The glenoid, or socket joint of the shoulder, is surrounded by a cartilage supporting structure called the labrum. Injuries to the tissue surrounding the shoulder socket can be caused by acute trauma or repetitive shoulder motions.
The reason in your case is a direct blow to the shoulder.
A SLAP lesion (superior labrum, anterior [front] to posterior [back]) is a tear of the rim above the middle of the socket that may also involve the biceps tendon.
Anti-inflammatory medication and rest to relieve symptoms are the things you should try first.
You should visit an Orthopedician where Rehabilitation exercises to strengthen the rotator cuff muscles also may be recommended. If these conservative measures are insufficient, your physician may recommend arthroscopic surgery.
I have followed this protocol for treatment and the orthopediac doctor has order an ultra sound. What is the purpose for the ultra sound. There are four different types of SLAP lesion. Can degeneration make the injury worser?
After the MRI there is lesser reason for an ultrasound, but if your Orthopedician thinks that he missed something he has ordered for an Ultrasound. Initially rest and anti inflammatory drugs will help. It is always good to go for strengthening of muscles and your Rotator cuff by Physical therapy to cure this and keep surgery as the last option.
Take care and follow up near your Orthopedician.