Anterior Shoulder Instability
The shoulder can lose its normal retraining structures that prevent the abnormal
subluxation of the humerus and the glenoid. The shoulder joint is surrounded
by a capsule which is reinforced by a thickened area known as a ligament. Stretching
or tearing of these reinforcement structures allow for abnormal slippage of
the arm bone (humerus) and the shoulder cup (glenoid).
Patients will experience a feeling that the shoulder “is coming
out of its joint” with activity. Sometimes, overhead activities
such as pitching a baseball or serving in tennis will cause
the arm to go numb. This is known as “dead arm syndrome.”
Evaluation usually involves a provocative physical exam and a specialized
study such as MRI or CT arthrogram. An arthrogram is a test
which involves injecting contrast material (dye) into a joint to better outline
the internal structures. This test helps differentiate between normal anatomy
and areas of injury.
This condition may respond to an exercise program but recurrent episodes and
non-responsive joints may require surgical treatment.