Tears on the bursal and articular sides of the rotator cuff tendons are known to behave differently and strain is thought to play a role in this difference. This study investigates the effect of tear location on the changes in three strain measurements (grip-to-grip, insertion, and mid-substance tissue) in a sheep infraspinatus tendon model during axial loading. We introduced a 14 mm wide defect near the insertion from either the articular or bursal side of the tendon to three depths (3 mm, 7 mm & full) progressively. For each condition, tendons were sinusoidally stretched (4% at 0.5 Hz) while insertion and mid-substance strains were tracked with surface markers. For a fixed load, grip-to-grip strain increased significantly compared to intact for both cuts. Insertion strain increased significantly for the bursal-side defect immediately but not for the articular-side until the 66% cut. Mid-substance tissue strain showed no significant change for partial thickness articular-side defects and a significant decrease for bursal-side defects after the 66% cut. All full thickness cuts exhibited negligible mid-substance tissue strain change. Our results suggest that the tendon strain patterns are more sensitive to defects on the bursal side, and that partial thickness tears tend to induce localized strain concentrations in regions adjacent to the damaged tissue.

References

1.
Soslowsky
,
L. J.
,
Carpenter
,
J. E.
,
Bucchieri
,
J. S.
, and
Flatow
,
E. L.
,
1997
, “
Biomechanics of the Rotator Cuff
,”
Orthop. Clin. North Am.
,
28
(
1
), pp.
17
30
.10.1016/S0030-5898(05)70261-3
2.
Perry
,
S. M.
,
Getz
,
C. L.
, and
Soslowsky
,
L. J.
,
2009
, “
After Rotator Cuff Tears, the Remaining (Intact) Tendons are Mechanically Altered
,”
J. Shoulder Elb. Surg. Am. Shoulder Elb. Surg. Al.
,
18
(
1
), pp.
52
57
.10.1016/j.jse.2008.07.003
3.
Breazeale
,
N. M.
, and
Craig
,
E. V.
,
1997
, “
Partial-Thickness Rotator Cuff Tears. Pathogenesis and Treatment
,”
Orthop. Clin. North Am.
,
28
(
2
), pp.
145
155
.10.1016/S0030-5898(05)70275-3
4.
McConville
,
O. R.
, and
Iannotti
,
J. P.
,
1999
, “
Partial-Thickness Tears of the Rotator Cuff: Evaluation and Management
,”
J. Am. Acad. Orthop. Surg.
,
7
(
1
), pp.
32
43
.
5.
Fukuda
,
H.
,
Hamada
,
K.
,
Nakajima
,
T.
,
Yamada
,
N.
,
Tomonaga
,
A.
, and
Goto
,
M.
,
1996
, “
Partial-Thickness Tears of the Rotator Cuff. A Clinicopathological Review Based on 66 Surgically Verified Cases
,”
Int. Orthop.
,
20
(
4
), pp.
257
265
.10.1007/s002640050075
6.
Flatow
,
E. L.
,
Altchek
,
D. W.
,
Gartsman
,
G. M.
,
Iannotti
,
J. P.
,
Miniaci
,
A.
,
Pollock
,
R. G.
,
Savoie
,
F.
, and
Warner
,
J. J.
,
1997
, “
The Rotator Cuff. Commentary
,”
Orthop. Clin. North Am.
,
28
(
2
), pp.
277
294
.10.1016/S0030-5898(05)70286-8
7.
Peterson
,
C. A.
, and
Altchek
,
D. W.
,
1986
, “
Arthroscopic Treatment of Rotator Cuff Disorders
,”
Clin. Sports Med.
,
15
(
4
), pp.
715
736
.
8.
Weber
,
S. C.
,
1999
, “
Arthroscopic Debridement and Acromioplasty Versus Mini-Open Repair in the Treatment of Significant Partial-Thickness Rotator Cuff Tears
,”
Arthrosc. J. Arthrosc. Relat. Surg. Off. Publ. Arthrosc. Assoc. N. Am. Int. Arthrosc. Assoc.
