Shoulder instability occurs when the shoulder’s ball (called the humeral head) slips out of its socket (called the glenoid), usually from an injury. This can range from a dislocation, where the ball comes completely out of the socket, to a subluxation, where the ball partially comes out of the socket.
If you dislocate your shoulder, it's very likely you have a tear in your glenoid labrum, a cartilage bumper that helps stabilize your shoulder joint. After the shoulder is put back into place, many patients will be able to recover by wearing a sling and participating in physical therapy. In patients at high risk of further instability or patients with multiple instability events, we can surgically repair the torn labrum back to the socket and stabilize the shoulder through minimally invasive arthroscopic techniques in the majority of cases. Repeated instability incidents can result in further damage to the shoulder’s cartilage and create bone defects that make surgical stabilization more difficult.
What causes shoulder instability?
Shoulder instability is commonly caused by an injury such as a fall with the arm overhead or through contact sports like football. Patients in their teens and 20s are at high risk for first-time shoulder instability as well as for further recurrent instability events, especially if they participate in contact sports. Patients over age 40 who dislocate the shoulder often tear the rotator cuff tendons.
What are the symptoms of shoulder instability?
Associated symptoms of a shoulder dislocation include pain that worsens when raising the arm, stiffness, lack of strength and mobility in the shoulder area and the sensation that the shoulder is slipping out of place.
Diagnosis and treatment of shoulder instability
Diagnosis of shoulder instability starts with patient symptoms such as feeling of shoulder slipping out of place, whether there was a specific injury, and if the shoulder had to be put back into place. A physical exam helps to determine if the shoulder is loose or unstable. Imaging with X-rays and MRI or a CT scan shows what damage is present to the bones, cartilage and rotator cuff of the shoulder.
The Ohio State Universty Wexner Medical Center shoulder specialists offer a number of treatment options, both nonsurgical and surgical.
You may be fitted with a sling that you will wear for several days to a week or two, followed by physical therapy to strengthen the muscles that stabilize your shoulder.
About 70 percent of patients overall do not have further instability. However, men under age 25 have more than an 80 percent chance of further instability events without surgery, particularly if they play contact sports.
If surgery is necessary, minimally invasive arthroscopic surgery is successful in stabilizing a shoulder for someone who has a first-time dislocation, reducing the risk of further instability to less than 20 percent. Along with a general anesthetic, a nerve block is usually injected into your shoulder to numb your shoulder and arm and to help reduce postsurgical pain. Your surgeon will make small incisions in your shoulder for the arthroscope, which projects images of your shoulder, and other instruments used to repair the labrum tear. Most arthroscopic procedures are on an outpatient basis and take less than an hour. The length of your shoulder surgery will depend on the extent of repair needed.
Your arm will be in a sling for four to six weeks after surgery, and you will work with a physical therapist for several months after the procedure. Full recovery and return to sports usually take from four to six months, depending on the activity and the amount of surgical repair.
You and your physician should weigh the risks and benefits of the treatment options as well as your lifestyle goals and preferences. Factors to consider include:
- Risk of recurrence
- Time in a sling with restricted arm motion
- Out-of-pocket cost
- Time away from sporting activities, particularly for in-season athletes
- Risks from anesthesia and surgery