e5-09: Plantar Plate Injuries (Predislocation Syndrome)

The pain with a plantar plate injury is underneath the toe next to the big toe and can either start suddenly with a sharp pain or can develop gradually over time. In either case, if it is not treated, the patient tends to suffer with constant pain under the ball of the foot.

The plantar plate is a supporting structure between the metatarsals and the remainder of the foot. The plantar plate, located at the level of the MTP joint, is made of fibrocartilage and fibrous slips. The plantar plate, as an extension of the plantar fascia, withstands compressive loads from the metatarsal. The plantar plate has attachments along the proximal phalanx, plantar fascia, and collateral ligaments. The plantar plate is weakest at the metatarsal neck due to the thin synovial attachment. The second metatarsal undergoes the most stress during weight bearing; therefore, the second plantar plate has a higher predisposition to injury.

A. Symptoms and Signs

Patients usually have some pain localized to the affected plantar plate, most often the second. They can experience some edema or a sensation of something “bunched” up under the metatarsal head. In the setting of an acute rupture or with chronic symptoms, the toe can drift medially (more often) or laterally and develop into a hammertoe deformity. During this process, the toe may lack ground purchase.

B. Imaging

Radiographs of the foot are helpful in showing dorsal dislocation of the proximal phalanx at the level of the MTP joint. MRI is often indicated to help assess the extent of plantar plate attenuation and degeneration. Arthrograms can be performed in conjunction with MRI.

A. Conservative

If the deformity is mild, then the toe can be taped or splinted down. Typically, Budin splints are used to hold the toe in proper alignment and allow purchase of the toe. Orthotics, both over-the-counter and custom made, can also be helpful in maintaining more normal mechanics, thus providing pain relief. If there is an equinus component (lack of dorsiflexion of ankle due to tight gastrocnemius or soleus muscle) to the etiology of the plantar plate injury, Achilles stretching may also be helpful in alleviating pain. Immobilization can help in some patients with acute onset of symptoms.

B. Surgical

Many surgical techniques have been described for repair of lesser MTP joint instability with plantar plate involvement. Both dorsal and plantar approaches have been described to repair plantar plate injuries and tears. Concomitant PIP joint fusion and a Weil shortening osteotomy of the metatarsal have been performed. Plantar plate tears can be repaired primarily, or they can be anchored into the base of the proximal phalanx. These treatment options have shown improvements with patient function and pain and have ultimately improved the patient's deformity.

• If patient is having forefoot pain in conjunction with lesser toe deformity.

• Difficulty with shoe gear due to lesser toe deformity.