It has been estimated that around 60 – 85 % of adults experience back pain at some point in their lives. Although for many people the symptoms resolve, for around 15 – 45% of people, the back pain becomes chronic lasting for more than 3 months. (Middleton & Fish, 2009) Lumbosacral spondylosis is a common cause contributing to this disabling low back pain. So what exactly is lumbosacral spondylosis?
What is lumbo sacral spine?
Our spine is composed of 33 vertebrae which are divided into regions; cervical, thoracic, lumbar, sacrum and coccyx. The vertebrae of the sacrum and coccyx are fused leaving only 24 movable bones.
Lumbar spine has 5 individual vertebrae and they are numbered from L1 to L5. These vertebrae are much larger in size than the rest because they have to bear the weight of the body and absorb shock. The sacrum connects the spine to the hip bone and assist in forming the pelvic girdle. There are inter vertebral discs between two vertebral bodies which are consisting of outer annulus fibrosus and an inner nucleus pulposus.
What is spondylosis?
Spondylosis of the lumbar spine can be applied to many changes seen in the vertebral bodies, inter vertebral discs and associated joints due to degenerative changes. However most commonly it is applied to bony outgrowths seen on the anterior and lateral margins of the vertebral bodies. (“Lumbar Spondylosis: Background, History of the Procedure, Problem”, 2017)
Disc degeneration is a process of normal aging in the inter vertebral discs. There are three phases in this disease. In the first phase, due to repetitive micro trauma due to general wear and tear, the outer part of the inter vertebral disc undergo circumferential tears. These are painful because the outer part has a good nerve supply.
These tears can become radial tears and reduce the capacity of the disc to retain water. Water is important to maintain the sponginess and bear weight. In the second phase, these changes are exaggerated and the joints also become involved. The degeneration of the facet joints causes instability and subluxation of the spine.
During the third stage, the integrity of the inter vertebral disc is lost leading to disc space narrowing and fibrosis. These changes alter the weight bearing of the vertebral bone. The bone reacts to degenerative changes and start overgrowing leading to bony sprout formation. These bony outgrowths are termed osteophytes. (Middleton & Fish, 2009)
What is myelopathy?
Usually these ostophytes are seen on the anterior and lateral sides of the vertebral body. The spinal canal containing the spinal cord runs posteriorly (back). If these osteophytes project into the spinal cord, there can be dysfunction seen due to that lesion. This is called myelopathy.
This can result in weakness of limbs and even loss of bladder and bowel control. However it is not seen commonly and this article therefore concentrates on lumbo sacral spondylosis without features of myelopathy. (Michael B. Furman et al., 2017)
How do you get pain in lumbo sacral spondylosis?
Lumbo sacral spondylosis usually doesn’t produce any symptoms. The symptoms are produced when there are complications due to lumbo sacral spondylosis. There can be narrowing within the spinal canal called spinal stenosis, hypertrophy of the inferior articular process, spondylolisthesis, bulging of the ligamentum flavum and disc herniation.
All these can result in a pain syndrome called neurogenic claudication. In this entity, there is lower back pain to a varying degree, leg pain and weakness and numbness of the lower limbs.
The pain increases with prolonged standing and walking and relieved with bending forward and sitting.
The pain is produced mainly due to two mechanisms. The bulging discs and osteophytes can directly impinge on nerves and compress them. When these changes are seen at the facet joints, the holes (foramina) from which the spinal nerve roots exist, can get narrowed. This can also result in nerve root compression.
The other mechanism is pain due to local inflammation. The degenerative changes can release various chemical mediators which can cause inflammation at the site. This can stimulate the pain receptors in the surrounding area. This results in tenderness and muscle spasms. (“Spondylosis”, 2017)
If there is pinching of a nerve that is supplying the lower limb, there can be pain and tingling shooting down that limb in addition to back pain. This is called radiculopathy. When the sciatic nerve is involved, it is called sciatica. There is constant pain on one side of the buttock or leg that radiates down the leg into the foot and toes.
What are the risk factors for developing lumbo sacral spondylosis?
This condition can not only affect elderly, it also affects young otherwise healthy people too. This suggests that there are other factors contributing to the disease other than the age. Researchers have found associations between genes, exercise, physical activity, occupation and nutrition. (Middleton & Fish, 2009)
Although lumbo sacral spondylosis is a common finding seen on X rays, unless it causes symptoms, there is no need for treatment. Currently there are many studies underway to prevent the disease and reduce the burden of low back pain seen in the population.
- Middleton, K., & Fish, D. E. (2009). Lumbar spondylosis: clinical presentation and treatment approaches. Current Reviews in Musculoskeletal Medicine, 2(2), 94–104. http://doi.org/10.1007/s12178-009-9051-x
- Lumbar Spondylosis: Background, History of the Procedure, Problem. (2017). Emedicine.medscape.com. Retrieved 16 October 2017, from https://emedicine.medscape.com/article/249036-overview#a9
- Michael B. Furman, D., Jennifer Yang, D., Faisel Zaman, M., Randy Shelerud, M., David S. Cheng, M., & Jeffrey E. Oken, D. et al. (2017). Lumbar spondylosis without myelopathy – PM&R KnowledgeNow. Now.aapmr.org. Retrieved 16 October 2017, from https://now.aapmr.org/lumbar-spondylosis-without-myelopathy/
- Spondylosis. (2017). Emedicinehealth.com. Retrieved 16 October 2017, from https://www.emedicinehealth.com/spondylosis/page3_em.htm