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 is a broad term and includes many associated pathologies including spinal stenosis, degenerative spondylolisthesis, and osteoarthritis, and also captures effects of daily use, aging, and trauma on the intervertebral discs, the vertebrae, and the other spine joints.
Thus, it is a nonspecific term and often denotes all degenerative conditions.
It is a common finding and often the cause of lower back pain.
The condition is said to be progressive and irreversible.
The 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 the mechanical stresses the spine undergoes due to upright posture.
About 85% of individuals aged 45–65 years demonstrate osteophytes within the lumbar spine. Men appear to have more significant degenerative changes than women. This applies to both the number and severity of osteophyte formation.
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.
Thus, in nutshell, lumbar spondylosis appears to be a nonspecific aging phenomenon.
Pathophysiology of Lumbar Spondylosis
The annular ligament is the concentric outer layer of the intervertebral disc. 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 and lead to degenerative changes in the vertebral body, and associated joints.
Degenerative Cascade cascade [Kirkaldy Willis and Bernard]
The cascade is in three phases which may overlap and span years to complete.
Dysfunction Phase
This phase highlights the initial effects of repetitive microtrauma. Important features are
- Circumferential painful tears of the outer annulus
- Tears may coalesce to become radial tears
- End-plate separation
- May compromise nutrition and waste removal
- Decreased disc hydration
- Desiccation and reduced disk height.
New vessels and nerves grow in tears and may increase disc’s capacity for transmission of pain signals.
Instability Phase
It is marked by
- Loss of mechanical integrity
- Progressive disc changes
- Resorption
- Internal disruption
- Additional annular tears
- Degeneration of fate joint
- It may lead to subluxation and instability of the joint
Stabilization Phase
This is the final phase and is characterized by
- Continued disc space narrowing and fibrosis
- Formation of osteophytes
- Transdiscal bridging
Risk Factors for Lumbar Spondylosis
- Age
- Obesity
- Occupations that load the spine
- [athlete, manual labor]
- Hereditary factors determine the progression pace and extent.
Recent studies have suggested obesity to be a variable factor and occupation as not a factor.
Symptoms and Signs 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 is 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 of pain in the back or radiculopathy.
The source of pain could be
- Facet joints
- Intervertebral disks
- Sacroiliac joints
- Nerve root
- Dura
- Myofascial structures within the spine
The cause of radiculopathy could be impingement of nerves due to
- Bulging disc
- Posterior osteophyte
- Structural hypertrophy leading to narrowing of the foramen stenosis.
Another important symptom that a patient may present with is neurogenic claudication where impairment of walking occurs due to impingement of nerves due to spinal stenosis [narrowing of canal]
In mild spondylosis, it may be absolutely normal. In advanced spondylosis, some patients may have dynamic scoliosis. The lumbar lordosis may be diminished and the lumbar spine’s decreased range of motion.
In case some specific entity is present such as disc herniation or spinal stenosis, the findings would depend on the entity.
Lab Investigations
Lumbar spondylosis does not require any work-up. In some cases, infections may be suspected. These cases may require the performance of blood tests.
Read more about spinal infections in pyogenic infections of the spine.
Imaging
Mostly lumbar spondylosis is an incidental finding. Asymptomatic cases do not require any imaging.
X-rays, CT scans, and MRIs are used only in the event of an issue like prolonged back pain or radiculopathy.
X-rays
X-rays show degenerative changes like
- Osteophytes
- Thickening of facet joints
- Narrowing of the intervertebral disc spaces.
CT and MRI
These are able to show vertebral and neural anatomy more clearly than x-ray. MRI is the best modality to show soft tissue details including discs, ligaments, and nerves. It is able to reveal a nerve compression.
Treatment
It must be reiterated that spondylosis is not symptomatic and is always not responsible for the symptoms.
The back pain or radicular pain needs treatment, not lumbar spondylosis.
And the treatment would depend on the cause of the pain.
For example treatment approach for herniated discs would be different than spinal stenosis, though both are covered within the scope of lumbar spondylosis.
Therefore, the treatment is required for back pain and radicular pain rather than lumbar spondylosis.
It is very important to make the patient understand that the lumbar spondylosis or degenerative changes do not change on imaging even after the patient has been cured of symptoms and should not be a concern.
The work-up and treatment of back pain is discussed in detail here.
The treatment of back pain and/or radiculopathy is mostly supportive and involves
- Drugs for control of pain
- Analgesics or painkillers
- Muscle relaxants
- Rest and modified activity
- Posture control
- Exercise
Rarely, surgery may be needed in selected patients.
References
- Schneck CD. The anatomy of lumbar spondylosis. Clin Orthop Relat Res. 1985;193:20–36.
- Gibson JNA, Waddell G. Surgery for degenerative lumbar spondylosis. Spine. 2005;20:2312–20 [Link]
