Dislocation
What is it?
- An abnormal separation from where the ends of two bones normally align. A partial dislocation is referred to as a subluxation.
- Examples: Glenohumeral Joint Dislocation or Acromioclavicular (AC) separation
- Dislocations occur when a sudden force such as a fall or a blow is applied to the joint. If the force is greater than the opposing force from the muscles, tendons, and ligaments a dislocation will occur.
- Pain
- Visible displacement of the shoulder
- Decreased movement
- Numbness of the arm
- Joint instability
- Reduced muscle strength
- Bruising around joint area
- Primary pain will be felt at the dislocation site
- Referral pain can be felt down the arm and into the fingers depending on dislocation direction and nerve entrapment
- Pre-reduction X-Rays are needed to confirm dislocation and to determine the direction of the dislocation
- CT scan to determine size of any bone fractures
- MRI to determine surrounding soft tissue damage
- Anterior Dislocation
- Arm held in an abducted and externally rotated
- Loss of normal contour of the deltoid and acromion is more prominent posteriorly and laterally
- Humeral head palpable anteriorly
- All movements limited and painful
- Palpable fullness below the coracoid process and towards the axilla
- Posterior Dislocation
- Arm is abducted and internally rotated
- May or may not lose deltoid contour
- May notice posterior prominence head of humerus
- Tear of subscapularis muscle (weak or cannot internally rotate)