A shoulder injury involving misalignment, which is the separation of the upper arm bone (humerus) from the shoulder socket (glenoid fossa), is a serious medical emergency. This injury, whether a full dislocation or a partial separation known as a subluxation, demands immediate professional care. The shoulder is a highly mobile ball-and-socket joint, making it the most frequently dislocated major joint in the body. Attempting to force the joint back into place without medical training risks causing permanent damage to nerves, blood vessels, and bone structures. Medical attention is mandatory for safe and successful realignment, a process called reduction.
Understanding Shoulder Misalignment
The shoulder’s high degree of mobility comes at the expense of stability, as the socket is shallow compared to the ball of the upper arm bone. Misalignment occurs when the humeral head moves out of its proper resting position within the glenoid fossa. A subluxation is an incomplete or partial separation where the joint surfaces momentarily lose contact but may spontaneously return to position.
A full dislocation is a complete separation of the humerus from the socket, often resulting in a visibly deformed shoulder contour. Approximately 95% of these injuries occur when the humeral head is forced forward and downward, known as an anterior dislocation. The shoulder relies heavily on surrounding soft tissues, including the joint capsule, ligaments, and the four muscles of the rotator cuff, to maintain stability.
These soft tissues are severely stretched or torn during a dislocation, which causes the joint to become unstable. The active stabilizers, such as the supraspinatus, infraspinatus, teres minor, and subscapularis muscles, are overwhelmed by the traumatic force. Damage to these structures during the initial injury often leads to chronic instability, making the shoulder prone to dislocating again.
Why Attempting Self-Realignment is Dangerous
Any forceful, untrained manipulation of a dislocated shoulder can increase the injury’s severity. One of the most serious risks is damage to the nerves that run near the joint. The axillary nerve, which supplies sensation to the outer part of the upper arm and controls the deltoid muscle, is the most commonly injured nerve following a dislocation.
Improper maneuvering can stretch or tear the axillary nerve, potentially leading to permanent loss of sensation or paralysis of the deltoid muscle. The blood vessels, particularly the axillary artery, lie in close proximity to the joint and can be compromised by the dislocated bone or an aggressive reduction attempt. Vascular injury can lead to a loss of blood flow to the arm or, in rare cases, compartment syndrome, where swelling causes dangerous pressure buildup.
Dislocations are frequently associated with fractures, such as a Hill-Sachs lesion (a compression fracture on the back of the humeral head) or a Bankart lesion (a tear of the shoulder socket rim). Attempting to realign the shoulder without an X-ray to rule out these fractures can turn a soft-tissue injury into a complex fracture-dislocation. Forcing a fractured bone back into the socket can worsen the break, requiring more extensive surgical repair and a longer recovery.
Professional Reduction Techniques
The process of reduction is performed by trained medical professionals and typically begins with procedural sedation and analgesia to manage pain and relax the powerful shoulder muscles. Relaxing the muscles is necessary, as muscle spasms can resist manipulation and increase the force required for the reduction. The primary principle of safe reduction involves applying gentle, sustained in-line traction.
This traction is often combined with counter-traction, where a strap or sheet stabilizes the torso while the provider pulls gently on the arm. The goal is to fatigue the protective muscle spasms and guide the humeral head back into the glenoid fossa along the path of least resistance. Low-force techniques are preferred to minimize the risk of iatrogenic injury.
One common, low-force method is the Stimson technique, where the patient lies prone with the arm hanging over the edge of the bed and a weight is attached to the wrist. Another is the external rotation technique, which involves slowly rotating the arm outward while keeping the elbow bent and close to the body. Techniques like the Kocher maneuver, which involves forceful rotation, are used less frequently due to a higher risk of complications.
Long-Term Stabilization and Rehabilitation
Following a successful reduction, often signaled by an audible clunk and immediate pain relief, the focus shifts to immobilization. The shoulder is typically placed in a sling or immobilizer for one to three weeks to allow stretched and torn soft tissues to begin healing. This period protects the joint without causing excessive stiffness, which could delay rehabilitation.
Physical therapy (PT) follows immobilization to restore joint function and reduce the risk of recurrence, especially in younger patients. Rehabilitation begins with restoring a pain-free range of motion before progressing to strengthening. The strengthening phase targets the rotator cuff muscles, which are the dynamic stabilizers of the joint.
Therapy also incorporates exercises to strengthen the scapular stabilizers, the muscles that control the shoulder blade’s movement. A final phase involves proprioceptive training, which focuses on retraining the joint’s sense of position. For patients with chronic instability or significant damage, surgical options like arthroscopic repair may be necessary to tighten or repair damaged tissues for long-term stabilization.