Fibularis brevis tendon variants: a classification-based surgical and radiological approach

Fibularis brevis tendon (FBT) variants are under-recognised and may alter both imaging interpretation and operative strategy. The purpose of this review was to synthesise the available anatomical, radiological, and surgical literature on distal FBT variants and to frame this evidence through a classification-based approach.

This study was designed as a narrative review. Anatomical/cadaveric, imaging, and surgical publications relevant to distal FBT morphology and clinical interpretation were synthesised using the Olewnik classification as the organising framework. No formal systematic-review protocol or meta-analysis was undertaken.

The available literature describes two main distal attachment types of the FBT: Type I and Type II, the latter further subdivided into subtypes IIa-IIc. The most consistent findings concern recognition of accessory slips and fused components, differentiation of variants from longitudinal split tears or pseudomass-like findings, and appreciation of how atypical insertions may influence distal operative exposure. The strongest evidence remains anatomical and imaging-based, whereas direct validation of classification-guided treatment is still limited.

The Olewnik classification provides a useful anatomical framework for radiological reporting and preoperative planning, but it should presently be regarded as clinically promising rather than fully validated. A structured, variant-aware interpretation can improve communication and operative preparation in patients with lateral ankle pain, tendon pathology, or instability.