Classification of Scoliosis Deformity Three-Dimensional Spinal Shape by Cluster Analysis
Bibliographic record
Abstract
STUDY DESIGN: Cluster analysis of existing database of spinal shape of patients attending a scoliosis clinic. OBJECTIVE: To determine whether patients with scoliosis can be classified into distinct groups by 3-dimensional curve shape. SUMMARY OF BACKGROUND DATA: Subjective or semiquantitative methods can be used to classify curve types in scoliosis, with the goal of rationalizing surgical planning. There are very few reports of using objective methods such as cluster analysis to improve this process. METHODS.: One hundred ten patients who underwent radiography of the spine by a stereo technique, at a scoliosis clinic in the period between 1982 and 1990, were studied. Fifty-six were studied longitudinally (average 3.4 clinic visits each), providing 245 total observations. Selected patients had 2 scoliosis curves with apex between T4 and L3, and both Cobb angles >9 degrees by an automated measurement. The 3-dimensional spinal shape was reconstructed from stereoradiographs. Each curve was quantified by its Cobb angle, apex level, apex vertebra rotation, and rotation of the plane of maximum curvature (PMC) (8 variables). Cluster analysis classified each patient at each visit by these variables. RESULTS: When the analysis searched for 4 clusters, the largest cluster (148 of 245 observations) was the pattern having counterclockwise rotation of the PMC of both curves (typically, a right upper scoliosis curve with kyphosis and left lower scoliosis curve with lordosis). The other 3 clusters (48, 34, and 15 observations) were the other permutations of these variables. Substantial overlap of all the other variables between groups was observed. Of the 56 patients seen longitudinally, 25 were consistently grouped at all clinic visits. CONCLUSION: Spinal shape of patients in a clinic population with 2 scoliosis curves form distinct groups according to the 4 permutations of the signs of the rotations of the PMC in 2 curve regions. The pattern can change with repeated observation, often because a slight curvature in the sagittal plane can change because of postural variation and measurement errors. Overlap of the other curve-shape variables between groups suggests that these spinal deformity classifications alone should not determine treatment strategy.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.008 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.004 | 0.003 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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 source (direct Gemma or distilled Codex), 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".