,
15
(
2
), pp.
126
131
.10.1053/ar.1999.v15.0150121
9.
Andarawis-Puri
,
N.
,
Ricchetti
,
E. T.
, and
Soslowsky
,
L. J.
,
2009
, “
Rotator Cuff Tendon Strain Correlates With Tear Propagation
,”
J. Biomech.
,
42
(
2
), pp.
158
163
.10.1016/j.jbiomech.2008.10.020
10.
Reilly
,
P.
,
Amis
,
A. A.
,
Wallace
,
A. L.
, and
Emery
,
R. J. H.
,
2003
, “
Mechanical Factors in the Initiation and Propagation of Tears of the Rotator Cuff. Quantification of Strains of the Supraspinatus Tendon In Vitro
,”
J. Bone Joint Surg. Br.
,
85
(
4
), pp.
594
599
.10.1302/0301-620X.85B4.12062
11.
Bey
,
M. J.
,
Song
,
H. K.
,
Wehrli
,
F. W.
, and
Soslowsky
,
L. J.
,
2002
, “
Intratendinous Strain Fields of the Intact Supraspinatus Tendon: The Effect of Glenohumeral Joint Position and Tendon Region
,”
J. Orthop. Res. Off. Publ. Orthop. Res. Soc.
,
20
(
4
), pp.
869
874
.10.1016/S0736-0266(01)00177-2
12.
Nakajima
,
T.
,
Rokuuma
,
N.
,
Hamada
,
K.
,
Tomatsu
,
T.
, and
Fukuda
,
H.
,
1994
, “
Histologic and Biomechanical Characteristics of the Supraspinatus Tendon: Reference to Rotator Cuff Tearing
,”
J. Shoulder Elb. Surg.
,
3
(
2
), pp.
79
87
.10.1016/S1058-2746(09)80114-6
13.
Lee
,
S. B.
,
Nakajima
,
T.
,
Luo
,
Z. P.
,
Zobitz
,
M. E.
,
Chang
,
Y. W.
, and
An
,
K. N.
,
2000
, “
The Bursal and Articular Sides of the Supraspinatus Tendon Have a Different Compressive Stiffness
,”
Clin. Biomech. Bristol Avon
,
15
(
4
), pp.
241
247
.10.1016/S0268-0033(99)00086-8
14.
Lake
,
S. P.
,
Miller
,
K. S.
,
Elliott
,
D. M.
, and
Soslowsky
,
L. J.
,
2009
, “
Effect of Fiber Distribution and Realignment on the Nonlinear and Inhomogeneous Mechanical Properties of Human Supraspinatus Tendon Under Longitudinal Tensile Loading
,”
J. Orthop. Res. Off. Publ. Orthop. Res. Soc.
,
27
(
12
), pp.
1596
1602
.10.1002/jor.20938
15.
Yang
,
S.
,
Park
,
H.-S.
,
Flores
,
S.
,
Levin
,
S. D.
,
Makhsous
,
M.
,
Lin
,
F.
,
Koh
,
J.
,
Nuber
,
G.
, and
Zhang
,
L.-Q.
,
2009
, “
Biomechanical Analysis of Bursal-Sided Partial Thickness Rotator Cuff Tears
,”
J. Shoulder Elb. Surg. Am. Shoulder Elb. Surg. Al.
,
18
(
3
), pp.
379
385
.10.1016/j.jse.2008.12.011
16.
Mazzocca
,
A. D.
,
Rincon
,
L. M.
,
O'Connor
,
R. W.
,
Obopilwe
,
E.
,
Andersen
,
M.
,
Geaney
,
L.
, and
Arciero
,
R. A.
,
2008
, “
Intra-Articular Partial-Thickness Rotator Cuff Tears: Analysis of Injured and Repaired Strain Behavior
,”
Am. J. Sports Med.
