What is the significance of loss of height in the L4-L5 (Lumbar 4-Lumbar 5) vertebral segment with a vacuum phenomenon?

From the Guidelines

Loss of height in the L4-L5 vertebral space with vacuum phenomenon is typically managed with conservative measures, including physical therapy, non-steroidal anti-inflammatory drugs (NSAIDs), and activity modification, with percutaneous vertebral augmentation (VA) considered for patients with osteoporotic vertebral compression fractures (VCFs) who have not responded to medical management, as it has been shown to provide better pain relief and improved functional outcomes compared to conservative therapy 1.

Key Considerations

• The natural history of most healing VCFs is gradual improvement in pain over 2 to 12 weeks, with variable return of function 1.
• Conservative management includes medical management with or without methods of immobility, and is the initial treatment of painful VCFs 1.
• VA may be a treatment option for osteoporotic VCFs, as it has been shown to provide immediate and considerable improvement in pain and patient mobility, and can help improve pulmonary function in patients with VCF 1.
• The timing of when VA is appropriate has been debated, but studies have found VA to be superior to placebo intervention for pain reduction in patients with acute osteoporotic VCF of <6 weeks’ duration, and patients with VCF >12 weeks compared to VCF <12 weeks had equivalent benefit 1.

Treatment Options

• Conservative measures, including physical therapy focusing on core strengthening exercises, NSAIDs like ibuprofen (400-800mg three times daily with food) or naproxen (500mg twice daily with food) for pain relief, and activity modification to avoid movements that worsen pain.
• Heat therapy for 15-20 minutes several times daily to help relax muscles, while maintaining proper posture and using ergonomic supports may reduce strain.
• For persistent pain, prescription medications like muscle relaxants (cyclobenzaprine 5-10mg at bedtime) or referral to pain management for epidural steroid injections might be considered.
• VA or other surgical options are typically reserved for cases with neurological deficits or intractable pain, or for patients who have not responded to medical management 1.

From the Research

Loss of Height in L4-L5 with Vacuum Phenomenon

• The loss of height in L4-L5 with vacuum phenomenon is a sign of advanced disc degeneration, as indicated by the presence of gas in the disc space 2.
• This condition can lead to symptoms such as low back pain and leg pain, as well as increased disability, as measured by the Oswestry Disability Index 3.
• The severity of the vacuum phenomenon at L4-L5 has been associated with greater preoperative back pain and worse Oswestry Disability Index scores, and may be an indication for fusion surgery 3.

Association with Clinical Parameters

• The correlation between intervertebral vacuum phenomenon (IVP) severity and low back pain in patients with degenerative spondylolisthesis has been analyzed, with results showing a significant increase in odds ratio for back pain in patients with more severe IVP at L4-L5 3.
• The severity of IVP at L4-L5 has also been associated with increased disability, as measured by the Oswestry Disability Index, and may be an indication for fusion surgery 3.

Treatment Options

• Surgical therapy, including decompression and fusion, may be an acceptable method for the treatment of vacuum disc phenomenon and accumulation of gas within the spinal canal 2.
• Standalone endoscopic decompression and interbody fusion surgery may be a more reliable treatment than decompression alone for patients with vertical instability and a vacuum disc 4.
• The majority of surgeons surveyed believed that vacuum phenomenon on radiographic studies is associated with vertical instability and collapse, resulting in dynamic foraminal and lateral recess stenosis, and should be treated surgically 4.

Risk Factors for Adjacent Intervertebral Disk Height Decrease

• The incidence rate and risk factors of the adjacent intervertebral disk height decrease phenomenon after single-level transforaminal lumbar interbody fusion (TLIF) of the lumbar spine have been studied, with results showing that age, preoperative lumbar lordosis, and facet joint sagittalization are significant risk factors 5.
• Distraction of the L4-5 intervertebral space by cage insertion can lead to a reduced height on the adjacent L3-4 segment in some patients 5.