The clavicle's nutrient foramen is a surrogate marker for its nutrient artery.

The nutrient foramen is variable in number and location.

The topographical anatomy contrasts that of contemporary textbooks.

Fractures through the nutrient foramen could play a role in non-union

Poor reporting and methodology are problems for providing high quality evidence.

The clavicle's nutrient foramen is a surrogate marker for its nutrient artery. Knowing its location may be useful for interpreting fractures and to avoid iatrogenic lesions. The aim of this review was to determine the prevalence, number, location, and direction of the nutrient foramen.

Embase, Medline, PubMed, Scopus, and Web of Science were searched and supplemented by Google Scholar, hand-searching major anatomical journals, and the reference list of included studies (updated March 08, 2022). Titles and abstracts were screened for eligibility, and observational studies with quantitative data were included based on full text evaluation. Internal validity was assessed using the anatomical quality assessment tool. Pooled prevalence proportions were derived using a random effects DerSimonian-Laird model using the Freeman-Tukey double arcsine transformation with Miller's inverse back-transformation.

From 18,889 unique reports, 33 studies with 3760 clavicles and 3358 foramina were included. All studies suffered from untransparent reporting. The prevalence of the nutrient foramen was 97.75%, 95% confidence interval 94.70%–99.60%. It was mainly found as a single foramen on the middle third segment's posterior surface with acromial (lateral) obliquity. Results were stable over time, robust to sensitivity analyses, albeit limited by unexplained heterogeneity and asymmetry.

This review may aid in interpreting fractures passing through a high-risk area (mean foraminal index range 36.31–61.03%) for lesions to the nutrient artery. Practical implications are a need to update current inaccurate textbook descriptions and further advocate evidence-based anatomy to improve conduct and reporting of anatomical research.

Human anatomy

Clavicle

Nutrient foramen

Systematic literature review

© 2022 The Author(s). Published by Elsevier Ltd on behalf of Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland.