Earl F. Craton, D.C.

My grandson, Joel E. Miller, who plans on entering chiropractic college this fall, had been impressed by my consistent clinical results from my special technique of occipital condyle adjustment. Trying to establish proof of my contentions, he discussed the matter with Dr. James Carnes, Ph.D., professor of gross anatomy at the Texas College of Osteopathic Medicine.

Dr. Carnes was interested in establishing proof of the anatomical design and function of the occipital condyles and atlas articulating facets and so offered Joel the opportunity to view a dissection of these articulations himself in the TCOM's dissecting laboratory.

The cadaver was an elderly white male. The muscles and ligaments were cut away from the occiput to the mid cervical region. The right mastoid process and right transverse of the atlas was sawed away to expose the lateral border of the right lateral mass of the atlas. The exposed capsular ligament was cut sufficiently to pry the occiput slightly apart from the atlas lateral mass. The outline of the articulating facets was visible but no connecting occipital/atlas ligament was in evidence (this proved one of my postulations to be in error.)

Further forceful prying broke the posterior arch of the atlas but allowed a greater internal view of the facet articulations. The only mobility we were able to elicit was an anterior (A) to posterior (P) and P to A rocking of the condyles in flexion and extension, which is considered a normal kinetic function. One to two millimeters of synkineses in all directions of rotation and lateral inclination were present and confirmed a flexibility in all directions of the articulation independent of the kinetic functions.

A complete separation of the facet articulations that removed the cranium from the spine allowed us to compare articulation sizes and shapes. It was obvious that the two condyle-glenoid groove articulations were unequal in size area and vertical dimensions. The condyles had side slipped to the right on the atlas glenoid grooves and had also rotated in a clockwise direction. The left condyle/glenoid groove articulation was less mobile than on the right and therefore, less erosion of the cartilage plates had occurred. The right anterior facet was approximately 30% eroded, presenting rough and jagged borders. Time consumed for this dissection was one hour and 35 minutes.

Later we did a two hour and 35 minute dissection on another elderly white male cadaver but spent more time and care in obtaining evidence of occipital flexion and extension on the atlas and video taped this mobility and architectural design of the condyle/atlas articulations. The muscles of flexion and extensions were cut away from the cranial base and cervical spine to the level of C6 and the greater portion of the occiput and spine to C6 was separated in one section from the cadaver.

This section then was manually moved under video camera to record the various directions and degrees of occipital/atlas mobility in simulated kinetic functions and the degree of synkinesis the ligaments would allow in flexion, extension, lateral inclination and rotation of this entire occipital/cervical section. The video recording confirms that the kinetic functions of the occipital/C1 articulations were limited to only flexion and extension without A to P or P to A slide but did rock from a stable hinge point fixed at the condyle apex/paraglenoid groove area. Mobility between C1 and C2 was limited to approximately 15 degrees of rotation to the right and a like degree to the left, with slight lateral inclination to either side of one to two degrees. The balance of the cervical section was near stable with only one to two degrees of flexibility and rotation.

One must view the video to appreciate this limited mobility. The capsular ligaments of the occiput/C1 joint were cut away from the anterior borders until we could slowly pry them apart exposing the tearing of ligaments and membranes thet held these articulations in functional relationship.

Under video recording we observed the facet separations and there was no evidence of an auxiliary ligament coming laterally off the capsular ligament that invaded the paraglenoid space from both sides of the lateral masses but did not join together in the paraglenoid grooves. This is the hinging anchor of the condyles on the glenoid grooves.

There was a difference in area size of the two condyles/glenoid groove surfaces which would result in a difference in articular mobility. The least mobile articulation exhibited the least erosion of the cartilage plates. A condyle side slip with a counter clockwise rotation had caused the variable erosion and size.

The cranial nerves, IX, X, and XI could be compromised after their exit from the jugular foramen because of the counter clockwise condyle rotation on the atlas. The positional atlas/axis relationship appeared to be normal.

It is glaringly evident that the illustrations appearing in our medical anatomy texts do not accurately depict the architectural design of the occipital/atlantal articulations. This has contributed to unrealistic concepts of this joint's type and range of mobility.

The evidence of an auxiliary ligament arising from the lateral borders of the capsular ligaments and encroaching into the paraglenoid grooves should be further investigated.

The manner in which we forced and tore the condyles from the atlas lateral masses could have broken any continuous ligaments in the paraglenoid grooves before the video camera could focus on this area.

This horizontal slicing in this cranial-vertebral-junction (CVJ) from above downward would be more revealing than the method we used.

These dissections establish several important facts relative to positional derangement of the occipital condyles on the atlas glenoid grooves and a resulting degeneration of ligaments, cartilage plates and facets, all of which are contributory to compromising nerve signal transmission and blood supply in this area, such as:

(a) The craniums anchorage to the atlas is subject to lateral side slip and rotation.

(b) Causing hypo mobility of head flexion/extension on the atlas unilaterally or bilaterally.

(c) This promotes erosion of the facets and cartilagenous plates and ligament atrophy or hyperthropy;

(d) The resulting postural imbalance of the cranium promotes cervical postural compensations that generate stresses resulting in joint degeneration.

(e) Atlas subluxations with C2 are not primary but are secondary to hypo-mobility of the condyle/atlas stress on the atlantal transverse ligament and capsular ligaments of C1 and C2.

(f) The cranium's lateral side slip and rotation compromises the vertebral artery at its entrance into the cranial vault.

(g) The positional condyle/atlas derangement can be physically realigned to lessen the nerve signal interference and increase the blood supply compromise in some degree or full degree.

(h) Stabilizing the atlas and correctly aligning the condyles on the glenoid grooves have proved to be more direct and efficient procedures than trying to align the atlas into correct position with the occipital condyles.

(i) Rehabilitation of degenerative articular tissues is promoted by passive motion joint stressing of specific directional demands, plus the usual nutritional supplements indicated and avoidance of further trauma.

The M & K Enterprises, Inc. are dedicated to excellence of clinical expertise and invite your requests for supportive literature about the above. A taped review of the dissection, with technique demonstrations and rehabilitory programs, is available.

My grandson and I are indebted to the Texas College of Osteopathic Medicine for the cadavers and use of their dissection laboratories and to James Carnes, Ph.D., for his expertise and the time spent performing these dissections.

About the author: Earl F. Craton, D.C., Ph.C., is a graduate of Palmer College who has practiced in Oklahoma and Texas.