E1529. Staying in the Groove: An Overview of Peroneal Pathology
  1. Shelby Payne; Stanford Medical Center
  2. Sydney Payne; Stanford Medical Center
  3. Jennifer Padwal ; Stanford Medical Center
  4. Kate Stevens; Stanford Medical Center
The lateral ankle and foot has complex anatomy and associated pathology that is critical for the radiologist to both understand and recognize in order to make an accurate diagnosis. The purpose of the exhibit is to review the normal anatomy of the peroneal muscles and tendons as well as normal anatomic variants, and to illustrate imaging examples of common and more unusual peroneal pathology on x-ray, MRI, ultrasound, and tenography.

Educational Goals / Teaching Points
The major teaching points of this exhibit are to examine the intricate anatomy of the lateral ankle and hindfoot and to identify the imaging features of peroneal pathology and some accompanying injuries. In addition, we will outline the mechanism and classification of superior peroneal retinacular injuries and associated peroneal tendon subluxation or dislocation. Finally, we will review pitfalls and common mimics of peroneal pathology.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The exhibit will show examples of peroneal muscle pathology including peroneal muscle strains and muscle hernias on MRI and ultrasound. In addition, we will review pathology of the peroneal tendons, including tendinopathy, tendon tears, tenosynovitis, and peritendinitis. The exhibit will show cases to help the radiologist learn to evaluate for the sequela of peroneal tendon injury. We will provide examples and discuss anatomic variants and associated potential pitfalls in diagnosis. We will outline the mechanism of injury and classification of superior peroneal retinacular injuries with resultant peroneal tendon subluxation/dislocation and show static and dynamic imaging examples on ultrasound and MRI. Lastly, we will provide examples of pathology resulting in lateral foot pain that may mimic peroneal tendon pathology, including stress fractures, ligamentous injuries, and the distal variant of plantar fasciopathy involving the lateral cord of the plantar fascia.

Lateral foot and ankle pain is common, and diagnosis based on clinical examination alone can be challenging. Imaging is frequently necessary to make a definitive diagnosis. Understanding the anatomy of the lateral ankle and foot and recognizing the pertinent imaging features of peroneal pathology and accompanying injuries is critical for accurate diagnosis. It is important to be aware of the mechanism of injury and classification of superior peroneal retinacular injuries with respect to ankle sprains, as this has important implications for treatment and surgical planning.