The shoulder is said to have been dislocated when the top of the humerus is forcefully removed from its usual location in the shoulder joint. The humerus is the round top bone of the shoulder that fits into the cup-shaped socket of the shoulder blade.
A related injury called a shoulder subluxation occurs when the humerus is only partially displaced out of its socket.
Usually, a lot of force is required to dislocate the shoulder. When the arm is pulled or twisted using brute force whether upward, outward or backwards, the shoulder joints separate from each other, leaving the arm immobile and in great pain. In other cases, a shoulder dislocation occurs due to a fall with the arm outstretched or as a result of electric shock that produces powerful muscle contractions. More information about this can be found at: https://sgbonedoctor.com/shoulder-arthroscopy/rotator-cuff-tear/
Doctors classify shoulder dislocations into three types, depending on the direction of the dislocation:
This type of dislocation happens when the humerus is displaced forward, towards the front of the body. This is the most common type of shoulder dislocation, accounting for more than 95% of cases. In young people, the cause is typically sports-related. In older people, it usually is caused by a fall on an outstretched arm.
This type of dislocation is easy to treat. The doctor will pop the shoulder back into its initial position, and the patient will rarely require surgery.
Posterior dislocations occur when the humerus is displaced toward the back of the body. This can happen when a patient falls forwards or is hit from the front when playing high impact sports. Posterior dislocations account for les s than 5% of all shoulder dislocations in Singapore and are the type most likely to be related to seizures and electric shock.
Posterior dislocations can happen because of a fall on an outstretched arm or a blow to the front of the shoulder.
When the top of the humerus is displaced downward, the type of dislocation is said to be inferior. This type of shoulder dislocation is rare to come across. Inferior dislocations can be caused by trauma when an excessive force pushes the arm downward.
While most shoulder dislocations occur due to trauma, other times, ordinary motions such as raising your arm can dislocate your shoulder. This is especially common if there is an underlying condition such as weak ligaments or bone diseases that render muscles impotent.
Shoulder dislocations are the most common joint dislocation especially in the sports in games like football and rugby and account for more than 50% of all dislocations treated in hospitals. Young adult men and older women tend to be the groups with the highest rate of shoulder dislocations.
Not unless the type of dislocation causes ligaments to tear or bones breaking, the process of treating a dislocation is quite straightforward. The doctor uses force to force the humerus back into the socket. The patient will undergo rehabilitation for a couple of months until full range of motion and strength is restored.