In this article surgeons from the Cleveland Clinic review humeral shaft (upper arm) fractures with radial nerve injuries. Anatomy of the upper arm and clinical exam of the fracture are described. Factors to be considered during treatment are also included.
Humeral shaft fractures are named by their location and the amount of contact between the broken pieces. When the bone is broken in half it’s called a simple fracture. The break may be straight across (transverse) or at an angle (oblique). Other more complex breaks may result in a spiral fracture or pieces of bone called a comminuted fracture.
Bone fragments can cut or damage the radial nerve as it travels down the arm. The risk of nerve injury is greatest along the lower third of the bone where the nerve is not separated from the bone by muscle. Radial nerve palsy after fracture may be partial or complete. Once the bone heals, the patient may or may not recover from the secondary nerve injury.
If the fracture is closed (doesn’t break through the skin), then treatment without surgery is possible. This is true even if there’s nerve damage. In 70% of the closed fracture cases, the bone and nerve heal without surgery. If the patient shows signs of delayed nerve healing, then surgery later is an option.
Surgery may also be needed for patients with severe trauma and fracture. The goal is to save nerve and blood supply to the arm. Pins to hold the bone in place may not be possible if the fracture is near the radial nerve. There is a danger of putting the pin through the nerve. A metal compression plate may work better. The condition of the nerve is investigated during the operation.
The authors review various methods of nerve repair. The location of the injury and how long it’s been there are important factors. They suggest nerve grafting if there is a large defect in the nerve or great tension on the nerve. Nerve transfer or nerve reconstruction may be needed for more complex injuries.