Diffuse Idiopathic Skeletal Hyperostosis (DISH), is a disease characterized by ossification and calcification of entheses and ligaments. Its predilection site of involvement is the spine, and in particular the thoracic segment. Nevertheless, involvement of peripheral skeletal sites such as peripheral entheses, joints' capsules, and hypertrophic involvement of peripheral joints is common. It has also been associated with features of the metabolic syndrome such as diabetes mellitus, hyperlipidemia, obesity, hypertension and a higher cardiovascular risk. The prevalence of DISH increases with age and can reach on average 10-15% of patients >50 years of age. At present the accepted diagnostic criteria, allow for diagnosis only in a late well established disease. Although the condition is known for many years, we lack good scientific evidence for its clinical manifestations, pathogenesis, genetics, early diagnosis, and treatment modalities. Stiffening of the spine due to new bone formation may cause several complications, and in particular complex fractures with possible dreadful complications. 

This special edition of Explorations on Diffuse Idiopathic Skeletal Hyperostosis, aims at providing a comprehensive review of our current knowledge and future challenges on important topics of DISH. These will discuss issues about the similarities and differences between DISH, inflammatory spondylitis, and ossification of the posterior longitudinal ligaments, mechanical complications of the condition and the current surgical approach, the clinical manifestations beyond the musculoskeletal system, our knowledge about its genetics and other topics. A better recognition of DISH will draw attention to this often neglected entity, and hopefully will stimulate researchers to further explore this condition.

(After the special issue was launched online, Dr. Reuven Mader passed away. Subsequently, all manuscripts submitted to the special issue were processed by the Editor-in-Chief or other editorial board members acting as the Academic Editors, and the Editor-in-Chief made the final decisions on all manuscripts for this special issue.)

Keywords: DISH, new bone formation, enthesopathies, metabolic syndrome, hypertrophic bone disease