What Is Adult Spinal Deformity?
Adult spinal deformity (ASD) refers to abnormal alignment of the spine that develops or progresses during adulthood. These changes may occur due to aging, degeneration of the spinal discs and joints, previous spinal surgery, or progression of a spinal condition that began earlier in life.
Adult spinal deformity may involve abnormal curvature of the spine in one or more planes, including:
- Scoliosis – side-to-side curvature of the spine
- Kyphosis – excessive forward curvature of the spine
- Sagittal imbalance – difficulty maintaining upright posture due to forward shift of spinal alignment
These deformities can affect overall posture and spinal balance, sometimes leading to pain, fatigue, and difficulty standing or walking for extended periods.
Incidence and Prevalence
Adult spinal deformity is relatively common and becomes more prevalent with age.
Research suggests:
- Up to 30–60% of adults over age 60 may have some form of spinal deformity visible on imaging.
- The prevalence increases significantly in older adults due to degenerative changes of the spine.
- Many individuals may have mild deformities without symptoms, while others develop significant functional limitations.
Because life expectancy continues to increase, adult spinal deformity is becoming an increasingly common reason patients seek evaluation by spine specialists.
Causes of Adult Spinal Deformity
Several conditions may contribute to abnormal spinal alignment in adults.
Common causes include:
- Degenerative Changes: Age-related degeneration of spinal discs and facet joints can gradually lead to loss of spinal alignment and curvature changes.
- Degenerative Scoliosis: Degeneration of discs and joints may cause the spine to gradually curve sideways, resulting in adult degenerative scoliosis.
- Kyphotic Deformity: Collapse of vertebral bodies, degenerative disc disease, or compression fractures may cause excessive forward curvature of the spine.
- Previous Spinal Surgery: Some patients develop deformity following spinal fusion surgery due to changes in spinal mechanics or degeneration of adjacent spinal segments.
- Untreated Childhood Deformity: Spinal conditions such as scoliosis or Scheuermann’s kyphosis that began during adolescence may progress during adulthood.
- Vertebral Compression Fractures: Osteoporosis-related fractures can lead to vertebral collapse and progressive kyphosis.
Symptoms of Adult Spinal Deformity:
Symptoms vary depending on the severity and type of spinal deformity.
Common symptoms include:
- Chronic back pain
- Difficulty standing upright
- Forward stooping posture
- Fatigue while standing or walking
- Muscle stiffness or tightness
- Leg pain or numbness due to nerve compression
In more severe cases, patients may experience progressive imbalance, requiring them to bend their knees or hips to maintain an upright position.
Sagittal Balance and Spinal Alignment
One of the most important factors in adult spinal deformity is sagittal balance, which refers to the alignment of the spine when viewed from the side.
Healthy spinal alignment allows the body to maintain an upright posture with minimal energy expenditure and muscular effort. When spinal curves become abnormal, the body must compensate by bending the hips, knees, or neck, which can lead to increased muscular effort, fatigue and pain.
Spine specialists often evaluate measurements such as:
- Cobb angle – measures the degree of spinal curvature
- Sagittal vertical axis (SVA) – measures forward spinal imbalance
- Pelvic incidence and pelvic tilt – describe pelvic alignment
- Lumbar lordosis – the natural curvature of the lower back
These measurements, among many others, help determine the degree of spinal imbalance and guide treatment decisions.
Understanding Spinal Alignment
Spine specialists evaluate several important measurements when assessing deformity, including:
- Cobb angle – measures the degree of spinal curvature
- Sagittal vertical axis (SVA) – measures forward spinal imbalance
- Pelvic incidence and pelvic tilt – describe pelvic alignment
- Lumbar lordosis – the natural curvature of the lower back
These measurements help determine the severity of the deformity and guide treatment decisions.
Diagnosis
Diagnosis begins with a detailed medical history and physical examination.
Your physician may evaluate:
- Posture and spinal alignment
- Walking pattern and balance
- Range of motion
- Neurological function
Imaging studies are used to evaluate the spine and measure deformity.
Common diagnostic tests include:
- Standing full-length spine X-rays, which show overall spinal alignment
- MRI scans, which evaluate nerve compression and soft tissues
- CT scans, which provide detailed images of bone structures
These studies help determine the severity of the deformity and whether nerves or the spinal cord are affected.
Treatment
Treatment depends on the severity of the deformity, symptoms, and overall health of the patient.
Non-Surgical Treatment
Many patients initially benefit from conservative treatment options such as:
- Physical therapy and core strengthening
- Anti-inflammatory medications
- Activity modification
- Pain management treatments
- Spinal injections
These treatments aim to reduce pain, improve posture, and maintain mobility.
Surgical Treatment
Surgery may be recommended when:
- Symptoms significantly affect quality of life
- Severe spinal imbalance develops
- Neurological symptoms occur due to nerve or spinal cord compression
- The deformity continues to progress despite conservative treatment
Surgical treatment for adult spinal deformity typically focuses on realigning the spine and stabilizing it in a more natural position. This is usually done using spinal fusion, in which two or more vertebrae are permanently joined together using bone grafts and surgical implants such as screws and rods.
In more complex deformities, additional procedures may be necessary to safely correct spinal alignment.
Osteotomy
An osteotomy is a surgical procedure in which a surgeon carefully cuts and reshapes a portion of the spinal bone to allow the spine to be repositioned into a better alignment.
This technique is sometimes required when the spine has become stiff or severely curved and cannot be corrected with standard surgical techniques alone. Osteotomies allow the surgeon to restore spinal balance and improve posture, helping patients stand more upright.
Corpectomy
A corpectomy involves removing a portion of a vertebral body—the front part of the spinal bone—when it is severely damaged, collapsed, or compressing the spinal cord or nerves.
After removing the damaged bone, the surgeon places a spacer or cage and stabilizes the spine with implants. This procedure can help relieve pressure on the spinal cord while also helping restore spinal alignment.
The exact surgical approach depends on the type of deformity, the severity of the curvature, and the patient’s overall health. The goal of surgery is to improve posture, reduce pain, and allow patients to stand and walk more comfortably.
Summary
Adult spinal deformity refers to abnormal spinal alignment that develops or progresses during adulthood, often due to degenerative changes of the spine. These deformities may involve scoliosis, kyphosis, or sagittal imbalance and can lead to pain, fatigue, and difficulty maintaining upright posture. Many patients improve with conservative treatment such as physical therapy and pain management. In more severe cases, surgical correction—including spinal fusion and, when necessary, advanced techniques such as osteotomy or corpectomy—may be recommended to restore spinal alignment, improve posture, and enhance quality of life.
