Establishing Safe Zones to Avoid Nerve Injury in the Approach to the Humerus in Pediatric Patients
Bibliographic record
Abstract
BACKGROUND: The surgical anatomy of upper-extremity peripheral nerves in adults has been well described as "safe zones" or specific distances from osseous landmarks. In pediatrics, relationships between nerves and osseous landmarks remain ambiguous. The goal of our study was to develop a model to accurately predict the location of the radial and axillary nerves in children to avoid iatrogenic injury when approaching the humerus in this population. METHODS: We conducted a retrospective review of 116 magnetic resonance imaging (MRI) scans of entire humeri of skeletally immature patients; 53 of these studies met our inclusion criteria. Two independent observers reviewed all scans. Arm length was measured as the distance between the lateral aspect of the acromion and the lateral epicondyle. We then calculated the distances (defined as the percentage of arm length) between the radial nerve and distal osseous landmarks (the medial epicondyle, transepicondylar line, and lateral epicondyle) as well between the axillary nerve and the most lateral aspect of the acromion. RESULTS: The axillary nerve was identified at a distance equaling 18.6% (95% confidence interval [CI], ±0.62%) of arm length inferior to the lateral edge of the acromion. The radial nerve crossed (1) the medial cortex of the posterior part of the humerus at a distance equaling 63.19% (95% CI: ±0.942%) of arm length proximal to the medial epicondyle, (2) the middle of the posterior part of the humerus at a distance equaling 53.9% (95% CI: ±1.08%) of arm length proximal to the transepicondylar line, (3) the lateral cortex of the posterior part of the humerus at a distance equaling 45% (95% CI: ±0.99%) of arm length proximal to the lateral epicondyle, and (4) from the posterior to the anterior compartment at a distance equaling 35.3% (95% CI: ±0.92%) of arm length proximal to the lateral epicondyle. A strong linear relationship between these distances and arm length was observed, with an intraclass correlation coefficient of >0.9 across all measurements. CONCLUSIONS: The positions of the radial and axillary nerves maintain linear relationships with arm lengths in growing children. The locations of these nerves in relation to palpable osseous landmarks are predictable. CLINICAL RELEVANCE: Knowing the locations of upper-extremity peripheral nerves as a proportion of arm length in skeletally immature patients may help to avoid iatrogenic injuries during surgical approaches to the humerus.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.002 | 0.010 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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 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".