A Bankart lesion is a form of instability in the front or anterior part of the shoulder. It results from a specific injury and is common in contact sports or after direct trauma to the shoulder. Surgery is not always required, but when it is, post-operative care is very important as re-injury is common.
Bankart lesions affect the stability of the shoulder joint, and knowing a little about shoulder anatomy is key to understanding them. Three bones meet at the shoulder: the upper arm bone (humerus), the shoulder blade (scapula), and the collarbone (clavicle). The shoulder blade has a small pocket called the glenoid where the head or top of the humerus fits. The head of the humerus is larger than the pocket, though, so there is a rim of soft tissue around the joint called the labrum that helps hold the head of the bone in place.
Inferior Glenohumeral Ligament
The shoulder also has ligaments, long fibrous connective tissue that connects bone to bone. There are many important ligaments in the shoulder, but the one involved in a Bankart lesion is the inferior glenohumeral ligament. This ligament runs around the front of the shoulder joint, playing a significant role in shoulder stability. A Bankart lesion results from a tear in the bottom part of the soft tissue edge of the labrum and injury to the inferior glenohumeral ligament.
Bankart lesions happen when the upper arm bone is dislocated and presses against the soft labrum, detaching it from the bony glenoid. Bankart lesions often result from injuries like a direct hit to the shoulder, falling on an outstretched arm, or a sudden pull. These injuries can also happen over time with repetitive motion as in weightlifting or throwing.
Soft vs. Bony Bankart Lesion
There are two types of Bankart lesions, soft and bony.
A soft Bankart lesion is when the labrum tears from the glenoid, and the injury involves only the soft tissue. A bony Bankart lesion occurs when the labrum tears and a part of the bony glenoid fractures or breaks off. Bony Bankart lesions are less common but more severe. They can lead to significant bone loss in the glenoid, which can cause chronic instability.
To diagnose a shoulder injury like a Bankart lesion the doctor will first establish how the injury occurred and check for stability, pain, and range of motion. They may ask for x-rays, but with a soft Bankart lesion, an x-ray will not reveal any damage as it does not show soft tissue. A CT or MRI can assess for any tears, but a confirmed diagnosis is often only made during surgery if it’s required.
Non-surgical treatment methods are often effective for Bankart lesion. Rest and anti-inflammatory medication can relieve symptoms, and physical therapy can strengthen the shoulder and increase stability. If non-surgical treatments are not successful, surgery is the next step. Open surgery was once the gold standard, but arthroscopic, minimally invasive surgery is becoming more and more common.
In arthroscopic surgery for Bankart lesion, the surgeon inserts a narrow tube into a small incision in the shoulder to examine the rim and ligaments. In most cases, they will not know the extent of the injury until this time. If the damage is minor and the shoulder is still relatively stable, the surgeon removes the torn section. If the damage is more significant, they will repair the damage, reattaching the ligament with sutures as needed.
Success Rates of Surgery
Arthroscopic surgery is generally successful for Bankart lesions, but the risk for re-injury is high. Recent studies show that reinjury after surgery occurs in between 4 and 19 percent of people. This risk is highest in young men with shoulder instability on both sides who return to contact sports soon after surgery.
Proper post-operative care can help prevent Bankart lesion reinjury, but it is not guaranteed. Usually, the first follow-up is the day after surgery for a dressing change and so the doctor can assess the incision site. The patient will use a shoulder sling most of the time initially but should remove the arm and allow it to hang freely for five minutes a few times every day.
Physical therapy is usually required to assist recovery as the patient slowly increases activity, strength, and range of motion after surgery.
Several complications can occur from a Bankart lesion. If surgery does not make normal mobility possible, the chance of re-injury is particularly high.
One of the most serious complications is bone loss of more than 25% in a bony Bankart lesion. If the bone is fractured this badly, the injury may require alternative surgical treatments. Regular arthroscopic surgery will not be effective at repairing the damage.