supra-scapular nerve compression
Like the median nerve at the carpal tunnel or the ulnar nerve at the elbow, the supra-scapular nerve may be subject to a compression through an osteofibrous gate. Concerning the supra-scapular nerve the usual point of compression is located at the level of the coracoid notch closed by the transverse ligament.
The nerve can also suffer after a trauma of the shoulder (stretching of the nerve) at 2 fixed points: the same coracoid notch and the spino-glenoid notch (see anatomy of the supra-scapular nerve)
Finally it can be compressed by a process occupying space, in particular a synovial cyst or mucoid often coming from the posterior labrum surrounding the glenoid, or even a tumor.
This lesion is rare and difficult to demonstrate (requires electromyography and MRI of the shoulder) especially if there is no visible muscular atrophy of the supra and / or infraspinous muscles (present in the severe form). However, this suffering may explain some shoulder pain, located in the supraspinatus muscle mass (deeper than the trapezius muscle)
The role of muscle retraction associated with a massive posterior and superior rotator cuff tear or after tendon’s reduction of the cuff during a repair (and therefore the traction on the corresponding muscle) are suspected in some cases of suprascapular nerve’s suffering.
Surgical treatment is indicated in severe cases to release the nerve (section of the transverse ligament of the coracoid notch under arthroscopy) and to treat a possible cause (cyst which must be sure of the benign character) Some surgeons advocate the release of this nerve during surgery of the massive cuff tear (for us no opinion currently sliced).
Video release of the supra-scapular nerve under arthroscopy
(section of the transverse ligament at the coracoid notch)