Lumbar spondylosis (spondylosis deformans, lumbar osteoarthritis), as shown in the image below, describes bony overgrowths (osteophytes), predominantly those at the anterior, lateral, and, less commonly, posterior aspects of the superior and inferior margins of vertebral centra (bodies).[1, 2, 3, 4] Lumbar spondylosis occurs as a result of new bone formation in areas where the anular ligament is stressed. The margins of vertebral bodies are normally smooth. Growth of new bone projecting horizontally at these margins identifies osteophytes. Most osteophytes are anterior or lateral in projection. Posterior vertebral osteophytes are less common and only rarely impinge upon the spinal cord or nerve roots.[5] This dynamic process increases with, and is perhaps an inevitable concomitant, of age. Lumbar osteophytes have long been thought to cause back pain because of their frequency and size. This has led to many studies of the distribution of vertebral osteophytes, not all of which are pertinent. The frequency of signs or symptoms among individuals with osteophytes is no greater than among those individuals without osteophytes.[1]
View Image | Anteroposterior view of lumbar spine. Vertical overgrowths from margins of vertebral bodies represent osteophytes. |
Lumbar spondylosis is usually asymptomatic, with no diagnostic or prognostic significance. When back or sciatic pains are symptoms, lumbar spondylosis is usually an unrelated finding.
Lumbar spondylosis appears to be a nonspecific aging phenomenon. Most studies suggest no relationship to lifestyle, height, weight, body mass, physical activity, cigarette and alcohol consumption, or reproductive history. Adiposity is seen as a risk factor in British populations, but not Japanese populations. The effects of heavy physical activity are controversial, as is a purported relationship to disk degeneration.[6]
Radiographs, CT scans, and MRIs are used only in the event of complications. Bone density scan (eg, dual-energy x-ray absorptiometry scan [DEXA]) is used. Ensure that no osteophytes are in the area used for density assessment for spinal studies. Osteophytes produce the impression of increased bone mass, thus invalidating bone density tests if in the field of interest and masking osteoporosis.[5]
Because back pain is an unrelated finding of lumbar spondylosis, seek the real cause of the patient's back or sciatica-type symptoms.[4] Do not assume that the patient's symptoms are related to osteophytosis. Look for an actual cause of a patient's symptoms. If actual symptomatic nerve root impingement occurs, 2 days of absolute bed rest is indicated. If that does not solve the problem, then surgical excision is indicated. Medication is not indicated in the absence of complications.
Surgery is indicated only for complications (eg, for impingement-documented sciatica that is unresponsive to 2 days of absolute bed rest) of lumbar spondylosis. Surgery is not indicated if no complications (eg, impingement) of lumbar spondylosis are present.
Nerve compression from posterior osteophytes is a possible complication only if a neuroforamen is reduced to less than 30% of normal. If lumbar spondylosis projects into the spinal canal, spinal stenosis is a possible complication. If osteophytes disappear, look for aortic aneurysm. Aortic aneurysms can cause pressure erosions of the adjacent vertebrae.[7] If osteophytes are present, the first sign is often erosion of those osteophytes, so they are no longer visible. An isolated report of a bony L4 mass pressing on the duodenum has been described.
For further reading, please see the Medscape article Lumbar Spondylosis and Spondylolysis.
Spondylolysis occurs in 6-10% of the general population and has been found to be as high as 25-60% in athletes. It is especially common in young athletes younger than 18 years who participate in sports that involve twisting or backward bending motions of the spine. This injury also runs in some families, suggesting that there may be a hereditary component.[8]
Lumbar spondylosis is present in 27-37% of the asymptomatic population. In the United States, more than 80% of individuals older than 40 years have lumbar spondylosis, increasing from 3% of individuals aged 20-29 years. Lumbar osteophytes have been found to be present in about 20% of men and 22% of women aged 45-64 years and in 30% of men and 28% of women aged 55-64 years. Sex ratio reports have been variable but are essentially equal. Spinal osteophytosis in postmenopausal Japanese women correlated with the CC genotype of the transforming growth factor β1 gene.[9, 10]
The prevalence of radiographic spondylosis increases with age. It is present only in a small percentage of the population in the first few decades of life, but is common by the age of 65 years . In those with low back pain, prevalence ranges from 7 to 75%, depending on the diagnostic criteria. Despite its frequency in patients with low back pain, there is no validated correlation between radiographic presence of lumbar spondylosis and the presence of low back pain. Age is the greatest risk factor, but other possibilities include disc desiccation, previous injury, joint overload from malalignment and/or abnormal z-joint orientation, and genetic predisposition. Studies evaluating the role of body mass index (BMI), level of activity, and gender on incidence and severity of lumbar spondylosis do not show a clear correlation.[11]
Lumbar spondylosis usually produces no symptoms. When back or sciatic pains are symptoms, lumbar spondylosis is usually an unrelated finding. Lumbar spondylosis is usually not found unless a complication ensues.
Other problems to consider include the following: