The anatomical features of denticulate ligament in human fetuses

To determine the morphological features of the denticulate ligament in fetal period.

Twelve formalin-fixed fetuses (six females and six males) with a mean gestational age of 27.0 ± 2.04 weeks (range between 25 and 32 weeks) were dissected to reveal morphological properties of the denticulate ligaments.

Denticulate ligament was observed as a continuous ligament extending throughout the length of spinal cord in all fetuses. It separated the vertebral canal into two as anterior and posterior parts and was anchored to the dura mater on either side of the spinal cord with mostly triangular processes as well as thin band-like extensions. The first denticulate ligament process was always a large and prominent fibrous band and was arising from the spinal cord surface, extending in an oblique direction upward to the anterolateral rim of foramen magnum, below and posterior to the hypoglossal canal. The last denticulate ligament process was observed either in the T11-12 (2 sides, 8%), T12-L1 (15 sides, 62%) or L1-2 (7 sides, 30%) and all were band-like processes. At certain spinal cord levels, denticulate ligament had no processes to attach duramater while in some other fetuses double denticulate ligament processes were detected within the same interval. The distance between the denticulate ligament process and the superior spinal nerve root and the distance between the denticulate ligament process and the inferior spinal nerve root were measured at each spinal level. This distance was found to be increased from upper to lower levels of the spine.

Detailed morphological data about fetal denticulate ligament presented in this study provide significant information which may be essential during several surgical interventions performed in early postnatal period and childhood focusing on the spinal cord, spinal nerve roots and meningeal structures.