What is the difference between a dislocated shoulder and a subluxation?

The shoulder joint is one of the most mobile joints in the human body, but it is also classified as the most susceptible to dislocation [1]. This joint is made up of three main bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone), which ends in a ball-shaped head that rests within a special socket in the shoulder blade. To understand the difference between a shoulder dislocation and a subluxation, we must look at the degree to which this ball-shaped head has moved out of its socket.

Shoulder Dislocation vs. Subluxation

A full shoulder dislocation occurs when the head of the humerus completely moves out of its designated socket in the shoulder blade [1]. A subluxation, which is sometimes medically referred to as a "partial dislocation," is a condition where the head of the bone moves out of the socket only partially; meaning that it remains in partial contact with the socket, but it loses its natural stability and correct anatomical position [1]. Both conditions lead to a malfunction in joint mechanics, which requires careful medical assessment to determine the extent of damage to the surrounding tissues.

Clinical Symptoms and Diagnosis

Although the severity of the injury varies between a full dislocation and a subluxation, symptoms are often similar and require immediate medical attention. Signs that necessitate a doctor's visit include:

• Sudden, severe pain concentrated in the shoulder area [1].
• Visible swelling or bruising in the shoulder or upper arm area [1].
• Noticeable difficulty moving the arm or total loss of motor function [3].
• The arm appearing abnormal or looking as if it is "out of place" [1].
• A sensation of numbness or weakness that may extend to the neck, hand, or fingers [1].

At the clinic, the doctor will take a medical history and perform a thorough clinical examination, and they will often order an X-ray to confirm the condition and determine if there are associated fractures or tissue damage [1].

First Aid and Immediate Measures

If you suspect a shoulder dislocation, it is essential not to attempt to put the joint back in place yourself, as this can lead to serious complications [3]. In emergency situations that include the inability to move the arm, an obvious deformity in the shape of the shoulder, or unbearable pain, you must head to the emergency department immediately. While waiting for medical care, you can take some simple steps:

• Support the injured arm using a sling or a piece of cloth to minimize movement [3].
• Place a bag of ice or a bag of frozen peas wrapped in a towel on the shoulder for up to 20 minutes every two to three hours to reduce swelling and pain [3].
• Avoid any forceful movement of the damaged joint entirely [3].

Recovery and Preventing Recurrence

Treatment for a dislocation depends on returning the bone to its natural position, a process known as closed reduction, followed by a rest period using an arm sling lasting several days or weeks, depending on the doctor's instructions [1]. Recovery time usually ranges up to 12 weeks to return to daily activities, and athletes may need a longer period of up to 16 weeks [3]. Since a dislocation makes the joint unstable, the likelihood of future recurrence increases; therefore, adhering to a rehabilitation program and exercises prescribed by a doctor or physical therapist is vital for strengthening the muscles surrounding the joint [1]. To learn more about practical steps, you can view our comprehensive article on Shoulder Dislocation: First Aid, Treatment, and Preventing Recurrence (Arabic).

Medical references

• Dislocated Shoulder
• Dislocated shoulder - NHS