Sani Baimai; Chutikan Kaensa; Kasem Koedpuech; Manit Kittiwangchai & Passawut Submaneeanant

The long head of the biceps tendon (LHBT) originates from both the supraglenoid tubercle and the superior glenoid labrum. Variations in its attachment are clinically significant, as they influence the pathogenesis of superior labrum anterior posterior (SLAP) lesions and affect outcomes of arthroscopic shoulder procedures. The aim of the study was to identify the anatomical variations of LHBT attachment to the glenoid labrum in Thai cadavers and compare the findings with previous reports. A total of 156 shoulders from 78 embalmed Thai cadavers (43 males, 35 females; mean age 69.41 years) were dissected at the Department of Anatomy, Faculty of Medicine Siriraj Hospital, Mahidol University. The type of LHBT attachment was classified according to the system of Vangsness Jr. et al. (1994). In cases where macroscopic identification was unclear, histological sections were examined. Type I (entirely posterior attachment) was the most common, observed in 148 shoulders (94.87 %). Type II (posterior-dominant) occurred in 6 shoulders (3.85 %), while Type III (equal anterior and posterior) and Type IV (anterior-dominant) were each found in one shoulder (0.64 %). The majority of attachments were oriented posteriorly at the 1 o’clock position in left shoulders and the 11 o’clock position in right shoulders. The LHBT in Thai cadavers demonstrates a predominantly posterior attachment pattern to the glenoid labrum, differing from earlier consensus studies. This knowledge may improve arthroscopic diagnosis, surgical planning, and postoperative outcomes in SLAP and Bankart repairs.

KEY WORDS: Biceps Brachii; Glenoid Labrum; Shoulder Joint; Cadaver; Anatomy.

BAIMAI, S.: KAENSA, C.; KOEDPUECH, K.; KITTIWANGCHAI, M. & SUBMANEEANANT, P. Anatomical variations of the attachment type of the long head of biceps brachii tendon at the glenoid labrum in Thais. Int. J. Morphol., 44(2):393-398, 2026.