Ganglion cysts on top of the glenoid (supraglenoid) can occur either without cause or secondary to labral pathology. The mere fact that a cyst is found on an MRI, does not mean that the cyst is the cause of whatever the problem is that led to getting the MRI. However, cysts can put pressure on the suprascapular nerve either at the locale of the Transverse Scapular Ligament, or more distally at the Spinoglenoid Ligament. In the former cases, this affects the nerve branches to both the supraspinatus and infraspinatus muscles; in the latter case, only the branches to the Infraspinatus muscle are affected. When this happens, muscle atrophy and weakness can result, and early on, pain may be the only symptom. Historically, the prevailing opinion about management of Supraglenoid ganglion cysts has been the following:
1. Electrodiagnostic tests are necessary to identify muscle denervation/suprascapular nerve dysfunction.
2. In the absence of any type of cyst on the MRI, (but in cases when nerve dysfunction is noted), treatment should be nonoperative--physical therapy,for 6 months, prior to considering any kind of "nerve decompression".
3. If a supraglenoid cyst is associated with an abnormal nerve test, arthroscopic decompression of the cyst may be successful in the majority of cases, thus it makes good sense to try this option relatively soon after diagnosis so that whatever nerve dysfunction exists might reverse itself before muscle atrophy worsens.
The arthroscopic "procedure" will vary depending on where the cyst is relative to the spinoglenoid notch. See the video below for a representative MRI.
1. Electrodiagnostic tests are necessary to identify muscle denervation/suprascapular nerve dysfunction.
2. In the absence of any type of cyst on the MRI, (but in cases when nerve dysfunction is noted), treatment should be nonoperative--physical therapy,for 6 months, prior to considering any kind of "nerve decompression".
3. If a supraglenoid cyst is associated with an abnormal nerve test, arthroscopic decompression of the cyst may be successful in the majority of cases, thus it makes good sense to try this option relatively soon after diagnosis so that whatever nerve dysfunction exists might reverse itself before muscle atrophy worsens.
The arthroscopic "procedure" will vary depending on where the cyst is relative to the spinoglenoid notch. See the video below for a representative MRI.
