Fig 1: Degenerative Disc Disease
(larger view)

Fig 2: X-ray of Degenerative Disc Disease
(larger view)

Lumbar Degenerative Disc Disease

By: Peter F. Ullrich, Jr., MD
November 6, 2006

Disc degeneration

Degenerative disc disease refers to a syndrome in which a compromised disc causes low back pain. Lumbar degenerative disc disease usually starts with a torsional (twisting) injury to the lower back, such as when a person rotates to put something on a shelf or swing a golf club. However, the pain is also frequently caused by simple wear and tear on the spine.

Despite its rather dramatic label, degenerative disc disease is fairly common, and it is estimated that at least 30% of people aged 30-50 years old will have some degree of disc space degeneration, although not all will have pain or ever receive a formal diagnosis. In fact, after a patient reaches 60, some level of disc degeneration is deemed to be a normal finding, not the exception.

Lumbar degenerative disc disease pain and symptoms

Most patients with lumbar degenerative disc disease will experience low-grade continuous but tolerable pain that will occasionally flare (intensify) for a few days or more. Pain symptoms can vary, but generally are:

• Centered on the lower back, although it can radiate to the hips and legs

• Frequently worse when sitting, when the discs experience a heavier load than when patients are standing, walking or even laying down

• Exacerbated by certain movements, particularly bending, twisting or lifting

The low back pain associated with lumbar degenerative disc disease is usually generated from one or both of two sources:

• Inflammation, as the proteins in the disc space irritate the surrounding nerves, and/or

• Abnormal micro-motion instability, when the outer rings of the disc - the annulus fibrous – are worn down and cannot absorb stress on the spine effectively, resulting in movement along the vertebral segment

Excessive micro-motion, combined with the inflammatory proteins, can produce ongoing low back pain (See Figure 1).

Fortunately, over time the pain from lumbar degenerative disc disease usually decreases, rather than becoming progressively worse. This is because a fully degenerated disc no longer has any inflammatory proteins (that can cause pain) and usually collapses into a stable position (see Figure 2), eliminating the micro-motion that generates the pain.

Lumbar degenerative disc disease diagnosis

Following a review of the patient’s history and a physical examination, a formal diagnosis of lumbar degenerative disc disease can be confirmed with magnetic resonance imaging (MRI). MRI findings that are closely linked to a painful disc include disc space collapse of greater than 50% and cartilaginous endplate erosion. More controversial are MRI findings of early disc space degeneration such as disc desiccation (disc are blacker on a scan because they do not have as much water as a healthy disc), a disc bulge, or an annular tear (tear into the outer annulus of the disc space on a scan that shows up as a bright white spot).

These subtle findings are for the most part just as likely to show up on a scan of someone who has not had pain as one who has had chronic low back pain. Also, these subtler findings are more consistent with natural aging of the back than of a pathological pain producing disc space. Disc degeneration is actually quite common among people who have no pain or other symptoms, so the patient’s history and physical examination are an essential part of the diagnosis.

Lumbar degenerative disc disease treatment

For most people, degenerative disc disease can be successfully treated with conservative (meaning non-surgical) care consisting of medication to control inflammation and pain (either oral or injection), and physical therapy and exercise. Surgery is only considered when patients have not achieved relief over six months of conservative care and/or are significantly constrained in performing everyday activities.

1. Non-surgical treatment for degenerative disc disease
   The ongoing pain, as well as the frequency and intensity of the flares, can be mitigated through a number of non-surgical options. Modifying activities to preclude lifting of heavy objects and playing sports that require rotating the back (e.g. golf, basketball or football) can be a good first step. Other options include:

   • Applying heat to stiff muscles or joints to increase flexibility and range of motion, or using ice packs to cool down sore muscles or numb the area where painful flares are concentrated.

   • Medications such as non-steroidal anti-inflammatories (e.g., ibuprofen, naproxen, COX-2 inhibitors) and pain relievers like acetaminophen (such as Tylenol) help many patients feel good enough to engage in regular activities. Stronger prescription medications such as oral steroids, muscle relaxants or narcotic pain medications may also be used to manage intense pain episodes on a short-term basis, and some patients may benefit from an epidural steroid injection. Not all medications are right for all patients, and patients will need to discuss side effects and possible factors that would preclude taking them with their physician.

   • An exercise program is essential to relieving the pain of lumbar degenerative disc disease and should have several components, including:

   • • Hamstring stretching, since tightness in these muscles can increase the stress on the back and the pain caused by a degenerative disc

     • A strengthening exercise program, such as Dynamic Lumbar Stabilization exercises, where patients are taught to find their ‘natural spine’, the position in which they feel most comfortable, and to maintain that position

     • Low-impact aerobic conditioning (such as walking, swimming, biking) to ensure adequate flow of nutrients and blood to spine structures, and relieve pressure on the discs

   • Chiropractic manipulation can relieve low back pain by taking pressure off sensitive nerves or tissue, increasing range of motion, restoring blood flow, reducing muscle tension, and, like more active exercise, promoting the release of endorphins within the body to act as natural painkillers

   • Epidural steroid injections can provide low back pain relief by delivering medication directly to the painful area to decrease inflammation

2. Surgery for degenerative disc disease
   Patients unable to function because of the pain, or who are frustrated with their activity limitations, may consider lumbar spinal fusion surgery. Fusion surgery works because it stops the motion at a painful motion segment. A one-level fusion at the L5-S1 segment does not significantly change the mechanics in the back and is the most common form of fusion, as this is the most likely level to break down for degenerative disc disease. Fusion of the L4-L5 level does remove some of the normal motion of the spine as this is a major motion segment (as opposed to L5-S1 which has really limited motion) Multi-level fusions are more problematic. A two-level fusion may be considered for patients with severe, disabling pain, but three-level fusions are not recommended because back movement is too diminished and altering the muscle composition can in and of itself cause pain (this has been termed fusion disease).
   
   While it is a major surgery, fusion surgery can be an effective option for patients to enhance their activity level and overall quality of life. This is particularly true now that minimally invasive techniques are available to decrease post-operative discomfort, preserve more of the normal anatomy of the low back, and result in higher rates of fusion than previous techniques.
   
   A newer surgery to treat pain and disability from lumbar degenerative disc disease is artificial disc replacement. The theory is that replacing the disc, instead of fusing the disc space together, maintains more of the normal motion in the lumbar spine, thereby reducing the chance that adjacent levels of the spine will break down due to increased stress. This procedure is still a new procedure in the US, so long-term efficacy, and potential risks and complications are still relatively unknown.

Peter F. Ullrich, Jr., MD
November 6, 2006