Proximal, Mid-Shaft, and Distal Humerus Fractures

Humerus fractures—breaks in the upper arm bone that connects the shoulder to the elbow—are generally divided into three types based where they occur.

• Proximal fractures are breaks in the top part of the humerus.
• Mid-shaft fractures occur in the middle of the bone.
• Distal fractures are breaks at the bottom of the humerus.

This article explains these different types of humerus fractures. It also covers causes of humerus breaks, treatment options, as well as potential complications of these injuries.

Proximal Humerus Fractures

The top of the humerus is the ball part of the shoulder's ball-and-socket joint. Breaks near it are considered proximal humerus fractures.

These fractures may involve the rotator cuff, a group of tissues that connect muscle to bone around the shoulder.

Assigned females are impacted by these fractures two times more often than assigned males. These types of fractures are also common among older individuals.

Mid-Shaft Humerus Fractures

Mid-shaft humerus fractures occur in the middle of the bone, away from the shoulder and elbow joints.

These fractures are commonly associated with injury to the radial nerve, which sends sensory and motor information. This bundle of fibers runs down the arm to the fingertips. Injury to it may cause symptoms in the wrist and hand.

Distal Humerus Fractures

Distal humerus fractures occur near the elbow joint. These fractures most often require surgical treatment unless the bones are held in proper position.

This type of fracture tends to impact assigned male teenagers more than any other population.

Causes

Humerus fractures are most commonly caused by falls. A car accident, motorcycle accident, or sports-related incident can also lead to a fractured humerus.

Sometimes a humerus fracture occurs when the bone is weakened by an abnormal growth called a tumor, an infection, or other problems. In this case, the break is referred to as a pathologic fracture.

Symptoms of Humerus Fractures

Symptoms will vary from person to person. However, possible symptoms of any type of humerus fracture include:

• Pain
• Swelling
• Difficulty with shoulder or arm movement
• Bruising or bleeding if the bone has gone through the skin
• A change in the arm's appearance
• Crepitus, or a grinding sound or feeling with movement

Treating a Humerus Fracture

Treatment for humeral fractures is impacted by how severe the injury is, the age of the individual, and if the individual has any other conditions.

Motion-Limiting Devices

In some cases, individuals may be given a sling or brace to help their arm stay still so the fracture heals. This may be worn for weeks to months depending on how severe the break is.

An imaging test like an X-ray may be done every couple of weeks to make sure the fracture is healing properly.

Surgery

Surgery may be required when the bones are far out of position. Fractures that impact the joint are more likely to require surgery. Those near the top or the center of the bone less commonly require surgery.

Plates, screw, or pins may be used to get the bones back in place. In severe cases, shoulder replacement surgery may be necessary. During this surgery some parts of the bones in the shoulder joint are replaced with artificial implants.

Physical Therapy

Physical therapy may be done to help reduce pain, increase strength, and restore movement. It may also help prevent the injured area from becoming too stiff.

Usually after a certain amount of time wearing a sling or brace, physical therapy may be introduced to help with the healing process. It may also be recommended as part of post-surgery recovery.

Your physical therapist, a licensed professional who is a movement expert, will give you various exercises to do. This may include some that you'll need to do on your own at home.

Potential Complications

There are some possible complications of a humerus fracture including:

• Nonunion: A nonunion occurs when the broken bone does not heal. There are many reasonsthis may happen. One of the most common causes of nonunion is smoking tobacco.
• Malunion: A malunion occurs when the bone heals, but not in the proper position. Malunions can occur if the bone was not kept still for long enough, if bones weren't properly aligned, or if medical treatment was delayed. Surgery may be needed to correct the position of the bone.
• Nerve injury: The radial nerve provides feeling to the back of the hand. It also helps with wrist and finger movement. Injuring the radial nerve can make wrist and finger movement difficult and cause numbness in that area. The nerve may recover within a few months.
• Shoulder or elbow stiffness or weakness: Problems with the shoulder joint are common after a proximal humerus fracture. Elbow problems are common after a distal humerus fracture. Loss of normal range of motion and weakness can also occur if there is muscle or connective tissue damage.

Summary

A humerus fracture is a broken bone in the upper arm that connects the shoulder to the elbow. Types of humerus fractures include proximal (ball part of the shoulder joint), mid-shaft (middle of the bone), and distal (near the elbow joint).

Humerus fractures are commonly caused by falls, car accidents, and sports injuries. Other conditions that weaken the bone can also lead to a humerus fracture.

Treatment may include surgery, motion-limiting devices, as well as physical therapy.