A shoulder dislocation occurs when the head of the upper arm bone, the humerus, completely separates from its natural position within the shallow, cup-shaped shoulder socket, the glenoid fossa. This painful injury can result from significant force, such as a fall onto an outstretched arm or a direct blow to the shoulder. When this displacement happens, a medical procedure known as a shoulder reduction is performed to carefully guide the humerus back into its proper alignment within the glenoid.
The Shoulder Reduction Procedure
A medical professional must perform a shoulder reduction to safely reposition the humerus into the glenoid socket. The goal is to gently guide the bone back into place, often overcoming muscle spasms around the injured joint. Various techniques are employed, focusing on principles of gentle pulling (traction), controlled rotation of the arm, or specific manipulations of the shoulder blade to facilitate relocation.
Before attempting the reduction, an X-ray is performed to confirm the dislocation and rule out any associated fractures to the humerus or glenoid. Muscle relaxation is important for a successful reduction, as tense muscles can hinder the process. To aid in muscle relaxation and patient comfort, medical professionals commonly use pain medication, muscle relaxants, or procedural sedation.
Common reduction methods include the Stimson technique, where weights are applied to the arm while the patient lies prone and the arm hangs freely, or the Milch technique, which involves gentle abduction and external rotation of the arm. The traction-countertraction method, often requiring an assistant to provide counter-pull, uses sustained force to realign the bones. These techniques are chosen based on the type of dislocation and the patient’s condition.
Post-Reduction Care and Recovery
Following a successful shoulder reduction, immediate steps stabilize the joint and confirm proper placement. The shoulder is immobilized in a sling to provide rest and restrict movement, allowing injured ligaments and soft tissues to begin healing. A post-reduction X-ray is performed shortly after to verify the humerus is correctly seated within the glenoid and to check for any new issues.
The duration of sling use varies, often ranging from a few days to several weeks, depending on the injury’s severity and healing progression. Adhering to the doctor’s instructions regarding immobilization and activity restrictions helps prevent re-dislocation and promotes tissue repair. During this period, gentle exercises for the wrist and elbow may be encouraged to maintain circulation and prevent stiffness.
Once the initial healing phase is complete and pain subsides, longer-term recovery often involves physical therapy. A physical therapist guides the patient through a progressive exercise program designed to restore the shoulder’s full range of motion, improve muscle strength, and enhance joint stability. This rehabilitation helps regain function and reduce the likelihood of future dislocations.
Potential Complications of a Dislocation
The significant force that causes a shoulder to dislocate can also lead to other injuries at the time of the event. Fractures are a common complication, potentially affecting the head of the humerus (such as a Hill-Sachs lesion, an indentation on the humeral head) or the glenoid socket itself (a Bankart lesion, involving the front lower rim of the socket). These bone injuries can sometimes complicate the reduction or affect long-term shoulder stability.
Damage to surrounding nerves and blood vessels is another concern. The axillary nerve, which runs close to the shoulder joint and supplies sensation to the outer part of the upper arm and controls the deltoid muscle, is particularly susceptible to stretching or injury. While nerve damage can cause temporary numbness, tingling, or weakness, severe cases may result in lasting effects if not addressed promptly. Injuries to blood vessels, such as the axillary artery, are less common but represent a more severe complication.
Dangers of Attempting Self-Reduction
Attempting to reduce a dislocated shoulder without proper medical training is dangerous and should be avoided. While often depicted in popular media as a simple maneuver, untrained attempts can worsen the injury. Applying incorrect force or technique can cause new fractures or exacerbate existing ones in the humerus or glenoid.
There is also a risk of damaging nerves or blood vessels that may have been stretched or compressed during the initial dislocation. Unguided movements could trap and tear these structures, potentially leading to permanent nerve damage, impaired blood flow, or even requiring emergency surgery. A straightforward injury could become a complex problem with prolonged recovery and lasting complications.