The condition may follow an injury to the joint or, in some cases, may arise without a well defined injury. The joint at the base of the great toe is called the metatarsal- phalangeal, or MTP joint. Like any other joint in the body, the joint is covered with articular cartilage , a very slick shiny covering on the end of the bone. If this material is injured, it begins a slow process of wearing out or degeneration . This can result in a wearing away of the articular surface, until raw bone rubs against raw bone.
Bone spurs form around the joint as part of the degenerative process .
The spurs may restrict the motion in the joint, especially the ability of the toe to bend upward when the foot moves forward. Causes There is still a question about what the true cause of Hallux Rigidus is. Many surgeons feel that, in many cases, the condition begins with an injury to the articular cartilage lining the joint. The injury sets in motion a degenerative process that may last for years before symptoms occur that need treatment. Other cases of hallux rigidus seem to arise without any type of serious injury.