CNY Orthopedic Sports Medicine, PC: Injury: Shoulder Instability

Injuries and Conditions: Shoulder: Shoulder Instability

Shoulder instability is related to defects, weakness or injury to the soft tissue capsule that surrounds the ball and socket joint of the shoulder. Instability indicates that the shoulder joint has become "loose" and excessive movement of the humeral head occurs within the joint and alters the mechanics and normal motion of the arm. Instability may result in recurrent dislocations or subluxations, as well as lead to the acceleration of the degenerative change in the joint
  • Recurrent shoulder instability can result from a traumatic event, which has weakened the rotator cuff tendons, damaged the joint supporting ligaments or stretched the joint capsule.
  • 50% of children without a history of shoulder problems have physical findings of shoulder instability.
  • Patients under the age of 20, who have experienced a traumatic shoulder dislocation, will have a 90% chance of experiencing long-term shoulder instability.
  • Non-surgical treatment focuses on strengthening the rotator cuff and deltoid muscles that support the shoulder joint.
  • Surgery is the preferred method of treatment to repair the damaged joint capsule and tighten the ligaments that stabilize the shoulder joint.

  • Signs and Symptoms
  • Shoulder instability can be multidirectional; excess joint movement can occur either forward (anterior), backwards (posterior), or downwards (inferior).
  • The shoulder may have the feeling of "popping in and out of joint".
  • Pain and shoulder weakness may be episodic.
  • The sensation that the arm is going to slip out of joint when the arm is moved into an extended throwing position, this is known as the apprehension sign.
  • Numbness or paralysis in the arm from pressure, pinching or cutting of blood vessels or nerves.

  • Contact the Doctor if ...
  • You experience shoulder subluxation or shoulder dislocation with even moderate arm movements.
  • Non-surgical treatment has failed to control the pain, restore function or manage the instability.
  • Surgical treatment has failed to relieve pain and restore stability.
  • Unexpected side effects occur from over the counter or prescription medications.

  • Common Causes of Injury
  • Shallow or abnormally formed joint surfaces (congenital) of the glenohumeral joint.
  • Rheumatoid arthritis or other diseases, which affect the ligaments and tissue surrounding the shoulder joint.
  • A traumatic event to the shoulder such as a fall.
  • A loose or unstable shoulder resulting from repetitive wear and tear or repeated shoulder injuries or dislocations.
  • The shoulder can loose its ability to balance and support all of the muscles surrounding the joint, due to poor strength, joint degeneration, or previous damage.

  • Expectations of Recovery
  • A successful recovery is dependent on the severity of the injury, type of treatment chosen and the intensity of physical therapy.
  • Through non-surgical treatment symptoms may diminish in several weeks, but intensive physical therapy should be considered for a minimum of 6 months to maintain shoulder strength and stability.
  • Severe instability requires that activities which cause the shoulder to be stretched or extended, such as throwing a ball or playing tennis, should be avoided.
  • Expect 4 to 6 months of intensive rehabilitation prior to returning to desired activities following surgery.


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