Shoulder Dislocation & Labral Tears
The most mobile joint in the body is the shoulder. It provides for movement in many directions but because of this mobility, the joint is at risk for dislocation. It is stabilized by a group of tendons and muscles called the rotator cuff. The rotator cuff provides complete movement and at the same time it holds the ball of the arm bone in the shoulder socket. There is also a protective cuff of cartilage called the Labrum. It offers stability, cushioning and range of motion along with the shoulder ligaments which hold the bones together. Dislocations displace the head of the arm bone, and may cause injury to supporting tissues.
What is a Shoulder Dislocation?
A dislocation occurs when the bones on each side of the joint don’t line up. Extreme force that impacts the joint can force the arm outward, upward or backward, causing the arm bone to pop out of the socket. Dislocations can occur from a fall, direct blow to the shoulder, or sharp twisting of the arm, as is seen in sports injuries like football, baseball, basketball and volleyball.
The most common type of shoulder dislocation occurs in the glenohumeral joint, a ball and socket joint made of the ball, the arm bone (humerus), and the socket (glenoid) in the shoulder blade. The socket is shallow and relies on surrounding tissue for stability. Dislocations may result in rotator cuff tears, labrum tears, and even fractures of the socket or humerus.
Dislocations are described by the location of the arm bone after it has come out of the socket.
The two most common types of dislocations
- Ninety-five percent of dislocations are anterior dislocations. Here force causes the head of the arm bone to be displaced toward the front of the body, and damages the labrum and ligaments. This is called a Bankart lesion. The head ends up in front of the joint. Anterior dislocation in young people can result when the shoulder is in a vulnerable position, as when the arm is above the shoulder and is forcefully twisted outward when throwing or hitting a ball. In the elderly, the cause is usually a fall on an outstretched arm.
- Posterior dislocations occur when extreme force causes the head of the arm bone to displace toward the back of the body, behind the shoulder blade. It often causes injury to the soft tissues, ligaments, tendons, muscles and the joint capsule. Additionally, these dislocations can cause tears in the rotator cuff and labral tears. This type is rare and the main causes are direct trauma and seizures.
What is a Labral Tear?
It is a tear in the soft tissue that surrounds and supports the shoulder joint.
- A tear in front of the shoulder is called a Bankart tear. Bankart tears result from trauma, cause instability and predisposed to future dislocations. Bankart tears are common in people under the age of thirty who suffer a shoulder dislocation.
- A tear at the top of the shoulder is called a SLAP tear.
- A tear on the back of the shoulder is called a Reverse Bankart tear.
- These tears may occur simultaneously, called a pan-labral tear.
Symptoms of a Dislocation
- Severe pain
- Bruising and swelling
- Inability to move the joint
- Muscle spasms
- Distorted shoulder contours
- Numbness, weakness and tingling
Symptoms of a Labral Tear
- Catching, locking, and grinding of the joint
- Night pain
- Pain during activities
- Decreased range of motion, and
- Loss of strength
Diagnosis of a Shoulder Injury
The orthopedic authorities at South County Orthopedic Specialists (SCOS) will take a medical history to learn what caused the injury, and whether the joint has been injured before. Previous injuries to the shoulder joint predispose a patient to future dislocations.
The SCOS physician will conduct a physical exam to check range of motion, stability and pain. In addition, they will evaluate the blood vessels and nerves that go through the area, and assess muscle strength. Loss of strength and numbness indicate an injury to the nerves. X-rays will confirm a displacement. Advanced imaging, such as an MRI, may be needed, because the soft tissues are not visible on an X-ray.
Though the arm bone is dislocated from its socket, the ligaments, muscles and tendons may still be attached. Tension on these structures will cause muscle spasms. In order to fix the dislocation, the patient will receive medication to relax these muscles and reduce pain. Once relaxed, the surgeon will pull on the shoulder to realign the bones. This is called reduction. An x-ray will confirm that the joint has been realigned.
Complications of a Shoulder Dislocation
- A frozen shoulder makes the joint unable to move
- Fractures of the shoulder joint occur in about twenty-five percent of patients with dislocation
- Nerve damage
- Rotator cuff injuries
- Damage to the blood vessels that supply blood to the arm and shoulder
- A broken shoulder
- A labral tear
- Tears in the bicep tendon- it may be a full tear or partial and may cause instability.
MRI imaging may be necessary to evaluate the extent of injury to the joint and the labrum and cartilage.
A CT scan may be used to assess the bones.
Depending on the patient’s age, and the risk of a recurrent dislocation, surgical repair may be indicated.
Labral tears are a clear indication that arthroscopic surgery is needed.
Surgery may be recommended for patients who have significant damage to the joint and tissues, to prevent future dislocations, especially when the damage is extensive.
Types of surgical repair:
- Arthroscopic surgery is minimally invasive, uses tiny incisions and a small camera to view the joint and soft tissue, and repair the damage. It is an outpatient procedure.
- Open surgery may be recommended when it is associated with other injuries such as fractures, bone loss, a large hill sacks lesion, recurrent instability or failed repair
When you have a shoulder injury, contact South County Orthopedic Specialists in Orange County (SCOS), California. Our Fellowship trained shoulder surgeons are experts in the diagnosis and repair of shoulder injuries. SCOS experts strive for compassionate, personalized care and treatment options geared towards the individual patient’s needs, and goals.
Our SOCS shoulder experts include our sports medicine fellowship trained team Dr. Scott Graham, Dr. Chris Veneziano and Dr. Nimish Kadakia who specialize in arthroscopic repairs for labral tears. We also have a fellowship trained orthopedic shoulder specialist, Dr. Ari Youderian, who specializes in the complex reconstructions including Latarjet procedure, open capsular repair, and instability/fracture repair.
Shoulder and Elbow Specialists
Ari Youderian, MD
Dr. Youderian is a board-certified, orthopedic surgeon who specializes in care of the shoulder, upper arm and elbow. Read Dr. Youderian’s biography.
Sports Medicine Shoulder Specialists
Scott Graham, MD
Dr. Graham is our Sports Medicine specialist, providing advanced and minimally invasive care for all sports medicine injuries. Read Dr. Graham’s biography.
Christopher Veneziano, MDS
Dr. Veneziano sees Orange County, CA patients for general orthopedic problems and injuries, and specializes in sports injuries. Read Dr. Veneziano’s biography.
Nimisha Kadakia, MD
Dr. Kadakia is a fellowship trained orthopedic surgeon who specializes in the care of sports injuries at SCOS. Read Dr. Kadakia’s biography.