Australian Doctor 16th May 2025 | Page 36

36 HOW TO TREAT: SHOULDER INSTABILITY

36 HOW TO TREAT: SHOULDER INSTABILITY

16 MAY 2025 ausdoc. com. au
Bony defects can be on the humeral side, glenoid side, or a combination of both. The injuries on either side can significantly contribute to the risk of recurrent instability events. When the labral injury is associated with a bony defect in the glenoid it is described as a bony Bankart lesion( see figure 6). A Hill – Sachs lesion is a chondral impaction injury in the posterosuperior humeral head. This lesion is associated with anterior shoulder dislocation( see figure 7). In a posterior dislocation, the anteromedial humeral head is usually impacted, and it is known as a reverse Hill – Sachs lesion.
PRESENTATION
History
PATIENTS with shoulder instability may present with an acute shoulder dislocation or report a history of recurrent shoulder dislocations or episodes of the shoulder feeling like it is slipping out of place( subluxation). They may describe a sensation of instability during certain movements, such as reaching overhead or throwing.
Obtain a detailed history of shoulder dislocation from the patient; include the mechanism of injury, age of first dislocation and frequency of dislocation.
Pain, swelling and limited range of motion are common accompanying symptoms. The patient may also complain of“ dead arm” from a brachial plexus stretch at the time of dislocation.
Examination
In patients with unreduced anterior shoulder dislocation, the arm is usually abducted and externally rotated, and the acromion appears prominent. In posterior dislocation, the arm is usually held in adduction and internal rotation, and the patient is unable to rotate it externally.
AXILLARY NERVE FUNCTION The axillary nerve is the one most commonly stretched following an anterior dislocation. It is therefore important to test sensation over the deltoid( see figure 8), and, if possible, test deltoid contraction by asking the patient to abduct the arm against resistance.
SHOULDER LAXITY
A test for shoulder laxity is the
sulcus sign. Instruct the patient
to sit on the edge of an examination
couch with their arms at their
side. The examiner then pulls the
patient’ s affected arm inferiorly. If there is a large sulcus( more than 1cm) that forms at the superior
Figure 1. Anatomy of the shoulder, posterior view.
aspect of the humeral head, the test
is positive. A positive sulcus sign
then applies a uniform downward
ROTATOR CUFF TEARS
impingement( see figure 11). When
90 ° of abduction and 90 ° of external
of more than 2cm is predictive of
force to the arm. While keeping the
Evaluate patients for rotator cuff
all three were positive, or if two
rotation. The test is positive when
multidirectional instability( see fig-
arm in the same position, the palm
tears because these are a relatively
tests were positive and the patient
patients experience apprehension.
ure 9). 5
is fully supinated, and the manoeu-
common complication of a dislo-
was aged 60 or older, the individ-
In the relocation test the patient
ual had a 98 % chance of having a
experiences a decrease in apprehen-
SLAP TEARS The O’ Brien test( also known as the active compression test) is useful to identify a SLAP tear. 6 With the patient seated comfortably on the examination table, ask the patient
The O’ Brien test is useful to identify a superior labrum from anterior to posterior tear.
rotator cuff tear; combined absence of these features excluded this diagnosis. 6
ANTERIOR INSTABILITY There are several clinical tests that
sion when the humerus is pushed down( relocated) during apprehension testing. An augmentation test is deemed positive when the patient experiences additional apprehension with an anterior force( see fig-
to forward flex the affected arm
are helpful in the diagnosis of ante-
ure 12). 5, 8
90 ° with the elbow in full extension. Ask the patient to adduct the arm 10-15 ° medial to the sagittal
vre is repeated. If pain is elicited in the first manoeuvre( with the thumb down) and is less in
cated shoulder, particularly in the elderly. The author and colleagues have identified three simple pre-
rior shoulder instability. The most useful are the apprehension test and its variants( augmentation and
IMAGING
X-RAYS are helpful to first, con-
plane of the body. The arm is internally rotated so that the thumb
the second( with the palms facing upwards), the test is positive( see
dictive tests for a rotator cuff tear. 7 These are supraspinatus weakness,
relocation tests). In the apprehension test, place the patient supine.
firm a dislocation, second, if a dislocation is present— to confirm the
points downward. The examiner
figure 10).
weakness in external rotation and
The arm is then gently moved to direction, and third, to
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