Treatment for lumbosacral transitional vertebrae (LSTV) ranges from physical therapy and targeted injections to surgical resection or spinal fusion, and the right approach depends heavily on which anatomical structure is generating pain. LSTV, sometimes called Bertolotti’s syndrome when symptomatic, describes a congenital variation where the lowest lumbar vertebra partially or fully merges with the sacrum, or an extra segment separates from the sacrum. Roughly one in five to one in eight people has some form of this variation, yet many never know it because they never develop symptoms. For those who do, the challenge is not just treating the pain but confirming that the transitional vertebra is actually the source.
Why a Transitional Vertebra Causes Pain
The spine’s biomechanics rely on each segment sharing the load of movement. When the lowest lumbar vertebra forms an abnormal joint or bony bridge with the sacrum, motion at that level becomes restricted and often asymmetrical. The body compensates by transferring extra mechanical stress to the segment above, accelerating disc degeneration and facet joint wear at that level. Disc herniation, bone spurs, and other degenerative changes appear at the segment above the transitional vertebra at significantly higher rates than at the same level in people without LSTV.1PubMed Central. Lumbosacral Transitional Vertebra Contributed to Lumbar Spine Degeneration: An MR Study of Clinical Patients The abnormal connection itself can also become a pain generator: the pseudoarticulation (false joint) between the enlarged transverse process and the sacrum develops its own inflammation, much like an arthritic joint.2Arquivos de Neuro-Psiquiatria. Transitional lumbosacral vertebrae and low back pain: diagnostic pitfalls and management of Bertolotti’s syndrome
Pain can also show up as sciatica. The enlarged transverse process may compress or irritate a nearby nerve root, producing radiating leg symptoms that mimic a disc herniation. This overlap with more common causes of low back pain is one reason Bertolotti’s syndrome often goes undiagnosed or gets treated with interventions aimed at the wrong structure.
Confirming the Transitional Vertebra Is Actually the Problem
Finding an LSTV on an X-ray or MRI does not prove it is the source of someone’s pain. Many people with transitional vertebrae are completely asymptomatic. The critical step before committing to any treatment is confirming that the anomalous joint is the pain generator, not an incidental finding riding alongside a disc bulge or facet problem at another level.
Diagnostic injections under fluoroscopic guidance are the most widely used confirmation method. A small amount of local anesthetic is injected directly into the pseudoarticulation. If the pain disappears temporarily, the transitional vertebra is likely the culprit. One retrospective review found that about 87% of patients experienced immediate relief after a fluoroscopically guided pseudojoint injection, supporting its use as a diagnostic block.3PubMed Central. Retrospective review of outcomes in patients with Bertolotti’s syndrome who underwent fluoroscopically-guided pseudojoint injections Targeted injections can also help distinguish Bertolotti-related sciatica from sciatica caused by a herniated disc or foraminal stenosis, because the two respond to different injection targets.4World Neurosurgery. Redefining the Treatment of Lumbosacral Transitional Vertebrae for Bertolotti Syndrome: Long-Term Outcomes Utilizing the Jenkins Classification to Determine Treatment
SPECT/CT, a hybrid imaging technique that combines a bone scan with a CT scan, has gained traction as another way to pin down the pain source. It detects areas of increased bone metabolism, essentially highlighting where the skeleton is under abnormal stress. When the pseudoarticulation lights up on SPECT/CT, it correlates well with the patient’s pain complaints and can help guide surgical planning.5PubMed Central. Case Report: SPECT-CT-guided minimally invasive transverse process resection for Bertolotti syndrome This functional imaging approach is especially useful when standard MRI or X-ray findings are ambiguous or when multiple potential pain generators coexist.6PubMed Central. Evaluation and Identification of Lumbosacral Transitional Vertebra Causing Intractable Low Back Pain Utilizing Bone Single-Photon Emission Tomography with Computed Tomography
Conservative Treatment
For most people newly diagnosed with symptomatic LSTV, conservative management is the starting point. This typically means anti-inflammatory medications, activity modification, and physical therapy focused on core stability and lumbosacral mobility. The evidence base for conservative treatment of Bertolotti’s syndrome specifically is thin, consisting mostly of case reports rather than large trials, but the reported results are encouraging for milder cases.
