Shoulder instability occurs when the head of the upper arm bone, the humerus, repeatedly slips partially or completely out of the shoulder socket, the glenoid. This condition often results from a traumatic event like a dislocation, which damages the ligaments and the labrum, or from repetitive overhead movements that stretch the joint capsule over time. Because the shoulder is the body’s most mobile joint, it relies heavily on surrounding structures for stability. Compromise to these structures leads to a feeling of looseness, slipping, or “giving out,” so treatment focuses on restoring the joint’s ability to remain centered in the socket and allowing a full return to function.
Immediate Conservative Management
The initial response to a shoulder instability episode, particularly after a first-time or acute subluxation, focuses on controlling symptoms and protecting the joint from further harm. This non-operative approach includes Rest, Ice, Compression, and Elevation (RICE) principles to manage pain and swelling, as applying a cold compress helps reduce inflammation.
Activity modification requires the patient to avoid positions that provoked the instability, especially movements involving the arm moving overhead or reaching into extreme ranges of motion. Over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, can alleviate pain and reduce the inflammatory response. For an acute traumatic dislocation, a brief period of immobilization in a sling, typically one to three weeks, may be recommended to allow initial soft tissue calming and prevent stiffness.
Focused Rehabilitation and Physical Therapy
Physical therapy (PT) is the primary long-term, non-surgical treatment for shoulder instability, aiming to create dynamic stability to compensate for damaged or loose static restraints like ligaments and the labrum. This comprehensive approach progresses through distinct phases, beginning with the restoration of pain-free range of motion (ROM) after the initial period of immobilization. Gentle exercises, such as passive and assisted ROM movements, are introduced to prevent joint stiffness without stressing healing structures.
The next phase transitions to progressive strengthening, targeting the rotator cuff muscles responsible for centering the humeral head in the glenoid socket:
- Supraspinatus
- Infraspinatus
- Teres minor
- Subscapularis
Exercises like side-lying external rotation and internal rotation with resistance bands specifically target these muscles to maintain joint alignment. Concurrently, strengthening the scapular stabilizing muscles, such as the trapezius and serratus anterior, is essential because the shoulder blade provides the stable base from which the arm operates. Exercises like prone horizontal abduction (“T”s), prone scaption (“Y”s), and the “push-up plus” engage these periscapular muscles to ensure proper shoulder mechanics.
The final component of rehabilitation is neuromuscular re-education, also known as proprioceptive training, which teaches the body to instinctively control the joint during movement. This involves dynamic stability drills that challenge the joint’s reaction time, often starting with closed kinetic chain exercises like rhythmic stabilization. Progression moves to open kinetic chain activities and sport-specific movements, requiring the patient to control the shoulder in unpredictable and high-demand situations.
Surgical Repair Options
When conservative management fails or in cases of severe structural damage, surgery becomes a necessary option. The decision to operate is based on factors such as patient age, activity level, the number of previous dislocations, and the presence of significant bone loss on the glenoid or humeral head. The goal of surgery is to anatomically repair damaged soft tissues or reconstruct any bony deficiencies causing the instability.
One common procedure is arthroscopic stabilization, a minimally invasive technique performed through small incisions, often used to fix soft tissue injuries. The Bankart repair, for example, reattaches the torn labrum and associated ligaments back to the front of the glenoid socket using suture anchors. If the joint capsule is simply stretched and loose, a capsular shift or plication procedure can be performed to tighten the redundant tissue.
Addressing Bone Loss
When instability involves significant bone loss, which often happens after multiple dislocations, a more robust procedure may be required. If a Hill-Sachs lesion (a compression fracture on the back of the humeral head) engages with the glenoid rim, a procedure called remplissage may be performed alongside a Bankart repair. Remplissage involves stitching the rotator cuff tendon into the bone defect to fill the void and prevent the lesion from engaging.
For substantial loss of bone from the glenoid socket, an open procedure like the Latarjet procedure may be necessary. This involves transferring the coracoid process, a piece of bone along with its attached muscles, to the front of the glenoid to reconstruct the socket and provide a bony block against future dislocation.
Recovery Timelines and Preventing Recurrence
Recovery varies significantly depending on whether the patient underwent surgery or completed non-operative rehabilitation, but adherence to a structured protocol is paramount. Following surgical stabilization, recovery is phased and can take six to nine months for a full return to high-demand activities or competitive sports. The initial four to six weeks typically involve immobilization to protect the healing soft tissue repair, followed by a gradual progression of range of motion exercises.
Strengthening exercises are introduced around six weeks post-operation, and functional, sport-specific drills begin around four months. Return-to-sport clearance is often based on achieving full painless range of motion and at least 90% strength compared to the unaffected side. Patients who undergo successful non-operative rehabilitation may return to full activity sooner, perhaps within three to six months, once their dynamic stability is robustly established. Preventing recurrence involves maintaining the strength of the rotator cuff and scapular stabilizers through regular maintenance exercises, and athletes must be psychologically confident in their shoulder’s stability before returning to high-risk activities.