Degenerative disc disease (DDD) can cause a sideways curvature of the spine, a condition known as scoliosis. This results in a specific diagnosis called Adult Degenerative Scoliosis, or “de novo” scoliosis, meaning it develops anew in adulthood. DDD is characterized by the age-related wear and tear of the intervertebral discs, the cushions that separate the bones of the spine. When this degeneration leads to instability, the spine shifts laterally, creating the abnormal curve. This acquired form is distinct from the scoliosis that often appears in adolescence.
Understanding the Role of Degenerative Disc Disease
The foundation for this acquired spinal curvature lies in the structural breakdown of the spinal motion segment. Intervertebral discs, which function as shock absorbers, begin to lose their water content and height, a process called disc dehydration. This loss of height reduces the space between adjacent vertebrae, placing greater stress on the small joints at the back of the spine, known as the facet joints. These changes destabilize the spine, creating a state of segmental instability.
A spinal segment that lacks disc height and stability can no longer handle normal loads efficiently. This instability is the necessary precursor that allows the spine’s alignment to be gradually altered by the continuous forces of gravity and movement. Any compromise in the discs’ ability to maintain spacing and cushion the vertebrae can begin a cascade of alignment issues.
How Spinal Instability Creates a Lateral Curve
The formation of the lateral curve is driven by the asymmetrical nature of the degenerative process. Degeneration rarely occurs uniformly across the entire disc and its corresponding facet joints. Instead, one side of a vertebral segment—either the left or the right—may experience a more rapid breakdown of disc cartilage and joint tissue. This uneven wear is often due to lifelong asymmetrical loading from posture, movement habits, or minor injuries.
When the disc on one side of the spine loses more height than the other, the vertebral body above it begins to tilt and wedge toward the compromised side. This tilting action is accompanied by a subtle rotation of the vertebra, a three-dimensional shift characteristic of scoliosis. As this process repeats across multiple segments, the cumulative effect is a progressive, compensatory lateral shift of the entire spinal column. The curve that develops is typically a single, C-shaped curve, most commonly found in the lumbar spine. This cycle of asymmetrical pressure perpetuates the widening of the scoliotic curve over time.
Recognizing Adult Degenerative Scoliosis
Adult Degenerative Scoliosis presents with a distinct set of symptoms related to the resulting spinal misalignment and nerve compression. A common complaint is persistent back pain, which is often accompanied by radiating leg pain, known as sciatica or radiculopathy. This nerve irritation occurs because the collapsing discs and the lateral curvature narrow the spaces where spinal nerves exit the column.
The misalignment can also cause a feeling of postural imbalance, where one shoulder or hip appears higher than the other. Patients frequently experience neurogenic claudication, which is a cramping or heaviness in the legs that worsens with walking or standing. This pain is typically relieved by sitting or leaning forward, a position that temporarily opens the narrowed spinal canal. Unlike Adolescent Idiopathic Scoliosis, this adult-onset type is an acquired condition caused by the mechanical breakdown of the spinal elements over decades.