What are the treatment options for anterolisthesis of L4 and L5 due to facet joint degeneration, degenerative end plate changes, and loss of disk height at L4/5 and L5/S1?

Anterolisthesis of L4 and L5: Definition and Treatment Options

What is Anterolisthesis?

Anterolisthesis at L4 and L5 represents anterior slippage of the L4 vertebra on L5 (and potentially L5 on S1), caused by facet joint degeneration, disc height loss, and endplate changes—this is degenerative spondylolisthesis, a form of spinal instability that typically requires surgical fusion when conservative management fails. 1

• Degenerative spondylolisthesis results from hypertrophic arthritis of the facet joints causing segmental instability, predominantly in the sagittal plane 1
• Disc degeneration accompanies this process to varying degrees, with loss of disc height contributing to abnormal motion patterns 1, 2
• The L4-L5 level is most commonly affected, particularly when the lumbosacral segment below is relatively rigid 1
• Degenerative endplate changes (Modic changes) indicate vertebral inflammation and advanced degenerative disease 3

Treatment Algorithm

Conservative Management (First-Line, 3-6 Months Minimum)

All patients must complete comprehensive conservative treatment for at least 3-6 months before surgical intervention is considered, including formal physical therapy—this is a critical requirement for medical necessity. 4

• Formal physical therapy for minimum 6 weeks is mandatory, not just home exercises 4
• Anti-inflammatory medications (NSAIDs) as first-line pharmacotherapy 4
• Trial of neuroleptic medications (gabapentin or pregabalin) for radicular symptoms 4
• Epidural steroid injections (ESIs) may provide short-term relief (<2 weeks) but have limited evidence for chronic low back pain without radiculopathy 3
• Facet joint injections can be diagnostic and therapeutic, with facet-mediated pain causing 9-42% of chronic low back pain in degenerative lumbar disease 3

Critical Pitfall: Incomplete conservative management, particularly lack of formal physical therapy, disqualifies patients from surgical consideration 4

Surgical Management (When Conservative Treatment Fails)

For patients with degenerative spondylolisthesis and stenosis who fail conservative management, decompression combined with fusion provides superior outcomes compared to decompression alone, with 96% reporting excellent/good results versus 44% with decompression alone. 3

Indications for Fusion Surgery:

• Documented instability or spondylolisthesis (primary indication) 4
• Persistent disabling symptoms after 3-6 months of comprehensive conservative management 4
• Imaging findings (anterolisthesis, facet degeneration, disc height loss) that correlate with clinical presentation 4
• Significant functional impairment despite conservative measures 4
• Cases where extensive decompression might create iatrogenic instability 4

Evidence Supporting Fusion:

• Class II medical evidence demonstrates that patients with stenosis and degenerative spondylolisthesis treated with decompression plus fusion report statistically significantly less back pain (p=0.01) and leg pain (p=0.002) compared to decompression alone 3
• Fusion rates of 92-95% are achieved with modern instrumented techniques 4
• Poor results with decompression alone are generally associated with progression of spinal deformity 3
• Patients with degenerative changes and low back pain combined with spondylolisthesis achieve better outcomes with fusion 3

Surgical Technique Options:

Transforaminal Lumbar Interbody Fusion (TLIF) is an appropriate technique for L4-L5 and L5-S1 anterolisthesis, providing high fusion rates (92-95%) with neural decompression and stabilization. 4

• Posterior lumbar fusion (PLF) with pedicle screw fixation provides optimal biomechanical stability 4
• TLIF allows for decompression of neural elements while stabilizing the spine to prevent progression 4
• Interbody cage placement with autologous bone graft or bone morphogenetic protein (BMP) 5
• Anterior approaches (ALIF, OLIF, XLIF) are alternatives depending on anatomy and surgeon preference 3

Complications to Anticipate:

• Instrumented fusion procedures carry higher complication rates (31-40%) compared to decompression alone (6-22%) 4
• Common complications include cage subsidence, new nerve root pain, and hardware issues that typically don't require immediate intervention 4
• When using rhBMP-2, postoperative radiculitis occurs in 14% of cases, though this can be reduced to 5.4% with hydrogel sealant shielding of the nerve root 4
• Risk of adjacent segment degeneration due to altered biomechanics 2

Special Considerations:

Patients with retrolisthesis (posterior slippage) at L5-S1 may have worse postoperative outcomes for bodily pain and physical function, though this does not affect surgical decision-making when indications are met. 6

• Degenerated discs cause abnormal loading patterns that accelerate degeneration in adjacent segments 2
• The presence of Modic endplate changes may predict better short-term response to epidural steroid injections, though long-term benefit remains limited 3
• Facet joint orientation abnormalities can predispose to degenerative spondylolisthesis development 7

Critical Pitfall: Performing fusion without adequate conservative management or in the absence of documented instability/spondylolisthesis leads to poor outcomes and is not medically necessary 4