Low back pain (LBP) is a widespread health issue often leading to significant disability. For many years, many chronic LBP cases were labeled as “non-specific” because a clear anatomical source could not be identified. Vertebrogenic low back pain (VLBP) is a distinct, diagnosable subtype of chronic pain that originates from the bony structures of the spine. This condition is estimated to account for up to one in six cases of chronic LBP, offering a specific target for diagnosis and treatment.
The Structures That Cause Vertebrogenic Pain
The pain signal in VLBP originates from the vertebral endplates, which are layers of cartilage and bone separating the intervertebral discs from the vertebral body. These endplates are vulnerable to the daily stress and compressive forces transmitted through the spine. Over time, repeated mechanical loading and degeneration can cause microfractures and structural damage.
Damage to the endplates leads to an inflammatory response and microinstability at the interface between the disc and the bone. This area is richly supplied by the sensory basivertebral nerve (BVN). The BVN runs through the center of the vertebral body and branches out to innervate the endplates.
When the endplates are damaged and inflamed, the sensory nerve endings of the BVN become chemically and mechanically irritated. This irritation causes the nerve to continuously transmit pain signals from the bone marrow to the central nervous system. VLBP is therefore pain derived directly from the vertebral body due to endplate compromise and BVN sensitization.
Specific Characteristics of the Pain
Patients with VLBP typically experience axial pain, meaning it is localized centrally in the lower back. The pain is characterized as a deep, aching, or sometimes burning sensation within the spine. This chronic pain is often intensified by activities that increase pressure across the vertebral bodies.
The symptoms are exacerbated by axial loading, such as prolonged sitting, standing, bending forward, or lifting heavy objects. Activities that compress the affected vertebrae tend to worsen discomfort. Relief is often found when the spine is unloaded, such as when lying down flat.
VLBP must be distinguished from radicular pain, such as sciatica, which involves pain traveling down the leg due to nerve root compression. VLBP remains centered in the low back, differentiating it from conditions originating from the spinal discs or facet joints.
Identifying the Source Through Diagnosis
The definitive diagnostic tool for identifying VLBP is Magnetic Resonance Imaging (MRI). MRI provides detailed images of the bone marrow and endplates, revealing specific changes that serve as the radiographic hallmark of the condition. These alterations are known as Modic changes, named after the radiologist who first classified them.
Modic changes are classified into three types, each representing a different stage of the degenerative and inflammatory process. Modic Type 1 changes are most strongly associated with active, painful VLBP, as they represent bone marrow edema and inflammation. This edema suggests an active process of microfracture and repair.
Modic Type 2 changes indicate that inflamed bone marrow has been replaced by fatty tissue, suggesting a more chronic state. Modic Type 3 changes involve subchondral bone sclerosis, which is a hardening of the bone tissue. While Types 2 and 3 show long-term damage, Type 1 changes are the most reliable indicator that endplate damage is the current source of pain. Physicians may also use a diagnostic basivertebral nerve block to confirm the precise pain source if imaging results are inconclusive.
Targeted Treatment Options
Since VLBP is caused by a specific anatomical source, targeted treatments are required when conservative measures fail to provide lasting relief. General approaches like physical therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), and steroid injections typically manage symptoms but do not address the underlying nerve-mediated pain source.
The most specialized treatment available is Basivertebral Nerve Ablation (BVA), a minimally invasive procedure designed to stop the pain signal at its origin. BVA involves inserting a small probe directly into the vertebral body, guided by fluoroscopic imaging. Radiofrequency energy is delivered through the probe to heat and disable the BVN.
This ablation effectively interrupts the transmission of pain signals from the damaged endplate to the brain. Because the treatment targets the specific nerve carrying the pain signal, it can offer long-term relief for patients who have not responded to six months or more of conventional care. The procedure is designed to be an implant-free, outpatient intervention.