The role of the trefoil shape of the lumbar vertebral canal in low back pain

Dušica, Marie, Bojana, Krstonošić, Biljana, Srdić, Dušan, Radmila, Gudović, Stefan, Veselinović

Glasnik Antropološkog društva Srbije

46

415

420

1820-7936

https://scindeks.ceon.rs/article.aspx?query=ISSID%26and%269345&page=0&so...

2011-2021/11/01/13:44:08

The shape of the lumbar spinal canal in its upper part is almost circular, and it changes gradually in a triangular shape in its lower part. The term trefoil refers to a triangular shape of lumbar vertebral foramen. It means that the angles of the foramen are twisted inside and can be seen only when the posterolateral sides are concave and protrude into the foramen. The trefoil shape of the lumbar canal is commonly seen on CT or MRI in adults with low back pain and radicular symptoms. The aim of this study was to determine the role of the trefoil shape of the lumbar spinal canal in the symptomatic adult males and females with low back pain. The study involved 32 patients with clinical evidences of lumbar canal stenosis confirmed by MRI. The trefoil configuration was found consistently at the L5 level (78%) and additionally at the L4 (22%). The trefoil shape was seen in 590% in men and 73% in women. Each patient with trefoil shape had a central and subarticular stenosis. The clinical relevance of the trefoil configuration was in a possible predisposition to compression of lumbar and sacral nerve roots. The correlation between clinical symptoms and radiographic images was necessary to make the clinical diagnosis of lumbar spinal stenosis. Our findings indicated that the trefoil shape is a common non-pathological condition at the L4 and L5 level. It was probably a developmental variation (sui generis) of spinal canal anatomy.