ĐẶC ĐIỂM GIẢI PHẪU CƠ DẠNG NGÓN CHÂN CÁI Ở NGƯỜI VIỆT NAM TRƯỞNG THÀNH

Abstract

Objective: To describe the anatomical characteristics of the abductor hallucis muscle, including its arterial supply and nerve innervation. Methods: A descriptive cross-sectional study was conducted on 30 amputated feet and cadaveric specimens from Vietnamese adults (≥18 years old) between March 2025 and September 2025. Results: The study was conducted on 30 foot specimens, including 16 fresh-frozen cadaveric feet and 14 amputated limbs, with a median age of 71.5 years (range: 23–85 years). Among them, 60% were left feet and 40% were right feet, with an equal gender distribution. The median foot length was 230 mm, ranging from 204 to 269 mm. The abductor hallucis muscle in adult Vietnamese individuals presented a slender, elongated shape, located superficially along the medial aspect of the plantar foot. Two morphological types were identified: the straight type (40%) and the curved type (60%). The muscle originated consistently from the medial process of the calcaneal tuberosity and additionally attached to the flexor retinaculum (73%), the medial intermuscular septum (83%), and the plantar aponeurosis (40%). The insertion patterns varied as follows: into the base of the proximal phalanx of the hallux (40%), both the base of the proximal phalanx and the medial sesamoid bone (23%), solely into the medial sesamoid bone (7%), and into the base of the proximal phalanx combined with the capsule of the first metatarsophalangeal joint (30%). The median total muscle length ranged from 125 to 160 mm (median 143 mm). The mean belly length was 96.3 ± 8.4 mm, width 24.4 ± 2.7 mm, and thickness 9.9 ± 0.7 mm. The mean cross-sectional area was 2027.2 ± 445.4 mm², and the mean muscle volume was 16.20 ± 4.5 ml (range: 10.57–25.04 ml). The muscle received its vascular supply mainly from branches of the medial plantar artery, with three arterial patterns identified: type A (90%), type B (3.3%), and type C (6.7%). Four arterial branches entered the muscle in 70% of specimens. The mean diameter of the medial plantar artery was 1.7 ± 0.2 mm, and the pedicle length averaged 29.1 ± 8.8 mm. Innervation was provided by the medial plantar nerve. Two motor branches were present in 86.7% of specimens, while 13.3% had a single branch. The mean lengths of the first and second motor branches were 24.3 ± 2.6 mm and 26.8 ± 3.2 mm, respectively. Conclusion: In Vietnamese adults, the abductor hallucis muscle is a slender, superficial muscle on the medial plantar aspect, with consistent morphology and vascular anatomy. It is mainly supplied by branches of the medial plantar artery (predominantly Type A) and innervated by branches of the medial plantar nerve.