A shoulder dislocation occurs when the humerus separates from the scapula at the glenohumeral joint. The most common type is an anterior dislocation, which can be reduced using techniques like external rotation or traction-countertraction. Complications of shoulder dislocation include recurrent dislocations, fractures, soft tissue injuries like Hill-Sachs or Bankart lesions, and nerve or vascular injuries. Careful examination is needed before and after reduction to identify any associated injuries.

1. SHOULDER DISLOCATION

2. • A dislocated shoulder occurs when the humerus separates from the scapula at
the glenohumeral joint.
• A partial dislocation (subluxation) means the humerus is partially out of the
socket (glenoid). A complete dislocation means it is all the way out of the socket.
( American Academy Of Orthopaedic Surgeon).
• Most common dislocation
• Common in young/athletic patients ( recurrence > 90% if < 25 y/o)
• a/w labral tears (< 40 y/o) and rotator cuff ( > 40 y/o)
• a/w fracture of tuberosity/ glenoid rim ( Bony bankart)

3. Rotator cuff
- supraspinatus muscle, infraspinatus muscle, teres minor
muscle, subscapularis muscle.

4. • Anterior ( > 90% )
• Posterior
• Inferior ( luxation erecta)
• Superior ( rare)

5. • Mechanisms of injury are usually traumatic but may vary.
• Mechanisms may include sports, assaults, falls, seizures, throwing an
object, reaching to catch an object, forceful pulling on the arm, reaching
for an object, turning over in bed or combing hair.
• Specific mechanisms or historical facts may be suggestive of certain types
of dislocations such as lightning injuries, electrical injuries and seizure with
posterior dislocations
• Throwing a ball, a punch, forceful pulling of the arm, fall on out-stretch
hand, shoulder is abducted and externally rotated with an anterior
dislocation
• Axial loading of an extremely abducted arm with inferior dislocation.

6. • Pain
• Inability to move shoulder/ decreased range of motion of the affected
extremity
• Deformity of shoulder

7. Anterior shoulder dislocation
• sub-coracoid dislocation, sub-glenoid, subcalvicular, intrathoracic (rare)
• Arm is held in slight abduction and external rotation.
• Shoulder is "squared off" (ie, boxlike) with loss of deltoid contour compared with contralateral side.
• Humeral head is palpable anteriorly (subcoracoid region, beneath the clavicle).
• Patient resists abduction and internal rotation and is unable to touch the opposite shoulder.
• Compare bilateral radial pulses to help rule out vascular injury.
• In all cases, evaluate the axillary nerve before and after reduction by testing both pinprick sensation in the "regimental badge"
area of the deltoid and palpable contraction of the deltoid during attempted abduction.
• Evaluate sensory and motor function of the musculocutaneous and radial nerves.

8. Posterior shoulder dislocation
• Arm is held in adduction and internal rotation.
• Anterior shoulder is "squared off" and flat with prominent coracoid
process.
• Shoulders may look identical in bilateral dislocation, making it a commonly
missed injury.
• Posterior shoulder is full with humeral head palpable beneath the
acromion process.
• Patient resists external rotation and abduction.
• Neurovascular deficits are infrequent.

9. Inferior (luxatio erecta) shoulder dislocation
• Arm is fully abducted with elbow commonly flexed on or behind
head.
• Humeral head may be palpable on the lateral chest wall.

10. • Absence of normal contour of shoulder
• Bryant’s sign – Anterior axillary fold looks elongated
• Callaway’s sign – Axillary girth get increased
• Duga’s test – Inability to touch the opposite shoulder by affected hand
• Displaced head is palpable below clavicle or coracoid process of axilla
• Deformity- Shoulder extended,abducted, external rotation
• Hamilton ruler test – A ruler can touch acromion process and lateral
epicondyle at the same time.

11. Shoulder trauma series[7] - Anteroposterior (AP) and axillary or scapular "Y" views:
• Anterior dislocation is characterized by subcoracoid position of the humeral head in the AP view. The
dislocation is often more obvious in a scapular "Y" view, where the humeral head lies anterior to the "Y." In
an axillary view, the "golf ball" (ie, humeral head) is said to have fallen anterior to the "tee" (ie, glenoid).
• In posterior dislocation, the AP view may show a normal walking stick contour of the humeral head, or it
may resemble a light bulb or ice cream cone, depending upon the degree of rotation. The scapular "Y" view
reveals the humeral head behind the glenoid (the center of the "Y"). In an axillary view, the "golf ball" falls
posteriorly off the "tee." [8, 9]
• In inferior dislocation (luxatio erecta), the AP view may show the arm raised over the head with the radial
head inferior to the glenoid.
Pre-reduction films
• These are commonly performed to document the nature of the dislocation and to establish the existence of
any associated pathology, such as a Hill-Sachs lesion or other humeral fractures.
• In cases where patients have experienced repeated anterior dislocations, prereduction films may not be
necessary prior to attempts at reduction. [10]
Post-reduction films:
• These confirm relocation of the humerus and may reveal new or previously obscured pathology.
Postreduction immobilization is imperative.

