X-ray image of lumbar spine region

6th Lumbar Vertebrae – A Rare Spinal Abnormality

About 10% of people have a 6th lumbar vertebrae, which in most cases goes unnoticed. This is a developmental anomaly and typically has very little effect on an individual’s health. It’s usually discovered when other health issues with the spine such as a lower back pain are being investigated.

Spinal Anatomy

The spine is split into different segments: the cervical, thoracic and lumbar regions as you head from the neck down to the pelvic area.

Anatomy of the Spine
Anatomy of the human Spine

Most humans have the same number of vertebrae. In some cases, however, abnormalities do occur. The 6th lumbar vertebrae is one such abnormality.

The human body is often subject to a range of different abnormalities that are the product of chance or genetic predisposition and occur naturally. In most cases, including the 6th vertebrae, these are relatively harmless and have no impact on the individual’s overall health.

6th Lumbar Vertebrae

Whilst there are normally five lumbar vertebrae in the human spine, it’s estimated that around 10% of adults have a 6th lumbar vertebrae. This is often called a transitional vertebrae and shouldn’t cause any particular issues in a healthy person. It can, in rare circumstances, have some complications if the individual sustains an injury in this region of the spine.

This 6th vertebrae is the lowest in the lumbar region and is found next to the tailbone, the fused area of the spine at the base or the midriff. It’s not something that suddenly appears or grows, but is there from birth.

Does an Extra Vertebrae Affect Overall Spinal Health?

The general consensus is that an extra vertebrae does not affect either spinal health or the overall health of the individual. In some very rare cases, the L6 vertebrae can become fused with another vertebral bone at the top of the sacral region and this may cause back pain.

If someone has an existing back problem, the discovery of an additional vertebrae may provide answers regarding the cause of the pain.

In some cases, the individual may experience reduced mobility because of the extra vertebrae. If the transitional vertebrae is fused in some way to the more rigid sacral bone, it could cause highly localised back pain. This is usually solved by injecting steroid medication.

For individuals who have sustained a spinal cord injury in the lumbar region, there may be some complicating issues that arise if they have a 6th lumbar vertebrae.

In cases where spinal surgery is necessary, for whatever reason, it’s important to identify whether or not the individual has an extra lumbar vertebrae to ensure that no avoidable complications arise during the operation.

Is Treatment Required for an Extra Bone in the Spine?

In almost all cases, no treatment is required if you have an extra lumbar vertebrae in the spine. Nor does a 6th vertebrae increase the odds of someone suffering from a spinal cord injury. In fact, most people will not even notice that they have this particular anomaly.

When Spinal Abnormalities Could Potentially Cause Health Issues

Spinal curvature abnormalities
Spinal curvature abnormalities

Not all spinal abnormalities are so benign. A problem like curvature of the spine, for instance, often leads to chronic back pain and stiffness. Kyphosis is caused by an anomaly in the thoracic or midsection of the spine.

Whilst this can occur because of bad posture, it is also caused by abnormal development in the womb or following a spinal injury. Once the spine curves beyond 45 degrees, it might mean that issues such as back pain are more prevalent.

In children with more severe kyphosis, treatment typically involves the use of a brace to limit the curvature of the spine from progressing.

Other spinal anomalies include a tethered spinal cord where the growth of abnormal tissue prevents the proper movement of the spine.

Scoliosis occurs when abnormal bones push the spine sideways.

Lordosis, on the other hand, happens when the spine bends too far backwards.

Block vertebrae occurs when one or more bones are fused together and is a condition which can cause loss of mobility and certain neurological problems.

All of these, however, are rare conditions and are treated in a variety of ways. Congenital spinal cord abnormalities may cause a variety of symptoms including back pain, difficulty walking and sitting as well as, in some circumstances, difficulty breathing.