Morphology of the torn rotator cuff

E. Itoi, H. C. Hsu, S. W. Carmichael, B. F. Morrey, K. N. An

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

The morphological characteristics of shoulders with torn rotator cuffs were determined using 41 embalmed specimens. The following parameters were measured in the supraspinatus (SSP), infraspinatus (ISP) and subscapularis (SSC) muscles: the length, thickness and width of the extramuscular tendon; the length of the intramuscular tendon; the length and width of a tear, if present, muscle fibre length; and muscle volume. The cross-sectional area (CSA) of the tendon was measured on the photographic image of slices of the tendon using an image analysis system, and the CSA of the muscle was calculated by dividing the muscle volume by muscle fibre length. The rotator cuff was intact in 11 shoulders. A partial-thickness tear of the cuff was present in 12 shoulders, a full-thickness tear of the SSP in 11 shoulders, and a full-thickness tear of more than 2 tendons in 7. Overall incidence of full-thickness tears of the rotator cuff was 44%, and that of partial-thickness tears 29%. With increase of tear size, the functional tendon length (extramuscular tendon length plus tear length) increased by a statistically significant amount in the SSP, ISP and SSC, whereas muscle fibre length decreased in SSP and ISP. It is concluded that the increased functional tendon length and decreased muscle fibre length are the main morphological changes that make the rotator cuff a physiologically abnormal unit. Surgical repair of the torn cuff would be expected to improve these anatomical changes and restore the kinetics of the glenohumeral joint. Our data encourage early repair of rotator cuff tears at a stage when these anatomical changes are still reversible in patients, such as manual labourers and athletes, who need functional shoulders.

Original languageEnglish (US)
Pages (from-to)429-434
Number of pages6
JournalJournal of Anatomy
Volume186
Issue number2
StatePublished - 1995

Fingerprint

Rotator Cuff
muscle
tendons
Tendons
Tears
shoulders
Muscles
muscle fibers
muscles
repair
image analysis
athletes
Shoulder Joint
joints (animal)
photographs
Athletes
kinetics
fibre
Cross-Sectional Studies

Keywords

  • Rotator cuff tears
  • Shoulder
  • Tendon rupture

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Anatomy

Cite this

Itoi, E., Hsu, H. C., Carmichael, S. W., Morrey, B. F., & An, K. N. (1995). Morphology of the torn rotator cuff. Journal of Anatomy, 186(2), 429-434.

Morphology of the torn rotator cuff. / Itoi, E.; Hsu, H. C.; Carmichael, S. W.; Morrey, B. F.; An, K. N.

In: Journal of Anatomy, Vol. 186, No. 2, 1995, p. 429-434.

Research output: Contribution to journalArticle

Itoi, E, Hsu, HC, Carmichael, SW, Morrey, BF & An, KN 1995, 'Morphology of the torn rotator cuff', Journal of Anatomy, vol. 186, no. 2, pp. 429-434.
Itoi E, Hsu HC, Carmichael SW, Morrey BF, An KN. Morphology of the torn rotator cuff. Journal of Anatomy. 1995;186(2):429-434.
Itoi, E. ; Hsu, H. C. ; Carmichael, S. W. ; Morrey, B. F. ; An, K. N. / Morphology of the torn rotator cuff. In: Journal of Anatomy. 1995 ; Vol. 186, No. 2. pp. 429-434.
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