Premium
Asymmetric atrophy of the supraspinatus muscle following tendon tear
Author(s) -
Meyer Dominik C.,
Pirkl Christoph,
Pfirrmann Christian W. A.,
Zanetti Marco,
Gerber Christian
Publication year - 2005
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1016/j.orthres.2004.06.010
Subject(s) - anatomy , medicine , supraspinatus muscle , tendon , atrophy , muscle atrophy , fascia lata , shoulders , denervation , rotator cuff , scapula , skeletal muscle , pathology
Muscle atrophy is a known consequence of muscle disuse, muscle denervation and tendon tear. Whereas after nerve injury muscle atrophies in the denervated area, the distribution of muscle atrophy following tear of its tendon is not known. Standardized MRI scans of 64 consecutive, painful shoulders were evaluated for supraspinatus tendon tearing, myotendinous retraction, supraspinatus muscle atrophy, fatty infiltration, ratio of the scapular (deep) and fascial (superficial) muscle area (“symmetry”) and position of the central tendon within the supraspinatus fossa. There were thirteen shoulders with no and eleven shoulders with partial thickness supraspinatus tendon tears. In the forty cases with full thickness tendon tear, there was significant muscle atrophy and fatty infiltration. Atrophy of the fascial muscle portion was 43%, on the bony side it was 9% ( p < 0.005). The position of the central tendon within the supraspinatus fossa, was unaltered. Muscular changes following tendon tear occur highly asymmetrically: The muscle portion originating from the fascia primarily atrophies, the portion originating from the scapula primarily undergoes fatty infiltration. Muscular changes are not simply a consequence of muscle disuse, but dependent on architectural changes in the muscle. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.