Bertolotti Syndrome

Bertolotti syndrome refers to anomalous enlargement of the transverse process(es) of the lowermost lumbar vertebra with articulation or fusion with the sacrum or ilium. It is thought that because of the lack of motion at the lowermost disc level, isolated L4-L5 disc disease is more commonly seen. Bertolotti syndrome is seen in about 4% - 8% of the population, the majority of whom are asymptomatic.

Patients may present with pain related to arthritis at the pseudoarticulation or the facets or disc disease at the level above the pseudoarticulation. Radiographs reveal a large transverse process (left in the case shown above). Planar projections in bone scans may be cold; however, single-photon emission computed tomography may reveal areas of increased uptake (seen in images above).

References

• Almeida DB, Mattei TA, Sória MG, Prandini MN, Leal AG, Milano JB, Ramina R. Transitional lumbosacral vertebrae and low back pain: diagnostic pitfalls and management of Bertolotti's syndrome. Arq Neuropsiquiatr. 2009 Jun;67(2A):268-72.
• Quinlan JF, Duke D, Eustace S. Bertolotti's syndrome. A cause of back pain in young people. J Bone Joint Surg Br. 2006 Sep;88(9):1183-6.