Anatomical and topographical study of the Filum Terminale in 31 human cadavers

Abstract

To describe the intra-dural anatomy of the Filum Terminales (FT), analysing morphological parameters, relevant for clinical relations to the Tight Filum Terminale Syndrome, aiming at the meticulous analysis of its diagnostic criteria and therapeutics. Methods: Thirty-eight fresh cadavers were dissected, and the following parameters were evaluated: FT lenght, diameters at the initial and medium point of the FT, topographical relation of the starting and ending points of the FT to the vertebrae, height, weight sex and age. Results: The average FT lenght was 157,56 mm (range 112,8 – 211,1), its average initial diameter 1,38 mm (range 0,4 – 2,5) and its medium point 0,75 mm (range 0,1 – 1,55). Four (10,53%) cadavers presented a FT thicker than 2 mm in its initial point. The FT begins most frequently at the mid-L1 level (18,42%) and ends at the upper-S2 level (34,21%). The variation range for both levels is large. Significant correlations were found (Pearson correlation) between weight and height (p = 0,018), initial and middle diameters (p< 0,001), initial vertebral level and height (p = 0,012) and starting and ending vertebrals levels (p = 0,005). Conclusion: Through this analysis of the FT, we discuss the diagnostic criteria and the therapeutic conduct for the Tight Filum Terminale Syndrome. There are evidences that about 10% of the normal population possess one of the criteria for the diagnosis of the Tight Filum Terminale Syndrome.