Around each joint in the body is what is called a joint capsule. This kind of capsule is what supports the bones each side of the joint together and keep the fluid in the joint that lubricates the joint in position. Portions of that joint capsule are usually thicker and stronger. These thicker and stronger portions would be the ligaments that provide stability to the joint. In the joints at the base of the toes in the foot, the metatarsophalangeal joints, the thickened underlying part of that joint capsule is usually called the plantar plate. This is required to be thicker and stronger as we place a lot of force through it when running and walking and it has to be able to take it. In some cases that force can be so great it might strain that plantar plate or ligament and it may become painful. When this occurs, the technical name is plantar plate dysfunction and sometimes it might progress to a small tear in the plate, therefore will get referred to as a plantar plate tear.
Usually the symptoms for this are pain under the joint when walking or on palpation, with the pain being more common towards the front edge of the joint. It in most cases only affects one joint but occasionally several may be affected. The toe may perhaps be moderatly raised as the plantar plate is not able to secure the toe down because of the damage to its integrity with the strain or tear. Frequently the diagnosis is clear, however, if not an ultrasound assessment is often done to confirm it. The treatment generally consists of strapping the toe to hold it in a downward position so that the plantar plate is rested to give it a chance to heal. A metatarsal pad can also be used in the shoe to help keep weightbearing off the affected location. If these kinds of procedures don't help, then a surgical repair of the plantar plate tear are usually necessary.