Surgery — What You Need to Know
When Fusion Works — and When the Evidence Is Less Clear
Spinal fusion is a surgical procedure that joins two or more vertebrae together using metal screws and rods, preventing movement between them. The goal is to stabilize an unstable segment of the spine.
When Fusion Has Strong Evidence
For the following conditions, there is solid evidence supporting spinal fusion:
| Condition | Description | Fusion success rate |
|---|---|---|
| Spondylolisthesis (a condition where one vertebra slips forward over the one below it) — Grade II or higher | A vertebra has slipped forward, causing instability | High |
| Unstable fractures | Vertebral fractures that compromise spinal stability | Established indication |
| Spinal tumors | Tumors that destroy the structural support of the spine | Established indication |
| Spinal infections | Osteomyelitis or discitis that damages bone integrity | Established indication |
| Severe spinal deformity | Scoliosis or kyphosis requiring correction | Established indication |
What these have in common: There is a clear structural problem that needs to be stabilized.
When Evidence Does Not Support Surgery: Nonspecific Chronic Low Back Pain
"Nonspecific chronic low back pain" refers to persistent back pain where no single structural cause can be identified. Approximately 85% of chronic low back pain falls into this category.
Three Major Randomized Controlled Trials
Spinal fusion for nonspecific chronic low back pain has been tested in three large randomized controlled trials:
| Trial | Fusion vs. | Result |
|---|---|---|
| Swedish trial | Standard physical therapy | Fusion appeared superior. However, the comparison group received only basic physical therapy |
| Norwegian trial | Cognitive behavioral therapy + exercise | No difference |
| UK trial | Intensive rehabilitation | No clinically meaningful difference |
Key finding: The Swedish trial was the only one that favored fusion, but its comparison group received basic physical therapy rather than a structured, intensive rehabilitation program. When fusion was compared against well-designed rehabilitation, the difference disappeared.
The 11-Year Follow-Up — The Landmark Study
A landmark long-term follow-up study combined data from all three trials, with an average follow-up period exceeding 11 years.
Results:
- There was virtually no difference between fusion and rehabilitation on any outcome measure
- All measured outcomes — disability, pain, and quality of life — showed no meaningful advantage for fusion
"At long-term follow-up, there was no difference between fusion and comprehensive rehabilitation in patient-reported outcomes. Given the risks of surgery and the fact that the benefits of conservative treatment do not deteriorate over time, fusion should not be the preferred option when a comprehensive rehabilitation program is available."