What is Lumbar Spondylosis?
Lumbar spondylosis is a chronic, age-related degenerative condition of the lumbar spine involving progressive deterioration of intervertebral discs and facet joints, commonly occurring in adults over 40 years of age. 1, 2, 3
Pathophysiology and Degenerative Process
Lumbar spondylosis represents a noninflammatory degenerative disease caused by breakdown of the lumbar disc and facet joints 3. The American College of Radiology explains that this degenerative cascade involves:
- Disc degeneration with loss of water content and structural integrity, leading to decreased disc height and altered biomechanics 2
- Osteophyte formation (bone spurs) developing at vertebral margins as a response to abnormal mechanical stress 2
- Facet joint hypertrophy with progressive arthritic changes 2
- Ligamentous thickening, particularly of the ligamentum flavum 2
The American College of Radiology notes that malalignment can develop secondary to asymmetric degeneration, further concentrating mechanical forces, particularly in individuals with congenitally short pedicles or developmentally narrow spinal canals 2, 4. Prior trauma, including minor injuries, can initiate or accelerate this degenerative cascade 2, 4.
Clinical Presentation
The etiology of lumbar spondylosis is multifactorial, and patients present with a broad variety of symptoms 3:
- Low back discomfort localized to the affected spinal segments 3
- Radiating leg pain when nerve root compression occurs 3
- Neurogenic intermittent claudication (activity-related leg pain worsening with prolonged standing or ambulation) when spinal stenosis develops 1, 3
- Many patients remain asymptomatic despite radiographic evidence of spondylosis 2, 4
Important Clinical Distinctions
A critical caveat: radiographic spondylosis does not always correlate with symptoms. The American College of Radiology emphasizes that spondylotic changes are commonly identified on imaging in asymptomatic individuals over 30 years of age 2, 4. This means imaging findings must be interpreted in the clinical context of the patient's symptoms.
Potential Complications
When degenerative changes become severe, they can lead to:
- Spondylotic myelopathy: develops when osteophytes, disc herniations, and ligamentous hypertrophy collectively compromise the spinal cord through direct mechanical pressure or ischemic changes 2, 4
- Radiculopathy: results from foraminal narrowing due to disc bulging, osteophytes, and facet hypertrophy compressing exiting nerve roots 2, 4
- Spinal stenosis: narrowing of the spinal canal causing neurogenic claudication 1
- Degenerative spondylolisthesis: displacement of one vertebra over another (affects approximately 11.5% of the US population) 5, 6
Distinction from Ankylosing Spondylitis
Lumbar spondylosis must be distinguished from ankylosing spondylitis, which is an inflammatory condition. Ankylosing spondylitis presents with inflammatory back pain (onset before age 45, improvement with exercise but not rest, morning stiffness) and is associated with HLA-B27 positivity in 74-89% of cases 1, 7. Spondylosis, in contrast, is degenerative and noninflammatory 3.
Natural History
Degenerative lumbar spondylosis is a normal, age-related phenomenon that is largely asymptomatic in most cases 8. Understanding the natural history is important to tailor an individualized management plan, as the condition may progress slowly over years or remain stable 6.