Bertolotti's syndrome, or lumbosacral transitional vertebra (LSTV), is a common anatomical variant where the lowest lumbar vertebrae fuse with the sacrum, affecting 4-8% of the population. It can cause low back pain through abnormal mechanical stress on nearby joints and tissues. Diagnosis is made through x-rays showing the transitional vertebra. Treatment focuses on physical therapy, steroid injections, and in some cases surgery to correct disc issues resulting from the anatomical abnormality.

1. Bertolotti's syndrome
Slides by Dr Ntambi Rogers

2. Introduction
Lumbosacral transitional vertebrae (LSTV) are a relatively common variant and
can be seen in ~25% (range 15-35%) of the general population.
● They can be thought of as a lumbarized S1 segment or sacralized L5
segment
● It is an important cause of low back pain in young patients.

3. Introduction
The term lumbosacral transitional vertebra (Bertolotti's syndrome) refers to a total
or partial unilateral or bilateral fusion of the transverse process of the lowest
lumbar vertebra to the sacrum.
The syndrome affects 4% to 8% of the population.
BS is characterized by anomalous enlargement of the transverse processes of
the most caudal lumbar vertebra, which may articulate or fuse with the sacrum or
ilium and cause isolated L4-5 disc disease.

4. Image

5. Pathoanatomy
The causes of back pain in BS are multifactorial. Most of the affected patients
have scoliosis.
The abnormal mechanical stress leads to facet joint arthropathy, as well as
iliopsoas and quadratus lumborum strain.
Nerve root compression due to narrowing of the intervertebral foramina by the
enlarged fan-shaped transverse foramina may lead to neurogenic claudication. An
increased prevalence of disc protrusion or extrusion in the disc above the
transitional L5 vertebra has been found in patients with LBP.

6. Pathoanatomy
A decreased prevalence of disc protrusion or extrusion was found in the disc
below the transitional vertebra.
Pseudoarticulation between the transverse process and the sacrum creates a
“false joint” susceptible to arthritic changes and osteophyte formation potentially
leading to nerve root entrapment.

7. Pathoanatomy
The presence of an LSTV disrupts normal spine biomechanics and anatomy.
The sacrum, lying at the base of the vertebral column, optimizes the dissipation of
the weight of the upper body toward the sacroiliac (SI) joint by working as a fused
mass of boney elements.
The sacrum's ability to dissipate load depends on its size and its surface area with
the SI joint.

8. Pathoanatomy
The formation of transitional states at the lumbosacral junction may be greatly
influenced by the functional requirements of load transmission at the SI junction
.
Sacra incorporating L5 possess significantly smaller heights than the normal sacra
if the fused L5 vertebra is excluded from the measurement.

9. Pathoanatomy
Disc degeneration is an important component in the pathophysiology of LBP in
BS.
The intervertebral disc most commonly involved is that of the L4-5 level, i.e., the
level just above the level of hemisacralization

10. Types
. The commonly used Castellvi classification is:
Type 1: a fusion at least 19 mm in width on one (1a) or both sides (1b)
Type 2: incomplete fusion with a pseudo joint created on one side (2a) or both
sides (2b)
Type 3: complete fusion of the L5 to the sacrum on one side (3a) or the other (3b)
Type 4: combination of Type 2 and Type 3

11. Signs and symptoms
Sacralization often has no symptoms. It’s sometimes is associated with lower back
pain or problems with posture and movement..
Biomechanical difficulties in movement
Limits to range of motion
Posture control problems
Scoliosis
Leg pain, buttock pain

12. Diagnosis
Diagnosis of BS is based on radiological findings and their correlation with the
clinical presentation.
Plain X-rays of the lumbosacral spine in anteroposterior view are usually sufficient.
Radicular features may necessitate an MRI for evaluation of prolapsed
intervertebral disc (PIVD), which may co-occur.

13. Management
Pain in patients with BS does not usually respond to interventional pain treatment.
A very dynamic treatment approach must be pursued while managing BS patients,
and the treatment plan must be individualized at various stages in order to obtain
satisfactory pain relief.

14. Management
Transformational (TF) steroid injections can be given using a subpedicular
approach. Injections containing depomedrol 40 mg in 0.25% bupivacaine, and an
interval of at least 4 weeks can be maintained between consecutive injections.
A maximum of 3 injections is given to obtain the maximum therapeutic benefit of
TF steroid injections
Rami communicantes (RC) block can be done for palliation of discogenic pain

15. Management
● Physical therapy interventions are also helpful in early cases and are focused
around mobilization, neural stretching, and core strengthening exercises.

16. Management
Surgery may be recommended to correct specific disc or other abnormalities that
result from the sacralization.
For example, sacralization may cause strain on the disc between the fourth and
fifth vertebrae, leading to disc slippage or degeneration.
Surgically ,posterolateral fusion or resection of the transitional articulation can be
done.