Occurrence and Importance of Posterior Condylar Foramen

 

Sahil Choudhari¹, M.S. Thenmozhi²

¹I BDS, Department of Anatomy, Saveetha Dental College, Chennai – 600 077

²HOD, Department of Anatomy, Saveetha Dental College, Chennai – 600 077

 

ABSTRACT:

Background: The posterior condylar foramen is a canal in the posterior condyloid fossa of the lateral parts of occipital condyle. The posterior condylar foramen is the largest emissary foramen of the posterior cranial fossa. It acts as a route for venous circulation. It has varied clinical importance.

Objectives: To determine the occurance and importance of posterior condylar foramen with respect to occurance, laterality and diameter.

Materials and methods: An observational study was carried out on 70 dry human skulls obtained from Department of  Anatomy, Saveetha Dental College, Chennai, India. The diameter of the foramen was measured using a vernier caliper.

Result: The posterior condylar foramen was found to be present in 88.57% of the skulls. The incidence of bilateral presence was more than the unilateral presence. The average diameter of the foramen was 3.9mm.

Conclusion: The anatomical knowledge of posterior condylar foramen and its variations is important for the neurosurgeons, radiologists and ENT surgeons. 

 

 

INTRODUCTION:

The posterior condylar foramen is a canal in the posterior condyloid fossa of the lateral parts of occipital condyle. The posterior condylar foramen is the largest emissary foramen of the posterior cranial fossa. Resection of the rectus capitus posterior major and minor muscles reveals the bony recess leading to the condylar foramen, which is situated posterior and lateral to the occipital condyle. It is immediately superior to the extradural vertebral artery. ^[1]

 

The anteriomedial wall of the posterior condylar foramen thickens to join the foramen magnum rim and connects to the occipital condyle. Through the condylar canal, the occipital emissary vein connects to the venous system including the suboccipital venous plexus, occipital sinus and sigmoid sinus. It is not always present, and can have variations of  being unilateral or bilateral. ^[2] The posterior condylar vein exits the skull through the posterior condylar foramen, which is a communication between the juguar foramen and condylar fossa, situated just posterior to the occipital condyles on either side of the foramen magnum. This foramen allows for venous anastomosis between the jugular bulb and the suboccipital venous plexus. ^[3] The purpose of this research was to study the anatomy of the posterior condyloid foramen. Recognition of this common canal is useful for understanding alternative pathways for venous flow. Misinterpretation of the posterior condyloid foramen has led to surgical intervention for presumed glomus jugulare tumor. ^[2][6]

 

MATERIALS AND METHODS:

An observational study was carried out on 70 dry human skulls (50 full skulls and 20 half skulls) obtained from the Department of Anatomy, Saveetha Dental College, Chennai, India. The study was done to determine the variations in the occurrence of posterior condylar foramen with respect to incidence, laterality and diameter of the foramen. The diameter of the posterior condylar foramen was measured in all 70 skulls using a vernier caliper.

 

 

 

The posterior condylar foramen was observed and the occurrence (present or absent), laterality (unilateral left, unilateral right or bilateral), and diameter (in mm) was obtained. The data thus obtained was tabulated and analysed using Microsoft excel worksheet. Photographs of few skulls in which the posterior condylar foramen was prominent were taken.

 

RESULTS:

Results of the present study has been shown in table 1.

 

Table 1 : Results obtained from the study.

INCIDENCE	Presence of foramina - 62          (88.57%)	Absence of foramina – 8  (11.43%)
LATERALITY	Bilateral - 42 (67.74%)	Unilateral - 20 (32.26%) Left sided - 12 (60%) Right sided - 8 (40%)

 

 

 

DIAMETER OF POSTERIOR CONDYLAR FORAMEN:

Mean diameter of left side : 3.88mm

Mean diameter of right side : 3.96mm

 

 

DISCUSSION:

During embryonic period, the posterior condylar foramen acts as an important path for venous circulation which connects the intracranial venous sinuses to the extracranial venous system. With gradual change from foetal to neonatal circulation this venous system atrophies lead to closure of venous bone tunnel. Failure of closure leads to persistence of the posterior condylar foramen in adult skulls. ^[4]

 

The posterior condylar foramen forms a communication between the jugular foramen and the condylar fossa posterior to the occipital condyles.^[5] The posterior  condylar foramen was identified in 88.57% of the skulls. A knowledge of high incidence of the foramen is necessary for neurosurgeons while performing surgeries. The presence of unilateral foramen was found in 32.26% of the skulls. In the presence of unilateral foramen more orientation was seen on the left side than the right side. The bilateral presence of foramen was seen in 67.74% of the skulls. The present study indicates that the foramen is wider on the right side than the left side. Recognition of posterior condylar foramen and other variant emissary foramina allows a deeper appreciation of the alternative channels of venous drainage from the brain. ^[7][8]

 

CONCLUSION:

The posterior condylar foramen is one of the larger emissary channels in the skulls. It is present, at least unilaterally in up to 85% of patients and is readily identifiable. This foramen should not be misinterpreted as abnormal. The anatomical knowledge of posterior condylar foramen and its variations is important for the neurosurgeons, radiologists and ENT surgeons. 

 

ACKNOWLEDGEMENT:

With sincere gratitude, we acknowledge the staff members of Department of Anatomy and Saveetha Dental College for the whole hearted support and permission granted to utilize the resources and conduct this study.

 

REFERENCES:

1.       Krause W. The posterior condylar canal. Treaty of human anatomy. Barcelona, Salvat 1998; 1: 152-158

2.       Ginsberg LE. The posterior condylar canal. Am J Neuroradiol 1994; 15: 969-972

3.       Williams PL, Warwick R, Dyson M, Bannister LH, eds. Gray’s anatomy, 37^th ed. New York: Churchill Livingstone, 1998: 286-287

4.       Boyd GL. The emissary foramina of cranium in man and anthropoids. J Anat 1930;65: 108-121

5.       Haas LL. The posterior condylar fossa, foramen and canal, and the jugular foramen. Radiology 1957;69: 546-552

6.       Boryslawski K, Kurlej W, Gworys B. Changeability of emissary foramina based on modern skull material. Dent med probl 2002; 39(2) 177-182

7.       S. Kavitha, A Anand. A study of the condylar canal and its incidence, morphology and clinical significance. Int j cur res rev, Jan 2013; 05(02): 66-70

8.       Galarza M, Hyoun YJ, Merlo A, Albanese AH, Alfonso AR. Channel anatomical variations condylar. Chilean journal of anatomy 1998; 16(1)

 

 

 

 

Accepted on 05.06.2016        © RJPT All right reserved

Research J. Pharm. and Tech 2016; 9(8):1083-1085.