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William P. Garth, Jr., MD, Robert
Lopez, MD, Stephen Brown, MD, Michael Pitt, MD
O: To differentiate lesions
of MGHL dysfunction from normal anatomical variations and
to determine results of arthroscopic repair.
M&M: Thirty-one consecutive
patients, 14-57 yrs old, failed conservative treatment for
predominantly straight anterior instability and had arthrogram/magnetic
resonance imaging and arthroscopic stabilization. Twenty two
experienced symptoms during overhead sports and 9 had contact
injury. Twenty three patients were males. Physical signs included
31 positive anterior apprehension-relocation tests, and 29
positive load, shift straight subluxations under anesthesia.
Lesions in the MGHL were difficult to distinguish from normal
anatomical variations of the MGHL by preoperative MRI. Arthroscopy
demonstrated: 17 cases of intrasubstance lesions distinguished
from a normal inferior foramen by inferomedial retraction
of torn ligament tissue, often obscured from view by the IGHL:
13 cases, similar to a normal sublabral foramen, but distinguished
by hypermobility of the superior labral origin of a lax MGHL;
and 1 case of inferomedial detachment with superolateral displacement
of the MGHL. Arthroscopic repair of the MGHL lesions and debridement/repair
of associated pathology was performed.
R: Correlation of the pre-op
MRI's with arthroscopic findings revealed that MGHL dysfunction
is suspect on imaging when there is paucity of the MGHL anterior
to the subscapularis, non-visualization of the glenoid attachment
of the MGHL, and a large axillary recess with a thick appearance
of the inferior capsule. Follow-up evaluation was at 6-49
months post-op. All patients reported reduced pain and improved
function. Seventeen of 22 overhead athletes have returned
to full activities without symptoms. Two overhead athletes
had recurrence of symptoms and required repeat repairs before
obtaining satisfactory results. A third patient has recurrent
signs of instability of the shoulder following an injury in
contact football.
C: A high index of suspicion
based on clinical signs of straight anterior instability is
necessary to distinguish, by imaging or arthroscopy, subtle
pathologic changes in the MGHL from normal anatomical variations.
If recognized, arthroscopic repair of these lesions can be
expected to alleviate symptoms and restore function.
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