Around each joint in the body is what is called a joint capsule. This capsule is what holds the bones either side of the joint together and keep the fluid in the joint that lubricates it in place. Parts of that joint capsule are thicker and stronger. These thicker and stronger parts are the ligaments that give stability to the joint. In the joints at the base of the toes in the foot, the metatarsophalangeal joints, the thickened bottom part of that joint capsule is commonly called the plantar plate. This needs to be thicker and stronger as we put so much force through it when walking and running and it has to be able to take it. Sometimes that force can be so great it can strain that plantar plate or ligament and it can become painful. When this happens, the technical term is plantar plate dysfunction and sometimes it can progress to a small tear in the plate, so gets called a plantar plate tear.
Typically the symptoms for this are pain under the joint when walking or on palpation, with the pain being more common toward the front edge of the joint. It usually only affect one joint but sometimes several may be affected. The toe may be slightly elevated as the plantar plate is not able to hold the toe down due to the damage to its integrity from the strain or tear. Usually the diagnosis is obvious, but if not and ultrasound examination is often done to confirm it. The treatment typically consists of strapping the toe to hold it in a plantarflexed position so that the plantar plate is rested to give it a change to heal. A pad can also be used in the shoe to keep weightbearing of the painful area. If these measures do not help, then a surgical repair of the plantar plate tear may be needed.