The standard approach for sectioning of t he filum terminale for a tethered spinal cord can be achieved via a limited S1 exposure. This is performed with the commonly believed idea that the filum fuses with the dura at S2. We dissected 27 cadavers to exclusively look at the level at which the filum pierces/fuses with the dura and also the level at which the dural sac ends. Most of the fila fused at S2 with a range from L5 to S3. The majority of dural sacs ended at S2 with a range from S1 to S3. However, 15% of the fila (4 of 27) fused above the S1 level. In addition, 11% of the fila (3 of 27) fused off the midline. We hope that this anatomical information may be useful for neurosurgeons when standard approaches fail to identify the filum at its usual level and location.