Pre dislocation syndrome is an isolated pain under the metatarsal phalangeal joints (MTPJs, the joints that form underneath the base of your little toes, not the actual toes themselves). It can happen to any little toe but it is almost always found affecting the second toe joint. These are usually identified as “grape-like” swellings in the ball of your foot (due to swelling and bruising), but it’s normally to have almost no visual signs at all besides the pain in the joint.
The toe itself has an increased joint range of motion both up and down as well as side to side; this motion is accompanied by increased pain in the joint. There is usually no callus in the area but there may be some swelling (“grape-like”). It is also not uncommon to have a hammertoe that is non-reducible; and if it does not look like a hammertoe yet, the proximal phalange will bend back over time and the front of the toe will curve down like a claw. It will eventually become rigid and need surgery if left unaddressed.
Predislocation syndrome of the second toe is usually accompanied by a bunion of the big toe, the second toe dislocates upward as the big toe drifts underneath it over time. It can also be caused by a short big toe leading to increased pressure on the second MTPJ.
Mechanism of injury
–Skip this unless you really want to know– it is not essential for understanding your condition.
-The plantar plate is a thickening of the plantar capsule consisting of fibrocartilage and attaches into the proximal phalanx and between the condyles of the metatarsal neck (it attaches more strongly at the base of the proximal phalanx & it is weakest at the base of the metatarsal neck). Unfortunately it almost always ruptures distally due to increased tension; this eventually leads to destabilization of the MTPJ collateral ligaments and allows transverse motion. So this is how we get sagittal plan instability as well as transverse plane instability.
-Basically predislocation syndrome is caused by excessive pressure on the base of that toe, a bunion under-riding the second toe, or perhaps even a short first ray.
Diagnosis of Pre-dislocation syndrome
-Morton’s Neuralgia is different because the pain is usually between the third and fourth metatarsal phalangeal joints (rarely between two and three- but possible), If the pain is between the second and third metatarsals it is more likely to be an intermetatarsal bursitis rather than Morton’s Neuralgia.
-Capsulitis and Bursitis are usually found in the same area and are more common, but you can differentiate predislocation syndrome by performing the Lachman test (aka the vertical drawer test) and by checking the joint range of motion.
-The Lachman test stabilizes the metatarsal and attempts to slide the base of the toe dorsally (upward) and see if it dislocates by more than two millimeters; this motion should be painful if it is predislocation syndrome. Pain with joint range of motion will differentiate this condition from other pain in the ball of the foot generally classified as metatarsalgia, but it will not differentiate it from arthritis (the 2mm dislocation will confirm that its not arthritis).
-Always compare both feet! If it is both feet then this argues against predislocation syndrome!
-X-rays are also needed to rule out arthritis, malalignment, Freiberg’s infraction, fractures or neoplasms.