Revisiting of the fibularis brevis muscle tendon classification according to attachment sites

Objectives: Variations and displacements in the attachment sites of the fibularis brevis tendon (FBT) are clinically significant, particularly due to the mechanical forces they exert on the fifth metatarsal bone and their potential role in fracture mechanisms involving this structure. This study aimed to investigate the anatomical characteristics of the fibularis brevis tendon attachment sites, its possible intertendinous connections with neighboring muscles, and its potential influence on fracture patterns at its bony insertion. Methods: A total of 27 embalmed lower extremities (15 males, 12 females; mean age: 69.48±14.39 years) from the Anatomy Department of Mersin University were dissected. The FBT was classified based on its attachments to surrounding tendons and bones. Results: The FBT was observed to attach to the medial cuneiform, the fifth metatarsal bone, and the proximal phalanx in various combinations. Specimens showing a low-lying muscle belly (n=2) were excluded from the main classification. Based on the attachment patterns, a single tendon slip was found in 52% of cases (n=13), while multiple tendon slips were observed in 48% (n=12) of specimens, two slips in 24% (n=6), three slips in 16% (n=4), and four slips in 8% (n=2). Conclusion: Knowledge of the anatomical variations in the attachment patterns of the FBT can provide valuable insights into the extent and localization of fractures at the tendon’s insertion site. Understanding these variations may also assist in surgical planning and interventions involving the FBT or the lateral aspect of the forefoot, particularly in cases of dislocation or trauma.