The shoulder joint is the main joint of the shoulder. It is a ball and socket joint that allows the arm to rotate in a circular fashion or to hinge out and up away from the body. The shoulder is the most mobile joint in your body. The ball (or “head”) of the arm bone (humerus) rests in a shallow socket called the glenoid. The “ball” of the joint is the rounded, medial anterior surface of the humerus and the “socket”. The socket is formed by 2 types of forms i.e. the glenoid cavity, the dish-shaped portion of the lateral scapula. The shallowness of the cavity and relatively loose connections between the shoulder and the rest of the body allows the arm to have tremendous mobility. Off course the mobility comes at the expense of being much easier to dislocate than most other joints in the body.
There is an approximately 4-to-1 disproportion in size between the large head of the humerus and the shallow glenoid cavity. To help make the socket deeper, the outer rim of the fibrocartilaginous glenoid is ringed by tough, flexible tissue called the labrum. An injury to the labrum can result in a Bankart lesion.
What is a Bankart lesion?
The shoulder joint is enclosed by a sheet of ligaments and other tough fibres called the capsule. Sometimes, however, a sudden shoulder injury or overuse can create a forceful dislocation that tears the cartilage and ligaments of the shoulder. When you tear your glenoid labrum below the center anterior (front) of the socket, this is called a Bankart lesion. When the labrum is torn, the cartilage rim around the socket is compromised, allowing the humeral head to slip from its socket farther than normal. This can take you in pain and feel as if your shoulder is slipping out of place.
Types of Bankart Injuries:
The types of Bankart Lesion depend on where the head of the humerus shifts. There are mostly 2 types of Bankart Lesion injuries. Bankart tears, typically occur with shoulder dislocation in younger patients.
- Anterior Dislocations – In this, the arm moves too far forward and down, toward the front of the body, leading to “anterior instability.”
- Posterior Dislocations – (when the arm is forced backwards) or the back of the body can also lead to a tear in the labrum, leading to “posterior instability.” though it is less common.
If your tear is accompanied by a fracture in the bone of the shoulder blade (scapula) or the shoulder socket (glenoid cavity), this is called a bony, or osseous, Bankart lesion. An untreated Bankart lesion can lead to chronic shoulder instability — meaning your shoulder may dislocate again in the future, probably in situations involving less force than the original injury.
The same mechanism of compression can result in a Hill-Sachs lesion. Bankart and Hill-Sachs lesions are 11x more likely to occur together than isolated injuries 5.
Perthes lesion of the shoulder: Perthes lesion of the shoulder is one of the types of the anterior glenohumeral injury in which the anterior inferior labrum is torn and lifted from the edge of the glenoid 1 but still attached to the intact lifted periosteum from the anterior aspect of the glenoid.
Anterior labroligamentous periosteal sleeve avulsion (ALPSA): (“medialised Bankart”) involves medial displacement of the torn labrum which is still attached to the medial scapular periosteum.
SIGNS AND SYMPTOMS OF A BANKART LESION
This type of labrum tear shares many symptoms with other shoulder injuries. A thorough doctor’s exam is necessary to properly diagnose your symptoms.
Symptoms of a Bankart lesion can include:
Instability and weakness: The shoulder may pop out of the joint, feel too loose or “just hang there,”.
Pain. Pain during throwing a ball. When reaching overhead, at night, or with daily activities may also cause a pain..
Limited range of motion. Sudden difficulty moving the shoulder in any direction may indicate a tear.
Unusual noises or sensations in the shoulder. Locking in place, grinding, catching (not moving fluidly), or popping can all be symptoms of torn tissue getting caught in the joint.
CAUSES OF BANKART LESIONS:
Bankart lesions are sudden injuries, frequently the results of sports injuries (either acute injuries or overuse injuries from repetitive arm motions), collisions and accidents. Though anyone can sustain this injury, young people in their twenties are most susceptible.
Possible causes of shoulder dislocations and lesions:
- Sports Injuries. Crashing into another person with speed and force — for example, during a footballor hockey tackle — can shove the shoulder out of alignment or drag the arm forward or backward, leading to dislocations.
- Falls from sports. Falling and landing on one’s shoulder can lead to shoulder dislocations in athletes, especially in sports where falling with height or speed is common, like Sliding into bases during softballor baseball can harm the shoulder also sports like gymnastics, skating, rollerblading, or skiing etc..
- Car accidents.A sudden blow to the shoulder can knock the ball from its socket, tearing the labrum.
- Domestic or other Falls.While cleaning the objects at height like fan, ceiling etc. Elderly people and those with gait problems can be highly susceptible to these types of falls. Falling off a ladder or tripping on a crack in the sidewalk can deliver enough force to dislocate the shoulder.
- Loose ligaments. Some people have a genetic predisposition to loosen ligaments throughout the body (e.g., double-jointed individuals). They may find that their shoulders pop out of alignment easily.
- Overuse injuries.In some athletes, overuse of the shoulder can lead to loosening of ligaments and instability. Swimmers, tennis players, volleyball players, baseball pitchers, gymnasts, and weight lifters are prone to this problem. In addition, non-athletes may develop instability from repeated overhead motions of the arm (for example, swinging a hammer).
- Physical abuse.Domestic violence, physical bullying, or fighting can involve falls, blows, or sudden wrenching movements that may pull the ball from the socket, damaging surrounding tissue.