Fusion surgery is typically performed to limit movement in the affected area of the back or neck to eliminate or minimize pain or restore stability to the backbone after a damaged disc is removed. However, sometimes a fusion fails to form as expected. When this happens, it’s referred to as a non-union, or pseudarthrosis, which is simply a term that describes an unsuccessful spinal fusion. Here’s a closer look at causes, symptoms, and treatment options for pseudarthrosis.
Pseudarthrosis may occur in any part of the spine where a fusion was attempted. The goal with fusion surgery—such as anterior cervical discectomy and fusion (ACDF) and anterior lumbar interbody fusion (ALIF)—is to join two adjacent vertebrae together as one. However, if the graft material used to allow the fusion to form doesn’t fully create new solid bone tissue, movement will continue in the affected area.
Non-unions are often caused by poor bone healing after a fusion procedure is performed, which sometimes happens due to surgical oversights, either with planning before the operation or steps taken during surgery. However, there are other times when a fusion fails to form because of long-term patient habits.
For instance, smoking reduces the chances of successful fusion by more than 30 percent. Taking certain steroid medications may also interfere with the body’s natural healing abilities enough to cause a non-union. Additional risk factors that may lead to pseudarthrosis include:
• Obesity • Hunter syndrome and other metabolic disorders • Uncontrolled diabetes • Malnutrition • Osteoporosis and certain chronic illnesses
The most common symptom of pseudarthrosis is continued pain within the affected area that lingers even after a reasonable healing period. Symptoms may also extend to nearby arms, shoulders, legs, or lower extremities if the non-union contributes to nerve irritation. Some patients also experience: • Stiffness in the affected area • Numbness and similar sensations • General weakness of the spine, especially in the affected area
If pseudarthrosis symptoms are nonexistent or mild, your Santa Monica spine surgeon may suggest no further treatment is necessary. Some patients with a non-union respond well to medication, physical therapy, and other non-surgical attempts at pain management. However, this is normally not the case.
Oftentimes, revision surgery is the recommended treatment option. Before this happens, image tests may be performed to rule out other potential sources of post-surgery symptoms. In some instances, patients don’t notice disruptive symptoms until several months or even years after their initial surgery, which can also make diagnosis difficult. If a second fusion is performed, a surgeon may:
• Use a different approach to fusion surgery than what was initially performed • Make corrections to existing hardware from the first surgery • Use a different type of bone graft material
A surgeon’s ability doesn’t necessarily influence fusion results. The Scoliosis Research Society notes that the risk for pseudarthrosis ranges from 5–15 percent, even in the best surgical hands. While there’s no guarantee of success with any type of spine surgery, you can increase your odds of beneficial results following a fusion by paying attention to your surgeon’s instructions and sticking to healthy eating and exercise habits as you heal and recover. The good news is that advances in medical technology have reduced occurrences of non-unions following fusion surgery.
Although the risk of pseudarthrosis is small, it’s best to be aware of it so you know what signs to look for after you’ve had a surgical procedure such as an ALIF or ACDF. Santa Monica patients who suspect they may have pseudarthrosis should reach out to the specialists at The Spine Institute. Our physicians are leading experts in every aspect of spinal health and spine surgery. Call us today at 310-828-7757 to schedule an appointment.