Sinus Tarsi Syndrome

Sinus tarsi syndrome (STS) is characterized by pain in the lateral aspect of the foot originating from the tarsal sinus and canal, with many different pathological correlates identified as potential etiologies. STS is a descriptive term rather than a precise diagnosis, encompassing a variety of conditions affecting the sinus tarsi area. This adds to the complexity and uncertainty in its characterization, fueling ongoing debates about recognition as a distinct clinical entity. We advocate for avoiding the generic term of STS and instead pursuing a more accurate diagnosis. This chapter provides a review of current literature on STS, encompassing its anatomy, biomechanics, and injury mechanisms. It also explores associated injuries and diverse treatment modalities, particularly arthroscopic interventions. There is a broad spectrum of potential etiologies of the STS, and clinical examination and radiologic assessment are crucial to pinpoint the specific cause of pain. When conservative treatment fails and diagnostic imaging remains ambiguous, subtalar arthroscopy emerges as a valuable tool for diagnosis and treatment.