Spinal fusion is a surgical procedure designed to stabilize segments of the spine, often performed to alleviate pain and improve spinal function. While effective, new disc issues, including herniations, can occur after fusion. These issues arise in the adjacent, unfused segments of the spine, not at the fusion site.
Understanding Spinal Fusion
Spinal fusion permanently connects two or more vertebrae, the bones of your spinal column. This procedure eliminates motion between these specific vertebrae, reducing pain from instability or degeneration. During surgery, a surgeon places bone or a bone-like material between the vertebrae, encouraging them to grow into a single, solid bone.
Metal plates, screws, or rods often hold the bones together while fusion occurs. The fused segment becomes a rigid unit, preventing disc herniation within that section. However, this alters the natural biomechanics of the spine.
New Disc Issues After Fusion
While the fused segment achieves stability, spinal levels directly above and below the fusion, known as adjacent segments, may experience increased stress and wear. This increased mechanical load on unfused segments can accelerate their degeneration, a condition often referred to as Adjacent Segment Disease (ASD). ASD can manifest as new disc issues, including herniation, spinal stenosis, or facet joint arthritis.
The altered biomechanics mean that adjacent discs must compensate for lost motion in the fused segment, leading to intensified degeneration. Studies indicate that ASD is a common occurrence following lumbar fusion surgery, with incidence rates increasing over time. For instance, one study found the incidence of adjacent segment degeneration increased from 12% at 5 years post-surgery to 40% at 10 years.
Identifying New Symptoms
If a new disc herniation develops at an adjacent level after spinal fusion, symptoms may include new or worsening localized back pain. Radiating pain, also known as radiculopathy, is a common symptom, extending into the arms or legs depending on the affected spinal region. This pain can be sharp and shoot down a limb, as seen with sciatica originating from a lumbar herniation.
Other symptoms can include numbness, tingling, or muscle weakness in the areas supplied by the affected nerves.
Diagnosis and Treatment
Diagnosing a new disc herniation after fusion involves a thorough physical examination and imaging tests. A healthcare provider assesses pain, reflexes, muscle strength, and sensation. MRI scans are often used to visualize the spinal column, discs, and nerves, helping to confirm the herniation’s presence and location. X-rays and CT scans may also be utilized to rule out other conditions or provide additional detail about spinal structures.
Treatment for a new disc herniation generally begins with conservative approaches. These may include physical therapy, pain medication, and spinal injections to reduce inflammation and pain. If conservative measures do not provide sufficient relief, surgical options might be considered. These could involve another discectomy to remove herniated disc material, or an additional fusion at the newly affected level to restore stability.
Maintaining Spinal Health
After spinal fusion, maintaining spinal health can help minimize the risk of developing new disc issues at adjacent segments. A healthy weight reduces excess pressure on the spine, which can lessen the strain on unfused levels. Engaging in regular, low-impact exercises like walking, swimming, or stationary cycling helps maintain flexibility, strengthen core muscles, and improve circulation without overloading the spine.
Practicing good posture, whether sitting, standing, or lifting, is important to properly align the spine and distribute weight. Avoiding activities that involve excessive bending, lifting heavy objects, or twisting the spine, especially during initial recovery, is advised. Adhering to post-operative guidelines and attending regular follow-up appointments allows for monitoring spinal health and early detection of issues.