Multidirectional Instability >> Diagnosis

Diagnosis

How is atraumatic shoulder instability diagnosed?

A thorough history and physical examination are the keys to the diagnosis and treatment of MDI (Multidirectional Instability). The classic findings are: 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.