,
36
(
1
), pp.
110
116
.10.1177/0363546507307502
17.
Gerber
,
C.
,
Schneeberger
,
A. G.
,
Beck
,
M.
, and
Schlegel
,
U.
,
1994
, “
Mechanical Strength of Repairs of the Rotator Cuff
,”
J. Bone Joint Surg. Br.
,
76
(
3
), pp.
371
380
.
18.
Turner
,
A. S.
,
2007
, “
Experiences With Sheep as an Animal Model for Shoulder Surgery: Strengths and Shortcomings
,”
J. Shoulder Elb. Surg. Am. Shoulder Elb. Surg. Al.
, Suppl.
16
(
5
), pp.
S158
S163
.10.1016/j.jse.2007.03.002
19.
Clavert
,
P.
,
Kempf
,
J. F.
,
Bonnomet
,
F.
,
Boutemy
,
P.
,
Marcelin
,
L.
, and
Kahn
,
J. L.
,
2001
, “
Effects of Freezing/Thawing on the Biomechanical Properties of Human Tendons
,”
Surg. Radiol. Anat. SRA
,
23
(
4
), pp.
259
262
.10.1007/s00276-001-0259-8
20.
Weiss
,
J. A.
, and
Gardiner
,
J. C.
,
2001
, “
Computational Modeling of Ligament Mechanics
,”
Crit. Rev. Biomed. Eng.
,
29
(
3
), pp.
303
371
.10.1615/CritRevBiomedEng.v29.i3.20
21.
Lake
,
S. P.
,
Miller
,
K. S.
,
Elliott
,
D. M.
, and
Soslowsky
,
L. J.
,
2010
, “
Tensile Properties and Fiber Alignment of Human Supraspinatus Tendon in the Transverse Direction Demonstrate Inhomogeneity, Nonlinearity, and Regional Isotropy
,”
J. Biomech.
,
43
(
4
), pp.
727
732
.10.1016/j.jbiomech.2009.10.017
22.
Kim
,
H. M.
,
Dahiya
,
N.
,
Teefey
,
S. A.
,
Middleton
,
W. D.
,
Stobbs
,
G.
,
Steger-May
,
K.
,
Yamaguchi
,
K.
, and
Keener
,
J. D.
,
2010
, “
Location and Initiation of Degenerative Rotator Cuff Tears: An Analysis of Three Hundred and Sixty Shoulders
,”
J. Bone Joint Surg. Am.
,
92
(
5
), pp.
1088
1096
.10.2106/JBJS.I.00686
23.
Coleman
,
S. H.
,
Fealy
,
S.
,
Ehteshami
,
J. R.
,
MacGillivray
,
J. D.
,
Altchek
,
D. W.
,
Warren
,
R. F.
, and
Turner
,
A. S.
,
2003
, “
Chronic Rotator Cuff Injury and Repair Model in Sheep
,”
J. Bone Joint Surg. Am.
,
85A
(
12
), pp.
2391
2402
.
24.
Mathewson
,
M. A.
,
Kwan
,
A.
,
Eng
,
C. M.
,
Lieber
,
R. L.
, and
Ward
,
S. R.
,
2013
, “
Comparison of Rotator Cuff Muscle Architecture Among Humans and Selected Vertebrate Species
,”
J. Exp. Biol.
,
217
(Pt. 2), pp.
261
273
.10.1242/jeb.083923
25.
Bey
,
M. J.
,
Ramsey
,
M. L.
, and
Soslowsky
,
L. J.
,
2002
, “
Intratendinous Strain Fields of the Supraspinatus Tendon: Effect of a Surgically Created Articular-Surface Rotator Cuff Tear
,”
J. Shoulder Elb. Surg. Am. Shoulder Elb. Surg. Al.
,
11
(
6
), pp.
562
569
.10.1067/mse.2002.126767
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