Common Shoulder Injuries

Shoulder injuries are prevalent, and millions of patients go to the doctor yearly with shoulder problems. It is often seen in athletes as repetitive motion, such as throwing, swimming, or weightlifting, can cause injury. In older patients, shoulder fractures frequently occur from ground-level falls due to decreased bone density. High-energy injuries may also cause shoulder fractures or dislocations associated with chest injuries.

Anatomy

The bones that make up the shoulder are the upper end of the arm bone (humerus), the shoulder blade (scapula), and the collarbone (clavicle). Some would describe this joint as a ball and socket joint, but it is more like a ball sitting on a golf tee, meaning that there is a tiny surface area of bone contact. The stability of the shoulder joint relies heavily on the soft tissues around the bone, including muscles, tendons, capsule, and labrum, that keep the arm centered with the shoulder blade. The collarbone or clavicle is another structure in the shoulder region that attaches to the shoulder blade at the front of the shoulder; this joint is called the acromioclavicular joint (AC joint).

Common Shoulder Conditions

Bursitis/Tendonitis

Inflammation of the soft tissues can cause significant issues with the shoulder. Bursae are tiny, thin sacs of fluid that overlay the bony prominences, allowing muscles and tendons to slide over the bones easily. These bursae commonly become inflamed, causing pain. Tendons, the terminal ends of the forces that attach to the bone, can also widely become inflamed. This is called bursitis and tendonitis, respectively. This can be caused by repetitive motion, overuse of the shoulder, or associated with other medical conditions.

Impingement

This generally occurs when soft tissues get pinched either with movement or because of bony deformity. This most commonly occurs around the shoulder blade as the muscles and tendons move between narrow pathways of bone.

Arthritis

The ends of our bones are covered in a protective layer of tissue called cartilage. It allows two or more bones to slide against each other smoothly, which makes up a joint. Damage to the cartilage from injury or normal wear-and-tear can cause pain and stiffness in the shoulder joint. Other conditions such as rotator cuff tear, chronic instability, and infection can lead to arthritis as well. In most cases, arthritis develops slowly and generally worsens with time.

Instability

When the humeral head is not centered in the socket, this causes the joint to be unstable. This may arise from a traumatic injury where the humerus is forced away from the scapula. The complete separation of the ball and socket joint is called a dislocation. Instability may also be caused by chronic overuse of the shoulder. The joint may be partially separated, but not entirely, called a subluxation. Ligaments, tendons, and muscles can become loose or torn. In many situations, these injuries may heal without surgery. However, repeat or long-term problems with dislocations or subluxation may benefit from surgical repair. Chronic issues with instability may lead to arthritis as well.

Rotator Cuff Injuries

A rotator cuff is a group of muscles responsible for shoulder movements. They lift the arm, help rotate it, and allow you to pull objects toward you. Injuries to the rotator cuff can cause pain, stiffness, and weakness. Major tears can cause worsening pain with time and significant limitations to shoulder function. There are different degrees of tears ranging from partial tears to complete thickness tears. Treatment will depend on the severity of the injury.

Fractures

Fractures of the humerus, scapula, or clavicle occur after traumatic injury. In younger patients, this can be a fall from a height or another high-energy accident, such as a car accident. In older patients with lower bone density, a typical energy injury may cause a fracture, for example, a trip and fall. Fractures can be treated with or without surgery depending on factors such as fracture patterns, whether or not there is an open wound around the fracture site, amount of fractures present, joint alignment, and overall positioning of the fracture.

Evaluation

Physical examination

A medical practitioner may examine the shoulder to check for a range of motion, apply pressure to various areas of the shoulder to see if this causes pain, and check nerve function in the muscles and skin of the arm/hand. Special tests may be performed to evaluate for specific shoulder conditions, like the ones mentioned above.

Imaging

Based on the history of the shoulder symptoms and the practitioner’s physical examination, imaging can be beneficial in identifying the critical cause of the shoulder complaint. X-rays are very effective in evaluating and monitoring the healing of fractures and dislocations. They may also aid in assessing the degree of arthritis.

A CT scan may give finer detail regarding fractures and bony abnormalities of the shoulder.

MRI is best for evaluating soft tissue injuries like rotator cuff or labral tears.

Treatment

Treatment of shoulder pain, stiffness, and instability will depend on the root cause of the symptoms. Some conditions may be best treated without surgery. Rest, medications, exercises, or physical therapy may be adequate for many diseases, such as frozen shoulder, tendonitis, and bursitis. Some forms of treatment may help to address pain and inflammation in or around the joint such as injections. Some tears or fractures may need surgery to heal well.