A shoulder dislocation occurs when the head of the humerus (upper arm bone) is forcibly displaced from the glenoid fossa (the shallow socket of the shoulder blade). This joint is the most frequently dislocated in the human body due to its high mobility and the small surface area of the socket. The injury causes immediate, intense pain, visible deformity, and an inability to move the arm. Because major nerves and blood vessels, like the axillary nerve, are nearby, immediate professional medical attention is mandatory due to the risk of associated damage.
Essential Safety Steps Before Medical Treatment
If a shoulder dislocation is suspected, seek emergency medical care immediately. While waiting for professional help, the primary goal is to minimize pain and prevent further injury. The arm should be immobilized using a sling, towel, or makeshift splint. Hold the arm close to the body in the position of least discomfort.
Applying ice helps manage swelling and pain immediately after the injury. Ice packs should be wrapped in a cloth to avoid direct skin contact and applied for no more than 20 minutes at a time, with breaks between applications. Over-the-counter pain relievers, such as nonsteroidal anti-inflammatory drugs (NSAIDs) or acetaminophen, can also be used if the patient has no contraindications. Always follow the recommended dosage.
Do not attempt to move the joint or force the humeral head back into the socket. An untrained person attempting reduction risks severe complications, including ligament tears, fractures of the humerus or glenoid, or permanent nerve and blood vessel damage. The axillary nerve, which runs close to the joint, is particularly vulnerable during improper reduction attempts.
Clinical Techniques for Shoulder Reduction
The process of returning the humeral head to the glenoid fossa, known as reduction, is performed by medical professionals in a controlled environment. Before manipulation, the patient receives procedural sedation and analgesia (PSA) to manage pain and induce muscle relaxation. Muscle spasm naturally resists reduction, so achieving adequate relaxation is essential for success.
The Traction-Countertraction Method involves applying a steady, opposing force to the limb and torso. The physician applies continuous, slow traction to the arm, usually with the elbow bent to 90 degrees. An assistant applies counter-traction using a sheet wrapped around the patient’s chest. Slow, consistent movements are favored over quick, forceful pulling, which increases muscle resistance.
The External Rotation Method requires the patient to lie supine while the injured arm is gently and slowly rotated away from the body. The arm is held close to the side with the elbow flexed. The physician uses the forearm as a lever to achieve external rotation. This technique relies on gradual muscle fatigue, with reduction often occurring as the arm reaches 70 to 110 degrees of external rotation.
The Stimson Maneuver utilizes gravity to achieve muscle relaxation and traction. The patient is positioned prone on an elevated surface with the injured arm hanging down. A weight of five to ten pounds is suspended from the wrist. This sustained, gentle downward pull can reduce the shoulder after 20 to 30 minutes and is often augmented by other maneuvers.
Scapular manipulation is often used with sustained traction, such as the Stimson method. The physician manually rotates the lower tip of the scapula (shoulder blade) medially toward the spine while stabilizing the superior aspect. The goal is to move the glenoid fossa into a favorable position to align with the humeral head.
Successful reduction is confirmed by a palpable or audible clunk as the bone slides back into the socket, an immediate return to a rounded shoulder contour, and a significant reduction in pain. Following the procedure, a thorough neurovascular examination checks for residual nerve or circulatory compromise. Post-reduction X-rays are always taken to confirm the joint’s correct position and identify any fractures that occurred during the injury or reduction.
Recovery and Preventing Future Dislocation
After successful reduction, the joint must be immobilized to allow damaged soft tissues to heal. Patients are placed in a sling or specialized shoulder immobilizer for two to four weeks, depending on the injury’s severity and age. The sling should only be removed for personal hygiene or to perform simple elbow and wrist exercises, keeping the upper arm close to the side.
Rehabilitation through physical therapy (PT) is necessary to restore full function and stability after immobilization. PT focuses on regaining the shoulder’s range of motion, followed by strengthening exercises for the rotator cuff and scapula-stabilizing muscles. Strengthening these surrounding muscle groups provides dynamic stability to the inherently unstable shoulder joint.
Recurrence is a significant risk after a traumatic dislocation, especially for younger, active patients. The initial dislocation often injures the labrum (the cartilage rim around the socket) or stretches the joint capsule and ligaments, causing instability. Damage, such as a Bankart lesion where the labrum tears away from the glenoid rim, increases the likelihood of subsequent dislocations.
If a patient experiences multiple dislocations or if the initial injury involved significant damage to the labrum or bone, surgery may be necessary to stabilize the joint permanently. A common procedure is the Bankart repair, which involves re-anchoring the torn labrum and tightening the stretched ligaments back to the glenoid rim. Recovery from such surgery often takes four to six months before a full return to sports or heavy physical activity is possible.