Plantar plate tear

Plantar plate tears are disruptions of the metatarsophalangeal joint (MTPJ) plantar plate(s). They are essentially a form of metatarsophalangeal joint capsular tear, and most frequently occur at the distal lateral aspect of the plantar plate.

Terminology

Plantar plate tears can be broadly divided into involving the hallux/great toe/first toe and termed turf toe or sand toe, or the lesser metatarsals/toes 2-5, and termed plantar plate tears ^1,7. 

Clinical presentation

Presentation can be acute or chronic and can be associated with other joint conditions such as rheumatoid arthritis. Patients may present with metatarsalgia and/or deformity in cases of full-thickness plantar plate tears.

Pathology 

In the lesser metatarsals, increased weight-bearing load and hyper-extension forces placed on the MTPJs by high-heeled, pointed shoes are thought to be possible predisposing factors.

Radiographic features

Ultrasound

• dynamic maneuvers with ultrasound can demonstrate discontinuity of the normal plantar plate

MRI

• partial-thickness tear:
  • following acute trauma, focal edema in an aspect of a plantar plate suggests low-grade sprain or tear, without discontinuity ⁷
• full-thickness tear:
  • discontinuity
  • proximal retraction
  • persistent hyper-extension of the proximal phalanx ¹, or valgus/varus deviation of the toe
• indirect features of a plantar plate injury
  • metatarsophalangeal joint synovitis
  • flexor tendon sheath tenosynovitis
  • pseudoneuroma sign ⁸
  • plantar plate - proximal phalanx distance >2.75 mm ⁸

Differential diagnosis

Clinical differential considerations include

• Morton neuroma
• adventitial bursitis