Mid-Shaft Humerus Fracture Treatment

A mid-shaft humerus fracture is a type of broken arm. The humerus is the bone in your upper arm, between your shoulder and elbow. It's especially strong and is capped with the ball of the ball-and-socket shoulder joint. It also includes the hinge of the elbow joint on the bottom.

Fractures of the humerus are divided into three types:

• Proximal humerus fractures of the shoulder
• Distal humerus fractures of the elbow
• Mid-shaft humerus fractures

Mid-Shaft Humerus Fractures

A mid-shaft humerus fracture represents about 3% of all broken bones. It typically doesn't involve the shoulder or elbow joints.

The most common cause of a humeral shaft fracture is a fall, but high-energy injuries (motor vehicle collisions, sports injuries) and penetrating trauma (gunshot wounds) also can cause this injury. Many humeral shaft fractures, especially in older people, occur as a result of the weakening of the bone from osteoporosis.

Some people with this kind of fracture say it feels like their arm isn't attached. However, there's much more holding your arm together than bone, so don't let the X-ray scare you.

Treatment

The vast majority of mid-shaft humerus fractures heal without surgery, which minimizes complications.

The most common treatment for a humeral shaft fracture is called a fracture brace, often referred to as a Sarmiento brace, named after the physician who popularized this treatment method.

Usually, the fracture is treated in a splint or sling for a week to allow swelling to subside, and then you're fitted with a fracture brace. The brace looks like a clamshell and holds the humerus in alignment. An advantage of the fracture brace is that as healing progresses, you can begin to use your shoulder and elbow.

Reasons to consider surgical treatment include:

• Multiple fractures
• Open fractures (when the bone is exposed)
• Injuries to blood vessels or nerves
• Failure to heal with nonsurgical treatment (nonunion)

However, surgery comes with additional risks, including nerve injury and failure of the bone to heal. Types of surgical procedures include:

• Metal Plates: The most common and successful surgery for treatment of a humerus fracture is to place a large metal plate along the humerus, and secure it with screws.
• Rods: An intramedullary rod or nail is a metal rod that is placed down the hollow center of the bone. The advantage of the metal rod is the surgery is less invasive, and the surgeon stays away from important nerves that travel down the arm.

Healing Time and Complications

Healing of a mid-shaft humerus fracture with non-surgical treatment generally takes ten to twelve weeks. Often, exercises to improve the mobility of the shoulder and elbow joints are initiated during that time.

Surgical management is growing in popularity because it can shorten healing times and improve alignment.

The two complications often seen are injuries to the radial nerve and nonunion of the fracture.

Radial Nerve Injury

Injuries to the radial nerve are fairly common in a mid-shaft break because this important nerve tightly wraps around the middle of the humerus. The radial nerve can be injured at the time of the fracture or during treatment.

Radial nerve injuries cause:

• Numbness on the back of the hand
• Difficulty straightening (extending) the wrist and fingers

Most radial nerve injuries typically improve with time, but your healthcare provider should follow up with you in case further treatment is needed.

Nonunion

Nonunion is a difficult problem and occurs when the fracture doesn't heal.

Nonunion can happen for a number of reasons. Interestingly, one of the most common reasons for nonunion is surgery . When you have surgery, the soft tissues surrounding the fracture are further disrupted, and this can compromise blood flow to the site of the fracture. One reason to avoid surgery is to prevent the risk of nonunion. However, if a nonunion does occur, then surgery is almost always needed to stimulate a healing response of the bone.​