A thorough history and physical examination are the keys to the diagnosis
and treatment of MDI (Multidirectional Instability). The classic findings
a history of generalized laxity.
no history of a forceful dislocation event.
a history of recurrent episodes of instability.
The patient's history may reveal a recent injury, an obvious dislocation, or a change in sport or
training that has led to instability in a previously healthy shoulder.
A general examination of joint mobility is very helpful. By moving
the arm around in several positions, the doctor can evaluate full
shoulder motion. Multidirectional laxity may be present in both shoulders
even though only one may be bothersome to the patient. A patient
with MDI has an increase in glenohumeral translation (shoulder joint
movement) in multiple directions, and symptoms can be recreated in
one or more directions. More than 2 cm of movement during the
sulcus test suggests the presence of MDI. The diagnosis
of MDI should be based on this result combined with the evaluation
of overall shoulder motion and the symptoms triggered when the doctor
moves the arm in several directions.
Further evaluation may include some form of visual study of the shoulder.
X-rays are always obtained, primarily to rule out any
associated injuries that would require treatment. Occasionally
the images reveal a congenital (present since birth) abnormality
that may be contributing to the instability.
An MRI (Magnetic Resonance Image) can reveal other sources
of the shoulder pain that may require more than a rehabilitation
program alone for successful treatment.
An arthroscopy allows the surgeon to visually
evaluate the structures of the glenohumeral joint using a tiny
fiberoptic instrument. Other related injuries may be revealed
since increased movement and repetitive trauma in the joint can
lead to injuries of the labrum and partial thickness
rotator cuff tears. With arthroscopy, these injuries can
be treated at the time of the examination, and the patient may
go on to achieve a pain free shoulder with a rehabilitation program.