Sternoclavicular Joint Dislocation
Sternoclavicular joint dislocation is a common trauma condition to the shoulder. Injuries range from a separated shoulder resulting from a fall onto the shoulder to a high-speed car accident that fractures the shoulder blade (scapula) or collar bone (clavicle). One thing is certain: everyone injures his or her shoulder at some point in life.
Cause & Symptoms
Fractures of the clavicle or the proximal humerus can be caused by a direct blow to the area from a fall, collision, or motor vehicle accident.
Because the scapula is protected by the chest and surrounding muscles, it is not easily fractured. Therefore, fractures of the scapula are usually caused by high-energy trauma, such as a high speed motor vehicle accident. Scapula fractures are often associated with injuries to the chest.
Anterior dislocations of the shoulder are caused by the arm being forcefully twisted outward (external rotation) when the arm is above the level of the shoulder. These injuries can occur from many different causes, including a fall or a direct blow to the shoulder.
Posterior dislocations of the shoulder are much less common than anterior dislocations of the shoulder. Posterior dislocations often occur from seizures or electric shocks when the muscles of the front of the shoulder contract and forcefully tighten.
Dislocations of the acromioclavicular joint can be caused by a fall onto the shoulder or from lifting heavy objects. The term “shoulder separation” is not really correct, because the joint injured is actually not the true shoulder joint.
Symptoms of fractures about the shoulder are related to the specific type of fracture.
- General Findings
- Swelling and bruising
- Inability to move the shoulder
- A grinding sensation when the shoulder is moved
- Deformity — “It does not look right”
- Specific Findings: Clavicle Fracture
Fractured clavicle (collarbone)
- Swelling about the middle of the collarbone area
- An area that may have a “bump,” which is actually the prominent ends of the fracture under the skin
- Shoulder range of motion is limited, although not as much as with fractures of the proximal humerus
- Specific Findings: Proximal Humerus Fracture
- Fractured head of the humerus.
- A severely swollen shoulder
- Very limited movement of the shoulder
- Severe pain
Specific Findings: Scapular Fracture
- Fracture patterns in the scapula
- Severe bruising about the shoulder blade
Specific Findings: Shoulder Separation (Acromioclavicular Joint Separation)
- An acromioclavicular joint dislocation with extreme elevation of the clavicle.
- Pain over the top of the shoulder
- A prominence or bump about the top of the shoulder
- The sensation of something sticking up on the shoulder
Specific Findings: Shoulder Dislocation (Glenohumeral Joint Dislocation)
- Shoulder instability
- A prominence about the front of the shoulder
- Inability to move the arm
- An arm rotated outward
- The sensation of a “dead arm
Most fractures are diagnosed with X-rays of the area and by physical examination. Sometimes, additional imaging techniques, such as computed tomography, are necessary.
Most clavicle fractures can be treated without surgery. Surgery is necessary when there is a compound fracture that has broken through the skin or the bone is severely out of place. Surgery typically involves fixing of the fracture with plates and screws or rods inside the bone.
Proximal Humerus Fractures
Most fractures of the proximal humerus can be treated without surgery if the bone fragments are not shifted out of position (displaced). If the fragments are shifted out of position, surgery is usually required. Surgery usually involves fixation of the fracture fragments with plates, screws, or pins or it involves shoulder replacement.
Most fractures of the scapula can be treated without surgery. Treatment involves immobilization with a sling or shoulder immobilizer, icing, and pain medications. The patient will be examined for additional injuries.
About 10% to 20% of scapula fractures need surgery. Fractures that need surgery usually have fracture fragments involving the shoulder joint or there is an additional fracture of the clavicle. Surgery involves fixation of the fracture fragments with plates and screws.
Shoulder Separations (Acromioclavicular Joint)
Treatment of shoulder separations is based on the severity of the injury as well as the direction of the separation and the physical requirements of the patient.
Less severe shoulder separations) are usually treated without surgery.
Severe separations in an upward direction or dislocations in the backward or downward directions often require surgery. Surgery involves repair of the ligaments.
Professional athletes and manual laborers are often treated with surgery, but the results are often unpredictable.
Shoulder Dislocations (Glenohumeral Joint)
The initial treatment of a shoulder dislocation involves reducing the dislocation (“putting it back in the socket”). This usually involves treatment in the emergency room.
The patient is given some mild sedation and pain medicine, usually through an intravenous line. Often, the physician will pull on the shoulder until the joint is realigned. Reduction is confirmed on an X-ray and the shoulder is then placed in a sling or special brace.
Additional treatment at a later date is based on the patient’s age, evidence of persistent problems with the shoulder going out of place, and the underlying associated soft-tissue injury (either to the rotator cuff or the capsulolabral complex).
Patients who are 25 years of age or younger generally require surgery. Persistent instability (repeat dislocations) of the shoulder usually requires surgery. Surgery involves repair of the torn soft tissues.