Fracture of the Shoulder Blade (Scapula), Causes and Symptoms
A fracture of the shoulder blade (also called the scapula) is not a common injury, as the scapula is shielded from trauma by muscles (which ensure that the shoulder joint moves fluidly). Additionally, the scapula is triangular in shape (which gives it strength) and is mobile. A fracture of the shoulder blade is responsible for less than 1% of all bone breakages. Since the shoulder blade is so hard to break, it is generally a major trauma that causes its fracture. And major traumas often cause more than one injury. About 80% of all people who have suffered a fracture of the shoulder blade have additional injuries. A fracture of the scapula is often accompanied by injury of the head, spinal chord and lungs, as well as by broken ribs and soft-tissue wounds.
The shoulder blade connects the upper-arm bone (also known as the humerus) to the chest wall (also known as the thorax). Because men between the ages of 25 and 45 are generally more likely to sustain traumas (from sports injuries, automobile accidents, etc.), they are also more likely to fracture their scapulae.
Anatomy of the Shoulder
The shoulder is the most flexible joint in the human body. It is composed of the following:
- The scapula (also known as the shoulder blade; it is triangular, mobile and protected by muscle)
- The humerus (the upper arm bone; it articulates with the scapula at its proximal end and the radius and the ulna at its distal end)
- The clavicle (the collarbone; it joins the scapula to the upper breastbone)
- The rotator cuff (four muscles that protect and hold in place the “ball-and-socket” joint where the humerus meets the shoulder blade)
- Bursa (a sac located between the humerus and the outward end of the shoulder blade that lubricates the rotator cuff)
Types of Shoulder Blade Fractures
Scapula fractures can be divided into five main types:
Scapular body fracture – Scapular body fractures are responsible for 50-60% of all fractures of the shoulder blade. This makes sense, as the scapular body is the largest part of the shoulder blade.
Scapular neck fracture – Scapular neck fractures are responsible for 25% of all fractures of the shoulder blade. The scapular neck is right below the socket that the ball at the end of the humerus connects with.
Glenoid fracture – The glenoid is the socket that the humerus articulates with. It is vulnerable to fracture, though its breakage is quite unlikely.
Acromion fracture – The acromion, the highest point on the shoulder blade, can be fractured, though it is not commonly broken.
Coracoid fracture – The clavicle connects to the scapula at the coracoid. The coracoid can be fractured, but it is not very likely that it will be.
Causes of Shoulder Blade Fractures
Fracture of the shoulder blade is generally the result of a fall or a blow to the arm. The following are the causes of fracture of the shoulder blade:
- Falling onto an extended arm – Falling onto an outstretched arm – while it protects your face and other vital parts of the body and is doubtless the right thing to do – renders your shoulder blade more vulnerable to injury, as its ligaments are pulled tight.
- Severe blow to the shoulder – If you receive an extreme blow to your shoulder – because you fall on it, hit it in an automobile accident or are hit with an object (such as a hammer or a bat), you are vulnerable to fracture of the shoulder blade.
Symptoms of Shoulder Blade Fractures
While different types of fracture of the shoulder blade have somewhat different symptoms, the symptoms are generalizable. If you have fractured your scapula, you will feel intense pain when attempting to move your arm, and you will not be able to lift it over your head. The back of your shoulder will swell and your skin will be scraped and irritated.
The following are common fracture of the shoulder blade symptoms:
- Skin abrasion
The symptoms of fracture of the shoulder blade may be mistaken for the symptoms of other medical conditions (separated shoulder, rotator cuff tear, etc.). Make sure you consult a doctor in order to determine if you have a fracture of the shoulder blade and get the appropriate treatment.
The multidisciplinary team of orthopaedic experts at North Shore-LIJ Orthopaedic Institute's Trauma Services in New York treats Fractures of the Shoulder Blade (Scapula) as well as a broad range of conditions that affect the bones within the body.