Pseudoarthrosis - Causes, Symptoms, Risk Factors, Diagnosis, and Treatment

What Is Pseudoarthrosis?

Pseudoarthrosis occurs due to non-union of the meeting end of the fractured bone. This fusion failure may resemble the fibrous joint; that is why it is called a false joint. This condition is usually seen after injury or surgery. A sudden movement of bone following surgery may be a reason for this condition. A study conducted in 2016 reported that 50 percent of spinal fusion surgeries failed due to this condition. Pseudoarthrosis is the main reason for experiencing pain immediately after surgery. However, it is reported that 30 percent of people with this condition are asymptomatic.

What Are the Risk Factors of Pseudoarthrosis?

Some medications, certain medical conditions, and lifestyle factors may increase the risk of developing pseudoarthrosis. The risk factors of pseudoarthrosis include:

Old age.

Smoking and alcohol intake.

Osteoporosis: A condition that affects strength and causes the bone to become fragile.

Diabetes.

Obesity.

Long-term usage of medications like steroids.

Malnutrition: A condition that occurs due to lack of nutrition.

Metabolic conditions.

Vitamin D deficiency.

The number of spinal levels that have undergone spinal fusion and body mass index (BMI) also play an important role in developing pseudoarthrosis.

What Are the Causes of Pseudoarthrosis?

Pseudoarthrosis can be caused by several medical conditions, congenital disorders, and surgical methods, which include:

Neurofibromatosis Type 1: It is a genetic condition that affects the nerves, resulting in skin pigmentation changes and the growth of non-cancerous tumors.

Ehlers-Danlos Syndrome: A cluster of genetic disorders that affect connective tissue like joints, skin, and blood vessels.

Osteogenesis Imperfecta or Brittle Bone Disease: A genetic condition that prevents strong bone formation in the body.

Fibrous Dysplasia: A non-cancerous bony condition due to bone replacement by abnormal fibrous tissue.

Ankylosing Spondylitis: A long-lasting inflammatory condition that causes fusion of the bones in the spine.

Diffuse Idiopathic Skeletal Hyperostosis (DISH): A condition of abnormal bone formation in the spine.

Congenital Pseudarthrosis: It is a genetic condition present from birth. This condition can develop in bones like the clavicle and tibia.

Bertolli Syndrome (BS): This condition causes back pain due to a genetic defect of the last vertebrae of the lumbar spine.

Failed Bone Graft: Bone graft failure occurs due to infection, which delays the site’s healing. Systemic conditions like diabetes and nicotine from smoking can also cause poor healing.

Nonunion of Fracture Due to Movement After Surgery: Quick movement after the surgery before the fusion of bone can lead to pseudoarthrosis.

Surgical techniques that had a higher chance of developing pseudoarthrosis include:

Osteotomy: This procedure involves cutting and reshaping the affected bone.

Long Fusion involves fusion extending outside the deformity, exceeding the vertebral upper end.

Pelvic Fixation: This involves the use of screws and rods for the immobilization of the base of the spine.

How Severe Is Pseudoarthrosis?

The severity of pseudoarthrosis varies depending on the bones involved and the surgical indications. For instance, if an individual sustains a non-healing neck fracture, it can lead to considerable pain, restricted neck movement, and potential complications. Pseudoarthrosis ranks among the primary causes of postoperative pain. However, approximately 30% of individuals with this condition experience no symptoms.

What Are the Symptoms of Pseudoarthrosis?

The symptoms mainly depend on the site of pseudoarthrosis. The common symptoms include:

Continuous pain.

Clicking sound over the joint.

Lack of movement over the affected area.

Fever.

Redness in some cases.

The symptoms of pseudoarthrosis look similar to those of osteoporosis or arthritis.

How Can Pseudoarthrosis Be Diagnosed?

Pseudoarthrosis can be difficult to diagnose in asymptomatic patients. This condition can be diagnosed through detailed medical history, physical examination, and imaging tests. In physical examination, health care professionals will check for non-healed areas, swelling, tenderness, and deformity, if any. They will also analyze the strength and mobility in the affected area. Imaging tests play an important role in differentiating pseudoarthrosis from other similar conditions. Extension and flexion radiographs are taken in case of pseudoarthrosis over the lumbar region. Computerized tomography (CT) and magnetic resonance imaging (MRI) can determine the areas where the nerve is compressed. All these imaging tests are performed to locate the non-union precisely. PET (positron emission tomography) scan is a recent imaging method that helps monitor active bone formation.

How Can Pseudoarthrosis Be Prevented?

Pseudoarthrosis caused by the surgical treatment following a fracture can be prevented by properly monitoring the surgical area to avoid infection. Congenitally occurring cases cannot be prevented, but proper treatment helps to control the symptoms and complications.

How Can Pseudoarthrosis Be Treated?

Pseudoarthrosis can be managed through conservative treatment, which includes pain management, physical therapy, and medications. Healthcare professionals may advise the patient to rest to heal the fractured area properly. Pain management is done with the help of medications like NSAIDs (non-steroidal anti-inflammatory drugs). Physical therapy exercises are advised to enhance muscle strength. If the methods mentioned above are ineffective, the healthcare professional will advise surgical options.

What Are the Surgical Options for Pseudoarthrosis?

There are different procedures available for surgery-indicated cases. The surgical treatment methods include:

• Fixation Devices: Internal fixation, like metal plates and screws, can be used along with bone grafting to promote new bone formation. Internal fixation is the commonly used method in treating this condition. External fixation involves inserting metal pins on either side of the fractured bone to stabilize and promote the natural healing process over the affected area.

• Bone Transport: This method is also helpful in treating pseudoarthrosis. This procedure is done by placing a metal rod into the bone, which helps stretch both ends of the bone. As a result, some space will be generated to form new bone.

• Electrical Stimulation Therapy: This involves using ultrasound or electromagnetic waves, which promote bone cell formation. In the later stage, these bone cells will create a hydroxyapatite structure that prevents bending and fracture of the bone. This therapy increases bone reunion rates in patients undergoing spinal fusion surgery.

• Bone Graft: This procedure involves using bone from a different body part of the patient or donor to promote the healing of the fractured bone.

• Recent advances in surgery include spinal instrumentation, genetic engineering (bone morphogenetic protein), and bone graft substitutes, which are beneficial in reducing the risk of pseudoarthrosis after spinal fusion surgery.

Conclusion:

Pseudoarthrosis is a commonly faced complication after spinal fusion surgery. It is common in adults after injury or surgical procedure. Children can also suffer from this condition due to genetic influence. Most cases of pseudoarthrosis can be cured with conservative and advanced surgical treatments available today. However, congenital pseudoarthrosis cases are difficult to treat. Therefore, prevention and early diagnosis of this condition play a key role in treatment outcomes.