-00002
11.
Marsh
,
J. L.
,
Weigel
,
D. P.
, and
Dirschl
,
D. R.
,
2003
, “
Tibial Plafond Fractures. How Do These Ankles Function Over Time?
J. Bone Joint Surg. Am.
,
85-A
(
2
), pp.
287
295
.
12.
Trumble
,
T.
, and
Verheyden
,
J.
,
2004
, “
Remodeling of Articular Defects in an Animal Model
,”
Clin. Orthop. Relat. Res.
,
423
, pp.
59
63
.10.1097/01.blo.0000132625.05916.48
13.
McKinley
,
T. O.
,
Tochigi
,
Y.
,
Rudert
,
M. J.
, and
Brown
,
T. D.
,
2008
, “
Instability-Associated Changes in Contact Stress and Contact Stress Rates Near a Step-Off Incongruity
,”
J. Bone Joint Surg. Am.
,
90
(
2
), pp.
375
383
.10.2106/JBJS.G.00127
14.
Lefkoe
,
T. P.
,
Trafton
,
P. G.
,
Ehrlich
,
M. G.
,
Walsh
,
W. R.
,
Dennehy
,
D. T.
,
Barrach
,
H. J.
, and
Akelman
,
E.
,
1993
, “
An Experimental Model of Femoral Condylar Defect Leading to Osteoarthrosis
,”
J. Orthop. Trauma
,
7
(
5
), pp.
458
467
.10.1097/00005131-199310000-00009
15.
Vaseenon
,
T.
,
Tochigi
,
Y.
,
Heiner
,
A. D.
,
Goetz
,
J. E.
,
Baer
,
T. E.
,
Fredericks
,
D. C.
,
Martin
,
J. A.
,
Rudert
,
M. J.
,
Hillis
,
S. L.
,
Brown
,
T. D.
, and
McKinley
,
T. O.
,
2011
, “
Organ-Level Histological and Biomechanical Responses From Localized Osteoarticular Injury in the Rabbit Knee
,”
J. Orthop. Res.
,
29
(
3
), pp.
340
346
.10.1002/jor.21259
16.
Beardsley
,
C. L.
,
Anderson
,
D. D.
,
Marsh
,
J. L.
, and
Brown
,
T. D.
,
2005
, “
Interfragmentary Surface Area as an Index of Comminution Severity in Cortical Bone Impact
,”
J. Orthop. Res.
,
23
(
3
), pp.
686
690
.10.1016/j.orthres.2004.09.008
17.
Tochigi
,
Y.
,
Zhang
,
P.
,
Rudert
,
M. J.
,
Baer
,
T. E.
,
Martin
,
J. A.
,
Hillis
,
S. L.
, and
Brown
,
T. D.
,
2013
, “
A Novel Impaction Technique to Create Experimental Articular Fractures in Large Animal Joints
,”
Osteoarthritis Cartilage
,
21
(
1
), pp.
200
208
.10.1016/j.joca.2012.10.004
18.
Callister
,
W. D. J.
,
1994
,
Materials Science and Engineering: An Introduction
,
Wiley
,
New York
.
19.
Abdel-Wahab
,
A. A.
, and
Silberschmidt
,
V. V.
,
2012
, “
Experimental and Numerical Analysis of Izod Impact Test of Cortical Bone Tissue
,”
Eur. Phys. J. Spec. Top.
,
206
, pp.
41
50
.10.1140/epjst/e2012-01585-3
20.
Thomas
,
T. P.
,
Anderson
,
D. D.
,
Mosqueda
,
T. V.
,
Van Hofwegen
,
C. J.
,
Hillis
,
S. L.
,
Marsh
,
J. L.
, and
Brown
,
T. D.
,
2010
, “
Objective CT-Based Metrics of Articular Fracture Severity to Assess Risk for Post-Traumatic Osteoarthritis
,”
J. Orthop. Trauma
,
24
(
12
), pp.
764
769
.10.1097/BOT.0b013e3181d7a0aa
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