Pseudarthrosis

Information about the causes, symptoms, and treatments for fractures that do not heal properly.

Symptoms and Causes

Pseudarthrosis occurs when a bone fracture does not heal properly; that is, the bone fails to unite completely and a false joint forms. This usually happens because the body perceives the fracture fragments as separate bones and therefore does not activate the mechanisms necessary for them to fuse.

It occurs more frequently in long bones, with the most commonly affected being the humerus, femur, and tibia.

Unlike delayed union, one of the complications that may occur after a fracture, pseudarthrosis involves a complete absence of bone union. Bone union is the natural process by which a callus forms to connect the fracture fragments, gradually remodeling over time to create a new, strong, mature bone.

According to its viability and progression, pseudarthrosis may be classified into three types:

Hypertrophic pseudarthrosis: an excessive amount of bone forms, preventing the fracture fragments from joining correctly. It usually occurs when the fracture is unstable.
Oligotrophic pseudarthrosis: an intermediate stage between hypertrophic and atrophic pseudarthrosis. Callus formation for fracture repair is insufficient.
Atrophic pseudarthrosis: the bone fragments become thin and weak due to inadequate blood supply or poor alignment.

The prognosis of pseudarthrosis varies depending on the underlying cause and the fractured bone involved. Current treatments allow complete recovery in many cases, although the process may be long and complex.

Symptoms

The symptoms of pseudarthrosis include:

Limited mobility.
Pain.
Instability (a sensation that the bones are moving at the fracture site).
Clicking or cracking sensations.
Redness.
Fever.

Causes

Pseudarthrosis is classified into different types depending on the underlying cause:

Septic pseudarthrosis: bone union fails due to an infection, which commonly occurs in open fractures or fractures treated surgically.
Aseptic pseudarthrosis: not associated with infection. It is usually caused by a combination of factors, including:
Damage to blood vessels.
Poor alignment of fracture fragments.
Inadequate fixation.
Health conditions that impair the healing process, particularly diabetes, obesity, or anemia.
Congenital pseudarthrosis: a very rare condition. It is a defect present at birth in which one of the long bones (tibia, fibula, femur, or clavicle) is not completely united and presents a false joint.

Risk Factors

The risk of pseudarthrosis increases in the following situations:

Advanced age.
Open fractures.
Comminuted fractures.
High-energy trauma.
Poor vascular supply (odontoid process, scaphoid, and femoral neck).
Nutritional deficiencies (protein, calcium, vitamin D).
Liver disease.
Metabolic disorders (diabetes, hypothyroidism, osteoporosis).
Smoking.
Certain medications: chemotherapy agents, anticoagulants, corticosteroids.
High doses of radiation.
Incorrectly placed osteosynthesis hardware (plates, screws, pins).

Complications

Failure to treat pseudarthrosis or inadequate management may lead to the following complications:

Instability.
Stiffness.
Mobility impairment.
Chronic pain.
Deformity and limb shortening.
Damage to muscles, nerves, or blood vessels.
Malalignment of fracture fragments.
Inflammation associated with bone degeneration (Sudeck syndrome).

Prevention

There is no specific way to prevent pseudarthrosis, but the following medical recommendations may help maintain overall bone health:

Do not smoke.
Avoid alcohol consumption.
Follow a balanced diet rich in calcium and vitamin D.
Exercise regularly.
Ensure daily sun exposure during routine activities without the need for direct sunbathing.
Prevent and appropriately treat infections.
Ensure proper fracture immobilization.

Which specialist treats Pseudarthrosis?

Pseudarthrosis is diagnosed and treated within the specialty of Traumatology and Orthopedic surgery.

Diagnosis

The diagnosis of pseudarthrosis includes the following procedures:

Physical examination: the affected area is inspected and palpated to determine the presence of:
- Changes in skin condition.
- Deformities.
- Swelling.
- Asymmetries.
- Absent or restricted mobility.
- Pain.
X-rays: images of the fractured bone and adjacent joints are obtained to assess their condition. They are usually taken in extension and flexion to evaluate the range of motion.
Computed tomography (CT): provides a more detailed representation than X-rays because it reveals the sclerotic portion of the bone (bone that has become denser and harder in response to injury). This test can identify any bridging bone between the two fragments.
Magnetic resonance imaging (MRI): used to assess the condition of the soft tissues surrounding the fracture, including muscles, ligaments, tendons, cartilage, and nerves. These images may reveal signs of regeneration, fibrosis, or necrosis.
Bone scintigraphy: a radiopharmaceutical agent is administered to facilitate the detection of specific tissues, and a tube-shaped camera is used to obtain images from multiple angles.
SPECT-CT: this test combines single-photon emission computed tomography (SPECT) and computed tomography (CT) to obtain three-dimensional images of the fracture structure and bone function. It is a highly accurate examination used to stage the extent of damage and rule out complications.

Treatment

Treatment for pseudarthrosis is selected according to the characteristics of the fracture and the individual needs of each patient. The most common options include:

Biological stimulation: promotes the body's natural ability to regenerate bone tissue.
- Platelet-rich plasma (PRP): a blood sample is collected from the patient and processed in the laboratory to obtain a high concentration of growth factors. Using ultrasound guidance, these factors are injected directly into the fracture site.
- Stem cells: these are usually obtained from the patient's bone marrow. When administered to the affected area, they initiate a regenerative process.
Electromagnetic stimulation: a non-invasive method administered through the skin. Electromagnetic waves are directed toward the fracture site to stimulate bone tissue formation.
Prolonged immobilization: a bandage or cast is applied to prevent bone movement and facilitate fracture healing.
Surgery: in most cases, surgical intervention is required to treat pseudarthrosis.
- Bone grafts: a type of biological stimulation that must be performed surgically. Bone cells are obtained from either the patient or a donor and implanted into the damaged area to promote bone repair.
- Osteosynthesis: a mechanical device is placed at the fracture site to support bone growth and fracture union. Once proper healing has been confirmed, the orthopedic hardware may be removed.