Shoulder Instability
A plain-language overview of shoulder instability.
- Where
- Shoulder (ball and socket)
- Common signs
- Looseness, dislocation
- Options
- Therapy or stabilization surgery
- Urgent?
- Severe pain, deformity, or numbness: seek care promptly.
Overview
Shoulder instability happens when the ball of the upper arm bone slips partly (subluxation) or fully (dislocation) out of the shoulder socket. It often comes with a tear of the labrum, the rim of cartilage around the socket.
Adapted from AAOS OrthoInfo, the patient education site of the American Academy of Orthopaedic Surgeons, and rewritten in plain language.
Anatomy
The shoulder is the most mobile joint in the body. Its shallow socket is deepened by the labrum, and ligaments and the rotator cuff help hold the ball in place. When these structures are stretched or torn, the shoulder can slip out more easily.
Causes
- A traumatic dislocation, often from a fall, collision, or a forceful pull on the arm
- Repeated overhead motion, as in swimming, throwing, or volleyball, stretching the ligaments
- Naturally loose ligaments in some people (multidirectional instability)
Symptoms
- Pain with the arm in certain positions
- Repeated shoulder slipping or dislocations
- A feeling the shoulder is loose or hanging
- Apprehension about raising the arm overhead
Doctor exam & imaging
Your doctor will check for looseness and apprehension in different positions. X-rays look for injury to the bone of the ball or socket, and an MRI shows the labrum, ligaments, and cartilage. A CT scan may be used to measure bone loss.
Treatment
Nonsurgical treatment
Treatment may begin with a period of rest and a sling, followed by physical therapy to strengthen the muscles that stabilize the shoulder and to improve control. Activity changes may reduce episodes.
Surgical treatment
Surgery may be recommended for repeated dislocations, especially in young and active people, or when bone or labral damage is significant. Common options include arthroscopic labral repair (Bankart repair) and, when there is bone loss, procedures that restore or add bone to the socket (such as the Latarjet procedure).
Dr. Gee has studied shoulder instability in military cadets and servicemembers.
Recovery & return to activity
After surgery, a sling protects the repair for several weeks, then therapy progresses from motion to strengthening. Return to contact or overhead sports is gradual and typically takes several months.
When to seek care
- The shoulder dislocates and stays out (go to urgent care or an emergency department)
- Numbness or weakness in the arm or hand
- Repeated episodes of the shoulder slipping
In an emergency, call 911.