In one case report, a patient who underwent six weeks of physiotherapy (including myofascial release of the thoracolumbar fascia and progressive spinal stabilization exercises) saw pain scores drop from 6 out of 10 to 1 out of 10, with disability scores falling to a level indicating essentially no functional limitation. By the end of treatment, the patient could sit for 80 minutes without pain, a significant gain from baseline.7PubMed Central. Use of Lumbosacral Myofascial Release and Therapeutic Exercises for a Patient with Bertolotti’s Syndrome: A Case Report Other case reports describe improvements from spinal manipulation and manual therapy, with patients noting substantial reductions in pain and improved mobility within two to four weeks, though the improvement was often incomplete.8PubMed Central. A Comprehensive Update of the Treatment and Management of Bertolotti’s Syndrome: A Best Practices Review
The honest limitation here is that these are single-patient reports. Nobody has run a controlled trial comparing, say, six weeks of targeted physical therapy against sham exercises for Bertolotti’s syndrome. But given the low risk, conservative management is a reasonable first line, especially for patients with moderate symptoms who have not yet undergone diagnostic confirmation of the pseudoarticulation as the pain source.
Steroid and Anesthetic Injections
When conservative care is not enough, injections into or around the pseudoarticulation serve a dual purpose: diagnostic confirmation and short-to-medium-term pain relief. Adding a corticosteroid to the local anesthetic aims to quiet the inflammation at the joint for weeks or months rather than just the hours an anesthetic provides on its own.
A randomized, placebo-controlled trial found that patients who received injections into the transitional vertebra area experienced a significant drop in pain scores at four weeks, and that improvement persisted at twelve weeks. Disability measures also improved, and no adverse events were recorded.9Joint Bone Spine. Efficacy of local glucocorticoid after local anesthetic in low back pain with lumbosacral transitional vertebra: A randomized placebo-controlled double-blind trial However, the relief from steroid injections tends to be temporary. In the retrospective review mentioned earlier, the median duration of relief was only about two weeks, though one outlier patient maintained relief for nearly six months.3PubMed Central. Retrospective review of outcomes in patients with Bertolotti’s syndrome who underwent fluoroscopically-guided pseudojoint injections A broader review of the literature concluded that steroid injections improve symptoms temporarily, while surgical management tends to produce more lasting results.10PubMed Central. Symptomatic lumbosacral transitional vertebra: a review of the current literature and clinical outcomes following steroid injection or surgical intervention
This does not mean injections are a failure. For someone whose pain flares periodically, periodic injections may keep things manageable enough to avoid surgery. And even when injections wear off quickly, that rapid relief confirms the diagnosis and helps the surgeon plan the next step with confidence.
Radiofrequency Ablation
Radiofrequency ablation sits between injections and surgery on the invasiveness spectrum. The idea is to use heat generated by radiofrequency energy to destroy the small sensory nerve fibers around the pseudoarticulation, cutting off the pain signal at its source without removing any bone. In one reported case, bipolar radiofrequency lesions created around the posterior margin of the pseudoarticulation produced complete pain relief and full restoration of function lasting 16 months.11PubMed. Radiofrequency sensory ablation as a treatment for symptomatic unilateral lumbosacral junction pseudarticulation (Bertolotti’s syndrome): a case report
The appeal of radiofrequency ablation is that it avoids the recovery time and structural consequences of bone removal or fusion. The downside is that nerves can regenerate, so the relief may not be permanent. Evidence for this technique in Bertolotti’s syndrome is limited to case reports, and there are no studies comparing it head-to-head against injections or surgery. It may be a reasonable option for patients who respond well to diagnostic blocks but want to avoid or delay surgery.
Surgical Resection of the Transverse Process
When conservative and injection-based treatments fail, surgery enters the picture. The most straightforward surgical option is removing the enlarged transverse process or the pseudoarticulation itself, eliminating the abnormal bony contact between the lumbar vertebra and the sacrum. This can be done through traditional open approaches or with minimally invasive endoscopic techniques.
