What is the Difference Between Disc Protrusion and Disc Extrusion?

Back pain strikes millions of people and can come from a number of different causes. A disc problem, such as disc protrusion, is one of the most common causes of back pain. Also called a slipped or herniated disc, this occurs when the disc bulges against the fibrous cushion, called the annulus.

The spine consists of the vertebral bones. Each pair of vertebral bones contains a vertebral disc. These discs act like cushions or shock absorbers. The disc consists of a fibrous outer ring, called the annulus, which encases a gel-like middle, or nucleus. Over a lifetime, these discs can be damaged from injuries and accidents or from poor body mechanics and decreased overall fitness. When damage occurs, the outer layer can tear. These tears can cause the disc to bulge or leak out.

Disc protrusion is the most common cause of back pain. The disc may push against the damaged fibers of the outer ring, but it stays within its confines. The protruding disc can press upon the surrounding nerves and cause pain not only in the back but into the buttocks area and sometimes even down the back of the leg.

Disc extrusion, on the other hand, is when the nucleus squeezes out of the annulus enclosure. It then breaks away from the fibrous enclosure and pushes out beyond the disc and the supporting ligaments. In other words, disc extrusion is when the nucleus leaks out.

Both disc protrusions and disc extrusions can occur with or without pain. If the gelatinous material does not press on any soft tissue or nerves, there may be no indication there is a problem. But if pain does occur, it is typically one-sided.

The pain from a protrusion can sometimes disguise itself. It can range from the buttocks to the thighs to the feet. Numbness, tingling or generalized weakness can also occur. Paresthesia is another common side effect of disc problems. This is when a tingling, pricking or numb sensation is present because the abnormal disc is pressing on a nerve. The most common nerve pain associated with these conditions is sciatica. Pressure from the damaged disc on the sciatic nerve can often cause an ache or sharp, shooting pain into the buttocks and down the back of the leg. In severe cases, the sufferer can experience symptoms in other areas, such as lack of bladder control or the inability to raise the foot.

Proper diagnosis to determine whether the pain is from disc protrusion or disc extrusion comes from studies such as x-rays, CT scans and MRI, or magnetic resonance imaging. If pain persists, the use of EMG’s, electromyography, also called nerve conduction studies may be able to pinpoint the exact nerve being irritated. Bone scans can reveal any abnormal bone activity.

Conservative treatment options for both conditions involve rest, anti-inflammatory medications, ice and/or heat, and physical therapy. If pain persists, epidural or nerve block injections may be useful in treating and diagnosing the cause of pain. Alternative methods such as massage therapy, acupuncture, and chiropractics may also valuable tools to gain relief.

The most important factor to stop pain from protruded or extruded discs is in the diagnosis. Just because an individual has back pain does not mean there is a problem with the disc. Conversely, just because there is a problem with the disc does not mean there will be back pain.