A nonhealing fracture, also called a nonunion, occurs when the pieces of a broken bone do not grow back together. Usually, bones start rebuilding immediately after a doctor has aligned the bone fragments and stabilized them into place. This process is called setting the bone.
During the following weeks or months, new bone tissue continues to form. As long as the bone fragments receive an adequate supply of blood and nutrients, the new tissue fuses the fragments together into a single bone.
In a nonhealing fracture, bones don’t produce new tissue. A fracture in which the bone does produce new tissue but does so very slowly—over months—is called a delayed union. In some instances, the broken bone heals but may not be completely straight. This is called a malunited fracture.
A nonunion, delayed union, or malunited fracture may occur in any bone, but these conditions are most common in the humerus, or upper arm, and the tibia, or lower leg.
Symptoms of a fracture that is not healing normally include tenderness, swelling, and an aching pain that may be felt deep within the affected bone. Often, the bone isn’t strong enough to bear weight, and you may not be able to use the affected body part until the bone heals. Pain and weakness usually persist until the bone has healed. Sometimes this takes years, if it does in fact finally heal.
A malunited fracture may heal fully but cause a visible bump beneath the skin where the bone isn’t straight. The affected bone may be weak or painful, and it may interfere with the way the affected body part functions. For example, a malunited fracture in the leg or foot may cause a persistent limp. Symptoms vary depending on how well the bone fragments unite and the severity of the malformation.
Orthopedic specialists at the Bone Healing Center diagnose a nonhealing fracture based on your symptoms and the results of imaging tests. A fracture that remains painful months after an injury indicates a problem with bone healing. If your doctor also sees on an X-ray or other imaging test that the bone is not healing, that is often enough information to confirm the diagnosis.
A bone may not be able to regenerate unless the bone fragments are reassembled and held in place. Several ways to stabilize broken bones without surgery include casts, braces, and slings. If surgery is required to reposition bone fragments, a doctor may use metal screws, rods, and plates to accomplish this.
The majority of broken bones heal normally when a doctor stabilizes them. However, an inadequate blood supply to the bone may lead to a nonhealing fracture. Blood vessels provide bone with oxygen and chemicals called growth factors that encourage healing. If trauma as the result of a serious injury damages blood vessels and reduces the bone’s blood supply, the bone stops producing new cells.
Diabetes, a condition that affects how the body processes sugar, may reduce the concentration of nutrients in the blood and decrease blood flow. Both factors increase the risk of a nonunion or delayed union fracture.
In addition, smoking cigarettes can interfere with adequate blood flow to bones. Doctors recommend quitting smoking as part of any treatment plan for a nonhealing fracture. Doctors and counselors at NYU Langone’s Tobacco Cessation Programs can help.
Some anti-inflammatory medications, such as ibuprofen and corticosteroids, can reduce blood flow and increase the risk of a nonhealing fracture. Doctors recommend avoiding these medications until a fractured bone has fully healed.
Bones also need adequate nutrition to regenerate. Low levels of vitamin C, vitamin D, and calcium may prevent a bone from healing.
An infection in the bone, which is called osteomyelitis, may also delay or prevent healing. A bone can become infected if bacteria from a wound on the surface of the skin travel through the bloodstream to the bone. This may occur as a result of an injury or a surgical incision.
Your doctor may ask how the fracture occurred, when it occurred, and whether you still feel pain at the site of the fracture.
Telling your doctor about any other medical conditions you may have, and whether you’ve been taking anti-inflammatory medication, may help your doctor determine the cause of a nonunion fracture. You should also tell your doctor if you have had previous fractures that healed slowly or not at all.
Your doctor examines the skin surrounding the fracture site for signs of infection, such as redness or swelling. Signs of a malunited fracture, such as a bump beneath the skin, weakness, or pain, may also be apparent.
An X-ray can reveal whether there is space between bone fragments. If more than a few weeks have passed since the fracture occurred and space remains between pieces of bone, it’s possible that new bone tissue did not form.
Doctors also use X-rays to confirm a malunited fracture, in which the bone does not heal straight.
CT scans use X-rays and a computer to create detailed two- and three-dimensional images of the inside of the body.
A doctor may order a CT scan to clarify the details of a fracture identified on an X-ray. For example, if a bone was broken into many small pieces, the space between bone fragments may not be clearly visible on a traditional X-ray.
Your doctor may use CT scans and X-rays to monitor bone healing during treatment. If images taken periodically show that there is no new bone filling the space between bone fragments, for instance, the doctor can confirm that the fracture is not healing.
MRI is an imaging test that uses a magnetic field and radio waves to create detailed images of soft tissue inside the body, including tissue produced by a bone that is healing.
Your doctor may recommend an MRI scan if he or she suspects that an infection has developed in or near a broken bone. MRI images can reveal inflammation associated with an infection.
If X-rays or other imaging tests reveal a nonunion fracture, your doctor may draw blood and send it to a laboratory to determine whether an infection or nutrient deficiency is contributing to the lack of bone healing.
Your doctor receives blood test results in about one week and calls you to discuss these.