Degenerative disc disease (DDD) is part of the natural process of growing older. Unfortunately, as we age, our intervertebral discs lose their flexibility, elasticity, and shock absorbing characteristics. The outer part of the disc, called the annulus fibrosis, becomes brittle and is more easily torn. At the same time, the soft gel-like center of the disc, called the nucleus pulposus, starts to dry out and shrink. The combination of damage to the intervertebral discs, the development of bone spurs, and a gradual thickening of the ligaments that support the spine can all contribute to degenerative arthritis of the lumbar spine.

Degenerative disc disease is as certain as death and taxes, and to a certain degree this process happens to everyone. However, not everyone who has degenerative changes in their lumbar spine has pain. Many people who have "normal" backs have MRIs that show disc herniations, degenerative changes, and narrowed spinal canals. Every patient is different, and it is important to realize that not everyone develops symptoms as a result of degenerative disc disease.

When degenerative disc disease becomes painful or symptomatic, it can cause several different symptoms, including back pain, leg pain, and weakness that are due to compression of the nerve roots. As the discs between the bones and spine start to wear out, the entire lumbar spine becomes less flexible. As a result, people complain of back pain and stiffness, especially towards the end of the day.

Symptoms
The most common symptom of degenerative disc disease is back pain. When DDD causes compression of the nerve roots, the pain often radiates down the legs or into the feet, and may be associated with numbness and tingling. In severe cases of lumbar DDD, where there is evidence of nerve root compression, individuals may experience symptoms of sciatica and back pain, and sometimes even lower extremity weakness.

Diagnosis
The diagnosis of degenerative disc disease begins with a complete physical examination of the body, with special attention paid to the back and lower extremities. Your doctor will examine your back for flexibility, range of motion, and the presence of certain signs that suggest that your nerve roots are being affected by degenerative changes in your back. This often involves testing the strength of your muscles and your reflexes to make sure that they are still working normally. You will often be asked to fill out a diagram that asks you where your symptoms of pain, numbness, tingling and weakness are occurring.

A routine set of x-rays is also usually ordered when a patient with back pain goes to see a doctor. If degenerative disc disease is present, the x-rays will often show a narrowing of the spaces between the vertebral bodies, which indicates that the disc has become very thin or has collapsed. Bone spurs begin to form around the edges of the vertebral bodies and also around the edges of the facet joints in the spine. These bone spurs can be seen on an x-ray, and are called osteophytes. As the disc collapses and bone spurs form, the space available for the nerve roots starts to shrink. The nerve roots exit the spinal canal through a bony tunnel called the neuroforamen, and it is at this location that the nerve roots are especially vulnerable to compression.

In many situations, doctors will order an MRI or a CT scan (CAT scan) in order to evaluate the degenerative changes in the lumbar spine more completely. A MRI scan is very useful for determining where disc herniations have occurred and where the nerve roots are being compressed. A CT scan is often used to evaluate the bony anatomy in the spine, which can show how much space is available for the nerve roots and within the neuroforamen and spinal canal.

The continuing dilemma in spine care is that single or multi-level rigid or even motion preserving spine fixation typically creates adjacent stress-related pathology of adjacent spinal segments. These problems  are not infrequent and create more patient disability than the problem for which the fusion or spine surgery was initially performed to address. Long-term follow-up studies of anterior discectomy and fusion patients show an appearance of new degenerative disease at levels adjacent to initial surgery segments.  In up to 25% of patients degenerative disease may develop at adjacent segments within 10 years of initial surgery and 7 to 15% of these patients have been reported to require reoperation.

The ideal candidates for degenerative disc treatment would be early to mid-stage low-back or neck pain patients, single or multiple affected levels, less than 65 years old. In addition, most spine surgery recipients (over 1 million worldwide) would benefit from a treatment of surgically altered (as in a microdiscectomy procedure) or adjacent discs as a secondary procedure. ILS believes that within 5 years of market launch we can capture 425% of the fusion market (25% of the current fusion market with 400% expansion into nonsurgical market, that amounts to less than 20% of back pain sufferers), plus 15% of the general spinal surgery market with an adjunct procedure. ILS expects this nonsurgical approach to revolutionize spine care, while also dramatically reducing the societal cost of DDD (estimated to be in excess of $100 billion in the US alone). Please sign in for more market information.