Resection has the advantage of being less invasive than a fusion and preserving segmental motion. A report of two adolescents who underwent surgical removal of the pathologic transverse process showed improved pain and increased overall function after the procedure. The authors argued that in young patients, early surgical intervention may be worth considering to prevent years of chronic pain and the cumulative disability that comes with it.12PubMed Central. Surgical management of Bertolotti’s syndrome in two adolescents and literature review
However, resection has a notable limitation. The therapeutic mechanism is not entirely understood. It likely works by reducing the mechanical load on the pseudoarticulation, but there is a risk that the bone grows back or the remaining structures re-engage, causing symptoms to return. For that reason, resection is sometimes recommended mainly for patients with milder symptoms or those who are poor candidates for more extensive surgery.13Journal of Minimally Invasive Spine Surgery and Technique. Surgical Options for Bertolotti Syndrome
Spinal Fusion and How It Compares to Resection
The alternative surgical strategy is the opposite approach: instead of removing the abnormal connection, you formalize it. Spinal fusion at the transitional segment locks the vertebra to the sacrum permanently, eliminating the painful micromotion at the pseudoarticulation. This is a bigger operation with a longer recovery, but the rationale is that by fully stabilizing the joint, you remove the mechanical irritation for good.
A study comparing the two approaches directly found a striking difference in long-term outcomes. In the short term (under six months), both fusion and resection performed well, with all fusion patients and about 78% of resection patients reporting pain improvement. But at longer follow-up beyond twelve months, the gap widened considerably: about 78% of fusion patients still reported sustained improvement, compared to only 28% of resection patients.14PubMed. Operative Treatment of Bertolotti Syndrome: Resection Versus Fusion This finding has shaped the conversation around Bertolotti’s surgery, with fusion increasingly favored for patients with more severe or persistent symptoms.
Fusion does carry its own risks, though. Locking a segment of the spine transfers more stress to the segments above it, potentially accelerating degeneration there over the years. Given that LSTV already predisposes the adjacent segment to early degeneration, adding a fusion creates a theoretical concern about compounding the problem. This trade-off is most relevant for younger patients who will live with the fused segment for decades. There is no large long-term study quantifying how much fusion at a transitional vertebra worsens adjacent segment degeneration compared to the natural history of the condition itself.
The Adjacent Segment Problem
Whether or not someone undergoes surgery, the disc just above a transitional vertebra takes a beating. Studies consistently show that this segment degenerates faster and more severely than the same level in people with normal spinal anatomy. In one MRI-based study, patients with type II LSTV had disc bulging at the segment above in about 88% of cases, compared to roughly 54% in controls. Rates of disc herniation, bone spurs, endplate defects, and facet joint degeneration were all significantly elevated.1PubMed Central. Lumbosacral Transitional Vertebra Contributed to Lumbar Spine Degeneration: An MR Study of Clinical Patients Another study found that the segment above the transitional vertebra had advanced disc degeneration in about 39% of LSTV patients, versus 16% at the same level in controls, with a similar pattern for vertebral endplate changes.15PubMed. Associations between lumbosacral transitional anatomy types and degeneration at the transitional and adjacent segments
This has real treatment implications. If you have LSTV and develop a herniated disc or stenosis at the level above, the transitional vertebra may have been a contributing factor even if it is not the direct pain generator. Any spine surgery planned at the adjacent level needs to account for the altered biomechanics, and the surgeon needs to know the transitional vertebra is there. Patients with Bertolotti’s syndrome also tend to have higher pelvic incidence, a measure of pelvic tilt that can further influence spinal alignment and how the remaining segments handle load.16PubMed. Examining degenerative disease adjacent to lumbosacral transitional vertebrae: a retrospective cohort study
The Wrong-Level Surgery Risk
One of the most underappreciated dangers of LSTV has nothing to do with treating the transitional vertebra itself. It has to do with counting. In a normal spine, surgeons localize the correct vertebral level by counting up from the sacrum or down from the last rib. When a transitional vertebra is present, the count can be off by one level. If the surgeon does not recognize that L5 has merged into the sacrum (sacralization) or that an extra segment has separated from it (lumbarization), they may decompress or fuse the wrong disc entirely.
