The shoulder is a ball and socket joint. It is one of the most complex joints in the human body. In a healthy shoulder joint, the ball, or humeral head, and socket, or glenoid, remain stable, while allowing maximal range of motion of function.
Reinforcing this stability if the joint is the glenoid labrum, a fibrocartilaginous rim that encircles the edge of the glenoid, making its concavity deeper, and therefore more stable.
Additional ligaments surrounding the joint (some of which are attached to the glenoid labrum), help to hold the humeral head inside its socket. Together, these bones and tissue keep your shoulder in place and stable through a wide range of motion.
Sometimes, injury or overuse can result in forceful dislocation or subluxation that tears the cartilage and ligaments of the shoulder. In dislocation, the humeral head comes away from the glenoid, therefore stretching and possibly tearing the surrounding soft tissues.
The most common type of shoulder dislocation is anterior. This most commonly occurs when the arm is abducted away from the body, and forced forward or downward in an injury. When the humeral head dislocates anteriorly, the ball forcefully pushes against the anterior glenoid labrum at the front of the socket. A glenoid labrum tear in the anterior joint is called a Bankart lesion. When the labrum is torn, the shoulder joint is less stable, and allows the humeral head to move around more than normal.
Posterior dislocation (when the arm is forced backwards) can also lead to a tear in the labrum, though less commonly.
If your tear is accompanied by a fracture in the bone of the shoulder socket (glenoid), 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.
Bankart lesions are frequently the results of high energy trauma and sports injuries (either acute injuries or overuse injuries from repetitive arm motions). Though anyone can sustain this injury, young people in their twenties are most susceptible.
Possible causes of shoulder dislocations and lesions:
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:
If your shoulder continues to dislocate or feel unstable, see a doctor for further evaluation. Your doctor may use X-rays, an MRI, and/or a thorough physical exam to help make a diagnosis.
Depending on the cause and severity of your shoulder instability, you may be prescribed an exercise program and/or surgery to stabilize the shoulder joint.
If you are healthy, the outlook for shoulder surgery of this kind is generally good, with most patients resuming gentle movement and non-contact sports within 6-12 weeks. Most patients will need to avoid heavy lifting and contact sports for at least three months while they undergo physical therapy to regain strength and range of motion in the shoulder.
To learn more, give Coastal Orthopedics located in Corpus Christi, TX a call.Telephone: 361.994.1166.
Article written by: Rob Williams, MD