Shoulder Dislocations and Instability

Shoulder instability occurs when the head of the upper arm bone is forced out of the shoulder socket. This can happen as a result of a sudden injury, or from a patient’s underlying ligamentous laxity (natural tendency to have “loose joints.” Once a shoulder has dislocated, it is vulnerable to repeat episodes. When the shoulder is loose and slips out of place repeatedly, it is called chronic shoulder instability.

Anatomy:

Your shoulder is made up of three bones:
  • The upper arm bone (humerus)
  • Shoulder blade (scapula)
  • Collarbone (clavicle)

rotator cuff muscles

Description:

 

rotator cuff muscles

 

Shoulder dislocations can be partial, which is called a subluxation, or a complete dislocation. Once the ligaments, tendons, and muscles around the shoulder become loose or torn, dislocations can occur repeatedly. Dislocations can also occur repeatedly if you are naturally “loose” (born this way).

Causes:

Acute Shoulder Dislocation
  • Severe injury/trauma is often the cause of an initial shoulder dislocation.
  • When the head of the humerus dislocates, the socket (glenoid) and the ligaments in the front of the shoulder are often injured. The labrum (the cartilage rim around the edge of the glenoid) may also tear. This is commonly called a Bankart lesion.
Repetitive Strain
  • Instability can sometimes be caused by repetitive overhead motion, such as in swimming, tennis, volleyball, and throwers (baseball, football, etc.)
  • This chronic overhead activity can lead to stretching out the ligaments.
Multidirectional Instability
  • Some patients have no history of excessive overhead activity or traumatic injury.
  • In these patients, the shoulder may feel loose or dislocate out the back, front, or bottom of the shoulder.
  • These patients may have naturally loose ligaments throughout their body.

Imaging:

To further evaluate your shoulder, Dr. Fleager may order x-rays to evaluate for any bone abnormalities. Sometimes, we may need to order an MRI to assess the soft tissues of your shoulder to further understand the best way to treat your instability. Injecting dye into the shoulder with your MRI (an MRI arhtrogram) will show your anatomy in better detail.

Treatment:

Nonsurgical Treatment

  • Activity modification: you may need to make some changes to your lifestyle to avoid activities that aggravate your symptoms.
  • Sling: a sling may be used to rest the shoulder after a traumatic shoulder dislocation.
  • NSAIDs like Ibuprofen or Aleve to reduce pain and inflammation.
  • Physical therapy: Therapy is absolutely essential to strengthen your rotator cuff and muscles around your scapula, to increase stability.

Surgical Treatment

  • Arthroscopy: Using minimally invasive techniques, Dr. Fleager will repair the capsule and labrum of the shoulder to increase stability in the shoulder joint. This is a day surgery.
  • Open Surgery: For more extensive instability, some patients may need an open surgical procedure, which involves making a larger incision over the front of the shoulder and to correct the abnormalities.
    • Whether an arthroscopic or open procedure is done, you will likely wear a sling for 4-6 weeks, but you would be allowed to move your elbow/wrist/fingers.
    • You will attend physical therapy for 8-12 weeks to improve your range of motion and strengthen your shoulder muscles.