Ex Vivo Experiments of a New Injection Cannula for Vertebroplasty
Bibliographic record
Abstract
In Brief Study Design. An experimental study using cadaveric vertebrae. Objectives. To measure the injection pressure in an ex vivo model and determine whether the redesigned cannula, featuring 2 distinct sections of different diameters, significantly reduces the injection pressure. Summary of Background Data. An important limitation of vertebroplasty is the excessive pressure required to inject sufficient cement. The redesigned cannula accounts for the “bottleneck” of the injection previously identified. It has a distal section that is adapted to the pedicles and a proximal section with a larger diameter. Methods. Two cannulas were tested, a conventional 8-gauge and the redesigned cannula. There were 3 mL of cement injected in small strokes of 0.75 mL into the left and right hemivertebrae. A custom-made injection device monitored the injection pressure and cement volume. Results. Average injection pressure was 2.3 MPa, often approaching the human physical limit and resulting in insufficient filling. The average pressure of the redesigned cannula was 44% lower than that of the conventional cannula, a highly significant result (P < 0.001). Conclusion. The new cannula may improve vertebroplasty by significantly easing cement injection. It is cost effective and can be easily integrated into the existing procedure. The injection pressure was examined for 2 cannulas, conventional and redesigned. The pressure of the redesigned cannula was 44% lower than for the conventional. This rate is clinically relevant because it may ease cement injection during vertebroplasty in a manner that is easy to integrate into the existing procedure.
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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) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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) | 0.000 | 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".