Treatment of Spondylolisthesis
For symptomatic spondylolisthesis, begin with at least 3-6 months of comprehensive conservative management including formal supervised physical therapy, NSAIDs, and activity modification; surgical decompression with fusion is indicated only when conservative treatment fails AND there is documented instability (any grade of spondylolisthesis) with corresponding neural compression on imaging. 1, 2
Conservative Management (First-Line Treatment)
Initial conservative therapy is mandatory for all patients with spondylolisthesis before considering surgery. 1, 2
Required Conservative Treatment Components:
- Formal supervised physical therapy for at least 6 weeks, focusing on flexion-based exercises (abdominal strengthening, posterior pelvic tilts) rather than extension exercises 1, 3
- NSAIDs and pain management including epidural steroid injections or transforaminal injections for radicular symptoms 4, 5, 6
- Activity modification and instruction in proper body mechanics 3, 5
- Minimum trial period of 3-6 months before surgical consideration 1, 7, 6
Evidence Supporting Conservative Approach:
- Flexion-based exercise programs result in only 19% of patients having moderate-to-severe pain at 3-year follow-up, compared to 67% with extension exercises 3
- Most patients with low-grade spondylolisthesis (Grade I-II) experience symptom relief with conservative treatment 5, 8
Surgical Indications
Surgery is appropriate only when ALL of the following criteria are met: 1, 2
Absolute Requirements for Fusion:
- Failed comprehensive conservative management for at least 3-6 months including formal physical therapy 1, 7
- Documented instability: Any degree of spondylolisthesis (even Grade I) constitutes spinal instability 1, 2
- Neural compression on imaging that correlates with clinical symptoms (stenosis, nerve root compression, or foraminal narrowing) 1, 2
- Persistent disabling symptoms including radiculopathy, neurogenic claudication, or progressive neurological deficits 1, 5
Critical Distinction - When Fusion is NOT Indicated:
- Decompression alone is recommended for stenosis without spondylolisthesis or documented instability 2
- In the absence of neural compression, fusion is not indicated regardless of the presence of spondylolisthesis 2
- Isolated back pain without radiculopathy or stenosis does not meet criteria for fusion 2
Surgical Approach Selection
For patients meeting fusion criteria, decompression with instrumented fusion provides superior outcomes compared to decompression alone. 1, 2
Evidence Supporting Fusion Over Decompression Alone:
- 96% of patients with spondylolisthesis and stenosis report excellent/good outcomes with decompression plus fusion, compared to only 44% with decompression alone 1, 2
- Patients with spondylolisthesis who undergo decompression alone have up to 73% risk of progressive slippage and delayed clinical failure 2
- Decompression alone in the setting of spondylolisthesis leads to iatrogenic instability in approximately 38% of cases 2
Instrumentation Recommendations:
- Pedicle screw fixation is recommended when spondylolisthesis is present, providing fusion rates of 83% versus 45% without instrumentation (p=0.0015) 2
- Instrumentation is specifically indicated when there is preoperative evidence of instability, such as any grade of spondylolisthesis 1, 2
Surgical Technique Options:
- Transforaminal lumbar interbody fusion (TLIF) provides high fusion rates (92-95%) and allows simultaneous decompression while stabilizing the spine 1
- Posterior lumbar interbody fusion (PLIF) and anterior approaches (ALIF, OLIF, XLIF) are alternatives depending on anatomy and specific pathology 1
Common Pitfalls to Avoid
Critical Errors in Management:
- Performing fusion without documented neural compression - this increases surgical risk without proven benefit 2
- Inadequate conservative management - fusion without completing at least 6 weeks of formal supervised physical therapy does not meet medical necessity criteria 1
- Decompression alone in the presence of spondylolisthesis - this leads to high rates of progressive instability and poor outcomes 1, 2
- Adding fusion at levels without documented instability - only 9% of patients without preoperative instability develop delayed slippage after decompression alone 2
Documentation Requirements:
- Flexion-extension radiographs to confirm dynamic instability 1
- MRI or CT demonstrating neural compression at the level corresponding to clinical symptoms 2
- Documentation of failed conservative therapy including specific physical therapy regimen and duration 1
Special Considerations by Spondylolisthesis Type
Degenerative Spondylolisthesis (Most Common at L4-5):
- Occurs most commonly in women over age 40 3
- Fusion is specifically recommended when combined with stenosis and failed conservative management 1, 2
- Better outcomes with fusion compared to decompression alone (statistically significant reduction in back pain p=0.01 and leg pain p=0.002) 1
Isthmic Spondylolisthesis (Most Common at L5-S1):
- Results from pars interarticularis defect 3, 8
- Bilateral pars defects with any grade of listhesis constitute clear indication for fusion when neural compression is present 2
- Grade I-II slippage may respond to conservative management in younger patients 3, 5
Retrolisthesis (Posterior Displacement):
- Surgery considered only after 3-6 months of failed conservative management with significant neurological symptoms or progressive instability 7
- Decompression alone may be sufficient without significant instability 7
- Pedicle screw fixation indicated if kyphosis or excessive motion present 7
Expected Outcomes
Surgical Success Rates:
- Clinical improvement occurs in 86-92% of patients undergoing fusion for appropriate indications 1
- Fusion rates of 89-95% achievable with appropriate instrumentation and technique 1, 2
- Patient satisfaction rates of 93% when fusion performed for documented spondylolisthesis with stenosis 2