This causes a rigid big toe joint and is often caused by osteoarthritis
Hallux rigidus is a condition in which the motion at the big toe joint of the foot is rigid and is often associated with osteoarthritis. The big toe joint of the foot is actually quite an important joint in the body as it needs to bend so the body can move forward over the foot when walking. If anything blocks the motion at that joint, then moving forward is going to be a lot harder and strain will be placed on other joints that have to move more as that joint is not moving properly. This can result in pain in the big toe joint and other joints. It also causes an abnormal wear pattern on the shoes. The main cause of hallux rigidus is usually a previous injury to the joint. Over time this sets up a process of abnormal use that results in further damage and osteoarthritis to the joint. Eventually the limited motion of the joint is further restricted and the joint becomes rigid with no motion possible.
The best way to deal with a hallux rigidus is proper management of the initial injury with good rehabilitation and the use of exercises to prevent or slow down the developments of the osteoarthritis. If the joint is painful, then drugs and injections into the joint can be used for the pain. The use of a stiffer sole shoe is often helpful as this reduces the demand on the joint to bend. Some shoes can also have a rocker added to them, so that you move over the rocker and do not need to use the joint as much. If these conservative measures are not helpful, then the next step is surgical. There are several options here. The simplest, if indicated, is to simply remove some bone of the top of the joint to allow it to move more. If that is not possible, then the joint can be surgically fused to prevent it moving. This fusion deals with the pain from the osteoarthritis as the joint can no longer move.