Shoulder instability occurs when the head of the upper arm bone is forced out of the shoulder socket due to injury or overuse. Once this has happened, the shoulder is vulnerable to repeat episodes. When the shoulder is loose and slips out of place repeatedly, it is called chronic shoulder instability. Treatment can help to improve stability of the shoulder and reduce the risk of repeat episodes.
There are several types of shoulder instability:
- Shoulder Dislocation: Shoulder dislocation occurs when the humerus (upper arm bone) comes out of the shoulder socket. This is usually caused by an injury or overuse and can cause the tissues to stretch, tear, or detach, leading to instability of the shoulder.
- Shoulder Subluxation: Subluxation is when the humerus partially slides in and out of place. This is usually caused by an injury or overuse and can cause the tissues to stretch, tear, or detach, leading to instability of the shoulder.
- Labral Tear: If the labrum cartilage surrounding the socket of the shoulder joint is torn, it can lead to shoulder instability. A labral tear may occur due to trauma, shoulder dislocation, or from repetitive motions (such as sports).
- Genetic Shoulder Instability: Some individuals born with looser tissues in the shoulder may be more likely to experience shoulder instability even without injury or repetitive motions.
Symptoms of shoulder instability include:
- Feeling that the ball of the shoulder is “giving way” (especially during specific activities or positions, such as reaching back or throwing something)
- Decreased range of motion
- Frequent dislocation and/or subluxation of the shoulder joint
Shoulder instability is usually treated with a combination of conservative and surgical approaches. The following treatments can help strengthen the shoulder and minimize the risk of future instability episodes.
- Physical Therapy: A guided PT course is recommended to help patients regain strength in their shoulder joint. Strengthening the muscles around the shoulder can provide some additional stability to protect and prevent the shoulder from dislocating or subluxing in the future.
- Activity Modification: If certain activities are known to trigger shoulder instability, those activities should be avoided or modified wherever possible. Whenever the shoulder is dislocated or subluxed, the patient should rest and avoid aggravating it for a few days. Shoulder bracing may be recommended. Range of motion exercises (guided by a trained physical therapist) should be started once the pain and swelling have subsided.
- Anti-Inflammatory Medication: Non-steroidal anti-inflammatory medications can decrease swelling, inflammation, and pain caused by shoulder instability. Patients undergoing physical therapy may benefit from taking anti-inflammatory medications (over-the-counter or prescription strength) to reduce pain while they work to regain strength and stability.
- Surgery: Surgery may be recommended for patients with a labral tear, patients for whom instability occurs routinely, and patients who are not willing to avoid activities that contribute to their shoulder instability. In some cases, arthroscopic surgery can stabilize the shoulder. For patients with severe shoulder instability, open surgery may be necessary to repair a labral tear and/or reattach and tighten the tissues. Small implants may be used to permanently anchor the shoulder together.
Frequently Asked Questions
Shoulder instability may be indicated if you have chronic shoulder pain along with episodes of instability (such as multiple shoulder dislocations and/or subluxations), as well as feeling that the ball of your shoulder is giving way during certain activities. Patients with a personal history of shoulder dislocation or subluxation are also more likely to have shoulder instability. A medical evaluation with X-rays and other testing (such as MRI) will be performed to diagnose your condition and determine a treatment plan.
Many patients will experience improvement in symptoms through conservative methods. However, patients with a labral tear will likely need surgery as this rarely heals on its own. Surgical candidates also include patients with chronic shoulder instability in their daily lives despite conservative treatments, as well as patients who are not willing to modify their activities to reduce the risk of instability episodes. Factors including the patient’s age, level of function, frequency of dislocation episodes, and lifestyle demands will all play a role in determining whether surgery should be considered.
The most common risks of not getting treatment include persistent pain, weakness, and tension in the shoulder. Recurrent shoulder instability can eventually lead to irreversible damage to the joint, including eventual arthritis. Patients who are not candidates for surgery will be advised to go through conservative treatments to minimize the risk of long-term damage and the recurrence of shoulder instability episodes.