Isolated infraspinatus atrophy in a collegiate volleyball player.
OBJECTIVE
To describe a case of isolated infraspinatus atrophy due to suprascapular nerve entrapment by a labral ganglion cyst in a volleyball player and to propose a mechanism for its formation.


METHODS
A female volleyball player was evaluated for shoulder pain and found to have atrophy of the infraspinatus muscle. Magnetic resonance imaging (MRI) showed a loculated ganglion cyst impinging on the suprascapular nerve.


CONCLUSIONS
Several etiologies for isolated infraspinatus atrophy in volleyball players are cited in the literature. It is suggested here that the rapid deceleration in the volleyball spike can result in a superior labral lesion (SLAP), which can lead to ganglion cyst formation. These ganglion cysts can then cause isolated infraspinatus atrophy by impinging on the suprascapular nerve at the spinoglenoid notch.


CONCLUSIONS
In one study, isolated infraspinatus atrophy was found in 12% of elite volleyball players. Since infraspinatus atrophy may result from impingement of the suprascapular nerve by ganglion cysts and not just traction injuries, imaging studies, such as an MRI, should be considered in the evaluation of these patients.
Wang
D H
DH
Department of Family Practice, University of Minnesota, Minneapolis, USA.
Koehler
S M
SM
D000328:Adult; D001265:Athletic Injuries / Q000209:etiology / Q000473:pathology*; D001284:Atrophy; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D018482:Muscle, Skeletal / Q000473:pathology*; D009408:Nerve Compression Syndromes / Q000175:diagnosis / Q000209:etiology; D012540:Scapula / Q000294:innervation; D012782:Shoulder; D013177:Sports; D013581:Synovial Cyst / Q000150:complications / Q000175:diagnosis