12. • In Kocher's original method, bend the arm at the elbow, press it against the body, rotate outwards until resistance is felt. Lift the
externally rotated upper part of the arm in the sagittal plane as far as possible forwards and finally turn inwards slowly.
• The Stimson technique requires that the patient lie prone on the bed with the dislocated arm hanging over the side. Traction is
provided by up to 10 kg of weight attached to the wrist or above the elbow. Apply gentle internal/external humeral rotation.
Reduction may take 20-30 minutes.
• In the external rotation method, while the patient lies supine, adduct the arm and flex it to 90° at the elbow. Slowly rotate the arm
externally, pausing for pain. Reduce the shoulder before reaching the coronal plane. Often successful, this procedure requires only
one physician and little force (see Special Concerns).
• For traction-countertraction, while the patient lies supine, apply axial traction to the arm with a sheet wrapped around the
forearm and the elbow bent at 90°. An assistant should apply countertraction using a sheet wrapped under the arm and across the
chest while the shoulder is gently rotated internally and externally to disengage the humeral head from the glenoid.
• Scapular rotation is a less traumatic technique and has success rates of more than 90% in experienced hands, often without
sedation. With the patient lying prone, apply manual traction or 5-15 lb of hanging weight to the wrist. After relaxation, rotate the
inferior tip of the scapula medially and the superior aspect laterally. Alternatively, the patient can be seated while an assistant
provides traction-countertraction by pulling on the wrist with one hand and bracing the upper chest with the other. The same
scapular rotation is then performed.

13. • For reduction of a posterior dislocation, apply gentle, prolonged axial
traction on the humerus. Then, add gentle anterior pressure while
coaxing the humeral head over the glenoid rim. Slow external rotation
may be needed.
• For reduction of an inferior dislocation, maintain gentle axial traction
on the humerus while gentle abduction is applied. Apply
countertraction across the ipsilateral shoulder. Following reduction,
slowly adduct the arm. Buttonholing of the humeral head through the
capsule usually requires open reduction.

14. • Complications
• See the list below:
• Recurrent shoulder dislocation (See Prognosis).
• Fractures and soft-tissue injuries (See Other Problems to be Considered.) Hill-Sachs lesions occur when the edge of the glenoid causes an impaction fracture in the posterolateral
aspect of the humeral head during anterior dislocation and in the anterolateral aspect in posterior dislocation (referred to as a "reverse Hill-Sachs" lesion).
• A Bankart lesion is fracture of the anterior rim of the glenoid labrum associated with joint capsule rupture and inferior glenohumeral ligament injury. Significantly displaced
anterior or posterior glenoid rim fractures require operative management. Most initial shoulder dislocations produce a Bankart lesion, particularly in younger patients.
• Fracture of the greater tuberosity, acromion, coracoid, clavicle, and humeral neck also occur.
• Rotator cuff traction injury is most common in elderly patients and in association with inferior dislocations. This is a commonly missed injury, with an average time of 7 months
from injury to diagnosis of rotator cuff rupture in patients older than 40 years.
• Nerve injury (See Other Problems to be Considered.) Approximately 3% (and higher in some series) of dislocations involve injury to the axillary nerve. Injury may resolve
spontaneously or require surgical exploration and possible nerve grafting.
• Patients exhibit numbness in the area of the deltoid muscle and weakness with abduction and external rotation.
• Axillary nerve injury does not change initial treatment, but pre-reduction and post-reduction neurologic examinations are important.
• Radial nerve injury should also be determined. The axillary and radial nerves both arise from the posterior cord. The thumb, wrist, and elbow will be weak on extension, and the
dorsal hand will be numb.
• Vascular injury (See Other Problems to be Considered.) Axillary artery injuries are rare but have been reported to occur with anterior, inferior, and intra-thoracic dislocations.
Especially susceptible are older adults with atherosclerotic axillary arteries. Arterial injury may be associated with decreased radial pulse.
• Lateral chest wall ecchymosis with associated axillary hematoma and bruit may be noted on physical examination.
• Angiography should be considered with any brachial plexus injury.