The Journal of Bone and Joint Surgery (American) 84:780-785 (2002)
© 2002 The Journal of Bone and Joint Surgery, Inc.
Biomechanical Comparison of Effects of Supraspinatus Tendon Detachments, Tendon Defects, and Muscle Retractions
A. M. Halder, MD,
S. W. O'Driscoll, PhD, MD,
G. Heers, MD,
N. Mura, MD,
M. E. Zobitz, MS,
K. N. An, PhD and
R. Kreusch-Brinker, MD
Investigation performed at the Biomechanics Laboratory, Division
of Orthopedic Research, Mayo Clinic, Rochester, Minnesota
A.M. Halder, MD
S.W. O'Driscoll, MD, PhD
G. Heers, MD
N. Mura, MD
M.E. Zobitz, MS
K.N. An, PhD
Biomechanics Laboratory, Division of Orthopedic Research, Mayo
Clinic, 200 First Street S.W., Rochester, MN 55905. E-mail address
for S.W. O'Driscoll: odriscoll.shawn{at}mayo.edu
R. Kreusch-Brinker, MD
Department of Orthopedics, Asklepios-Klinik, Birkenwerder, Hubertusstrasse
12-22, 16547 Birkenwerder, Germany
In support of their research or preparation of this manuscript, one
or more of the authors received grants or outside funding from National
Institutes of Health (NIAMS [National Institute of Arthritis and
Musculoskeletal and Skin Diseases]) AR41171. None of the authors
received payments or other benefits or a commitment or agreement
to provide such benefits from a commercial entity. No commercial
entity paid or directed, or agreed to pay or direct, any benefits
to any research fund, foundation, educational institution, or other charitable
or nonprofit organization with which the authors are affiliated
or associated.
Background:
Rotator cuff ruptures are frequently associated with loss of strength
of the shoulder. However, the characteristics of the rotator cuff
tear that are responsible for the loss of force generation and transmission
have not yet been identified. The purpose of this study was to compare
the effects of supraspinatus tendon detachments, tendon defects,
and muscle retractions on in vitro force transmission by the rotator cuff
to the humerus.
Methods:
The rotator cuff tendons from ten cadaver shoulders were loaded
proportionally to the respective cross-sectional areas of their
muscles. A fiberglass rod was cemented into the medullary canal
of the humerus and connected to a three-component load cell for
the measurement of the forces transmitted by the rotator cuff to
the humerus. This study was performed with the humerus in a hanging
arm position and with various sizes of supraspinatus tendon detachments,
tendon defects, and muscle retractions.
Results:
Detachment or creation of a defect involving one-third or two-thirds
of the supraspinatus tendon resulted in a minor reduction in the
force transmitted by the rotator cuff (≤5%), while detachment
or creation of a defect involving the whole tendon resulted in a
moderate reduction (11% and 17%, respectively). Simulated muscle
retraction involving one-third, two-thirds, and the whole tendon
resulted in losses of torque measuring 19%, 36%, and 58%, respectively.
Side-to-side repair of the one-third and two-thirds defects nearly restored
the force transmission capability, whereas a deficit remained after
side-to-side repair following complete resection.
Conclusions:
Our results support the rotator cable concept and correspond to
the clinical observation that patients with a small rupture of the
rotator cuff may present without a loss of shoulder strength. Muscle
retraction is potentially an important factor responsible for loss
of shoulder strength following large rotator cuff ruptures.
Clinical Relevance:
Supraspinatus muscle retraction diminishes glenohumeral abduction
torque significantly more than either a defect in the tendon or
a simple detachment of the tendon from the tuberosity. In cases
of irreparable defects, side-to-side repair may be worthwhile to
restore muscle tension and the integrity of the rotator cable.
 CiteULike  Connotea  Del.icio.us  Technorati What's this?
This article has been cited by other articles:
|
|
|
|
 
A. B. Wolff, P. Sethi, K. M. Sutton, A. S. Covey, D. P. Magit, and M. Medvecky
Partial-Thickness Rotator Cuff Tears
J. Am. Acad. Ortho. Surg.,
December 1, 2006;
14(13):
715 - 725.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Y. Morag, J. A. Jacobson, D. Lucas, B. Miller, M. K. Brigido, and D. A. Jamadar
US Appearance of the Rotator Cable with Histologic Correlation: Preliminary Results.
Radiology,
November 1, 2006;
241(2):
485 - 491.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Y. Morag, J. A. Jacobson, B. Miller, M. De Maeseneer, G. Girish, and D. Jamadar
MR Imaging of Rotator Cuff Injury: What the Clinician Needs to Know.
RadioGraphics,
July 1, 2006;
26(4):
1045 - 1065.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. S. Burkhart and I. K. Y. Lo
Arthroscopic Rotator Cuff Repair
J. Am. Acad. Ortho. Surg.,
June 1, 2006;
14(6):
333 - 346.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
B. Jost, M. Zumstein, C. W.A. Pfirrmann, and C. Gerber
Long-Term Outcome After Structural Failure of Rotator Cuff Repairs
J. Bone Joint Surg. Am.,
March 1, 2006;
88(3):
472 - 479.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. G. McFarland, H. S. Selhi, and E. Keyurapan
Clinical Evaluation of Impingement: What To Do and What Works
J. Bone Joint Surg. Am.,
February 1, 2006;
88(2):
432 - 441.
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. J. Matava, D. B. Purcell, and J. R. Rudzki
Partial-Thickness Rotator Cuff Tears
Am. J. Sports Med.,
September 1, 2005;
33(9):
1405 - 1417.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
I. K. Y. Lo and S. S. Burkhart
Spotlight on Surgical Techniques. Current Concepts in Arthroscopic Rotator Cuff Repair
Am. J. Sports Med.,
March 1, 2003;
31(2):
308 - 324.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
