Back pain is second only to upper respiratory tract infection as the cause of visits to the doctor. Sixty to 80% of people will suffer from low back pain in their lifetime. More than half of patients who seek treatment for low back pain will recover in one week and 90% will we recover within 1 to 3 months.
Healthcare costs regarding this diagnosis is $100 billion annually. Risk factors of developing low back pain and disk problems include smoking, obesity, vibration (truck drivers, machine operators,etc.) and job dissatisfaction.
The lumbar intravertebral disc is made up of two components. The outer layer is called the annulus fibrosis. It is made up of type one collagen fibers that are cross hatched in orientation like the fibers in the radial tire and provide strength in tension. The second component is called the nucleus pulposus. This is contained within the annulus fibrosis fibers as its central core. This is made up of type two collagen and is 90% water. It gives strength in compression and has a more gelatinous consistency or "jelly like". It is the nucleus pulposus that bulges, protrudes or herniates through defects or tears in the outer annulus that can cause issues.
With aging, there is a decrease in water content of the disc and this decreases its material properties which leads to degeneration; this can be a normal part of the human condition and aging process. It is this process that can lead to a disk that bulges, protrudes or herniates.
A bulge is when the nucleus pulposus pushes on the outer annulus fibrosis as it shows signs of wear and tear but the annulus remains intact. The annulus may have degenerative " tears" but as long as it is intact it is considered quite a normal finding as we go through life. A protrusion is when the nucleus pulposus protrudes into the annulus but remains contiguous with the disk space. Again this can be a normal finding as we go through life. In fact, scientific studies have shown that disk "bulges", "Protrusions", and "annular tears" can be found on MRI scans in the majority of completely asymptomatic individuals. Asymptomatic people between the ages of 40 and 50 have "bulges", "protrusions", or annular tears on MRI scans 55% of the time. MRI scans have these findings 60% of the time in the age group between 50 and 60 years old. And, over the age of 60, there is an 80% rate of these findings on MRI scans in individuals who are completely asymptomatic.
The bottom line is that MRI reports are only descriptions of an image using adjectives that may seem daunting but can be a normal finding in the human condition. It should be a spine specialist/surgeon who puts these findings in context and explains what they mean.
A herniation is when the nucleus pulposus passes through the annulus and is no longer continuous with the disc space and compresses the spinal cord or nerves. This condition presents as back pain and more importantly as leg pain that worsens with sitting, coughing, sneezing and can improve with standing or lying down. The leg symptoms can present as pain, weakness or numbness. The initial treatment consists of activity restrictions, anti-inflammatory medications, and physical therapy. Ninety per cent of the time, these symptoms in this condition will improve without surgery. In fact, only 5 to 10% of patients with lumbar disc herniations on MRI become symptomatic. The majority of these will be resolved by the body over time. The L5-S1 level is most commonly involved. MRI is only necessary when symptoms persist for greater than 4 to 6 weeks of conservative care utilizing activity restrictions, anti-inflammatory medications, and physical therapy, or when there is a progressive neurologic deficit. If this symptomatology persists, more invasive measures become an option. These include the potential of an epidural steroid injection or surgery. These decisions should be guided by your spine surgeon.
David Cicerchia, MD