A posterior shoulder dislocation occurs when the head of the humerus moves backwards out of the socket. This is a rare shoulder injury as most shoulder dislocations are anterior.
Posterior shoulder dislocation symptoms
Dislocated shoulder symptoms include sudden severe pain in the shoulder joint at the time of injury with rapid swelling. There will be complete loss of shoulder function with constant pain and inability to use the arm. The shoulder will appear deformed with the patient often wanting to hold the arm out to the side and rotated inwards. The end of the humerus bone will most likely be felt at the back of the joint.
Posterior dislocations of the shoulder most frequently occur for two reasons. A direct impact to the front humeral head, pushing it posteriorly or back, or a fall onto an outstretched arm.
Both of these situations can occur in sports, especially contact sports, but also traumas such as car accidents and epileptic seizures where the individual thrashes the arms violently.
Treatment of a posterior shoulder dislocation
Seek medical attention for a dislocated shoulder immediately. Do not try to move the shoulder or put it back yourself. Once at hospital, a Doctor will examine the injury. Investigations such as an X-ray or MRI will be conducted to check for associated fractures or soft tissue damage.
Pulses and sensations in the arm, wrist and hand will also be checked to determine if there is any nerve or blood vessel damage. Treatment depends on the extent of the dislocation and how long the shoulder has been dislocated. In cases without associated fractures and where the dislocation is minor it can be reduced (popped back in!) by a doctor. Muscle relaxants, sedatives or anesthetic may be given to allow this.
The shoulder will then require rest to allow the sift tissues to heal, followed by a rehabilitation program to regain full movement and strength. In more complex cases involving fractures, extensive soft tissue injury or damage to blood vessels or nerves, surgery may be required to reduce the humeral head and repair injured structures.
Again a period of immobilization and rest will be required, followed by a rehabilitation program.