What is Lumbar Pseudo-Joint Fusion?
Lumbar pseudo-joint fusion, also known as a Bertolotti joint/lumbosacral transitional vertebra (LSTV), refers to the formation of a pseudo-joint between the transverse process of the last lumbar vertebra (usually L5) and the sacrum or ilium. This joint is part of a congenital condition called a lumbosacral transitional vertebra, often associated with Bertolotti’s Syndrome.
Causes of Lumbar Pseudo-Joint Fusion
A congenital spinal anomaly causes lumbar pseudo-joint fusion called lumbosacral transitional vertebra or LSTV, where the last lumbar vertebra (usually L5) develops an enlarged transverse process that abnormally articulates or fuses with the sacrum or ilium. This forms a “pseudo-joint” - an abnormal joint that is not a true anatomical joint but behaves like one. When this joint becomes painful (Bertolotti’s Syndrome), it may be surgically fused to eliminate movement and relieve symptoms - this is referred to as lumbar pseudo-joint fusion.
Signs and Symptoms of Lumbar Pseudo-Joint Fusion
Signs and symptoms of lumbar pseudo-joint fusion include:
- Chronic low back pain (often one-sided, near the sacroiliac area)
- Pain worsens with activity or prolonged sitting/standing
- Limited lower back mobility
- Referred pain into the buttock or thigh (rarely below the knee)
- Muscle spasms in the lower back
- Pain relief after diagnostic injection into the pseudo-joint (helps confirm diagnosis)
These symptoms result from the abnormal movement or stress at the pseudo-joint formed by the transitional vertebra.
Diagnosis of Lumbar Pseudo-Joint Fusion
Diagnosis of lumbar pseudo-joint fusion involves:
- X-rays: Reveal the abnormal joint formation at L5-S1
- CT Scan: Provides detailed bone anatomy to assess partial fusion or articulation
- MRI: Evaluates nearby discs and nerves for degeneration or nerve impingement
- Diagnostic Injection: A local anesthetic is injected into the pseudo-joint - if pain relief occurs, it confirms the pseudo-joint as the pain source
This combination helps differentiate it from other causes of low back pain.
Treatment for Lumbar Pseudo-Joint Fusion
Treatment for lumbar pseudo-joint fusion, often associated with Bertolotti’s Syndrome, typically begins with conservative management. This includes physical therapy to strengthen the core and improve spinal alignment, nonsteroidal anti-inflammatory drugs (NSAIDs) or other pain relievers to manage pain and inflammation, and activity modification to reduce strain on the lower back. Image-guided steroid or anesthetic injections into the pseudo-joint may be used both for pain relief and to confirm the joint as the source of symptoms. If conservative treatments fail to provide lasting relief, surgical options may be considered. These include resection (removal) of the enlarged transverse process or pseudo-joint, or surgical fusion to stabilize the abnormal articulation between the lumbar spine and the sacrum or pelvis. The goal of treatment is to eliminate painful movement at the pseudo-joint and restore function.