In a study of 550 consecutive patients undergoing lumbar spine surgery, LSTV was present in about 13%. Among those with LSTV, vertebral levels were miscounted at the initial outpatient visit in over half the cases. More critically, surgical plans were altered from the original level in about 15% of LSTV cases after the true spinal count was confirmed using whole-spine imaging.17The Tohoku Journal of Experimental Medicine. Lumbosacral Transitional Vertebrae Cause Spinal Level Misconception in Surgeries for Degenerative Lumbar Spine Disorders A systematic review similarly highlighted case examples where LSTV led to initial misidentification of the fractured or stenotic level, requiring re-evaluation before the correct segments were treated.18PubMed. Risks Associated with Surgical Management of Lumbosacral Transitional Vertebrae: Systematic Review of Surgical Considerations and Illustrative Case
The practical takeaway: if you know or suspect you have a transitional vertebra, make sure your spine surgeon knows too. A whole-spine X-ray that includes the cervical region allows the surgeon to count down from C2 and confirm the identity of each level unambiguously. This is not routine at every institution, but it should be standard for anyone with LSTV undergoing any spinal procedure.
Young Patients and Pediatric Considerations
Bertolotti’s syndrome is often thought of as an adult condition, but it can present in adolescents and teenagers, particularly those who are athletic. The transitional vertebra is present from birth, but symptoms typically emerge as the skeleton matures and mechanical loads increase. In a literature review focused on pediatric cases, lower back pain was the universal presenting symptom, with radiating leg pain described in roughly half the studies reviewed. Treatment in these younger patients followed the same general stepladder: physical therapy and anti-inflammatory medications first, then targeted injections, and finally surgical resection or fusion for refractory cases. All patients in the reviewed studies showed at least partial symptom resolution.19PubMed Central. Bertolotti Syndrome in the Pediatric Population: A Literature Review and Management Algorithm
The argument for earlier intervention in young patients is that Bertolotti’s syndrome is progressive in nature. The pseudoarticulation continues to bear abnormal stress with every year, and the adjacent segment keeps accumulating degenerative changes. Waiting until someone is in their thirties or forties to address the problem may mean treating not just the transitional vertebra but also the worn-out disc above it. That said, fusion in a teenager means a lifetime of living with a fixed segment, and the long-term data on how that plays out over many decades is sparse.
How Common Are Transitional Vertebrae
Prevalence estimates vary depending on the population studied and the imaging methods used, but transitional vertebrae are far from rare. A study of asymptomatic young men found LSTV in about 23%, with sacralization (the lowest lumbar vertebra fusing toward the sacrum) making up the majority at roughly 18% and lumbarization (an extra segment separating from the sacrum) accounting for about 5%.20Hitit Medical Journal. Prevalence of Lumbosacral Transitional Vertebrae in Asymptomatic Young Men A cadaveric study found a lower prevalence of about 13%, with the mildest forms (just an enlarged transverse process without actual joint formation) being the most common type.21Clinical Spine Surgery. Lumbosacral Transitional Vertebrae: A Cadaveric Investigation of Prevalence and Relation to Lumbar Degenerative Disease In a large cohort study of over 4,600 participants aged 45 to 80, about 18% had LSTV. Among those, roughly equal proportions had simple enlargement of the transverse process (type I) or a pseudoarticulation (type II), with full fusion (type III) in about 12% and mixed types in the remainder.22PubMed Central. Lumbosacral transitional vertebrae: association with low back pain
The range of severity matters for treatment decisions. The milder forms may never cause symptoms and require no treatment at all. The more advanced types, particularly those with true pseudoarticulations or complete fusion, are the ones more likely to produce pain at the abnormal joint or accelerate degeneration above. This is why the classification system, developed by Castellvi in the 1980s and still in use today, is more than academic taxonomy: it helps guide whether the transitional vertebra is likely to be clinically relevant.
A Genetic Component
There is growing recognition that transitional vertebrae run in families. Research in German Shepherd dogs, a breed with a high rate of lumbosacral transitional vertebrae, estimated the heritability of LSTV at a moderate level, with positive genetic correlations between the subtypes usually considered pathologic.23PubMed. Genetic background of lumbosacral transitional vertebrae in German shepherd dogs Human genetic studies are less developed, but the segmentation of vertebrae during fetal development is governed by a well-known cascade of genes. Variations in these developmental pathways likely explain why some people end up with 4 free lumbar vertebrae and others with 6, and why the condition clusters in certain families. For now, this does not change treatment decisions directly, but it does mean that if you have Bertolotti’s syndrome and a sibling develops unexplained low back pain, it may be worth mentioning the family connection to their doctor.