The causes of<unk>  are unknown. However, genetic and environmental factors appear to play a role in pathogenesis.<unk>  may also be associated with diffuse idiopathic skeletal hyperostosis
Ossification of the posterior longitudinal ligament
Ischemia-reperfusion injury of the appendicular musculoskeletal system
Humeral avulsion of the glenohumeral ligament
Protrusio acetabuli
Anterior vertebral body tethering
Discoid meniscus
Fibroma of tendon sheath
Posselt's envelope of motion