Threshold Cervical Range-of-Motion Necessary to Detect Abnormal Intervertebral Motion in Cervical Spine Radiographs
Bibliographic record
Abstract
STUDY DESIGN: Whole human cadaver model to assess a common diagnostic test for cervical spine stability. OBJECTIVE: Determine criteria that can be used to determine if sagittal plane angular motion of the head/neck during a cervical spine flexion/extension study is adequate to reliably assess intervertebral motion (IVM). SUMMARY OF BACKGROUND DATA: Flexion/Extension radiographs of the cervical spine are commonly used to help identify specific abnormalities in IVM. Several authors have recognized that inadequate patient effort can make flexion/extension studies unreliable, but validated guidelines for assessing the adequacy of these studies are not available. METHODS: Increasingly severe anterior-to-posterior (N = 6), and posterior-to-anterior (N = 6) soft tissue injuries were simulated in the cervical spines of 12 human cadavers. Sagittal plane radiographic images were taken with 4 gradually increasing amounts of overall flexion and extension motion of the head. IVM was measured for each level of sagittal plane rotation of the head/neck using previously validated computer-assisted methods. RESULTS: With less than 60 degrees of sagittal plane rotation of the head/neck, intervertebral rotation or displacement was almost never greater than the 95% confidence interval previously established for asymptomatic people. Even with 60 degrees or more motion, intervertebral rotation and displacement were within normal limits after extensive damage to the soft-tissues. The center-of-rotation was the most sensitive measure for detecting soft tissue damage. CONCLUSION: The results of this study suggest that clinicians should make sure patients can flex and extend their head/neck to a minimum range of 60 degrees before evaluating them for a dynamic motion study to assess cervical spine stability. Even with adequate motion, interverterbral rotation and translation can remain within normal limits in the presence of extensive soft tissue damage. The most sensitive measure for detecting soft tissue damage was center-of-rotation although it lacks specificity, particularly in the presence of underlying degenerative changes, and is not readily assessed in most clinical situations.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".