The posterior condylar canal: An anatomical study on dry human skulls

The human skull contains various foramina, including the posterior condylar canal (PCC), which allows the passage of emissary veins. The PCC connects the jugular foramen to the condylar fossa and facilitates venous drainage between the jugular bulb and suboccipital venous plexus. Due to its variable size and location, the PCC can be mistaken for pathological structures, posing challenges during neurosurgical procedures. While the transcondylar approach has gained popularity in craniovertebral surgeries, limited research exists on PCC variations. The aim of this study was to estimate the prevalence of PCC in the dry adult human skulls and to study their morphology due to its clinical importance.

A cross-sectional observational study was conducted on 52 well-preserved dry adult human skulls. Skulls with pathological changes or deformities were excluded. The presence, openness, and length of the PCC, as well as the external and internal diameters of the foramina, were assessed using Kerr endodontic files and measured with digital Vernier caliper. Conventional statistical methods were used to evaluate the data.

Among 52 skulls, 98.1% (n=51) had visible PCCs, with 84.6% (n=44) showing bilateral and 13.5% (n=7) unilateral presence. The mean PCC length was 11.8±2.9mm on the right and 11.5±2.8mm on the left, with no significant difference between sides (P=0.96). External diameters averaged 3.9±1.7mm (right) and 3.4±1.2mm (left), and internal diameters were 5.0±1.7mm (right) and 4.8±1.5mm (left), with no statistical difference (P>0.24). Most PCC openings were medium-sized (2-5mm) while large (>5mm) and small (<2mm) orifices were less common.

The PCC was found to be highly prevalent, predominantly bilaterally, with most openings exhibiting medium sizes. These findings highlight the PCC's anatomical significance and its relevance in radiology and surgical procedures involving the occipital condyle and jugular foramen.