Arthritis of this joint, or cartilage wear, occurs when there is abnormal pressure or positioning of the joint bones. This results in grinding down of the smooth cartilage that covers the bone surface at the joint, allowing for smooth motion. As this cartilage erodes, the bone underneath begins to become exposed, and parts of the joint surface start to see bone rubbing during joint motion.
In addition to this, thickened spurs of bone can develop along the margins of the joint, further hampering motion. When bone grinds on bone and when spurs limit joint motion, pain usually results. This condition will gradually worsen, leading to destruction of much of the joint surface. In severe cases, the bones will even partially fuse together. The structural cause of arthritis can be due to many factors. Natural bone structure can contribute to this, such as seen in people with longer or shorter first metatarsals, as well as first metatarsals that are angled too steeply in elevation or declination with respect to the ground surface. Bunions and other rotational deformities of the big toe joint can also contribute to cartilage wear and tear. Fractures, crushes, sprains, and other injuries to the joint can also result in arthritis after awhile. Finally, certain body-wide joint-affecting diseases will cause joint erosion as well, such as seen with rheumatoid arthritis and psoriasis.
Non-surgical treatment is limited, consisting of measures to limit the painful motion of the joint and decrease the resulting inflammation. Stiff soled shoes and specialized custom foot inserts can be used to limit the painful motion. There are advantages and disadvantages to each design, and certain conditions like diabetes with nerve disease, poor circulation, and obesity limit their use. Their lifespan is much longer than hip or knee implants, which have to be replaced after a certain number of years. The motion restored by these implants is rarely equal to the motion of the joint before the onset of arthritis, but in generally is significant enough to relieve all motion pain and limitation. When these fail, or if the surgeon is not advising their use, a joint fusion is the preferred method of relieving joint pain.
This procedure fuses the bones across the joint, resulting in no motion at all. It differs from painful arthritis that is partially fused in that there are still areas of motion in those cases that produce pain. By removing all motion, the joint is no longer painful, leading to a stiff lever upon which the foot rolls off during the walking cycle. Eventually the body adapts to this, although some minor strain can occur to the joint in the middle of the big toe, or the complex of joints in the middle of the foot. If the arthritis is only mild, the surgeon may elect to preserve the joint. In this technique, the surgeon simply removes any bone spur limiting motion, and drills holes in the eroded areas of cartilage.
The drilling promotes growth of a tissue called fibrocartilage, which is a rough form of cartilage that is not as functional as regular joint cartilage, but is better than the bare bone below. It is usually necessary to address the underlying structural problem if this procedure is selected, as leaving the reason behind the arthritis alone will simply result in further arthritic change years down the road. big toe joint pain