Lower Back Pain: Is it Bertolotti’s Syndrome?

The National Institutes of Health estimate that upward of 80 percent of adults experience low back pain at some point in their lifetimes.[1] Sometimes, this pain is the result of disc degeneration, strain from overuse or poor lifting, or perhaps a fall or injury.

In other cases, however, the pain may be the result of a congenital skeletal abnormality. Most people have five lumbar vertebrae. They are mobile and not attached to the sacrum. In 1917, Dr. Mario Bertolotti determined that in some patients, the transverse process on the last lumbar vertebra (L5) is elongated. The transverse process is the small bony projection on the right and left side of each vertebra. Because this bony projection is larger than usual, it can “fuse” with the sacrum. The sacrum is the triangular bone in the lower back. When the L5 is connected to the sacrum, it is not mobile. This puts more stress on lumbar vertebrae above it (L3-4 and L4-5).

Some call Bertolloti’s Syndrome “a partially sacralized L5.” It falls into a broader category known as “transitional anatomy.” Anatomic variation in the spine is fairly common. Studies indicate that 10 to 25 percent of people have some type of variation in their backbone anatomy. There are different types of variations. These include additional vertebrae (six lumbar vertebrae as compared to five), or a sacrum that looks more like a lumbar vertebra. Many people are not aware that they have an anatomic variation because they do not have low back pain. In some patients, however, the change in anatomy can cause wear and tear in the structures of the lower back. This can result in pain.

Symptoms of Bertolotti’s Syndrome

Patients with Bertolotti’s Syndrome sometimes report lower back pain that radiates from the sides of the waistline. The pain may be mistaken for sacroiliac joint pain or lumbar disc or lumbar facet joint pain. This is why the condition is often misdiagnosed.

For reasons that are not entirely clear, many patients with Bertolotti’s Syndrome begin to experience pain while in their 20s and 30s. In older patients, arthritic changes or nerve irritation may trigger lower back pain from their atypical anatomy.

Reasons for Pain from Bertolotti’s Syndrome

There are several causes of pain as a result of Bertolotti’s Syndrome. Some patients may have a combination of causes. Some report that their pain alternates depending on activity. Pain can come from:

1. Spine joints, also known as facet joints. Because the L5 is attached to the sacrum and that segment is not mobile, there is more stress on the segments above, especially L4-5. Over time, these joints can become swollen, inflamed and arthritic.
2. Sacroiliac joint and adjacent ligaments. An imbalance in the structure of the lumbar vertebrae where it connects to the sacrum and iliac bone can create greater stress on the sacroiliac joint. The joint can become swollen, inflamed and arthritic.
3. The “pseudo-joint.” When the L5 transverse process (or the backbone) touches the sacrum, it creates a “pseudo-joint” if not fully fused. Unlike regular joints, this joint does not have cartilage to cushion the impact of the bones touching each other. There is no joint fluid to lubricate and absorb shock. The result is swelling and degeneration that leads to pain.
4. The disc and nerve. Greater impact at the L4-5 level above the pseudo-joint may lead to increased risk of disc degeneration and/or disc herniation. This disc and nerve root pain may cause pain in the back, as well as in either or both legs.
5. Neighboring muscles. Anatomical variation can result in unequal forces on nearby muscles. Often one side of the back has more muscle spasm, although both sides can be affected. Muscle tightness and spasm in the region of the lower back and pelvis can lead to feeling of stiffness and pain, especially with transition in movement.

Treatment for Bertolotti’s Syndrome

Bertolotti’s Syndrome affects less than 10 percent of the population. Many people with this skeletal abnormality will not experience pain or discomfort, but those who do are likely to suffer from chronic lower back pain that can be severe enough to significantly impact their daily living.

Bertolotti’s Syndrome is very treatable. A thorough physical exam will include efforts to recreate movement that triggers the pain. A simple x-ray of the lumbar spine, with special focus on the lower vertebrae and the sacral area, can quickly identify this abnormality.

Once a positive diagnosis has been reached, there are numerous conservative and minimally invasive interventions which can reduce, and in some cases, eliminate the pain.

Your doctor may recommend a regime of over-the-counter anti-inflammatories, rest or lifestyle modification to address the pain. He or she may perform a direct treatment to the area including injections of corticosteroid medications into the joints or along the nerves. Your treatment plan might also include physical therapy.

Other minimally invasive interventions include medial branch blocks or sacroiliac joint injections to block the pain signals. Neurotomy (radiofrequency ablation) may also be an option. This involves using thermal energy (heat) to deaden nerve endings around the pseudo-joint that are sending pain signals. Regenerative treatments such as prolotherapy and platelet rich plasma therapy may be excellent non-surgical options.

In very rare situations, surgery may be necessary to reduce the size of the transverse process in order to eliminate the pseudo-joint and the pain it causes.