Shoulder Dislocation

INTRODUCTION:
  • When the top of the humerus moves out of its usual location in the shoulder joint, the shoulder is said to be dislocated.
  • Recurrent dislocation are common in Shoulder 
  • Commonest type of shoulder dislocation Subcoracoid 
  • Attitude in subcoracoid dislocation of shoulder includes Limb on side of body 
  • Stryker's view is used in shoulder joint to visualise Recurrent subluxation
TYPES:
  • Anterior dislocation(98%)
  • Posterior dislocation(2%)
  • Inferior dislocation(luxatioerecta)(very rare)
ANTERIOR DISLOCATION:
  • The top of the humerus is displaced forward, toward the front of the body.
  • This is the most common type of shoulder dislocation more than 95% of cases.
  • In older people, it usually is caused by a fall on an outstretched arm with history of abduction & external rotation
  • Sensory loss in lateral side of forearm and weakness of flexion of elbow joint, most likely injured nerve is Musculocutaneous nerve
  1. Preglenoid It is the most common type of anterior dislocation and head lies in front of glenoid.
  2. Subcoracoid :- The head lies below the coracoid process.
  3. Subclavicular (infraclavicular) :- The head lies below the clavicle.
  4. Intrathoracic :- It is very rare.
POSTERIOR DISLOCATION:
  • The top of the humerus is displaced toward the back of the body.
  • Most likely to be related to seizures and electric shock.
  • Posterior dislocations also can happen because of a fall on an outstretched arm or a blow to the front of the shoulder.
  • The position of arm in posterior dislocation of shoulder is In internal rotation 
  • Posterior dislocation is often over-looked & Radiography may be misleading
INFERIOR DISLOCATION:
  • The top of the humerus is displaced downward. This type of shoulder dislocation is the rarest.
  • Referred to as Luxatio erecta 
  • Nerve most common injured is Axillary nerve 
  • It can be caused by various types of trauma in which the arm is pushed violently downward.
CLINICAL PRESENTATION:
  • Pain on affected side
  • Holds the injured limb with other hand close to the trunk
  • The shoulder is abducted and the elbow is kept flexed

PHYSICAL EXAMINATION:

  • Loss of the contour of the shoulder may appear as a step
  • Anterior bulge of head of humerus may be visible or palpable
  • A gap can be palpated above the dislocated head of the humerus
  • Limited ROM
  • Dugar’s sign- touch the opposite shoulder by crossing arm in front of body.
  • Ruler’s sign
INVESTIGATION:
  • X-RAY
  • show following joint dislocation with or without fracture.
  1. Gleno-humeral dislocation
  2. Acromio-clavicular joint dislocation
  • MRI
  1. Shoulder joint MRI scanning shows details of soft tissue of bones of the shoulder joint.
  • Electrical study - Electromyogram (EMG):Arthroscopy
  1. It is performed to evaluate sensory and motor nerve injury nd brachial plexus injury
  • It is performed to rule out following injuries associated with shoulder joint dislocation :-
  1. Shoulder Joint Fracture
  2. Joint haematoma
  3. Tendon injury and tearLigament tear and injury
MANAGEMENT:
  • Velpeau & Sling and swathe bandage are used for shoulder dislocation, proximal humerus fracture and humeral fracture.
  • Hippocratic method- Longitudinal traction on the arm and a counterforce to the axilla, usually with the heel of the foot.
  1. Stimson technique- The patient's arm is allowed to hang over the edge of the bed with about 10 pounds of weight hanging from the wrist
  • Kocher's method -
  1.  Involves traction to the elbow with external rotation of the humerus and adducting the elbow toward the chest.
  • External rotation-
  1.  It is a modification of the Kocher maneuver, involves flexing the elbow to 90° and slowly adducting the arm to the patient's side
Surgical Intervention:
  • Both posterior and anterior dislocation may require surgery if a tear in the capsule prevents stable reduction or if soft tissue intervenes to prevent it.
  • Primary surgical repair: for young adults who have had acute traumatic shoulder dislocations and who will continue to be engaged in demanding physical activity - eg, sports, military.
COMPLICATIONS:
  • Fractures of the bone-. Hill-Sachs deformity - 75% of anterior shoulder dislocations.
  • Nerve damage
  • rotator cuff injuries in older patients.
  • Recurrent shoulder dislocation.
Exam Question of:
  • In Inferior shoulder dislocation nerve most common injured is Axillary nerve
  • Velpeau bandage and Sling and Swathe splint are used in Shoulder dislocation
  • Hill Sachs lesion' is a consequence of Anterior dislocation of shoulder joint
  • Inferior dislocation of shoulder is referred to as Luxatio erecta
  • Attitude in subcoracoid dislocation of shoulder includes Limb on side of body
  • The position of arm in posterior dislocation of shoulder is In internal rotation
  • Loss of the normal contour of the shoulder and a abnormal-appearing depression below the acromion.
  • Recurrent dislocation are common in Shoulder
  • Commonest type of shoulder dislocation Subcoracoid 
  • Recurrent dislocation of shoulder occurs, because of Crushed glenoidal labrum 
  • Hill sachs defect ,Bankart lesion,Lax capsule are related to recurrent shoulder dislocation 
  • The most common complication of dislocation of shoulder joint is Injury to circumflex nerve
  • A patient with anterior dislocation of shoulder will most likely give a history of Abduction and external rotation
  • The easiest way to reduce dislocation of shoulder is by simple pressure with the patient under general anesthesia with muscle relaxation
  • Dugar's test is helpful in Anterior dislocation of shoulder Traumatic anterior dislocation of shoulder with sensory loss in lateral side of forearm and weakness of flexion of elbow joint, most likely injured nerve is Musculocutaneous nerve
  • Head of humerus usually dislocates forward from shoulder joint
  • Injury is produced by forced extension & external rotation of abducted arm
  • Posterior dislocation is often over-looked & Radiography may be misleading
  • Fixed medial rotation in posterior dislocation
  • Kocher's manoeuvre is effective in anterior dislocation
  • Stryker's view is used in shoulder joint to visualise Recurrent subluxation
  • Commonest shoulder dislocation is Preglenoid
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