Effects of occipital-atlas stabilization in the upper cervical spine kinematics: an in vitro study.
Level 5 - mechanism / opinion, no new human data
In vitro biomechanical cadaver study (bench research)
PubMed 34035331 · doi:10.1038/s41598-021-90052-6
What was done
Ten cryopreserved upper cervical spine specimens with fixed C2 vertebrae and dissected superficial structures were manually mobilized in the three cardinal planes before and after C0-C1 screw stabilization. Upper cervical range of motion (ROM) and mobilization resistance force were measured using a Vicon motion capture system and a load cell.
What was found
Without versus with C0-C1 stabilization, upper cervical ROM decreased from 19.8° ± 5.2° to 11.5° ± 4.3° in flexion, from 14.3° ± 7.7° to 6.6° ± 3.5° in extension, from 4.7° ± 2.3° to 2.3° ± 1.4° in right lateral flexion, from 5.6° ± 3.2° to 2.3° ± 1.2° in left lateral flexion, from 33.9° ± 6.7° to 28.5° ± 7.0° in right rotation, and from 28.0° ± 6.9° to 23.7° ± 8.5° in left rotation. C0-C1 stabilization reduced overall ROM by 46.9% in the sagittal plane, 55.3% in the frontal plane, and 15.6% in the transverse plane, while increasing resistance to movement during mobilization.
Why it matters
The findings quantify the plane-specific kinematic restrictions caused by C0-C1 stabilization, showing that lateral and sagittal motion are substantially limited while axial rotation remains largely preserved.
Limits
The study was conducted in vitro using a small sample of ten cadaveric specimens subjected to manual mobilization rather than physiological muscle loads. Superficial tissue dissection may alter passive mechanics relative to living anatomy, and clinical fusion outcomes cannot be evaluated.
Cited by
- supports Human body movement occurs across three primary anatomical planes: the sagittal, frontal, and rotational (transverse) planes.