The shoulder consists of three bones: the collarbone (clavicle), the shoulder blade (scapula) and the top of the arm bone (humerus). The bones are held together by ligaments, tendons and muscles. These bones join together to make three joints: the glenohumeral, the acromioclavicular and the sternoclavicular joint. The glenohumeral joint is the main joint in the shoulder.
The shoulder can be injured in a number of ways:
- Fractures – breaks in the bones of any one or more of the three bones that make up the shoulder
- Dislocations – occur when a bone slips out of joint and is not held into position. This can occur in any of the three joints of the shoulder, however, the term dislocated shoulder usually refers to the glenohumeral joint.
- Soft tissue injuries – these are injuries to the ligaments, tendons, cartilage or muscles of the shoulder.
A fracture can range from a hairline crack through to complete displacement of the bone or fractures in multiple pieces. Fractures of the clavicle or top of the humerus usually result from a fall directly onto the shoulder. Fractures of the scapula are not as common, as the scapula is protected by surrounding muscles. Fractures to the scapula are generally the result of a direct high impact blow such as a high speed car accident or fall from a height.
Shoulder dislocations are usually caused by a fall or a direct blow or can occur during a seizure or electric shock. They are often seen on the sports field in young patients, or after a simple fall in more elderly patients.
Dislocations of the acromioclavicular or sternoclavicular joints are often the result of a heavy fall onto the shoulder or can occur during sporting tackles.
General symptoms following shoulder trauma include:
- Inability to move your arm
- Grinding sensation with movement
If you are experiencing any of the symptoms above following an injury, you should see your doctor or present to the emergency department.
Your doctor will discuss your symptoms and nature of the injury and conduct a physical examination. Your doctor will refer you for an x-ray to view the affected bones. A CT (computed tomography) scan will often be useful to look at eh fracture in more detail. An MRI (magnetic resonance image) scan is often helpful in shoulder injuries to look for damage to the soft tissues including tendons or ligaments.
Fractures or dislocations that are aligned can sometimes be immobilised with a sling or brace, and you may be given instructions on restricted use for a period of time.
Your surgeon will determine if your shoulder injury requires surgery. Fractures that are not aligned or have broken into several pieces may require metal plates and screws to hold the bone together. The shoulder will typically be immobilised with a sling after surgery, but the time of immobilisation and the exact schedule for returning to normal function will depend heavily on the specific injury you sustained.
Shoulder dislocations require relocation of the humerus back into the shoulder socket. This can be done without surgery although repeated dislocations may require surgery to tighten structures within the joint to prevent further dislocation.