Proximal Humerus Fractures

Anatomy of the Humerus

The humerus is the bone that forms the upper arm. It articulates with the glenoid cavity of the scapula (shoulder blade) to form the shoulder joint and with the lower arm bones the ulna and radius to form the elbow joint. The proximal humerus is the upper end of the arm bone that forms the shoulder joint. The humerus is broadly divided into the head, neck and shaft region. Just below the head are two processes called the greater and lesser tubercles, which form the sites of attachment for the rotator cuff muscles. 

Causes of Proximal Humerus Fractures

Fractures of the proximal humerus are common in elderly individuals suffering from osteoporosis. In younger individuals, a severe trauma such as a fall from a height on an outstretched hand or motor vehicle accident can cause these fractures. 

Types of Proximal Humerus Fractures

Proximal humerus fractures can be categorized into 4 groups:

Humeral head fractures: Humeral head fractures often occur in elderly individuals and chances are more in those with osteoporotic bone. While mild trauma can break the humeral head in the elderly, a more significant trauma results in this fracture in the young. 

Surgical neck fractures: Fractures of the surgical neck are most common in osteoporotic bone. These fractures can also damage the axillary nerve that carries sensory information from the shoulder. 

Greater tuberosity fractures: Greater tuberosity fractures are less common and are seen in cases of shoulder dislocations and in those with osteoporosis. A fragment of the greater tuberosity is pulled off when the rotator cuff muscle contracts or the anterior shoulder dislocates. Direct impact on the shoulder can cause the tuberosity bone to break into multiple fragments. Partial rotator cuff tears often accompany non-displaced fractures, and these fractures can be diagnosed using MRI or diagnostic arthroscopy. 

Lesser tuberosity fractures: These fractures are often caused by posterior shoulder dislocations or traumatic muscle contractions by electrical shock or convulsions. If left untreated, these fractures can cause subscapularis muscle (stabilizer and mobilizer muscle) deficiency and require a muscle transfer procedure.

In addition to the above, another way to classify proximal humerus fractures is by the number of bone fragments or “parts” involved. This classification divides the injury into two-part, three-part and four-part fractures.

Symptoms of Proximal Humerus Fractures

You may experience severe pain, swelling and restricted motion of the shoulder.

Diagnosis of Proximal Humerus Fractures

A proximal humerus fracture is diagnosed by a physical examination and X-ray of the affected area. A computerized tomography (CT) scan may also help assess the severity of the injury.

Treatments for Proximal Humerus Fractures

Most proximal humerus fractures are minimally displaced and can be treated with conservative approaches such as the use of a sling to immobilize your arm and early physical therapy to improve the functional outcome. Surgery may be necessary for certain displaced fractures. The multiple fragments may be fixed with a plate and screws, a rod and screws, and/or heavy sutures, and in severe cases, shoulder replacement surgery may be necessary.