Exploring the anatomical basis of piriformis syndrome: A systematic review

Piriformis syndrome remains underdiagnosed, particularly due to the anatomical complexity of the gluteal region. The aim of this study is to identify the anatomical variations most at risk for piriformis syndrome.

A systematic search was conducted in English in PubMed and Scopus between November 2024 and December 2025. The search covered various types of studies reporting extractable data on the anatomical aspects of piriformis syndrome. The selection process for this study was conducted by a single reviewer in accordance with PRISMA guidelines.

A total of 16 studies were selected. Data analysis showed that anatomical variations of types A, B, C, D, and F according to the Beaton and Anson classification appear to be the most common. However, only types C and D of this classification, as well as the morphological variant of type A of the piriformis muscle, were clearly identified as the etiology of piriformis syndrome.

Anatomical variations of the piriformis muscle and its relationship with the sciatic nerve are not uncommon and must be taken into account in the etiology of piriformis syndrome. Incorporating this anatomical data into an algorithm could enable earlier diagnosis and optimised treatment.