This is an injury where the upper arm bone (humerus) pops out of the cup-shaped socket at the shoulder joint, which is part of the shoulder blade. The shoulder, being the most mobile body joint, is prone to dislocation. There are cases of a partial as well as complete dislocation, both causing pain and instability in the shoulder.
When the head of the humerus dislocates, the socket bone (glenoid) and the ligaments in front of the shoulder are also injured. Shoulder dislocation types depends on the direction of dislocation of the ball:
- Anterior: from front of the socket
- Posterior: from behind the socket
- Inferior: from below the socket
What is Recurrent Shoulder Dislocation?
In this condition, the patient’s shoulder dislocations take on a recurrent nature, and they are said to have an Unstable Shoulder or Shoulder Instability.
The shoulder joint of a potentially unstable joint will have a wider circumference than the socket or glenoid and also shallow. The stability of the shoulder depends on the neighboring soft tissues like labrum, capsule and ligaments.
The disruption of the labrum, capsule and the ligaments in the front of the shoulder is called the Bankart’s Lesion. When the head of the humerus lies over the edge of the glenoid and causes an indentation on the ball, then it’s called Hill-Sach Lesion.
Causes
This can happen after:
- Traumatic dislocation from a fall or injury to shoulder
- Generalized laxity of the ligaments.
- Gradual stretching of the joint capsule due to a repetitive injury, like a throwing athlete.
- Multidirectional: this happens for patients with inborn laxity in their joints and the shoulder can dislocate in multiple directions.
Symptoms
- Patients can feel the ball come out of the socket.
- Pain caused
- Repeated shoulder dislocations
- Persistent feeling of shoulder feeling loose as if its hanging there.
Diagnosis
The doctor performs a complete physical evaluation with study of the patient’s medical history. The shoulder’s looseness or laxity of the shoulder joint can be further diagnosed from the following tests:
- X-rays to rule out fracture and also to find the possible causes of the instability.
- Magnetic Resonance Imaging (MRI) or MR Arthrography: will exhibit the Bankart as well as the Hill-Sach lesions. Patients with ligament laxity will have a broad joint with a lax capsule, as seen by arthrography.
- Computed Tomography (CT) Scan or CT Arthrography: demonstrates the bone loss in the glenoid socket. The amount of bone loss will determine which surgical procedure to be performed.
Treatment
The treatment options can be broadly classified as:
- Non-Surgical Treatment: recommended only for ligament laxity and multi directional instability ,and is usually not successful as tissues would have had permanent damage by that time :
- Activity Modification: making some changes to your lifestyle and avoiding activities that will aggravate the symptoms.
- Physical Therapy: Strengthening the shoulder muscles and work on shoulder control to increase stability.
Surgical Treatment: This is done to repair the torn ligaments and the different procedures are:
- Arthroscopy: A minimal invasive surgery where a tiny camera is used to perform the surgery with special pencil-thin instruments.
- Open Surgery: By making a large incision on the shoulder with the repair being done under direct visualization.
- Again the type of surgery is individualized depending upon the severity of damage to the ligaments, bone loss and laxity of the tissues.
- Rehabilitation: Post-procedure, the shoulder is immobilized temporarily using a sling. specific exercises are recommended from next day to regain the functions of the shoulder.
