What is lumbar spondylosis?

What is Lumbar Spondylosis?

Lumbar spondylosis is a chronic, noninflammatory degenerative disease of the lumbar spine caused by progressive deterioration of the intervertebral discs and facet joints, resulting in structural changes that may or may not produce clinical symptoms. 1

Pathophysiology and Structural Changes

Lumbar spondylosis represents the end result of age-related degenerative processes affecting multiple spinal structures 1:

• Disc degeneration leads to narrowing of the disc space, which triggers a cascade of interdependent degenerative changes throughout the lumbar spine 2
• Facet joint arthropathy develops as altered biomechanics place abnormal stress on the posterior elements 1
• Ligamentous hypertrophy occurs as the spine attempts to stabilize degenerative segments 2
• Osteophyte formation develops along vertebral endplates and facet joints 2

The narrowing of disc intervals is particularly important because it serves as a primary driver of many secondary degenerative changes, making disc space reconstitution a major consideration in surgical planning 2.

Clinical Presentation Spectrum

Patients with lumbar spondylosis present with highly variable symptoms 1:

• Axial low back pain is the most common complaint, ranging from mild discomfort to severe disability 1
• Radicular leg pain occurs when nerve root compression develops 1
• Neurogenic claudication manifests in approximately 75% of patients with associated spinal stenosis, caused by blood hypoperfusion secondary to nerve root compression during ambulation 3
• Asymptomatic disease is common—many patients with radiographic spondylosis have no symptoms whatsoever 4

Critical pitfall: The severity of symptoms does not correlate with the degree of radiographic degeneration 3. Degenerative changes on MRI are frequently observed in asymptomatic individuals and their presence alone does not mandate treatment 4.

Associated Conditions

Lumbar spondylosis frequently coexists with or progresses to other degenerative conditions 1, 3:

• Spinal stenosis develops when degenerative changes narrow the spinal canal or lateral recesses 1
• Degenerative spondylolisthesis (Type III in the Wiltse classification) results from progressive disc and facet degeneration leading to vertebral slippage, most commonly at L4-L5 3
• Foraminal stenosis occurs as disc height loss and facet hypertrophy narrow the nerve root exit zones 2

Degenerative spondylolisthesis predominantly affects elderly women (5:1 female-to-male ratio) and rarely exceeds 30% slip 3.

Anatomical Considerations

The anatomy of lumbar spondylosis involves specific structural relationships 2:

• Lateral recesses vary in size at different vertebral levels based on pedicle dimensions and interarticular process relationships 2
• Nerve root canals demonstrate normal narrowing at the level of opposed intervertebral discs and facet joint capsules, creating a "beaded appearance" that correlates with common entrapment points 2
• Intervertebral canals have a "long-necked gourd" appearance due to physiologic narrowing, which becomes pathologic when degenerative changes further compromise these already narrow zones 2

First-Line Management Approach

The majority of patients with lumbar spondylosis can and should be treated nonsurgically 1:

• NSAIDs or COX-2 inhibitors are first-line pharmacologic agents for pain control 1
• Formal structured physical therapy for a minimum of 6 weeks is mandatory before considering any surgical options 5
• Prostaglandin E1, epidural injections, and transforaminal injections may provide relief for radicular symptoms and claudication 1
• Comprehensive rehabilitation combining cognitive-behavioral therapy with structured physical therapy for 3-6 months achieves outcomes comparable to fusion surgery for chronic low back pain without stenosis or spondylolisthesis 4

When Conservative Treatment Fails

Surgery should only be considered after documented failure of comprehensive conservative management 5:

• Minimum 3-6 months of formal physical therapy, NSAIDs, and other conservative measures must be completed 5
• Operative therapy is reserved for patients who are totally incapacitated by their condition despite maximal conservative treatment 1
• Decompression with fusion is superior to decompression alone in patients with stenosis and associated spondylolisthesis, with 96% reporting excellent/good results versus 44% with decompression alone 6

Prognosis and Natural History

The natural history of lumbar spondylosis is generally favorable 5:

• Most patients improve within the first 4 weeks of conservative management 5
• Approximately 96% of appropriately managed patients achieve minimal disability with nonsurgical treatment 4
• Neurological deterioration is most likely in patients with neurogenic claudication or vesicorectal symptoms who do not undergo surgery 7

Never proceed to surgery without documented completion of formal physical therapy for at least 6 weeks, as this represents a critical deficiency in care 5.