What is a shoulder (joint) instability?

Shoulder instability is a condition that occurs when structures around the shoulder joint don’t work to keep the ball in the shoulder socket. If the joint is too loose, it can slide out of place and cause a partial dislocation of the shoulder joint (subluxation). If it remains loose but is not treated, it can lead to arthritis in the shoulder.  

The shoulder is the most moveable joint in the human body. This greater range of motion makes it more susceptible to joint instability.  

Causes of shoulder joint instability

The three main causes of shoulder instability are shoulder dislocation, repetitive strain or multidirectional instability.
  • Shoulder dislocation — a shoulder dislocation occurs when the humorous dislocates from the socket due to severe injury or trauma. Severe dislocations can lead to continued dislocations and instability in the shoulder.
  • Repetitive strain — repetitive overhead motion that could be caused by sports such as swimming or tennis can stretch out the shoulder ligaments and cause instability.
  • Multidirectional instability — if you are double-jointed, your shoulder may feel loose or dislocate out the front, back or bottom of the shoulder.

Risk factors of shoulder joint instability

  • Repetitive stress — movements from participating in sports such as swimming, volleyball, baseball or tennis can put pressure on the shoulder joint and weaken the ligaments and cause instability in the shoulder joint.
  • Traumatic events — events such as falling down stairs or from a high distance or participating in contact sports can cause instability in the shoulder joint.
  • Prior shoulder dislocation  — once you have had a shoulder dislocation, you are more likely to have another dislocation.
  • Genetics — some people have loose joints or are double-jointed, the loose ligaments do not provide enough support to keep the shoulder in the socket.

Symptoms of shoulder joint instability

Chronic shoulder instability symptoms include:

  • Pain caused by shoulder injury
  • Repeated shoulder dislocations or shoulder “giving out”
  • Loose sensation in the shoulder
  • Feeling of the shoulder slipping in and out of the joint

Diagnosis of a shoulder joint instability

Your doctor can diagnose shoulder instability after discussing your medical history and symptoms and then examining your shoulder. He or she will check for looseness in the ligaments and do specific tests to assess instability.

Your provider may order other imaging tests that can help confirm your diagnosis including:
  • X-rays can show injuries other bones that make up the shoulder joint
  • MRIs can identify injuries to ligaments and tendons around the shoulder joint.

Treatment for shoulder joint instability

You may need several months of nonsurgical treatment for shoulder joint instability before you notice an improvement.  
Nonsurgical treatments can include:

  • Medications — non-steroidal, anti-inflammatory medications can reduce pain and swelling resulting from shoulder instability.
  • Modify activity level — avoid activities where symptoms are the worst. 
  • Physical therapy and rehabilitation — your physical therapist can prescribe exercises that help you strengthen your shoulder muscles and provide stability.

In some cases, surgery is necessary to repair the soft tissues in the shoulder so they can hold the humorous in the socket.

Surgical treatments for shoulder instability include:

  • Arthroscopy — tiny incisions are made in the shoulder and surgical instruments are inserted to repair the damaged tissue.
  • Open surgery — some patients have a more severe condition and need open surgery to correct shoulder instability; open surgery requires a larger incision and a greater area of view by your orthopedic surgeon.

Recovery from shoulder joint instability

Most patients are immobilized in a sling during nonsurgical treatments as well as after surgery. Physical therapy and rehabilitation will begin as quickly as possible after the sling is removed. Physical therapy will help you improve your shoulder range of motion.

Follow your doctor’s and therapist’s instructions closely to ensure you can return to your everyday activities.

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