The Gracilis Muscle Reappraised: An Integrative Synthesis of Anatomy, Embryology, Imaging, and Surgical Applications

Background and Objectives: Fragmented anatomical, imaging, and surgical accounts of the gracilis muscle hinder reproducible reporting and operative planning. We aimed to integrate prior systems into an Integrated Gracilis Framework (IGF)—an integrative synthesis, not a new classification—that harmonizes terminology, defines imaging correlates/pitfalls, and links morphology to surgical decisions. Methods: Integrative narrative review (January 1900–October 2025) of PubMed/MEDLINE, Scopus, and Web of Science covering vascularization (pedicles, perforators), innervation (motor points/segments), imaging (ultrasound, MRI, MR neurography, CTA/MRA), and clinical applications (facial reanimation, elbow flexion, perineal and breast reconstruction). Two reviewers screened/extracted with consensus adjudication. Searches were restricted to English or records with reliable English-language summaries. Results: IGF consolidates morphological variants, motor-point/segmental innervation, and pedicle/perforator patterns with imaging correlates and common pitfalls. It provides a crosswalk mapping historical systems to IGF and a proposed preoperative workflow (anatomy → imaging → harvest → neurotization) for structured planning and reporting (proposed framework; not prospectively validated). We summarize considerations for free/functional gracilis in facial reanimation and elbow-flexion, and for pedicled/free myocutaneous or perforator flaps in perineal and breast reconstruction. Conclusions: IGF offers a standardized language and decision scaffold to improve study comparability and transparency in operative reporting; as a nonvalidated synthesis, it requires systematic validation through cadaver–imaging correlation and prospective surgical cohorts.