Your shoulder keeps dislocating because the first dislocation almost certainly damaged the soft tissue structures that hold the joint in place, and those structures often don’t heal well enough to prevent it from happening again. The younger you were at your first dislocation, the higher the risk: people who first dislocate in their teens have a recurrence rate as high as 92%, while those over 50 have about a 12% chance of it happening again.
The shoulder is the most mobile joint in your body, which also makes it the least inherently stable. Understanding what’s going wrong inside the joint helps explain why this keeps happening and what can actually fix it.
Why the Shoulder Is Prone to Instability
Most joints have bony structures that limit how far they can move. The shoulder doesn’t. The ball of the upper arm bone sits against a shallow, flat socket on the shoulder blade, with very little bony coverage keeping it in place. Imagine a golf ball resting on a tee. Almost all of the joint’s stability comes from soft tissues: a ring of cartilage (the labrum) that deepens the socket, a capsule of ligaments that surrounds the joint, and the rotator cuff muscles that actively compress the ball into the socket during movement.
These structures work together through a feedback loop. Nerve endings embedded in the ligaments and capsule detect the position and movement of the joint, then signal the surrounding muscles to contract at precisely the right time to keep the ball centered. When the ligaments and capsule are torn, this signaling system breaks down. The muscles respond too slowly or in the wrong pattern, making the joint vulnerable to slipping out of place again.
What the First Dislocation Does to Your Joint
A single dislocation causes real structural damage. In a study of 110 patients with anterior shoulder instability, 84% had a dent pressed into the back of the ball of the upper arm bone (called a Hill-Sachs lesion, created when the bone impacts the rim of the socket on its way out). And 73% had a tear where the labrum pulled away from the front of the socket (a Bankart lesion). These two injuries frequently occur together.
The Bankart tear is particularly important for recurrence. When the labrum detaches from the socket rim, it takes the lower ligaments of the joint capsule with it. This effectively removes the front bumper of the joint. If this tear doesn’t heal back in the right position, the shoulder has a permanent weak spot. Each subsequent dislocation can extend the tear further along the socket rim, stretch the capsule more, and erode bone from the socket edge, making the next dislocation even easier.
The dent on the back of the arm bone can also contribute. If it’s large enough, it can catch on the front rim of the socket when you raise and rotate your arm, mechanically levering the joint out of place.
Two Patterns of Instability
Recurrent shoulder instability generally falls into two categories, and knowing which one you have changes the treatment approach entirely.
The first and more common pattern follows a clear injury. You fell, were tackled, or caught yourself with an outstretched arm, and the shoulder came out. The instability is in one direction (almost always forward), caused by a specific structural tear. This pattern typically responds to surgical repair if rehabilitation alone isn’t enough.
The second pattern develops without a memorable injury. The shoulder may feel loose in multiple directions, sometimes on both sides. This is often linked to naturally loose ligaments throughout the body. People with generalized joint laxity (sometimes screened by checking whether they can hyperextend their elbows, knees, and fingers beyond normal range) are more susceptible. For this group, strengthening the muscles around the shoulder through physical therapy is the primary treatment, since the problem isn’t a single torn structure but an overall looseness of the joint capsule.
Age and Activity Level Matter
Age at first dislocation is the single strongest predictor of recurrence. The 92% recurrence rate in teenagers drops steadily with age, landing at roughly 12% for people over 50. Younger patients tend to be more active and place higher demands on the joint, but biology also plays a role: younger tissue may be more likely to tear away from bone rather than heal in place.
Contact sports, overhead athletes, and anyone whose work involves repetitive overhead motions face higher recurrence risk simply because they’re repeatedly putting the arm in the vulnerable position (out to the side and rotated back) where the joint is least protected by its remaining soft tissue.
How Repeated Dislocations Cause Long-Term Damage
Each dislocation isn’t just a temporary event. It grinds away bone, stretches tissue, and accelerates wear on the joint surface. In a population study with an average 15-year follow-up, roughly 23% of patients under 40 who experienced shoulder instability went on to develop symptomatic arthritis in that shoulder. That’s nearly one in four people dealing with chronic pain and stiffness well beyond the instability itself.
This is one reason many orthopedic surgeons now recommend earlier surgical stabilization for young, active patients after a first dislocation rather than waiting through multiple recurrences. Each episode can make the eventual repair more complex and less likely to succeed.
Getting the Right Diagnosis
A standard MRI can show large labral tears and bone bruising, but it misses subtler damage. An MR arthrogram, where contrast dye is injected into the joint before scanning, is significantly more accurate for detecting labral tears and partial rotator cuff injuries. Multiple studies have confirmed MR arthrography has superior sensitivity for anterior labral tears and cartilage lesions compared to conventional MRI. If your standard MRI looked “normal” but your shoulder still feels unstable, an arthrogram may reveal what was missed.
Your doctor will also assess how much bone has been lost from the socket rim. This is a critical measurement. Research now suggests that when 15% or more of the socket width has been eroded away, a soft tissue repair alone can’t restore normal joint mechanics. The traditional threshold was 20% to 25%, but more recent evidence has pushed that number down, meaning some patients who would have been offered a simpler repair a decade ago now benefit from a bone-restoring procedure.
Physical Therapy for Shoulder Stability
Rehabilitation targets three layers of muscles. The rotator cuff (four muscles that wrap around the ball and compress it into the socket) is the most obvious target, but it’s not the only one. The muscles that control the shoulder blade are equally important, since the socket is part of the shoulder blade, and a poorly positioned blade means a poorly positioned socket. Exercises like side-lying external rotation, prone horizontal abduction, and the “push-up plus” are commonly used to activate the middle and lower trapezius and serratus anterior, which are the muscles most responsible for keeping the shoulder blade stable against the rib cage.
Rehabilitation also addresses core and trunk stability, because the shoulder generates force through a chain that starts at the legs and trunk. A weak core can overload the shoulder during throwing, lifting, or even reaching overhead. Most people begin to notice improvement within two weeks of consistent training, performing 8 to 10 repetitions for 2 to 3 sets twice daily. A full rehabilitation program typically takes several months before you can confidently return to demanding activities.
For people with generalized joint laxity and no specific structural tear, physical therapy is the first-line treatment and often the only treatment needed. For those with a clear Bankart tear or bone loss, rehab is essential both before and after surgery, but it won’t fix the underlying structural problem on its own.
When Surgery Is Needed
The two most common surgical options are an arthroscopic Bankart repair and the Latarjet procedure. A Bankart repair reattaches the torn labrum and capsule back to the socket rim using small anchors, done through tiny incisions with a camera. It works well when there’s minimal bone loss and a clear soft tissue tear. However, recurrence rates after arthroscopic Bankart repair range from about 7% to 23%, depending on the study and the patient population.
The Latarjet procedure is a more involved operation. A small piece of bone from the front of the shoulder (the coracoid process) is transferred to the front of the socket, effectively rebuilding the eroded rim and adding a muscular sling across the front of the joint. Recurrence rates are lower, around 3.5% to 6.5%. In high-demand patients, those who underwent the Latarjet returned to sports or work in about 5 months compared to 7 months for the Bankart repair, and a higher percentage (67% vs. 53%) returned to their pre-injury level of activity.
The Latarjet is generally recommended when there’s significant bone loss from the socket or arm bone, when a previous Bankart repair has failed, or when the patient is a high-level contact athlete with elevated re-injury risk. Both procedures produce similar functional outcomes and range of motion scores when used for the right patient, so the choice depends heavily on the specific anatomy of your injury.