Predislocation syndrome in the foot describes a painful condition involving the 2nd metatarsal phalangeal joint.  This joint, found at the base of the 2nd toe, can develop a painful inflammatory condition that leads to joint dislocation and damage.  It is not uncommon in people with flat feet, but can also be seen in those with regular or even high arches if the metatarsal bone is angled steeply enough.

 
The symptoms of predislocation syndrome often include swelling and warmth under the base of the 2nd toe, with pain to pressure under the ball of the foot at this site.  A hammertoe deformity of the 2nd toe is usually present with this condition, and it actually worsens as the condition progresses.
 
Due to a complicated relationship between the 2nd metatarsal, the 2nd toe, and the metatarsals next to it (primarily the first metatarsal), an injury can develop in the soft tissue that comprises the bottom of the 2nd metatarsal phalangeal joint, called the plantar plate.  With increased pressure to this plate, either through excessive pressure from a longer metatarsal, a more steeply angled metatarsal, or even the downward pressure of the attached hammertoe, a gradual tear will develop in the plantar plate.  This tear starts out as small, but gradually increases as the metatarsal head is pushed further downward into the tear.  As the tear increases, so will the inflammation.  The toe deforms even further as the joint dislocates, and becomes unstable.  Pain can become debilitating in many cases.
 
Treatment involves stabilizing the joint and reducing inflammation.  In some cases, nonsurgical care, including downward toe taping, anti-inflammatory medications, icing, and immobilization in a walking boot, can be sufficient to reduce the inflammation.  The use of prescription orthotics is then vital to reducing the ongoing pressure under this joint.  Steroid injections directly in the joint will actually worsen the condition as the steroid crystals weaken the plantar plate, and should be avoided.  These measures can help predislocation syndrome heal when it is in it's early stages, and sometimes with more advanced cases.  The majority of the time, however, surgery is necessary to reduce the pressure on the plantar plate to allow it to heal.  This typically involves a procedure that moves the 2nd metatarsal head back and up, and corrects the hammertoe deformity.  The plantar plate injury will often heal on its own, although some surgeons may prefer to physically repair it.