Shoulder instability is when the ball of the shoulder slips partially or fully out of its socket — often after a traumatic dislocation that tears the labrum. It can become recurrent, with the shoulder dislocating more easily over time. Treatment ranges from physical therapy to arthroscopic instability repair, matched to your injury and activity level.
What is shoulder instability?
The shoulder is the most mobile joint in the body, which also makes it prone to instability. Shoulder instability is when the ball at the top of the arm bone slips partially (subluxation) or fully (dislocation) out of the socket. It commonly follows a traumatic dislocation that damages the labrum — the rim of cartilage that deepens and stabilizes the socket.
Why the shoulder keeps slipping
A first traumatic dislocation can tear the labrum and stretch the supporting ligaments, so the shoulder dislocates more easily afterward — sometimes with progressively less force. Younger, active patients are at higher risk of recurrence, and repeated instability can cause additional damage to the labrum, bone, and cartilage over time, which is why timely evaluation matters.
Common symptoms
- The shoulder slipping, subluxating, or fully dislocating
- A feeling of apprehension that the shoulder will "come out," especially overhead or reaching back
- Pain, weakness, or swelling after an episode
- Recurrent dislocations with decreasing force over time
Treatment options
- Non-surgical care: physical therapy to strengthen the rotator cuff and the muscles that stabilize the shoulder, with activity modification
- Arthroscopic instability repair: minimally invasive reattachment of the torn labrum and tightening of the supporting tissue (labral / Bankart repair) so the ball stays centered in the socket
- Related shoulder care: instability can occur alongside rotator cuff injury; both can be addressed arthroscopically
After surgery, recovery follows a staged shoulder rehabilitation protocol — sling, then range-of-motion, then progressive strengthening.
Frequently asked questions
What is shoulder instability?
Shoulder instability is when the ball of the shoulder (the top of the arm bone) slips partially (subluxation) or fully (dislocation) out of the socket. It often follows a traumatic dislocation that damages the labrum — the rim of cartilage that deepens the socket — and can become recurrent, with the shoulder slipping with progressively less force.
What causes a shoulder to keep dislocating?
A first traumatic dislocation can tear the labrum and stretch the surrounding ligaments, so the shoulder is more likely to dislocate again. Younger, active patients are at higher risk of recurrence. Repeated instability can cause additional damage to the labrum, bone, and cartilage over time.
Does shoulder instability need surgery?
Not always. Some patients are managed with physical therapy to strengthen the muscles that stabilize the shoulder. Surgery is considered for recurrent instability, a labral tear, or when activity demands make re-dislocation likely. Dr. Gomoll discusses the right approach based on your exam, imaging, and goals.
How is shoulder instability repaired?
Most instability is repaired arthroscopically — through small portal incisions — by reattaching the torn labrum and tightening the supporting tissue (often called a Bankart or labral repair) so the ball stays centered in the socket. The minimally invasive approach generally means less soft-tissue disruption than open surgery.
What is recovery like after instability repair?
Recovery is staged to protect the repair: a period in a sling, then gradual range-of-motion, then progressive strengthening over several months, guided by a shoulder rehabilitation protocol. Following the protocol closely is important to prevent re-injury.
Dr. Gomoll evaluates shoulder instability at the Hospital for Special Surgery, 523 East 72nd Street on Manhattan's Upper East Side. See our location and directions or request an appointment.
Medical disclaimer
This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a board-certified orthopedic surgeon who has reviewed your imaging, history, and physical examination. Individual outcomes vary.