Hallux rigidus is a osteoarthritis of the large joint at the base of the great toe (1st 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.
Pain and a stiffness in the MTP joint cause painful gait and footwear problems.
Diagnosis is usually apparent on examination but x-rays are usually required to determine the extent of the degeneration.
Treatment begins with anti-inflammatory medication to control the inflammation of the degenerative arthritis. Special shoes that reduce the amount of bend in the toe during walking will also help the symptoms initially. A rocker-type sole allows the shoe to take some of the bending force, and may be combined with a metal brace in the sole to limit the flexibility of the sole of the shoe and reduce the motion needed in the MTP joint.
Injection of cortisone into the joint may temporarily relieve symptoms.
Surgery may be suggested if all else fails. These are:
If less than 50% of the MTP joint is worn out, an operative procedure canned cheilectomy is used to remove only the spur and worn out bone. However the success rate of this procedure is unpredictable.
Fusing the joint relieves pain but makes it rigid. The worn out joint is excised and the raw bones are brought together and fixed with a screw, staple or a plate. Over several months bone grows across the joint. The toe is fused in an upward angle to facilitate normal walking pattern in the shoes.
Although replacing the joint is an attractive option of relieving pain and allowing mobility, it has the drawback of not lasting a lifetime and therefore revision fusion is often necessary. There are ceramic joints and metal on plastic (HMWPE) joints available.