Lumbar spondylosis is a type of spondylosis that occurs in the lumbar spine.
Lumbar spondylosis as a term refers to degenerative conditions affecting the discs, vertebral bodies, and/or associated joints of the lumbar spine. Spondylosis deformans and lumbar osteoarthritis are other names of lumbar spondylosis.
Lumbar spondylosis includes many associated pathologies including spinal stenosis, degenerative spondylolisthesis, osteoarthritis and also captures effects of daily use, aging, trauma on the intervertebral discs, the vertebrae, and the other spine joints.
The condition is said to be progressive and irreversible.
Likelihood of spondylosis increases with age and is considered an inevitable part of aging.
Lumbar spondylosis is the price of upright posture we have. It is quite a common occurrence because of mechanical stresses it undergoes.
Studies have reported that 85% of individuals aged 45–64 years demonstrate osteophytes within the lumbar spine. The men appear to have more significant degenerative changes than women, both with regard to the number and severity of osteophyte formation.
An MRI study in asymptomatic patients > 60 years has revealed that 80% of them have disc protrusions and 20% have spinal stenosis.
Even younger persons are found with evidence of lumbar spondylosis.
Degenerative changes have been found to be present in 3% of individuals aged 20–29 years.
Pathophysiology of Lumbar Spondylosis
When the annular ligament is put to stress body responds by forming new bone i.e. osteophytes which results in lumbar spondylosis.
The change is thought to begin with the degeneration of the intervertebral disc. Simultaneous degenerative changes in the vertebral body, and associated joints interdependent changes occurring secondary to disk space narrowing.
Intervertebral discs are believed to undergo a degenerative cascade [suggested by Kirkaldy Willis and Bernard]
The cascade is in three phases
The first phase is Dysfunction Phase and highlights the initial effects of repetitive microtrauma. This phase is marked by
- Development of circumferential painful tears of the outer annulus
- End-plate separation
- May compromise nutritional supply and waste removal
- Tears may coalesce to become radial tears
- A decrease in the capacity of the disc to maintain hydration
- Desiccation and reduced disk height.
- New vessels and nerves grow in tears
- Increase the disc’s capacity for pain signal transmission
After this begins the second phase which is also called Instability Phase. It is marked by
- Loss of mechanical integrity
- Progressive disc changes
- Internal disruption
- Additional annular tears
- Facet degeneration
- May induce subluxation and instability.
Phase III is the Stabilization Phase
- Continued disc space narrowing and fibrosis
- Formation of osteophytes
- Transdiscal bridging
Age, obesity, occupations that load the spine [athlete, manual labor] and hereditary factors determine the progression pace and extent.
Recent studies have suggested obesity to be a variable factor and occupation as not a factor.
Presentation of Lumbar Spondylosis
Lumbar spondylosis usually produces no symptoms. Even when there is back pain or radiculopathy, lumbar spondylosis may not be causing it and just an unrelated finding.
The symptoms occur only when it has progressed so much to cause complications like pressure effects or painful arthropathy.
The symptoms are those of pain in the back or radiculopathy.
The source of pain could be facet joints, intervertebral disks, sacroiliac joints, nerve root dura, and myofascial structures within the spine]
Similarly, the radiculopathy could be from many possible sources and the correlation to the structural change becomes important.
It could be a bulging disc, posterior osteophyte, or structural hypertrophy causing narrowing of the foramen stenosis.
In mild lumbar spondylosis, the may be absolutely normal. In advanced lumbar spondylosis, some patient may have dynamic scoliosis. The lumbar lordosis may be diminished and there is a decreased range of motion of the lumbar spine.
In case some specific entity is present such as disc herniation or spinal stenosis, the findings would depend on the entity.
No laboratory studies are required for making a diagnosis. In cases where there is a confusion regarding infective etiology i.e. pyogenic infections of spine, routine blood tests may be performed.
Mostly lumbar spondylosis is an incidental finding and radiographs, CT scans, and MRIs are used only in the event of complications.
X-rays show osteophytes, thickening of facet joints, and narrowing of the intervertebral disc spaces.
CT and MRI are able to shoe spinal canal anatomy better.
MRI is the best modality to show the details of soft tissue including discs and ligaments and nerves. It is able to reveal a nerve compression.
Treatment of Lumbar Spondylosis
It must be reiterated that lumbar spondylosis is not symptomatic and always not responsible for the symptoms.
It is always to make a diagnosis that correlates with the pain and identify pain generator for treatment.
The back pain or radicular pain needs the treatment, not the lumbar spondylosis.
And the treatment would depend on the cause of the pain.
For example treatment approach for herniated disc would be different than the spinal stenosis, though both are covered within the scope of lumbar spondylosis.
So what is being mentioned here is a treatment for back pain and radicular pain rather than lumbar spondylosis.
Therapy is supportive and symptomatic and involves painkillers, rest, physiotherapy and surgery [rarely] if required.