Background
Enthesopathy refers to the inflammation, degeneration, or structural abnormalities occurring at the site where tendons, ligaments, or muscles attach to bone, known as the enthesis. It often involves changes in the bone, soft tissues, and adjacent structures and can result from various factors such as mechanical stress, inflammatory diseases, or overuse injuries. The term “enthesopathy” is frequently used in radiology reports and encompasses a vast array of enthesis-related findings, from pathologic states (i.e., inflammatory arthritis) to diffuse hypertrophic bone formation that some radiologists consider normal. The goal of this educational exhibit is to emphasize when enthesopathy is a relevant finding to include in a radiology report.
Educational Goals / Teaching Points
Review the anatomy of an enthesis. Understand the pathophysiology of different types of enthesopathy and recognize their radiological features. Show examples where enthesopathy may be relevant and should be mentioned in a radiology report.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Enthesopathy in systemic inflammatory disease can affect synovial entheses: Cartilaginous, syndesmosis, and extra-articular entheses undergo inflammation, erosions, and bone formation that can be seen on imaging as an ill-defined sclerotic surface, irregular bridging enthesophytes, and sometimes redefinition of the osseous contour. Degenerative enthesopathy is common and affects synovial, cartilaginous, syndesmosis and extra-articular entheses. It causes lteration of the tendon fibers, disruption of the bundles adjacent to the bone and hyperostosis that can be identified as bone spurs. These findings are usually associated to joint space narrowing and cartilage disease. When extensive, it is described as diffuse idiopathic skeletal hyperostosis. Trauma-related: the most common site of rupture of a tendon is the enthesis where an avulsion fragment is typically seen on posttraumatic radiographs. Associated soft tissue swelling is indicative of an acute injury. Crystal deposition disease: gout or pseudogout can lead to the deposition of crystals in and around the enthesis. Soft tissue swelling, periarticular erosions, calcifications and a joint effusion can be seen on imaging.
Conclusion
Radiological enthesopathy holds significant clinical relevance in various contexts: diagnosis of systemic inflammatory or crystal deposition disease, trauma-related disease, and degenerative enthesopathy that can affect surgical interventions. It is important to understand the clinical significance of various enthesopathies.
